JP5216292B2 - Electricity storage element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage element which includes a multilayer electrode made by alternately laminating a positive electrode capable of occluding/discharging anions and a negative electrodes capable of occluding/discharging lithium ions with a separator interposed between both electrodes, and allows smooth and quick processes of melting of a preocclusion metal lithium and preocclusion of lithium ions by the negative electrode to improve production efficiency, reduce internal resistance, thus improve quality stability. <P>SOLUTION: The storage element includes a hard container (shape retaining jig) 11 which contains the metal lithium 42 disposed along the lamination end face of the multilayer electrode 20, together with a nonaqueous electrolytic solution 24, and a lid 13 which presses the multilayer electrode 20 in the direction of lamination. The hard container 11 and the lid 13 are entirely encased in an element container 15 of a soft packaging material. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a power storage device, and particularly uses a stacked electrode body in which a positive electrode capable of inserting and extracting anions and a negative electrode capable of inserting and extracting lithium ions are alternately stacked with a separator interposed therebetween. It is effective to apply to.

  In recent years, there has been a demand for a storage element capable of rapidly charging / discharging relatively large electric energy, for example, for load leveling in wind power generation, solar cells, etc., countermeasures for voltage sag and power failure, and energy regeneration in automobiles. I came.

  Conventionally, secondary batteries using chemical reactions such as lithium ion secondary batteries, nickel metal hydride secondary batteries, lead storage batteries, and nickel-cadmium batteries have been used as power storage elements for this purpose. However, these secondary batteries are rapidly deteriorated in characteristics due to repeated charge / discharge, and the number of charge / discharge cycles (life) is limited. In addition, the time required for charging is long, and rapid charging as required by the energy regeneration is impossible.

  If attention is paid to the charge / discharge characteristics, an electric double layer capacitor is more suitable than the secondary battery. The electric double layer capacitor stores charges in the physical adsorption layer (electric double layer) of ions formed on the electrode, and in principle does not use an electrochemical reaction, so it has no maintenance and long life, Fast response to charging / discharging and rapid charging / discharging. However, although the electric double layer capacitor can have a very large capacity (capacitance) as a capacitor, the electric capacity that can be charged and discharged is considerably inferior to that of a lithium ion secondary battery or the like. In other words, there was a weak point that the energy density was low.

Increasing the cell voltage is effective as a method for improving the energy density of the electric double layer capacitor. Since the energy stored in the capacitor is proportional to the square of the charging voltage, increasing the cell voltage can greatly contribute to an improvement in energy density.
As means for increasing the cell voltage of the electric double layer capacitor, an electrode material in which lithium ions are occluded (lithium pre-doped) in advance in the negative electrode is used. As the main material of this electrode material, for example, a carbon material has been studied.

By preliminarily storing lithium ions in the negative electrode, the potential of the negative electrode can be made lower, so that the cell voltage can be increased. In order to obtain this high cell voltage, it is necessary to reliably perform the above-mentioned pre-occlusion.
As a power storage element in which lithium ions are preliminarily occluded in a negative electrode and used for charging and discharging, for example, a laminated electrode body in which sheet-like positive electrodes and sheet-like negative electrodes are alternately laminated via separators is used. There is known a structure in which metallic lithium is disposed so as to face each laminated surface (see, for example, Patent Document 1).

FIG. 7 shows an example of the configuration of the laminated electrode body 200 accommodated in a conventional power storage element.
A laminated electrode body 200 shown in FIG. 7 is formed by laminating a positive electrode 21 and a negative electrode 23 formed in a sheet shape with a separator 22 interposed therebetween, and a metallic lithium 42 is disposed below the positive electrode 21 and the negative electrode 23.

  The sheet-like positive electrode 21 is produced by attaching a positive electrode material 211 capable of occluding and releasing anions to a sheet-like positive electrode current collector 212 in a layered manner by a method such as coating. Similarly, the sheet-like negative electrode 23 is produced by attaching a negative electrode material 231 capable of occluding and releasing lithium ions, which are electrolyte cations, to the sheet-like negative electrode current collector 232 by a method such as coating. In the positive electrode current collector 212 and the negative electrode current collector 232, holes penetrating the front and back surfaces (hereinafter referred to as through holes) are distributedly formed.

