JP5519356B2 - Lithium ion secondary battery and manufacturing method thereof - Google Patents

Description

  The present invention relates to a lithium ion secondary battery and a method for manufacturing the same. More specifically, the present invention relates to an all-solid-state lithium ion secondary battery that is small and has a large discharge capacity and that is easy to manufacture and a method for manufacturing the same.

  In recent years, the development of electronic technology has been remarkable, and portable electronic devices have been made smaller, lighter, thinner, and multifunctional. Accordingly, it is strongly desired to reduce the size, weight, thickness, and improve the reliability of batteries that serve as power sources for electronic devices. In order to meet these demands, a multilayer lithium ion secondary battery in which a plurality of positive electrode layers and negative electrode layers are laminated via a solid electrolyte layer has been proposed. A multilayer lithium ion secondary battery is assembled by stacking battery cells having a thickness of several tens of μm. Therefore, the battery can be easily reduced in size and weight and reduced in thickness. In particular, parallel or series-parallel stacked batteries are excellent in that a large discharge capacity can be achieved even with a small cell area. In addition, an all-solid-state lithium ion secondary battery using a solid electrolyte instead of the electrolytic solution has high reliability without fear of liquid leakage or liquid depletion. Furthermore, since the battery uses lithium, a high voltage and a high energy density can be obtained.

  Regarding a multilayer all solid-state type lithium ion secondary battery, Patent Document 1 proposes a battery in which a negative electrode layer, a current collector layer, a negative electrode layer, an electrolyte layer, a positive electrode layer, a current collector layer, and a positive electrode layer are sequentially laminated. ing. FIG. 7 is a cross-sectional view of a conventional lithium ion secondary battery described in Patent Document 1. In the battery 101, a positive electrode layer 103 sandwiching a current collector layer 105 and a negative electrode layer 104 sandwiching a current collector layer 106 are stacked with an electrolyte layer 102 interposed therebetween. The battery shown in FIG. 7 is a parallel type battery in which a positive electrode terminal 107 and a negative electrode terminal 108 which are output terminals of the battery are arranged on the side surfaces of the stacked body and are in contact with the plurality of positive electrode layers 103 and the plurality of negative electrode layers 104, respectively. It is. In the battery described in Patent Document 1, the material of the positive electrode layer and the negative electrode layer is made of an active material. As a material for the positive electrode layer, an active material made of a metal oxide or a metal sulfide, and as a material for the negative electrode layer, an active material made of metal lithium or a lithium alloy is described as a suitable material.

  As shown in FIG. 7, the parallel multilayer battery has a long distance from the electrode terminal to the end of the electrode layer (positive electrode layer, negative electrode layer). Among the active material materials used in lithium ion batteries, oxide materials have the advantage that the volume change accompanying the movement of lithium ions is small compared to alloy materials, and the electrode is less likely to be pulverized and peeled off. There is a disadvantage that the conductivity is small. When the electrical resistance in the electrode layer increases, there is a problem that the internal impedance of the battery increases, the discharge load characteristics deteriorate, and the discharge capacity decreases. Therefore, in Patent Document 1, a current collector layer having a high conductivity is stacked on an electrode layer having a low conductivity so as to reduce the impedance of the electrode.

  In the structure shown in FIG. 7, the surface of the positive electrode terminal 107 is continuously covered with the positive electrode active material layer 103 for the purpose of increasing the electrode area (Patent Document Paragraph No. (0018)).

  However, in order to manufacture a battery having such a structure, each of the electrode layer, the current collector layer, and the electrode layer needs to be applied and dried in order to form the positive electrode and the negative electrode. Furthermore, an alignment process between the electrode layer and the current collector layer is also required. Therefore, particularly when the number of stacked layers is large, there is a problem that the process is complicated and the manufacturing cost increases. In addition, since the coating and drying process is increased, the solvent used in the electrode layer and current collector layer forming process reduces the strength and damage of the underlying electrolyte layer sheet (sheet attack), and decreases the manufacturing yield of the battery. There was a problem to do.

  Further, in order to manufacture the battery having the structure shown in FIG. 7, a complicated process as shown in FIG. 8 must be performed. That is, first, the inorganic solid electrolyte paste and the positive electrode / negative electrode active material paste are used on the sheet-like support 12, and the inorganic solid electrolyte region 31 and the positive electrode active material region 44 and the negative electrode active material region 64 are provided at both ends thereof. It is necessary to produce a composite electrode active material sheet. That is, in order to produce an electrolyte sheet, three different regions must be formed on one plane.

  Further, the first positive electrode active material region 41 is partially formed so as to straddle the positive electrode active material region 44 and the inorganic solid electrolyte region 31 of the composite electrode active material sheet. It is necessary to form the negative electrode active material region 65 on the negative electrode active material region 64 in the same manner as the gap filling inorganic solid electrolyte region 32. That is, in order to produce the positive electrode sheet, three different regions must be formed on one plane. The same applies to the production of the negative electrode sheet.

  Not only that, the battery having the structure shown in FIG. 7 was found to have a reduced capacity retention after a long-term cycle. The inventor has eagerly searched for the cause, and has found that the cause is the interface between the current collector and the solid electrolyte layer (or electrolyte layer). This finding is a finding obtained for the first time by the present inventors.

  In addition, in patent document 1, about the specific connection of an end electrode, "<positive electrode / negative electrode terminal connection process> External electrode connected to the positive electrode current collector 5 and the negative electrode current collector 7 of the obtained battery element, respectively. No. 8 and 9 ”are only described, and the specific connection relationship between the external electrode 8, the positive electrode current collector 5, and the negative electrode current collector 7 is not disclosed.

  After further pursuing the basic cause of interface degradation, I was inspired by the fatigue caused by the generation of internal stress due to expansion and contraction during charging and discharging. Therefore, when a tensile test was performed, it was confirmed that the tensile strength was low when the decrease in capacity retention was large.

  Therefore, when the interfacial structure where the internal stress does not occur was eagerly searched and a structure in which a conductive matrix made of a conductive material carried an active material as an end electrode was tried, the tensile strength might be improved. I found. However, there were cases where it was not improved, and when the reason was further explored, it was found that the area ratio of the two affected. By conducting extensive experiments on the area ratio, it became possible to obtain a battery in which the tensile strength was reliably improved and the capacity retention rate after a large number of cycles was little reduced.

  In Patent Document 2, the positive electrode layer and the negative electrode layer have a structure in which the conductive matrix supports the active material. However, the objects are the positive electrode layer and the negative electrode layer, not the end electrode, and in Patent Document 2, the object is simply to reduce the impedance of the positive electrode layer and the negative electrode layer. It is not intended to improve the interface state with the main body.

JP 2006-261008 A WO 2008/099508

  According to the present invention, it is an object to provide a solid electrolyte battery that can be manufactured by a simple manufacturing method, has a good interface state between an end electrode and a battery body, has a large output current, and has excellent battery characteristics.