  The metallic lithium 42 is formed on the conductive support 40 and is disposed to face the surfaces of the positive electrode 21 and the negative electrode 23.

A lead terminal 213 is formed on a part of the positive electrode current collector 212 of each layer, and each lead terminal 213 is integrally connected directly or via a conductive wire.
A lead terminal 233 is formed on a part of the negative electrode current collector 232 of each layer, and a connecting lead 44 is formed on a part of the conductive support 40. Each lead terminal 233 and the connecting lead 44 are integrally connected directly or via a conductive wire.

In this way, the laminated electrode body 200 is formed. The lead terminal 213 is connected to a positive terminal (not shown), and the lead terminal 233 and the connecting lead 44 are connected to a negative terminal (not shown).
When this laminated electrode body 200 is hermetically housed in an element container (not shown) of a soft packaging material (for example, a laminate film) together with a non-aqueous electrolyte, the metal lithium 42 is dissolved in the non-aqueous electrolyte as lithium ions. . Lithium ions diffuse through the laminated electrode body 200 through the through holes of the positive electrode current collector 212 and the negative electrode current collector 232, and are stored in the negative electrode 23.

In addition, it is known that the internal resistance of an electric storage element using such a laminated electrode body 200 is reduced by applying pressure (improving adhesion) in the laminating direction of the laminated electrode body (for example, Patent Documents). 2).
Japanese Patent No. 3485935 JP 2001-244156 A

  In the above-described storage element, since it is necessary to pass the positive electrode (through hole of the positive electrode current collector) in order to diffuse lithium ions in the laminated electrode body, for example, when the through hole has a low hole area ratio, the laminated electrode It took a long time to occlude lithium ions throughout the negative electrode of the body. Further, there is a problem that it takes time to pre-occlude lithium ions as the number of stacked positive and negative electrodes increases. Further, since lithium ions pass through the positive electrode, the lithium ions preliminarily occluded in the negative electrode are difficult to be uniform in the upper and lower layers and the inner layer of the laminated electrode body.

  Moreover, in the electrical storage element using the element container of a soft packaging material, the laminated electrode body could not be pressed sufficiently in the laminating direction, and it was difficult to reduce the internal resistance. As a result, there is a problem that the stability of quality cannot be improved.

  The present invention solves the above problems, and its purpose is to provide a separator between a positive electrode capable of absorbing and releasing anions and a negative electrode capable of inserting and releasing lithium ions. In storage elements that use alternately stacked electrode bodies, the production efficiency is improved and the internal resistance is reduced by smoothly and quickly pre-occluding metal lithium for pre-occlusion and pre-occluding lithium ions to the negative electrode. It is to improve the stability of quality.

  Other objects and configurations of the present invention will be clarified in the description of the present specification and the accompanying drawings.

The solution provided by the present invention is as follows.
(1) A positive electrode material capable of inserting and extracting anions is attached to a sheet-like positive electrode current collector, and a negative electrode material capable of inserting and extracting lithium ions is provided on the sheet-like negative electrode current collector. A laminated electrode body in which the attached negative electrode is alternately laminated in the vertical direction with a separator interposed therebetween, a non-aqueous electrolyte containing a lithium salt, and the negative electrode current collector are conductively connected to each other. In a power storage device comprising metal lithium for preliminarily occluding lithium ions in the negative electrode, and an element container of a soft package in which the laminated electrode body is hermetically housed together with the non-aqueous electrolyte,
Metal lithium conductively connected to the negative electrode current collector is disposed facing the laminated end faces on the left and right sides of the laminated electrode body,
The laminated electrode body and the metallic lithium are housed together with the non-aqueous electrolyte in a box-shaped shape holding jig whose upper side is open at the bottom, and the laminated electrode body is formed of the shape retaining jig. Pressed from above in the stacking direction by the lower surface of the lid covering the opening,
The inner wall of the shape retaining jig is formed with a protrusion protruding toward the laminated end face of the laminated electrode body, and the metallic lithium faces the laminated end face at a portion where the protrusion is not formed. By being arranged, even after the metallic lithium is dissolved by the non-aqueous electrolyte, the laminated electrode body is held in place by the protrusions,
The shape retaining jig and the lid are hermetically housed in the element container;
A power storage element.

In (2) above means (1), the upper Symbol laminated electrode body, in the shape-retaining jig in a state of being covered with the cover body, an end surface of the side where the metal lithium is not disposed and the shape retaining jig The nonaqueous electrolyte solution is filled between the inner wall surfaces, and the nonaqueous electrolyte solution is accommodated in the shape retention jig in a larger amount than the multilayer electrode body is impregnated. element.
(3) In the above means (1) or (2), each negative electrode current collector of the laminated electrode body and the separator are in contact with lithium metal disposed on the side of the shape retaining jig. Power storage element.
(4) In the above means (3), the lead terminal drawn from each of the positive electrode current collectors is connected to the positive electrode terminal, the lead terminal drawn from each of the negative electrode current collectors is connected to the negative electrode terminal, and the shape retaining jig And the positive electrode terminal and the negative electrode terminal are formed in accordance with the joint shape of the lid body.

(5) The electricity storage device according to any one of the above means (1) to (4), further comprising a fixture that holds the lid and the shape retaining jig in a pressed state.
(6) In any one of the above means (1) to (5), an isolation wall for partitioning the internal space of the shape retaining jig is provided, and the stacked electrode body and the stacked layer are provided in each region partitioned by the isolation wall. The metal lithium and the non-aqueous electrolyte disposed on the laminated end face of the electrode body are respectively accommodated, the positive electrodes of the laminated electrode bodies are connected to each other, and the negative electrodes are connected to each other. Power storage element.

  In a storage element using a laminated electrode body in which a positive electrode capable of occluding and releasing anions and a negative electrode capable of occluding and releasing lithium ions are alternately laminated with a separator interposed therebetween, The production efficiency can be improved by smoothly and rapidly performing the pre-occlusion of lithium ions into the negative electrode and the negative electrode, and the internal resistance can be reduced to improve the quality stability.

  The operations / effects other than the above will be clarified in the description of the present specification and the accompanying drawings.

  FIG. 1 shows a first embodiment of a power storage device 10 according to the present invention. In the figure, (a) is a cross-sectional view in the longitudinal direction of the electricity storage element 10, and (b) is a cross-sectional view in the direction orthogonal to (a). Moreover, FIG. 2 shows an example of the structure of the laminated electrode body 20 accommodated in the electrical storage element 10 by this invention. 1A is a sectional view of the laminated electrode body 20 in the same direction as FIG. 1A, FIG. 1B is a sectional view of the laminated electrode body 20 in the same direction as FIG. ) Is a plan view of the positive electrode 21, and (d) is a plan view of the negative electrode 23.

First, the structure of the electrical storage element 10 is demonstrated, referring FIG. 1 (a), (b).
1A and 1B, a storage element 10 of the present invention includes a laminated electrode body 20, a metal lithium 42, a non-aqueous electrolyte 24, a positive electrode terminal 31, a negative electrode terminal 33, and a hard container (shape retaining jig) 11. The lid body 13 and the element container 15 are configured.

  As shown in FIGS. 1A and 1B, the laminated electrode body 20 is accommodated in a hard container 11 to be described later, and metallic lithium 42 is disposed along the laminated end face. The laminated electrode body 20 is pressed in the laminating direction by a lid body 13 which will be described later.