The invention according to claim 1 is an all-solid-state lithium ion battery comprising a positive electrode end electrode and a negative electrode end electrode provided on an electrode body made of a laminate in which positive electrode layers and negative electrode layers are alternately laminated via a solid electrolyte layer. a next cell, the negative end electrode connected to the said is connected to the positive electrode layer positive end electrode and / or the negative electrode layer comprises a conductive matrix composed of a conductive material carrying an active material structure The ratio (S _d ) of the area (S _d ) of the region of the conductive material and the area (S _k ) of the region of the active material in the cross section of the positive electrode end electrode and / or the negative electrode end electrode / S _k ) is in the range of 90:10 to 40:60, and is an all solid-state lithium ion secondary battery.
The invention according to claim 2, wherein the conductive material in the positive end electrode (or the negative end electrode) to form the positive electrode layer (or negative electrode layer) conductive material and the same or an alloy in the material The all-solid-state type according to claim 1, wherein the active material in the positive electrode end electrode (or negative electrode end electrode) is the same as the positive electrode active material (or negative electrode active material) of the positive electrode layer (or negative electrode layer). Lithium ion secondary battery.
Invention, wherein the conductive material in the positive end electrode (or the negative end electrodes) is a metal or alloy, a conductive material is metal in the positive electrode layer (or negative electrode layer) according to claim 3 The all-solid-state lithium ion secondary battery according to claim 2, which is an alloy.
The invention according to claim 4, wherein the conductive material in the positive end electrode (or the negative end electrode) is an oxide, a conductive material in the positive electrode layer (or negative electrode layer) is conductive oxide The all-solid-state lithium ion secondary battery according to claim 2, which is a product.
The invention according to claim 5, wherein said metal or alloy in the positive end electrode (or the negative end electrodes), the positive electrode layer (or negative electrode layer) metal or alloy in are different, both solid solutions The all-solid-state lithium ion secondary battery according to claim 4, wherein an all-type alloy is formed.
The invention according to claim 6 is the positive electrode layer comprising a positive electrode current collector layer and a positive electrode active material layer, and the negative electrode layer comprising a negative electrode current collector layer and a negative electrode active material layer. An all-solid-state lithium ion secondary battery according to claim 1.
The invention according to claim 7 is characterized in that the positive electrode layer (or negative electrode layer) has a structure in which a conductive matrix made of a conductive material carries a positive electrode active material (or a negative electrode active material). 2. An all solid state lithium ion secondary battery according to item 1.
According to an eighth aspect of the present invention, the positive electrode end electrode and / or the negative electrode end electrode are formed by baking a paste of a conductive material and a positive electrode active material applied to the unfired laminate. The all-solid-state lithium ion secondary battery according to claim 1, wherein:
In the invention according to claim 9, the positive electrode end electrode and / or the negative electrode end electrode is formed by baking a paste of a conductive material and a positive electrode active material applied to the fired laminate. The all-solid-state lithium ion secondary battery according to claim 1, wherein:
The invention according to claim 10 is characterized in that the active material is a transition metal oxide or a compound comprising a transition metal composite oxide. Next battery.
The invention according to claim 11 is characterized in that the active material is lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt composite oxide, lithium vanadium composite oxide, lithium titanium composite oxide, manganese dioxide, titanium oxide, oxidation The lithium ion secondary battery according to any one of claims 1 to 10, wherein the lithium ion secondary battery is one compound selected from the group consisting of niobium, vanadium oxide, and tungsten oxide, or two or more compounds.
The invention according to claim 12 is characterized in that the conductive substance is a metal selected from the group consisting of silver, palladium, gold, platinum, aluminum, copper, nickel, or silver, palladium, gold, platinum, aluminum, copper, nickel. The lithium ion secondary battery according to claim 1, wherein the lithium ion secondary battery is an alloy made of two or more metals selected from the group consisting of tin.
According to a thirteenth aspect of the invention, the active material constituting the positive electrode end electrode is a lithium manganese composite oxide, the active material constituting the negative electrode end electrode is a lithium titanium composite oxide, and the conductive The lithium ion secondary battery according to claim 1, wherein the active substance is silver palladium.
The invention according to claim 14 is characterized in that the conductivity of the positive electrode end electrode and the negative electrode end electrode is 1 × 10 ¹ S / cm or more. The lithium ion secondary battery as described.
The invention according to claim 15 includes a step of producing a solid electrolyte sheet in which a solid electrolyte paste layer for forming a solid electrolyte layer is formed, and a positive electrode paste layer for forming a positive electrode layer on the solid electrolyte paste layer Forming a negative electrode sheet by forming a negative electrode paste layer for forming a negative electrode layer on the solid electrolyte paste layer, a plurality of the positive electrode sheets and a plurality of positive electrode sheets the negative electrode sheet and the step of fabricating a laminate by alternately laminating and forming a positive end electrode for each other electrically through a plurality of the positive electrode layer on the side surfaces of the laminate, a plurality of the negative electrode Forming a negative electrode end electrode for electrically connecting the layers to each other side surface of the laminate, and the positive electrode end electrode and / or the negative electrode end electrode is made of a conductive material. sex An active material is supported on a matrix, and the area of the conductive material (S _d ) and the area of the active material (S _k ) in the cross section of the positive electrode end electrode and / or the negative electrode end electrode The ratio (S _d / S _k ) is in the range of 90:10 to 40:60. A method for producing an all-solid-state lithium ion secondary battery,
The invention according to claim 16, wherein the conductive material in the positive end electrode (or the negative end electrode) to form the positive electrode layer (or negative electrode layer) conductive material and the same or an alloy in the material The all-solid-state type according to claim 15, wherein the active material in the positive electrode end electrode (or negative electrode end electrode) is the same as the positive electrode active material (or negative electrode active material) of the positive electrode layer (or negative electrode layer). A method for producing a lithium ion secondary battery.
Invention, wherein the conductive material in the positive end electrode (or the negative end electrodes) is a metal or alloy, a conductive material is metal in the positive electrode layer (or negative electrode layer) according to claim 17 17. The method for producing an all solid state lithium ion secondary battery according to claim 16, wherein the method is an alloy.
The invention according to claim 18, wherein the conductive material in the positive end electrode (or the negative end electrode) is an oxide, a conductive material in the positive electrode layer (or negative electrode layer) is conductive oxide The method for producing an all solid state lithium ion secondary battery according to claim 16, wherein the method is a product.
The invention according to claim 19, wherein said metal or alloy in the positive end electrode (or the negative end electrodes), the positive electrode layer (or negative electrode layer) metal or alloy in are different, both solid solutions The manufacturing method of the all-solid-state type lithium ion secondary battery of Claim 18 which forms a type alloy.
The invention according to claim 20 is characterized in that the positive electrode layer comprises a positive electrode current collector layer and a positive electrode active material layer, and the negative electrode layer comprises a negative electrode current collector layer and a negative electrode active material layer. A method for producing an all-solid-state lithium ion secondary battery according to claim 1.
The invention according to claim 21 is any one of claims 15 to 20, wherein the positive electrode layer (or negative electrode layer) has a structure in which a conductive matrix made of a conductive material carries a positive electrode active material (or a negative electrode active material). A method for producing an all solid state lithium ion secondary battery according to claim 1.
The invention according to claim 22 is characterized in that the positive electrode end electrode and the negative electrode end electrode are negative electrodes for forming a positive electrode end electrode paste layer and a negative electrode end electrode for forming a positive electrode end electrode on the laminate. 16. The method for producing an all solid state lithium ion secondary battery according to claim 15, wherein the extreme electrode paste layer is formed on each side surface of the laminate and then fired.
According to a twenty-third aspect of the present invention, the positive electrode end electrode paste layer and the negative electrode end electrode paste layer are formed in an unfired laminate, and the positive electrode end electrode paste layer, the negative electrode end electrode paste layer, 23. The method for producing an all solid state lithium ion secondary battery according to claim 22, wherein the fired laminate is fired at once.
According to a twenty-fourth aspect of the present invention, the positive electrode end electrode paste layer and the negative electrode end electrode paste layer are formed in a fired laminate, and the positive electrode end electrode paste layer, the negative electrode end electrode paste layer, and the 23. The method for producing an all solid state lithium ion secondary battery according to claim 22, wherein the fired laminate is fired at once.
The invention according to claim 25 is the method for producing an all solid state lithium ion secondary battery according to claim 22 or 23, wherein the firing is performed at a firing temperature of 600 ° C to 1100 ° C.
According to Claim 26 invention, by firing the only laminate, the laminate after firing, a plurality of the the positive end electrode for a positive electrode layer electrically communicate with each other positive end electrode paste coating, dried Applying a negative electrode end electrode paste serving as a negative electrode end electrode serving as a negative electrode end electrode for electrically connecting the plurality of negative electrode layers to each other, drying, and then performing a second firing. Item 24. The method for producing an all solid state lithium ion secondary battery according to Item 22 or 23.

  According to the present invention, it is possible to provide a solid electrolyte battery that can be manufactured by a simple manufacturing method, has an excellent interface state between the end electrode and the battery body, has a large output current, and has excellent battery characteristics.

It is sectional drawing of the all-solid-state type lithium ion secondary battery which concerns on the 1st example of a form of this invention. It is sectional drawing of the all-solid-state type lithium ion secondary battery which concerns on the 2nd form example of this invention. It is sectional drawing of the all-solid-state type lithium ion secondary battery which concerns on the 3rd form example of this invention. It is a manufacturing-process figure of the all-solid-state type lithium ion secondary battery which concerns on the 1st example of a form of this invention. It is a manufacturing-process figure of the all-solid-state type lithium ion secondary battery which concerns on the 2nd example of a form of this invention. It is a manufacturing-process figure of the all-solid-state type lithium ion secondary battery which concerns on the 3rd form example of this invention. It is sectional drawing of the all-solid-state type lithium ion secondary battery which concerns on a prior art example. It is a manufacturing-process figure of the all-solid-state lithium ion secondary battery which concerns on a prior art example.

An all-solid-state lithium ion secondary battery and a manufacturing method thereof according to an embodiment for carrying out the present invention will be described with reference to the drawings.
A: Structure of Battery An all solid-state lithium ion secondary battery according to an embodiment for carrying out the present invention has a positive electrode end on a laminate 21 in which positive electrode layers 1 and negative electrode layers 2 are alternately stacked via a solid electrolyte layer 3. An all-solid-state lithium ion secondary battery comprising a partial electrode 8 and a negative electrode end electrode 9,
The positive electrode end electrode 8 connected to the positive electrode layer 1 and the negative electrode end electrode 9 connected to the negative electrode layer 2 have a structure in which an active material is supported on a conductive matrix made of a conductive material. The ratio (S _d / S _k ) of the area (S _d ) of the conductive material region and the area (S _k ) of the active material region in the cross section of the electrode 8 and the negative electrode end electrode 9 is 90:10 to 40:60 Is in range.

This will be described in more detail below.
A-1 structure (first form)
FIG. 1 shows a basic structure of an all solid-state lithium ion secondary battery 10 according to an embodiment for carrying out the present invention.

  The battery 10 includes a battery main body 21 and end electrodes 8 and 9.

  The battery body 21 is a laminate in which a plurality of layers are laminated. The battery body portion 21 which is a laminate is configured by a laminate in which a plurality of positive electrode layers 1 and a plurality of negative electrode layers 2 are alternately laminated via a solid electrolyte layer 3.

In the embodiment shown in FIG. 1, the positive electrode layer 1 is configured by sandwiching a positive electrode current collector layer 5 between two positive electrode active material layers 4. The negative electrode layer 2 is configured by sandwiching a negative electrode current collector layer 7 between two negative electrode active material layers 6.

  That is, the battery body 21 includes the positive electrode layer 1, the negative electrode layer 2, and the solid electrolyte layer 3. The positive electrode layer 1 and the negative electrode layer 2 are meshed with each other so as to face each other with the inorganic solid electrolyte layer 3 therebetween, and the inorganic solid electrolyte 3 is filled therebetween.

Connected to the end face of each positive electrode layer 1 to connect the plurality of positive electrode layers 1 to each other and extract the current to the outside, and connected to the end face of each negative electrode layer 2 to connect the plurality of negative electrode layers 2 to each other. A negative electrode end electrode 9 is provided which is electrically connected to each other and takes out a current to the outside.

The positive electrode end electrode 8 connected to the positive electrode layer 1 and the negative electrode end electrode 9 connected to the negative electrode layer 2 have a structure in which an active material is supported on a conductive matrix made of a conductive material. 8 and the ratio (S _d / S _k ) of the area (S _d ) of the conductive material and the area (S _k ) of the active material in the cross section of the negative electrode end electrode 9 is 90:10 to 40:60 Is in range.