  The positive electrode terminal 31 and the negative electrode terminal 33 are respectively connected to the lead terminals 213 and 233 of the laminated electrode body 20, and the inner and outer sides of the element container 15 are maintained while the element container 15 is kept sealed as shown in FIG. It is installed across. The positive electrode terminal 31 and the negative electrode terminal 33 are formed in accordance with the shapes of the hard container 11 and the lid body 13. For example, in the case of FIG. 1A, the positive electrode terminal 31 and the negative electrode terminal 33 are formed in an L shape in accordance with the joint shape of the hard container 11 and the lid body 13. By doing so, it is possible to save the trouble of forming the lead-out portion of the positive electrode terminal 31 and the negative electrode terminal 33 in the hard container 11, and the laminated electrode body 20 connected to the positive electrode terminal 31 and the negative electrode terminal 33 is replaced with the hard container. 11 can be easily installed.

  The nonaqueous electrolytic solution 24 is an electrolytic solution in which a lithium salt containing lithium ions as a cation is dissolved in a nonaqueous solvent such as a cyclic carbonate or a chain carbonate.

  The hard container 11 is, for example, a bottomed box-shaped container having an open upper surface, and accommodates the laminated electrode body 20 and the lithium metal 42 together with the nonaqueous electrolytic solution 24. The storage volume of the hard container 11 is formed to be sufficiently larger than the volume of the laminated electrode body 20, so that the surplus nonaqueous electrolyte solution 24 can be accommodated with respect to the amount impregnated in the laminated electrode body 20. .

  The lid body 13 is a kind of drop lid that covers the upper surface of the hard container 11 and presses the laminated electrode body 20 in the hard container 11 in the laminating direction. The hard container 11 and the lid 13 are formed of an insulator (for example, resin) that is not affected by the non-aqueous electrolyte 24 and does not cause plastic deformation.

  The element container 15 hermetically seals the hard container 11 containing the laminated electrode body 20, the metal lithium 42, and the nonaqueous electrolyte solution 24, and the lid body 13 covering the upper surface of the hard container 11. As the element container 15, a soft container obtained by processing an airtight soft packaging material such as a laminate film into a rectangular bag shape by fusion or the like is used. This soft container can be easily sealed by heat-sealing the opening. Sealing by thermal fusion can be performed in a state where the positive electrode terminal 31 and the negative electrode terminal 33 are sandwiched between the fusion portions. As another method, the hard container 11 and the lid 13 may be bonded with an adhesive or the like, or may be joined by welding or the like.

Next, the configuration of the laminated electrode body 20 will be described with reference to FIG.
The laminated electrode body 20 is configured by alternately laminating positive electrodes 21 and negative electrodes 23 with separators 22 therebetween, as shown in FIGS.

  As shown in FIG. 2 (c), the positive electrode 21 is layered by applying a positive electrode material 211 capable of occluding and releasing anions on both surfaces of a sheet-like positive electrode current collector 212 made of a metal (eg, Al) foil. By attaching, the whole is formed in a sheet shape. Similarly, as shown in FIG. 2D, the negative electrode 23 is coated on both surfaces of a sheet-like negative electrode current collector 232 in which a negative electrode material 231 capable of inserting and extracting lithium ions is made of a metal (for example, Cu) foil. Thus, the whole is formed into a sheet shape. The separator 22 is formed in a sheet shape using a non-conductive porous film such as, for example, poreolyfin.

  The positive electrode current collector 212 and the negative electrode current collector 232 are integrally formed with lead terminals 213 and 233 for connection to the positive electrode terminal 31 and the negative electrode terminal 33, respectively, as shown in FIG.

  The positive electrode 21 and the negative electrode 23 are sequentially stacked while sandwiching the separator 22 to form the stacked electrode body 20. At this time, the lead terminals 213 of the respective positive electrode current collectors 212 and the lead terminals 233 of the respective negative electrode current collectors 232 are respectively drawn out from two opposing surfaces of the stacked end surfaces of the stacked electrode body 20 as shown in FIG. It is.