  Here, the “conductive matrix” means a structure in which conductive material particles are in contact with each other three-dimensionally. When the conductive material is a metal, the term “metal matrix” may be used. In addition, “a structure in which an active material is supported on a conductive matrix” means a structure in which active material particles are distributed between conductive material particles that are in contact with each other three-dimensionally. The active material particles may be distributed continuously or discontinuously, but are preferably distributed uniformly in the end electrodes. Further, “three-dimensionally continuous” means that even if there is a discontinuous part in a two-dimensional cross section, it is continuous in three dimensions if there is a surface that is continuous in at least another cross section.

  Even when a small amount of additives other than the active material and the conductive material is added as the material for the end electrode, the amount of the active material and the conductive material is reduced so much as the addition of the additive. Otherwise, the volume ratio of the conductive material to the paste material and the active material is in the range of 90:10 to 40:60, so that the structure of the end electrode is conductive with the active material supported. An excellent battery having a low impedance and a large discharge capacity can be manufactured.

The battery structure of this embodiment is particularly suitable for small batteries. For example, the thickness of the positive electrode active material layer 4 is 500 to 0.1 μm, more preferably 50 to 1 μm, and the thickness of the positive electrode current collector layer 5 is 500 to 500 μm. 0.1 μm, more preferably 50-1 μm, the thickness of the inorganic solid electrolyte layer 3 is 500-0.1 μm, more preferably 50-1 μm, and the thickness of the negative electrode active material layer 6 is 500-0.1 μm, more preferably Is 50 to 1 μm, and the thickness of the negative electrode current collector layer 7 is 500 to 0.1 μm, more preferably 50 to 1 μm.
A-2 structure (second form)
In the structure shown in FIG. 1, as shown in FIG. 2, the end face 5b of the positive electrode current collector layer 5 opposite to the end face 5a connected to the positive end electrode 8 is covered with a positive electrode active material. The configuration of the end electrode of the present invention may be applied to the battery main body portion 21.

That is, the positive electrode layer 1 is connected to the end surfaces of the positive electrode current collector layers 5 and the positive electrode current collector layers 5 arranged in parallel with each other at intervals, thereby electrically connecting the multiple positive electrode current collector layers 5 to each other. The positive electrode end electrode 8 from which current is taken out, and the positive electrode current collector layer 5 are provided with a positive electrode active material layer 4 that covers both the end surface and both surfaces of the positive electrode end electrode 8 other than the surface to which the positive electrode end electrode 8 is connected.
The same applies to the negative electrode side.
The negative electrode layer 2 is connected to a plurality of negative electrode current collector layers 7 arranged in parallel with each other at an interval, and is connected to an end face of each negative electrode current collector layer 7 to electrically connect the plurality of negative electrode current collector layers 7 to each other. The negative electrode end electrode 9 and the negative electrode current collector layer 7 are provided with a negative electrode active material layer 6 that covers both the end surface and both sides of the negative electrode end electrode 9 other than the surface to which the negative electrode end electrode 9 is connected.

  In this case, the effect achieved in the invention according to Patent Document 1 is achieved. That is, a larger output current can be obtained, and cracks can be prevented from occurring in the solid electrolyte layer.

  The same applies to the negative electrode current collector layer 7.

Other points are the same as the example of the A-1 structure.
A-3 structure (third form)
Furthermore, as shown in FIG. 3, it is preferable that the positive electrode layer 1 has a structure in which an active material is supported on a conductive matrix made of a positive electrode layer conductive material. In this case, it is preferable that the ratio (S _d / S _k ) of the area (S _d ) of the conductive material and the area (S _k ) of the active material is in the range of 90:10 to 40:60. In this case, the positive electrode layer 1 is more preferably made of the same material as the end electrode 8.

  In addition, the electrode layer may be formed of a material in which an active material and a conductive material are mixed in an optimal range of mixing ratio, and may be applied to both the positive electrode layer and the negative electrode layer, or only to one of the electrode layers. You may apply. Even when it is applied to only one of the electrode layers, it is effective in simplifying the process and reducing the manufacturing cost.

The same applies to the negative electrode layer 2.
Other points are the same as the example of the A-1 structure.

B: Manufacturing method of battery The manufacturing method of the all-solid-state type lithium ion secondary battery which concerns on embodiment of this invention,
Producing a solid electrolyte sheet 22 on which a solid electrolyte paste layer 3g for forming the solid electrolyte layer 3 is formed;
Forming a positive electrode paste layer 1g for forming the positive electrode layer 1 on the solid electrolyte paste layer 3g to produce a positive electrode sheet 23;
Forming a negative electrode paste layer 2g for forming the negative electrode layer 2 on the solid electrolyte paste layer 3g to produce a negative electrode sheet 24;
A step of alternately laminating a plurality of positive electrode sheets 23 and a plurality of negative electrode sheets 24 to produce a laminate 30;
Forming a positive electrode end electrode 8 for electrically connecting a plurality of the positive electrode layers 1 on the side surface of the laminate 30;
Forming a negative electrode end electrode 9 for electrically connecting a plurality of the negative electrode layers 2 on the other side surface of the laminate;
Have
The positive electrode end electrode 8 and / or the negative electrode end electrode 9 has a structure in which an active material is supported on a conductive matrix made of a conductive material, and the positive electrode end electrode 8 and / or the negative electrode end. The ratio (S _d / S _k ) of the area (S _d ) of the conductive material and the area (S _k ) of the active material in the cross section of the electrode 9 is in the range of 90:10 to 40:60. .

This will be described in more detail below.
B-1 Method An example of a method for manufacturing the battery shown in FIG. 1 will be described with reference to FIG.

  For example, a solid electrolyte paste is applied on a sheet-like support 12 made of polyethylene terephthalate (PET) and dried to form a solid electrolyte sheet 22 having a solid electrolyte paste layer 3g formed (FIG. 4A).

  On the solid electrolyte paste layer 3g of the solid electrolyte sheet 22, the positive electrode active material paste, the positive electrode current collector paste, and the positive electrode active material paste are sequentially dried, and the positive electrode active material paste layer 4g, the positive electrode current collector paste layer 5g, and the positive electrode An active material paste layer 4g is formed, and a positive electrode sheet 23 integrated with a solid electrolyte sheet is produced (FIG. 4B).

  At this time, one end face (the left side face in the drawing) of the solid electrolyte paste layer 3g, the positive electrode active material paste layer 4g, the positive electrode current collector paste layer 5g, and the positive electrode active material paste layer 4g is flush.

  The other end surface (the right side surface in the drawing) has a step between the positive electrode layer and the solid electrolyte layer.

  The negative electrode sheet 24 is similarly manufactured (FIG. 4C).

  A plurality of positive electrode sheets 23 and negative electrode sheets 24 are prepared.

  The sheet-like support 12 is removed from the plurality of positive electrode sheets 23 and the plurality of negative electrode sheets 24. A plurality of positive electrode sheets 1g and a plurality of negative electrode sheets 2g from which the sheet-like support 12 has been removed are alternately laminated to form a laminate 30 (FIG. 4 (d)).

  This laminated body 30 is an unfired laminated body.

  A positive electrode end electrode paste layer to be a positive electrode end electrode 8 for electrically connecting the plurality of positive electrode layers 1 to each other is formed on the side surface of the laminate 30.

  The negative electrode end electrode 9 may be formed similarly.

The positive electrode end electrode paste and the negative electrode end electrode paste are pastes (active material / conductive material mixed paste) made of a mixture of a conductive material and an active material. To make the ratio (S _d / S _k ) of the area (S _d ) of the conductive material after sintering and the area (S _k ) of the active material to be in the range of 90:10 to 40:60 The volume ratio of the conductive material that is the starting material and the active material may be in the range of 90:10 to 40:60.

  In addition, in order to obtain a structure in which an active material is supported on a conductive matrix made of a conductive material, the volume ratio of the conductive material, which is a starting material, to the active material is set in the range of 90:10 to 40:60. At the same time, batch firing may be performed under predetermined firing conditions.

  The present inventor further manufactured and evaluated positive and negative end cells by changing the mixing ratio of the active material and the conductive material constituting the positive and negative end electrodes, and as a result, the conductive material and the positive electrode as the paste material were evaluated. Excellent characteristics when the mixing ratio of the active material and the mixing ratio of the conductive material and the negative electrode active material are 90:10 to 40:60, both in terms of volume ratio. It was found that the battery can be produced. As a result of observing the cross section of the battery manufactured under this optimum condition with SEM and EDS, it was found that the area ratio of the conductive material and the active material in the electrode cross section was 90:10 to 40:60 as well as the volume ratio. It was. Further, when the mixing ratio of the conductive material is 40% or more by volume ratio, the conductive material is continuous in a matrix shape in the cross section, and the active material is supported in the matrix conductive material. I found out. It has also been found that in order to form such a matrix structure, it must be fired at a high temperature of 600 ° C. or higher.

  Firing conditions are: active material paste, active material mixed current collecting electrode paste, organic binder, solvent, coupling agent, and dispersant included in inorganic solid electrolyte slip, active material species included in active material paste, active material It selects suitably by the metal seed | species used for a mixed current collection electrode paste. The undecomposed organic matter in the firing process may cause peeling of the laminated body after firing and may cause a short circuit inside the battery due to residual carbon. In particular, when firing is performed in an atmosphere not containing oxygen, it is preferable to further oxidize organic substances by further introducing water vapor and firing in order to minimize residual carbon in the battery.