  Further, as shown in FIG. 2B, the positive electrode current collector 212 and the negative electrode current collector 232 have a length between two sides orthogonal to the side on which the lead terminals 213 and 233 are formed. The negative electrode current collector 232 is formed to be larger than 212 (d2> d1). In the laminated electrode body 20, the negative electrode current collector 232 is laminated so as to protrude from the positive electrode current collector 212 on the laminated end face side different from the laminated end face from which the lead terminals 213 and 233 are drawn. The lowermost negative electrode current collector 232 of the laminated electrode body 20 also serves as a support for supporting the metal lithium 42. In other words, as shown in FIG. 2B, the lowermost negative electrode current collector 232 is formed such that the length between the two opposing sides is larger than d2, and is formed on the laminated end face of the laminated electrode body 20. It is bent toward. The metallic lithium 42 is attached to the side of the laminated end face of the bent portion and is in direct contact with the edge of each negative electrode current collector 232 on the laminated end face of the laminated electrode body 20.

  Further, the current collector on which the metallic lithium 42 is stuck may be provided separately from the laminated electrode body 20. In that case, the same effect can be obtained when metallic lithium is stuck and the current collector is laid on the bottom, the laminated electrode body is placed thereon, and the lithium metal portion is bent toward the side surface. It is even better if the lead terminal is drawn out to the current collector and connected to the negative electrode current collector.

  Further, the separator 22 disposed above and below each positive electrode 21 on the laminated end face different from the laminated end face from which the lead terminals 213 and 233 are drawn, envelops the edge of the positive electrode 21 as shown in FIG. It is out. For example, after laminating | stacking with the separator 22, the positive electrode 21, and the separator 22, the edge parts of those separators 22 are heated so that the edge part of the positive electrode 21 may be wrapped. Thus, by enveloping the edge of the positive electrode 21 with the separator 22, the positive electrode current collector 212 and the metal lithium 42 can be prevented from contacting each other, and safety can be improved. In this case, preferably, both end portions of the separator are brought into contact with the metal lithium 42.

  The lead terminal 213 of each positive electrode current collector 212 of the laminated electrode body 20 is integrally connected as shown in FIG. 1A and is connected to one end side of the positive electrode terminal 31. Similarly, the lead terminal 233 of each negative electrode current collector 232 is connected integrally and connected to one end side of the negative electrode terminal 33.

  Thus, the laminated electrode body 20 is configured, and the metal lithium 42 is arranged along the laminated end face.

  The positive electrode 21 occludes the anion in the non-aqueous electrolyte 24 during charging and releases it during discharging. The negative electrode 23 occludes lithium ions (cations) in the non-aqueous electrolyte 24 during charging and releases it during discharging. A reversible charging / discharging process is performed by reversible occlusion / release of these anions and lithium ions. As the material for the positive electrode material 211 and the negative electrode material 231, a carbon material is suitable.

  Next, the arrangement of the laminated electrode body 20, the metallic lithium 42 in the hard container 11, and the pre-occlusion of lithium ions will be described with reference to FIG. FIG. 3 shows a state in which the laminated electrode body 20 is accommodated in the hard container 11. In the figure, (a) is a plan view, (b) is a cross-sectional view in the AA direction of (a), and (c) is a cross-sectional view in the BB direction of (a). FIGS. 3B and 3C show cross sections after the non-aqueous electrolyte 24 is injected.

  As shown in FIG. 3A, the hard container 11 contains a laminated electrode body 20, a positive electrode terminal 31, a negative electrode terminal 33, and metallic lithium 42. The metallic lithium 42 is disposed along a laminated end face (upper side and lower side in FIG. 3A) of the laminated electrode body 20 different from the laminated end face from which the lead terminals 213 and 233 are drawn. The metallic lithium 42 is conductively connected to each negative electrode current collector 232 in the laminated electrode body 20 through the lead terminal 233.

  If the lead terminal 213 and the lead terminal 233 shown in FIG. 3A, or the positive electrode terminal 31 and the negative electrode terminal 33 are formed so as to have different widths or shapes, the polarities can be easily distinguished. When the electrode body 20, the positive electrode terminal 31, and the negative electrode terminal 33 are accommodated, mistakes can be prevented.

  When the nonaqueous electrolytic solution 24 is injected, the lithium ions eluted from the metallic lithium 42 to the nonaqueous electrolytic solution 24 by the nonaqueous electrolytic solution 24 along each layer from the laminated end surface of the laminated electrode body 20 ( It spreads in the horizontal direction of the paper shown in FIG. Therefore, since lithium ions do not need to pass through the positive electrode 21, it is possible to smoothly and quickly preliminarily store lithium ions in the negative electrode 23. At that time, surplus (a larger amount than impregnating the laminated electrode body 20) is poured into the hard container 11, so that the metal lithium 42 disposed on the laminated end face of the laminated electrode body 20 is formed. It becomes easy to melt | dissolve in the non-aqueous electrolyte 24, and the preliminary occlusion of lithium ion can be performed more rapidly.

  As described above, in the electric storage element 10 of the present invention, the metal lithium 42 is disposed so as to face the laminated end surface excluding the surface from which the lead terminals 213 and 233 are drawn out of the laminated end surface of the laminated electrode body. As a result, lithium ions eluted from the metal lithium 42 move along each layer of the laminated electrode body 20. Thereby, it becomes possible to diffuse lithium ion only by the negative electrode 23, and the preliminary occlusion of the lithium ion to the negative electrode 23 of each layer can be performed rapidly and uniformly.

  Furthermore, since the lithium metal 42 that is a supply source of the lithium ions is arranged so as to face the laminated end face of the laminated electrode body 20, the lithium ions eluted from the metallic lithium 42 are separated from each layer in the laminated electrode body 20. It reaches the negative electrode 23 simultaneously and is occluded. As a result, lithium ions can be preoccluded more rapidly and uniformly in the negative electrode 23 of each layer in the electrode body 20 regardless of the number of stacked positive electrodes 21 and negative electrodes 23. Therefore, the pre-occlusion that conventionally required a long time can be greatly shortened.

  Moreover, the internal resistance of the electrical storage element 10 can be reduced and the stability of quality can be improved by pressing the laminated electrode body 20 accommodated in the hard container 11 in the laminating direction by the lid body 13.

  4A and 4B show a second embodiment of the electricity storage device according to the present invention, wherein FIG. 4A is a longitudinal sectional view, and FIG. 4B is a sectional view perpendicular to FIG.

If it demonstrates paying attention to the difference with the said embodiment, the fixing tool 17 is attached to the outer side of the element container 15 in 2nd Embodiment shown in the figure.
The fixture 17 holds the lid 13 and the hard container 11 in a pressed state. By holding the lid 13 and the hard container 11 in a pressed state using the fixture 17, the laminated electrode body 20 can be reliably pressed and the internal resistance can be reduced more reliably.

  In the present embodiment, the fixing tool 17 is provided outside the element container 15. However, the lid body 13 and the hard container 11 may be fixed by the fixing tool 17 and the outside may be wrapped by the element container 15. Moreover, in this actual child form, although the fixing tool 17 was made into the U shape as shown in FIG.4 (b), it is not limited to this. For example, the entire outer periphery of the element container 15 shown in FIG. Further, the lid 13 and the hard container 11 may be fixed using a wire or the like.

FIG. 5 shows a plan view of the main part of a third embodiment of the electricity storage device according to the present invention.
If it demonstrates paying attention to the difference with the said embodiment, the protrusion 51a, 51b, 51c for positioning of the laminated electrode body 20 will be formed in the housing | casing side of the laminated electrode body 20 of the hard container 51 of 3rd Embodiment shown in the figure. Has been.

The protrusions 51a, 51b, 51c are formed so as to protrude from the inner wall of the hard container 51 toward the laminated end surface of the laminated electrode body 20, as shown in FIG.
Further, the metallic lithium 42 is disposed so as to face the laminated end surface in the portions where the protrusions 51a, 51b, 51c of the hard container 51 are not formed.