(Batch firing conditions)
-Firing temperature The firing temperature is preferably 600 to 1100 ° C.
When the temperature is lower than 600 ° C., the structure in which the active material is supported in the matrix conductive material is not achieved. More preferably, it is 700-900 degreeC.
-Firing atmosphere The firing atmosphere may be an air atmosphere, a neutral atmosphere, or a reducing atmosphere. What is necessary is just to select suitably according to the kind of constituent material of a battery.

B-2 Method In this embodiment, the laminate 30 is once fired (first firing), the end electrode paste is applied to the laminate after the first firing, and dried to form an end electrode paste layer, A second firing is performed.
In the case of firing in this example (referred to as two-stage firing) as compared to the batch firing described in B-1,
Since materials that can be sintered at a low temperature can be applied, the choices of materials are widened. For example, there is a merit that the manufacturing cost is reduced by selecting an inexpensive material or the conductivity is improved by selecting a material having high conductivity. Also, because of firing at a low temperature, the difference in linear expansion coefficient between the conductive material and current collector material in the end electrode during cooling, the active material material in the end electrode and the solid electrolyte material of the battery stack, and the active material Cracks and delamination caused by the can be suppressed.

In this example, the first firing can be performed under the same firing conditions as described in the method B-1.
The firing temperature in the second firing is preferably 600 to 1100 ° C. However, it is preferable to carry out at a temperature lower than the first firing temperature. By firing at a temperature lower than the first firing temperature, generation of voids due to oversintering can be prevented.

B-3 Method This embodiment is a method for manufacturing a battery having the structure shown in FIG. The method is shown in FIG.
The positive electrode sheet positive electrode current collector paste 5 g is formed shorter than the positive electrode active material paste 4 g. That is, as shown in FIG. 5B, the gap 13 is provided to form the positive electrode current collector paste and the positive electrode active material paste 4g.
The same applies to the negative electrode sheet.
When the positive electrode sheet, the solid electrolyte sheet, and the negative electrode sheet are alternately laminated and then subjected to pressure bonding, the active material flows into the gap 13 and the end face of the current collector is covered with the active material. Firing may be performed in that state.

B-4 Method This embodiment is a method for manufacturing a battery having the structure shown in FIG.
In this embodiment, a conductive matrix made of a conductive material is supported on the positive electrode layer or the negative electrode layer.
In the aforementioned B-1 method, the active material paste, the electrode current collector paste, and the active material paste are sequentially applied onto the solid electrolyte paste. On the other hand, in this embodiment, a paste of a mixture of a conductive material and an active material is applied on the solid electrolyte paste. After firing, the paste of the mixture of the conductive material and the active material has a structure in which the conductive matrix supports the active material, like the end electrodes.
Here, as the conductive substance used, it is particularly preferable to use the same material as the conductive substance used for the end electrodes or a material forming an alloy. The active material is preferably the same material as the active material used for the end electrodes. Furthermore, the ratio between the conductive material and the active material is preferably the same as or within 10% of the ratio between the conductive material and the active material in the end electrode.
By setting this ratio, the bond between the mixture and the end electrode can be further strengthened.
In this method, the number of layers is smaller than in other methods. That is, in another method, for example, in FIG. 1, three layers of the active material layer 4, the current collector layer 5, and the active material layer 4 are formed on the solid electrolyte layer 3. On the other hand, in this method, only one layer 45 g of the mixture layer is formed on the solid electrolytic layer 3. Therefore, in the case of this method, even if a large number of unit cells are stacked, the small size is maintained. Moreover, manufacture is easy.
In addition, in the manufacturing process, the level difference from the solid electrolyte layer is only one layer of the mixture layer. Accordingly, it is possible to prevent delamination and other deterioration of battery characteristics due to the step.

  Other procedures are the same as the B-1 method.

C-1: Combination of materials In the present invention, the positive electrode end electrode connected to the positive electrode layer and / or the negative electrode end electrode connected to the negative electrode layer has a conductive matrix made of a conductive material carrying an active material. It has a structure.
Here, the conductive material in the positive electrode end electrode is the same material as the conductive material in the positive electrode layer or forms an alloy, and the active material in the positive electrode end electrode is the same as the positive electrode active material in the positive electrode layer. It is particularly preferable to do this. The same applies to the negative electrode side.
In this case, first, the conductive material of the positive electrode layer 1 (the current collector layer 5 in the case of FIG. 1, the conductive material (not shown) carried on the matrix of the positive electrode layer in the case of FIG. 3), and the positive electrode end Since the conductive substance constituting the matrix of the partial electrodes 8 is the same material or a material that forms an alloy with each other, the two are joined together. At the same time, the positive electrode active material of the positive electrode layer 1 (the positive electrode active material layer 4 in the case of FIG. 1 and the matrix of the positive electrode layer 1 in the case of FIG. 3) and the active material carried on the matrix in the positive electrode end electrode 8. Since they are the same material, they are joined together. In this way, since the entire end portion of the positive electrode layer 1 is bonded to the positive electrode end electrode 8, a strong bond can be obtained. The same applies to the negative electrode side.
That is, when a metal or alloy is used as the conductive material in the positive electrode end electrode, a metal or alloy is used as the conductive material used in the positive electrode layer, and conductive oxide is used as the conductive material in the positive electrode end electrode. When a material is used, it is particularly preferable to use a conductive oxide as the conductive material used in the positive electrode layer. In this case, the constituent elements of the conductive material are preferably the same, and the composition ratios of the constituent elements are more preferably the same.
When a metal or an alloy is used as the conductive substance, a metal or alloy having the same constituent element may be used on the positive electrode layer side and the end electrode side. In the case of a metal (pure metal), since an alloy region is not formed, it is possible to provide an extraction electrode (end electrode) having a low resistance value. Furthermore, bonding with higher ductility can be obtained as compared with the case where an alloy described below is formed, and bonding that is difficult to peel off even when an impact external force is applied can be obtained.
On the other hand, metals or alloys having different constituent elements may be used. A combination of metals that does not cause precipitation of intermetallic compounds or eutectics during alloy formation is preferred. In particular, a combination that forms a solid solution type alloy is preferable. What is necessary is just to select suitably from the starting material described below.
C-2: Starting material (positive electrode active material)
The positive electrode layer 1 is composed of, for example, a positive electrode current collector layer 5 and a positive electrode active material layer 4.

  As the positive electrode active material constituting the positive electrode active material layer 4 of the lithium ion secondary battery of this embodiment, it is preferable to use a material that efficiently releases and adsorbs lithium ions. For example, it is preferable to use a transition metal oxide or a transition metal composite oxide. In addition, various metal oxides, metal sulfides, and the like can be used. In particular, when a metal oxide is used, battery element sintering can be performed in an oxygen atmosphere, and the resulting battery can obtain an active material with few oxygen defects and high crystallinity. It is desirable because a battery with a high capacity close to the theoretical capacity can be produced.

Specific examples of the positive electrode active material include manganese dioxide (MnO ₂ ), titanium oxide, niobium oxide, vanadium oxide, tungsten oxide, iron oxide, copper oxide, nickel oxide, and lithium manganese composite oxide (for example, Li _x Mn ₂ O ₄ Or Li _x MnO ₂ ), lithium nickel composite oxide (eg, Li _x NiO ₂ ), lithium cobalt composite oxide (LixCoO ₂ ), lithium nickel cobalt composite oxide (eg, LiNi _1-y Co _y O ₂ ), lithium manganese cobalt composite oxide (e.g., _{LiMn y Co 1-y O 2} ), spinel type lithium-manganese-nickel composite oxide _{(Li x Mn 2 -yNi y O} 4), lithium phosphates having an olivine structure _(Li x FePO _{4, Li x Fe 1-y Mn y} PO 4, Li x CoP _4, etc.), include at least one selected from iron sulfate _{(Fe 2 (SO 4)} 3), vanadium oxide (e.g. _V 2 _{O 5).} In these chemical formulas, x and y are preferably in the range of 0-1. )

More preferable positive electrode active materials include lithium manganese composite oxide (Li _x Mn ₂ O ₄ ), lithium nickel composite oxide (Li _x NiO ₂ ), and lithium cobalt composite oxide (Li _x CoO ₂ ) lithium nickel having a high battery voltage. Cobalt composite oxide (Li _x Ni _1-y Co _y O ₂ ), spinel-type lithium manganese nickel composite oxide (Li _x Mn _2-y Ni _y O ₄ ), lithium manganese cobalt composite oxide (Li _x Mn _y Co) _1-y O ₂ ), lithium iron phosphate (Li _x FePO ₄ ), and the like. (Note that x and y are preferably in the range of 0 to 1.) These positive electrode active materials have improved crystallinity and improved battery characteristics by sintering in an oxidizing atmosphere. Furthermore, lithium manganese composite oxide and lithium titanium composite oxide are particularly suitable for use as an active material material because the volume change due to adsorption and release of lithium ions is particularly small, and the electrode is not pulverized or peeled off easily. Can do.
(Negative electrode active material layer)

  There is no clear distinction between the positive electrode active material and the negative electrode active material, and the potentials of the two compounds are compared, and a compound having a more noble potential is used as the positive electrode active material. . A compound exhibiting a lower potential can be used as the negative electrode active material.

The negative electrode active material includes metallic lithium or a lithium alloy. As the lithium alloy, at least one alloy selected from lithium and Sn, In, and Zn is desirable because it has a large capacity and can be thinned, and stress at the interface can be suppressed. Specific examples of the alloy composition include Li _4.4 Sn, LiIn, LiZn, and the like, and particularly Li _4.4 Sn is desirable because it has a high capacity and can be thinned.

  The negative electrode active material layer 6 of metallic lithium or lithium alloy can be deposited at the time of initial charge after battery assembly. When a conductive metal oxide is used as the negative electrode current collector layer 7, a material that reacts with lithium ions released from the positive electrode active material layer 4 or the inorganic solid electrolyte layer 3 (for example, tin oxide, indium oxide, zinc oxide) A lithium alloy layer to be the negative electrode active material layer 6 is formed between the inorganic solid electrolyte layer 3 and the negative electrode current collector layer 7. Further, when a conductive metal oxide is used as the negative electrode current collector layer 7, a material in which the conductive metal oxide as the negative electrode current collector layer 7 does not react with lithium ions released from the positive electrode (for example, titanium oxide) ), A metallic lithium layer to be the negative electrode active material layer 6 is formed between the inorganic solid electrolyte layer 3 and the negative electrode current collector layer 7. The negative electrode active material layer 6 formed by such charging forms a good interface rich in bondability with the adjacent inorganic solid electrolyte 3 or the negative electrode current collector layer 7. As a result, an excellent battery with low interface resistance can be produced.

  Moreover, the negative electrode active material used for the negative electrode active material layer 6 for secondary batteries may use an active material in which the operating potential of the negative electrode 2 is nobler than 1.0 V with respect to the potential of metallic lithium. When a conductive metal oxide is used for the negative electrode current collector 7, the potential at which lithium ions are inserted / extracted is 1.0 V or less. Therefore, the conductive metal oxide of the negative electrode current collector layer 7 does not react with lithium ions at a potential at which the insertion / extraction reaction of lithium ions proceeds in the negative electrode active material layer 6. Accordingly, the reaction of the conductive metal oxide of the negative electrode current collector layer 7 does not hinder the electrode reaction of the negative electrode active material itself, and the repeated life of the battery is improved.

(Materials for positive electrode current collector layer and negative electrode current collector layer)
Next, materials for the positive electrode current collector layer 5 and the negative electrode current collector layer 7 will be described.

As the conductive substance constituting the current collector electrode layer of the lithium ion secondary battery of the present invention, it is preferable to use a material having high conductivity. For example, a metal or alloy having a conductivity of 1 × 10 ¹ S / cm or more after firing. Specifically, for metals, silver (Ag), palladium (Pd), gold (Au), platinum (Pt), copper (Cu), aluminum (Al), nickel (Ni), cobalt (Co), etc. Is preferably used. If it is an alloy, the alloy which consists of 2 or more types of metals chosen from silver, palladium, gold | metal | money, platinum, copper, aluminum, nickel, cobalt, and tin is preferable, for example, it is preferable to use AgPd. As AgPd, it is preferable to use a mixed powder of Ag powder and Pd powder or a powder of AgPd alloy as a starting material.

  Also, the selection of a suitable metal species is such that the side reaction with the active material is minimal during batch firing, the fluidity of the surface of the metal powder is increased during firing, and necking between the metal powders occurs. Metal powder, mixed powder, and alloy powder that can maximize current collection efficiency are preferable.

  Further, a conductive metal oxide layer can be used for at least one of the positive electrode current collector layer 5 and the negative electrode current collector layer 7. The conductive metal oxide layer refers to a layered shape in which conductive metal oxides are integrated with each other. It may be a porous body having fine pores in the layer. By applying this material, it is possible to simultaneously sinter the electrode, electrolyte and current collector, thereby increasing the crystallinity of the active material and further improving the electrical conductivity. Very suitable.

When a conductive metal oxide is not used for either the positive electrode current collector layer 5 or the negative electrode current collector layer 7, a metal or alloy collection such as copper or nickel that does not react with lithium at the charge / discharge potential of the negative electrode Although it is possible to use an electric conductor, it is particularly desirable to use a conductive metal oxide layer for both the positive electrode current collector layer 5 and the negative electrode current collector layer 7.
Examples of the conductive metal oxide include oxides of at least one element selected from Sn, In, Zn, and Ti. More _{specifically, SnO 2, In 2 O 3} , ZnO, TiO x (0.5 ≦ x ≦ 2) and the like. These conductive metal oxides may contain a trace element (for example, 10 at% or less) for enhancing conductivity such as Sb, Nb, Ta in the structure.

(Material of solid electrolyte)
As the solid electrolyte constituting the solid electrolyte layer of the lithium ion secondary battery of the present invention, it is preferable to use a material having low electron conductivity and high lithium ion conductivity. Moreover, it is preferable that it is an inorganic material which can be baked at high temperature in an atmospheric condition. For example, lithium silicophosphate acid _{(Li 3.5 Si 0.5 P 0.5 O} 4), titanium phosphate lithium _{(LiTi 2 (PO 4) 2} ), phosphate germanium lithium _{(LiGe 2 (PO 4) 3} ), At least one selected from the group consisting of Li ₂ O—SiO ₂ , Li ₂ O—V ₂ O ₅ —SiO ₂ , Li ₂ O—P ₂ O ₅ —B ₂ O ₃ , Li ₂ O—GeO ₂ . It is preferable to use materials. Further, a material doped with a different element, Li ₃ PO ₄ , LiPO ₃ , Li ₄ SiO ₄ , Li ₂ SiO ₃ , LiBO ₂ or the like may be used for these materials. The material of the solid electrolyte layer may be crystalline, amorphous, or glassy.

(End electrode material)
A positive electrode end electrode connected to the positive electrode current collector of the obtained laminate is formed. In the lithium ion secondary battery of the present invention, a material obtained by mixing an active material and a conductive material is used as the end electrode material.

The active material described above is used as the active material. The following materials may be used as the conductive substance.
(Conductive substance)
As a conductive substance constituting the electrode layer of the lithium ion secondary battery, it is preferable to use a material having high conductivity. For example, a metal or alloy having a conductivity of 1 × 10 ¹ S / cm or more after firing. Specifically, if it is a metal, it is preferable to use silver, palladium, gold, platinum, aluminum, copper, nickel or the like. If it is an alloy, the alloy which consists of 2 or more types of metals chosen from silver, palladium, gold | metal | money, platinum, copper, aluminum, nickel, cobalt, and tin is preferable, for example, it is preferable to use AgPd. As AgPd, it is preferable to use a mixed powder of Ag powder and Pd powder or a powder of AgPd alloy as a starting material.

D: Paste preparation, printing, etc. (active material paste preparation process)
The active material paste is produced as follows. After pulverizing a predetermined active material powder to a particle size suitable for an all-solid-state secondary battery using a dry pulverizer / wet pulverizer, it is dispersed in an organic binder or solvent using a dispersing machine such as a planetary mixer or a three-roll mill. scatter. For the purpose of improving the active material dispersion in the organic binder, a coupling agent and a dispersing agent may be appropriately added.
The dispersion method applied to the present invention is not limited to the above-described dispersion method, and high dispersion that does not interfere with the printing on the solid electrolyte sheet is realized without aggregation of the active material in the paste. I need it. In addition, it is preferable to adjust the viscosity of the paste used in the present invention by appropriately adding a solvent in order to improve the printability. Furthermore, an auxiliary conductive material, a rheology modifier and the like may be added as appropriate in accordance with the required battery performance.

(Solid electrolyte sheet manufacturing process)
The solid electrolyte thin layer sheet is produced as follows. Solid electrolyte powder is pulverized to a particle size suitable for an all-solid secondary battery using a dry pulverizer / wet pulverizer, then mixed with an organic binder and solvent, and dispersed in a wet pulverizer such as a pot mill or a bead mill. An inorganic solid electrolyte slip is obtained. The obtained solid electrolyte slip is thinly applied onto a substrate such as a pet film by a doctor blade method or the like, and then dried to evaporate the solvent, thereby obtaining a solid electrolyte thin layer sheet on the substrate. For the purpose of improving the dispersion of the solid electrolyte powder in the organic binder, a coupling agent and a dispersing agent may be appropriately added. Further, the dispersion method applied to the present invention is not limited to the above-described dispersion method, and the aggregation of the inorganic solid electrolyte powder is not recognized in the solid electrolyte sheet and on the surface, which prevents the printing on the solid electrolyte sheet. What is necessary is just to realize a high dispersion that does not occur.

(Active material paste on solid electrolyte, active material mixed collector electrode paste, active material paste printing process)
The active material paste, the active material mixed collector electrode paste, and the active material paste are further printed on the solid electrolyte sheet thus obtained, and then dried to obtain an active material printed solid electrolyte sheet. Printing of the active material paste to the solid electrolyte sheet, be subjected to drying for each application of the paste, may even after the active material paste, the active material mixture collector electrode paste, the three layers of active material paste was printed. Examples of the printing method include screen printing, inkjet printing, and the like. In the case of screen printing, the former printing / drying process is preferable, and in the case of inkjet printing, the latter printing / drying process is more preferable. In the case of the latter printing / drying process, the active material mixed collector electrode paste is printed without passing through the drying process after the active material paste is printed on the inorganic solid electrolyte. Bonding with the electrode paste printing interface can be formed better.

(Battery edge treatment)
The active material paste printed end face and the active material mixed collector electrode paste printed end face, or the active material mixed collector electrode paste printed end face are printed so as to extend to either end face of the inorganic solid electrolyte sheet. Alternatively, the solid electrolyte sheet obtained by laminating and printing the active material and the active material mixed current paste is peeled off from the substrate, the sheets are further laminated and pressed, and the obtained laminate is cut to form a predetermined end face. Can be obtained.

(Addition of flux)
In order to match the sintering behavior of the active material, current collector metal, and inorganic solid electrolyte of each layer constituting the laminate, or to enable sintering at a low temperature, the active material paste, the active material mixed collector electrode paste A flux that promotes sintering may be added to the inorganic solid electrolyte slip. The addition method of the flux is a method of adding in advance when synthesizing the active material powder or the inorganic solid electrolyte from the raw material powder, and adding to the step of dispersing the synthesized active material and the inorganic solid electrolyte in an organic binder, a solvent or the like. Any method is acceptable.

(End electrode paste manufacturing process)
The active material / conductive mixture paste is prepared as follows. After a predetermined active material powder is pulverized to a particle size suitable for an all-solid-state secondary battery using a dry pulverizer / wet pulverizer, it is mixed with a metal powder to be an end electrode, a planetary mixer, a three roll mill Disperse in an organic binder or solvent using a dispersing machine such as For the purpose of improving the active material dispersion in the organic binder, a coupling agent and a dispersing agent may be appropriately added.

  The dispersion method is not limited to the above-described dispersion method, and any dispersion method may be used as long as active material aggregation is not recognized in the paste and high dispersion that does not hinder printing on the solid electrolyte sheet is realized. In addition, it is preferable to adjust the viscosity of the paste used in the present invention by appropriately adding a solvent in order to improve the printability. Furthermore, an auxiliary conductive material, a rheology modifier and the like may be added as appropriate in accordance with the required battery performance.

  The multilayer body constituting the multilayer all solid-state lithium ion secondary battery of the present invention is made by pasting, coating, and drying each material of the positive electrode layer, solid electrolyte layer, negative electrode layer, and optional protective layer constituting the multilayer body. A green sheet is produced, the green sheets are laminated, and the produced laminate is fired at once.

  Here, each material of the positive electrode active material, the negative electrode active material, the solid electrolyte, the conductive material, and the mixture of the active material and the conductive material used for pasting is obtained by calcining an inorganic salt as a raw material. Can be used. The calcination temperature of the positive electrode active material, the negative electrode active material, and the solid electrolyte are all set to 700 ° C. or more from the viewpoint that the chemical reaction of the raw material is advanced by calcining and the respective functions are fully exhibited after the batch firing. Is preferred.

The method for forming the paste is not particularly limited, and for example, a paste can be obtained by mixing the powder of each of the above materials in a vehicle of an organic solvent and a binder. For example, a mixture of a powder of LiMn ₂ O ₄ as a positive electrode active material and a metal powder of Ag and Pd as a conductive material is mixed at a predetermined volume ratio, and the mixture is dispersed in a solvent and a vehicle to produce a positive electrode paste. Can do. The diameter (particle diameter) of the particles of the active material powder and the conductive material powder is preferably 3 μm or less for any of the positive electrode active material, the negative electrode active material, and the conductive material. The particle size ratio between the active material powder and the conductive material powder is preferably 1:50 to 50: 1 in the case of either the positive electrode active material or the negative electrode active material. If the particle size and particle size ratio are in the above range, the conductive matrix is appropriately formed in the end electrode by firing, and the active material is appropriately supported on the matrix. It is effective for improving the performance of The volume ratio of mixing the conductive material powder and the active material powder is preferably in the range of 90:10 to 40:60. In the case of using AgPd as the conductive material, in addition to a mixture of Ag and Pd metal powder, for example, a synthetic powder by an Ag / Pd coprecipitation method or an Ag / Pd alloy powder can be used. By this method, a positive electrode layer paste, a solid electrolyte layer paste, and a negative electrode paste are prepared.

  The prepared paste is applied in a desired order on a substrate such as PET and dried as necessary, and then the substrate is peeled off to produce a green sheet. The paste application method is not particularly limited, and a known method such as screen printing, application, transfer, doctor blade, or the like can be employed.

  The produced green sheets for the positive electrode layer, the solid electrolyte layer, and the negative electrode layer are stacked in the desired order and the number of layers, and alignment, cutting, etc. are performed as necessary to produce a laminate. In the case of manufacturing a parallel type or series-parallel type battery, it is preferable to align and stack the end surfaces of the positive electrode layer and the negative electrode layer so that they do not coincide with each other.

  The produced laminate is pressed together. The pressure bonding is performed while heating, and the heating temperature is, for example, 40 to 80 ° C. The pressure-bonded laminated body is heated and fired, for example, in an air atmosphere. Here, firing refers to heat treatment for the purpose of sintering. Sintering refers to a phenomenon in which when a solid powder aggregate is heated at a temperature lower than the melting point, it solidifies into a compact body called a sintered body. In the production of the lithium ion secondary battery of the present invention, the firing temperature is preferably in the range of 600 to 1100 ° C. When the temperature is lower than 600 ° C., the conductive matrix is not formed in the electrode layer, and when the temperature exceeds 1100 ° C., problems such as melting of the solid electrolyte and changes in the structure of the positive electrode active material and the negative electrode active material occur. . The firing time is, for example, 1 to 3 hours.

Example 1
A secondary battery was produced according to the following procedure. FIG. 1 is a schematic sectional view showing the structure of the secondary battery, and FIG. 4 shows a part of the manufacturing process.

<Preparation of solid electrolyte sheet>
100 parts by weight of Li _3.5 Si _0.5 P _0.5 O ₄ powder as an inorganic solid electrolyte, 16 parts by weight of polyvinyl butyral as a binder, 4.8 parts by weight of benzylbutyl phthalate as a plasticizer, and ethanol as a solvent 100 parts by weight and 200 parts by weight of toluene were mixed and dispersed by a ball mill to obtain a paste. This paste was defoamed to prepare a solid electrolyte ceramic paste.
This paste was applied onto a polyethylene terephthalate (PET) sheet-like support carrier sheet 12 and dried to form a solid electrolyte paste layer 3g on the carrier sheet 12 to produce a solid electrolyte sheet 22 (FIG. 4A). .

<Preparation of positive electrode sheet>
Next, 100 parts by weight of LiMn ₂ O ₄ powder as a positive electrode active material, 15 parts by weight of ethyl cellulose as a binder, and 65 parts by weight of dihydroterpineol as a solvent are mixed and kneaded and dispersed with a three roll to obtain a paste. Foaming was performed to prepare a positive electrode active material paste.
This paste was applied onto the solid electrolyte paste layer 3g of the solid electrolyte sheet 22 and dried to form a first positive electrode active material paste layer 4g.
Next, 100 parts by weight of a powder obtained by mixing Ag / Pd powder having a weight ratio of 70/30 and LiMn ₂ O ₄ powder in a volume ratio of 60:40, 10 parts by weight of ethyl cellulose as a binder, and 50 of dihydroterpineol as a solvent. Weight parts were mixed, kneaded and dispersed with a three roll to obtain a paste, and the paste was defoamed to prepare a positive electrode current collector paste.
This paste was applied on the first positive electrode active material paste layer 4g and dried to form a positive electrode current collector paste layer 5g on the positive electrode active material paste layer 4g on the solid electrolyte paste layer 3g.

Further, using the positive electrode active material paste, a second positive electrode active material paste was applied onto the positive electrode current collector region 5g and dried to form a second positive electrode active material paste layer 4g.
In this way, a positive electrode sheet 23 shown in FIG.
<Preparation of negative electrode sheet>
The negative electrode sheet 24 was produced in the negative electrode sheet forming step described in B-4 above.
100 parts by weight of Li _4/3 Ti _5/3 O ₄ powder as a negative electrode active material, 15 parts by weight of ethyl cellulose as a binder, and 65 parts by weight of dihydroterpineol as a solvent are mixed, and kneaded and dispersed with a three roll to obtain a paste. The paste was degassed to produce a negative electrode active material paste.

This paste was applied onto the solid electrolyte paste layer 3g of the solid electrolyte sheet 22 and dried to form a first negative electrode active material paste layer 6g.
Next, 100 parts by weight of a powder obtained by mixing Ag / Pd powder having a weight ratio of 70/30 and Li _4/3 Ti _5/3 O ₄ powder in a volume ratio of 60:40, and 10 parts by weight of ethyl cellulose as a binder Then, 50 parts by weight of dihydroterpineol as a solvent was mixed, kneaded and dispersed with a three roll to obtain a paste, and this paste was defoamed to prepare a negative electrode current collector paste.
This paste was applied on the first negative electrode active material paste layer 6g and dried to form a negative electrode current collector paste layer 7g on the negative electrode active material paste layer 6g on the solid electrolyte paste layer 3g.

Further wherein the negative electrode active material paste applied to the anode current collector paste 7g on, and then dried to form a second anode active material paste layer 6 g.

In this way, the negative electrode sheet 24 shown in FIG.
<Lamination process>
The carrier sheet 12 was peeled from the obtained positive electrode sheet 23 and negative electrode sheet 24, and the both 23 and 24 were alternately laminated.

  After lamination, this was sandwiched between ceramic cover sheets and laminated by an isostatic press so that the positive and negative electrode current collectors were exposed on different surfaces of the laminate 30.

<Preparation of positive electrode end electrode paste>
In this example, LiMn ₂ O ₄ was used as the positive electrode active material, which is the starting material of the positive electrode end electrode, and Ag / Pd having a weight ratio of 70/30 was used as the conductive material.

The powder of LiMn ₂ O ₄ as an active material and the powder of Ag / Pd with a weight ratio of 70/30 as a conductive material are mixed so as to have a volume ratio of 60:40, and an acrylic binder as a binder has a weight of 5 wt. An active material / conductive material paste was prepared by mixing 10 parts by weight of dihydroterpineol as a part and a solvent.
This active material / conductive material paste was applied to the side where the end face of the positive electrode current collector of the unfired laminate 30 was exposed and dried.

The applied paste had a thickness of 5 μm.
<Preparation of negative electrode end electrode paste>
In this example, Li _4/3 Ti _5/3 O ₄ was used as the negative electrode active material, which is the starting material of the negative electrode end electrode, and Ag / Pd having a weight ratio of 70/30 was used as the conductive material.

The powder of Li _4/3 Ti _5/3 O _{4 as} the active material and the powder of Ag / Pd with a weight ratio of 70/30 as the conductive material are mixed at a volume ratio of 60:40, and further An active material / conductive material paste was prepared by mixing 5 parts by weight of an acrylic binder as a binder and 10 parts by weight of dihydroterpineol as a solvent.
This active material / conductive material paste was applied to the side of the unfired laminate 30 where the end face of the negative electrode current collector was exposed and dried.

  The applied paste had a thickness of 5 μm.

<Baking>
The laminated body 30 which apply | coated the positive electrode end part electrode paste and the negative electrode end part electrode paste was baked.
Firing was performed under the following conditions.

Firing temperature: 800 ° C
Holding time: 30 minutes Temperature increase rate: 1500 ° C / hr
Firing atmosphere: air atmosphere

<Battery evaluation>
With respect to the battery obtained by firing, the characteristics of the following items were evaluated.
(A) Battery capacity Lead wires were attached to the positive electrode end electrode and the negative electrode end electrode, and the capacity of the battery was measured. The measurement conditions were such that the current during charging and discharging was 0.1 μA, and the cutoff voltage during charging and discharging was 4.0 V and 0.5 V, respectively.
(B) Capacity maintenance rate characteristic after charge / discharge The capacity maintenance rate was defined as the ratio of the battery capacity at the 500th cycle to the battery capacity at the first cycle when charge / discharge was repeated under the above conditions.
(C) Presence / absence of cracks in solid electrolyte layer after charge / discharge The battery after charge / discharge was repeated 5 cycles was disassembled and observed by SEM.
(D) Interfacial strength between the end electrode and current collector after charging / discharging The joint strength between the battery end face and the end electrode is determined by soldering the lead wire perpendicularly to the center of the end electrode and using a load cell tester. It investigated by performing a tensile test.
As the sample, the sample after 500 cycles was used.

<Positive electrode / negative electrode end electrode connection step>
The positive electrode current collector 5 and the negative electrode current collector 7 of the laminate 30 thus obtained are attached with the positive electrode end electrode paste 8 and the negative electrode end electrode 9 respectively connected thereto, and an inorganic solid electrolyte secondary battery whose cross section is shown in FIG. Was completed.

<Battery evaluation>
The capacity of the completed battery was 1.2 μAh, and the capacity retention rate after 500 cycles was 98%.
As a result of disassembling the battery after the cycle life and observing with a SEM, the end face of the current collector was covered with the active material, and no defects such as cracks were observed in the inorganic solid electrolyte layer. The cycle life test was conducted at 20 ° C., the charge current was 0.1 μA and the discharge current was 0.1 μA , the charge and discharge end voltages were 4.0 V and 0.5 V, and the charge / discharge cycle was repeated to increase the capacity maintenance rate. It was measured.
In this example, the positive electrode sheet and the negative electrode sheet were prepared by the method shown in FIG. 4 and described in the method B-1, but the methods described in the methods B-2, B-3, and B-4 were used. Even when the positive electrode sheet and the negative electrode sheet were formed, it was confirmed that a battery having substantially the same characteristics as in this example was obtained.

In addition, when a positive electrode sheet and a negative electrode sheet are formed by the B-1 method and these are laminated to produce a laminated battery, there are no steps at the end portions that are not connected to the terminals of the positive electrode and the negative electrode. There was an advantage that defects such as delamination were less likely to occur. In the case of the manufacturing process by the B-4 method, it was advantageous in that the process could be simplified.
It was also found that it is desirable to employ the B-1 method described in Example 1 above up to about 100 layers, and to employ the B-4 method when exceeding 100 layers.

(Example 2)
In this example, the mixing ratio of the conductive material and the active material was changed.
The volume ratio of conductive material: active material was changed as follows.

Sample 1 100: 0 (conventional example)
Sample 2 90:10 (Example)
Sample 3 80:20 (Example)
Sample 4 70:30 (Example)
Sample 5 60:40 (Example)
Sample 6 50:50 (Example)
Sample 7 40:60 (Example)
Sample 8 30:70 (comparative example)

Battery capacity (μAh) Bond strength Conductivity (S / cm)
Sample 1 1.0 × ○ 1 × 10 ⁵
Sample 2 1.1 △ ○ 6 × 10 ⁴
Sample 3 1.2 △ ○ 2 × 10 ⁴
Sample 4 1.3 ○ ○ 1 × 10 ⁴
Sample 5 1.4 ○ ○ 5 × 10 ³
Sample 6 1.5 ○ ○ 6 × 10 ³
Sample 7 1.6 ○ ○ 6 × 10 ³
Sample 8 0 ○ × 2 × 10 ⁻⁴

* Explanation of symbols for bonding strength ○: Battery sample breaks before bonding with end electrode (bonding of end electrode is stronger than battery sample)
(Triangle | delta): The edge part electrode removed substantially simultaneously with the battery sample.
X: The end electrode was detached prior to the destruction of the battery sample.
(The end electrode is weaker than the battery sample)
* Description of symbols in conductivity ○: less than ^{1 × 10 1 S / cm:} 1 × greater than ¹⁰ 1 S / cm ×

** Sample 8 had good bonding strength, but its low electrical conductivity resulted in high battery internal resistance and zero battery capacity.

(Example 3)
In this example, a battery having the structure shown in FIG. 2 was manufactured.
That is, it has a structure in which the end face of the current collecting electrode layer is covered with the active material.
Other points are the same as in the first embodiment.
The manufacturing procedure was according to the procedure described in B-3 shown in FIG.
In this example, the capacity retention after charge / discharge was superior to that in Example 1, and the number of cracks in the solid electrolyte layer after charge / discharge was less than in Example 1.

Example 4
In this example, a battery having the structure shown in FIG. 3 was manufactured.
That is, the positive electrode layer and the negative electrode layer have a structure in which an active material is supported in a matrix made of a conductive material. As the paste for forming the layer, the same paste as that used to form the end electrodes was used.
The other points were the same as in Example 1.
In this example, a superior discharge capacity was obtained as compared with Example 1.
In this example, the same material was used for the positive electrode layer and the positive electrode end electrode, but similar results were obtained when different materials were used.

(Example 5)
In Example 1, after the end electrode paste was applied to the unfired laminated body (battery body part) after pressure bonding, the battery body part and the end electrode were collectively fired.
On the other hand, in this example, first, the unfired battery main body was once fired (first firing).
After the first firing, the end electrode paste was applied and dried.
Next, the second firing was performed.
The first firing was performed under the same conditions as in Example 1.
The second firing was performed at a temperature lower by 50 ° C. than the first firing temperature. Further, the rate of temperature rise until reaching the firing temperature was set to three times that during the first firing.
In addition, the holding time at the firing temperature was half that at the time of the first firing.
In this example, a higher battery capacity than that in Example 1 was obtained.
When the second firing was performed at a higher temperature than the first firing, some voids were observed.

(Example 6)
In Example 1, a metal was used as a material for the positive electrode current collector layer 5 (negative electrode current collector layer 6), and a metal was used as a conductive substance for the positive end electrode 8 (negative end electrode 9). In this example, a conductive oxide is used as the current collector material of the positive electrode current collector layer 5 (negative electrode current collector layer 6), and a conductive material is used as the conductive material of the positive end electrode 8 (negative end electrode 9). An oxide was used.
Specifically, indium tin oxide was used as the conductive oxide.
The other points were the same as in Example 1.
When the conductive material: active material has a volume ratio of 90:10 to 40:60, the battery sample is destroyed before the joining portion with the end electrode, and the joining of the end electrode has higher strength than the battery sample. Was confirmed.

(Example 7: Comparative example of claim 2)
In this example, a conductive oxide is used as the current collector material of the positive electrode current collector layer 5 (negative electrode current collector layer 6), and a conductive material is used as the conductive material of the positive end electrode 8 (negative end electrode 9). An oxide was used. Also, an alloy active material is used as the active material of the positive electrode current collector layer 5 (negative electrode current collector layer 6), and an alloy active material is used as the active material of the positive end electrode 8 (negative end electrode 9). It was.
Specifically, indium tin oxide was used as the conductive oxide, and silicon was used as the alloy-based active material.
The other points were the same as in Example 1.

  When the conductive material: active material has a volume ratio of 90:10 to 40:60, the battery sample is destroyed before the joining portion with the end electrode, and the joining of the end electrode has higher strength than the battery sample. Was confirmed.

(Example 8: Comparative example of claim 2)
In Example 1, a metal was used as the conductive material of the positive electrode current collector 5 (negative electrode current collector layer 6).
In this example, an alloy active material is used as the active material of the positive electrode current collector layer 5 (negative electrode current collector layer 6), and an alloy active material as the active material of the positive end electrode 8 (negative end electrode 9). Was used.

Specifically, silicon was used as the alloy-based active material.
The other points were the same as in Example 1.

  When the conductive material: active material has a volume ratio of 90:10 to 40:60, the battery sample is destroyed before the joining portion with the end electrode, and the joining of the end electrode has higher strength than the battery sample. Was confirmed.

(Comparative Example 1)
In this example, silicon was used as the positive electrode active material layer 4 (negative electrode active material layer 6) of the positive electrode layer 1 (negative electrode layer 2).
The other points were the same as in Example 1.
In any ratio, the end electrode was detached prior to the destruction of the battery sample.

(Comparative Example 2)
In this example, a conductive metal oxide was used as the conductive material for the end electrodes.
Specifically, indium tin oxide was used.
The other points were the same as in Comparative Example 1.
In any ratio, the end electrode was detached prior to the destruction of the battery sample.

(Comparative Example 3)
In this example, a conductive oxide is used as the conductive material of the positive electrode current collector layer 5 (negative electrode current collector layer 6), and the positive electrode active material layer 4 (negative electrode active material layer 6) of the positive electrode layer 1 (negative electrode layer 2). ) Was used as silicon.
The other points were the same as in Example 1.
In any ratio, the end electrode was detached prior to the destruction of the battery sample.

(Comparative Example 4)
In this example, a conductive oxide is used as the conductive material of the positive electrode current collector layer 5 (negative electrode current collector layer 6), and the positive electrode active material layer 4 (negative electrode active material layer 6) of the positive electrode layer 1 (negative electrode layer 2). ) Was used as silicon.
Further, a conductive metal oxide was used as a conductive substance for the positive end electrode 8 (negative end electrode 9).
Specifically, indium tin oxide was used.
The other points were the same as in Example 1.
In any ratio, the end electrode was detached prior to the destruction of the battery sample.

DESCRIPTION OF SYMBOLS 1 Positive electrode layer 1g Positive electrode paste 2 Negative electrode layer 2g Negative electrode paste 3 Solid electrolyte layer 3g Solid electrolyte paste 4 Positive electrode active material layer 4g Positive electrode active material paste 5 Positive electrode collector layer 5g Positive electrode collector paste 5a, 5b End surface 7a, 7b End surface 6 Negative electrode active material layer 6g Negative electrode active material paste 7 Negative electrode current collector layer 7g Negative electrode current collector paste 8 Positive electrode end electrode 9 Negative electrode end electrode 10 All-solid-state lithium ion secondary battery 21 Battery body (laminate)
22 Solid electrolyte sheet 23 Positive electrode sheet 24 Negative electrode sheet 30 Pre-firing laminate 45g, 67g Conductive material / active material mixture paste 101 Battery 102 Solid electrolyte layer 103 Positive electrode layer 104 Negative electrode layer 105, 106 Current collector layer 107 Positive electrode terminal 108 Negative terminal

Claims (26)

An all-solid-state lithium ion secondary battery in which a positive electrode end electrode and a negative electrode end electrode are provided on an electrode body composed of a laminate in which a positive electrode layer and a negative electrode layer are alternately stacked via a solid electrolyte layer,
Wherein the positive end electrode and / or the negative end electrodes where the are connected to the negative electrode layer is connected to the positive electrode layer has a conductive matrix composed of a conductive material carrying an active material structure, the positive The ratio (S _d / S _k ) of the area (S _d ) of the region of the conductive material and the area (S _k ) of the region of the active material in the cross section of the extreme part electrode and / or the negative electrode end electrode is 90 : All-solid-state type lithium ion secondary battery characterized by being in the range of 10-40: 60. Wherein the conductive material in the positive end electrode (or the negative end electrodes) is a material for forming the positive electrode layer (or negative electrode layer) conductive material and the same or an alloy in,
2. The all solid-state lithium ion battery according to claim 1, wherein the active material in the positive electrode end electrode (or negative electrode end electrode) is the same as the positive electrode active material (or negative electrode active material) of the positive electrode layer (or negative electrode layer). Next battery. Wherein the conductive material in the positive end electrode (or the negative end electrodes) is a metal or alloy, a conductive material in the positive electrode layer (or negative electrode layer) is according to claim 2 wherein the metal or alloy All solid-state lithium ion secondary battery. The positive electrode unit and the conductive material in the electrode (or the negative end electrode) is an oxide, the positive electrode layer (or negative electrode layer) in claim 2, wherein the electrically conductive material is a conductive oxide All-solid-state lithium ion secondary battery. Claim wherein said metal or alloy in the positive end electrode (or the negative end electrodes), the positive electrode layer (or negative electrode layer) metal or alloy in are different, both forming a solid solution alloy 4. The all-solid-state lithium ion secondary battery according to 4. The all-solid-state type according to any one of claims 1 to 5, wherein the positive electrode layer includes a positive electrode current collector layer and a positive electrode active material layer, and the negative electrode layer includes a negative electrode current collector layer and a negative electrode active material layer. Lithium ion secondary battery. 6. The all solid lithium according to claim 1, wherein the positive electrode layer (or the negative electrode layer) has a structure in which a conductive matrix made of a conductive material carries a positive electrode active material (or a negative electrode active material). Ion secondary battery. The positive electrode end electrode and / or the negative electrode end electrode are formed by baking a paste of a conductive material and a positive electrode active material applied to the unfired laminate. The all-solid-state lithium ion secondary battery according to 1. The positive electrode end electrode and / or the negative electrode end electrode is formed by baking a paste of a conductive material and a positive electrode active material applied to the fired laminate. The all-solid-state lithium ion secondary battery according to 1. The lithium ion secondary battery according to any one of claims 1 to 9, wherein the active material is a transition metal oxide or a compound made of a transition metal composite oxide. The active material is lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt composite oxide, lithium vanadium composite oxide, lithium titanium composite oxide, manganese dioxide, titanium oxide, niobium oxide, vanadium oxide, or tungsten oxide. 11. The lithium ion secondary battery according to claim 1, wherein the lithium ion secondary battery is one compound selected from the group consisting of two or more compounds. The conductive material is selected from the group consisting of silver, palladium, gold, platinum, aluminum, copper and nickel, or selected from the group consisting of silver, palladium, gold, platinum, aluminum, copper, nickel and tin The lithium ion secondary battery according to claim 1, wherein the lithium ion secondary battery is an alloy composed of two or more kinds of metals. The active material constituting the positive electrode end electrode is a lithium manganese composite oxide, the active material constituting the negative electrode end electrode is a lithium titanium composite oxide, and the conductive material is silver palladium. The lithium ion secondary battery of any one of Claims 1 thru | or 12 characterized by these. 14. The lithium ion secondary battery according to claim 1, wherein electrical conductivity of the positive electrode end electrode and the negative electrode end electrode is 1 × 10 ¹ S / cm or more. Producing a solid electrolyte sheet on which a solid electrolyte paste layer for forming the solid electrolyte layer is formed;
Forming a positive electrode paste layer for forming a positive electrode layer on the solid electrolyte paste layer to produce a positive electrode sheet;
Forming a negative electrode paste layer for forming a negative electrode layer on the solid electrolyte paste layer to produce a negative electrode sheet;
A step of alternately laminating a plurality of the positive electrode sheets and a plurality of the negative electrode sheets to produce a laminate;
Forming a positive end electrode for each other electrically through a plurality of the positive electrode layer on the side surfaces of the laminate,
Forming a negative electrode end electrode on the other side surface of the laminate for electrically connecting a plurality of the negative electrode layers;
Have
The positive electrode end electrode and / or the negative electrode end electrode has a structure in which an active material is supported on a conductive matrix made of a conductive material, and a cross section of the positive electrode end electrode and / or the negative electrode end electrode. The ratio (S _d / S _k ) of the area (S _d ) of the conductive material and the area (S _k ) of the active material in the range of 90:10 to 40:60 A method for producing an all solid-state lithium ion secondary battery. Wherein the conductive material in the positive end electrode (or the negative end electrodes) is a material for forming the positive electrode layer (or negative electrode layer) conductive material and the same or an alloy in,
16. The all-solid-state lithium ion battery according to claim 15, wherein the active material in the positive electrode end electrode (or negative electrode end electrode) is the same as the positive electrode active material (or negative electrode active material) of the positive electrode layer (or negative electrode layer). A method for manufacturing a secondary battery. Wherein the conductive material in the positive end electrode (or the negative end electrodes) is a metal or alloy, a conductive material in the positive electrode layer (or negative electrode layer) is according to claim 16 wherein the metal or alloy Manufacturing method of all solid-state type lithium ion secondary battery. The positive electrode unit and the conductive material in the electrode (or the negative end electrode) is an oxide, the positive electrode layer (or negative electrode layer) in claim 16, wherein the electrically conductive material is a conductive oxide A method for producing an all solid state lithium ion secondary battery. Claim wherein said metal or alloy in the positive end electrode (or the negative end electrodes), the positive electrode layer (or negative electrode layer) metal or alloy in are different, both forming a solid solution alloy 18. A method for producing an all solid state lithium ion secondary battery according to 18. The all-solid type according to any one of claims 15 to 19, wherein the positive electrode layer comprises a positive electrode current collector layer and a positive electrode active material layer, and the negative electrode layer comprises a negative electrode current collector layer and a negative electrode active material layer. A method for producing a lithium ion secondary battery. 21. The all solid lithium according to claim 15, wherein the positive electrode layer (or the negative electrode layer) has a structure in which a conductive matrix made of a conductive material carries a positive electrode active material (or a negative electrode active material). A method for manufacturing an ion secondary battery. The positive electrode end electrode and the negative electrode end electrode are formed by stacking the positive electrode end electrode paste layer for forming the positive electrode end electrode and the negative electrode end electrode paste layer for forming the negative electrode end electrode on the laminate. The method for producing an all-solid-state lithium ion secondary battery according to claim 15, wherein the method is formed by firing after forming each side of the body. Forming the positive electrode end electrode paste layer and the negative electrode end electrode paste layer in an unfired laminate,
23. The method for producing an all solid-state lithium ion secondary battery according to claim 22, wherein the positive electrode end electrode paste layer, the negative electrode end electrode paste layer, and the unfired laminate are fired together. Forming the positive electrode end electrode paste layer and the negative electrode end electrode paste layer in a fired laminate,
23. The method for producing an all solid-state lithium ion secondary battery according to claim 22, wherein the positive electrode end electrode paste layer, the negative electrode end electrode paste layer, and the fired laminate are collectively fired. . The method for producing an all solid state lithium ion secondary battery according to claim 22 or 23, wherein the firing is performed at a firing temperature of 600 ° C to 1100 ° C. Firing the only laminate, the laminate after baking, applying a positive end electrode paste for forming the positive end electrode for each other electrically through a plurality of the positive electrode layer, dried, together a plurality of the negative electrode layer 24. The all solid according to claim 22 or 23, wherein a negative electrode end electrode paste to be a negative electrode end electrode to be conducted is applied, dried, and then subjected to a second firing. Of manufacturing a lithium ion secondary battery.

Images