  As shown in the figure, by providing the protrusions 51a, 51b, 51c on the laminated electrode body 20 side of the hard container 51, even if the metallic lithium 42 is dissolved in the non-aqueous electrolyte 24, the protrusions 51a, 51b, 51c. Thus, the laminated electrode body 20 can be supported stably. Therefore, for example, when used in a train or a car, it is possible to suppress arbitrary movement of the laminated electrode body 20 due to vibration.

6A and 6B show a fourth embodiment of a power storage device according to the present invention, in which FIGS. 6A and 6D are plan views of main parts, FIG. 6B is a cross-sectional view taken along the line CC in FIG. The equivalent circuit diagrams are respectively shown.
If it demonstrates paying attention to the difference with the said embodiment, in 4th Embodiment shown to the figure, as shown to Fig.6 (a), (b), the hard container 61 will isolate the internal space of the hard container 61. A wall 62 is provided.

  In each region of the hard container 61 partitioned by the isolation wall 62, the laminated electrode body 20, the lithium metal 42 disposed along the laminated end surface of the laminated electrode body 20, and the nonaqueous electrolyte solution 24 are accommodated, respectively. Yes. The lead terminals 213 of each laminated electrode body 20 are connected by connection leads 45, and the connection leads 45 are connected to the positive electrode terminal 31. Similarly, the lead terminal 233 of each laminated electrode body 20 is connected by a connection lead 46, and the connection lead 46 is connected to the negative electrode terminal 33.

  As shown in FIG. 6C, an equivalent circuit with this configuration is a parallel arrangement of a capacitor CA (capacitance is C1) by one laminated electrode body 20 and a capacitor CB (capacitance is C2) by the other laminated electrode body 20. Connect. Therefore, the combined capacity C is C = C1 + C2, and is an added value of each capacity of each stacked electrode body 20.

  That is, by connecting the stacked electrode bodies 20 in parallel, the combined capacity can be increased without increasing or shortening the diffusion distance of lithium ions eluted from the metal lithium 42. In this case, as shown in FIG. 6B, a lid 63 is formed in the shape of the hard container 61 so that each laminated electrode body 20 in the hard container 61 can be pressed.

  Further, as shown in FIG. 6D, a slit-shaped isolation wall 72 may be provided. By doing so, the non-aqueous electrolyte 24 in the hard container 61 can flow through each region through the gap between the isolation walls 72, and lithium ion pre-occlusion can be performed more smoothly.

  Further, in the present embodiment, two laminated electrode bodies 20 are connected in parallel, but two or more separation walls 62 may be provided, and three or more laminated electrode bodies 20 may be connected in parallel.

  Thus, by connecting a plurality of laminated electrode bodies 20 in parallel and disposing metallic lithium 42 on the laminated end face of each laminated electrode body 20, it is possible to quickly preliminarily occlude lithium ions, and to further store an electric storage element. Capacity can be increased. Further, by using the hard container 61, the stacked electrode bodies 20 connected in parallel can be stably accommodated.

<Example>
Production of positive electrode:
Activated carbon YP-17 (manufactured by Kuraray Chemical Co., Ltd.), acetylene black HS-100 (manufactured by Denki Kagaku Kogyo Co., Ltd.), PTFE (polytetrafluoroethylene) aqueous dispersion (Mitsui Dupont Fluorochemical) 30J) and 2% by weight aqueous solution of CMC (Daiichi Pharmaceutical Co., Ltd. Cellogen 4H) in a weight ratio of 88: 8: 2: 2, mixed with distilled water and kneaded into a paste, A mixture slurry was prepared. In addition, the ratio of 30J and CMC is a ratio of solid content. The slurry was applied to both surfaces of an aluminum foil 2 having a thickness of 20 μm, dried and rolled, and cut into a width of 56 mm to produce a positive electrode sheet. The end portion of the positive electrode also includes an uncoated portion that becomes a lead terminal for connection with the positive electrode terminal.

Production of negative electrode:
A non-graphitizable carbon material (PIC manufactured by Kureha Chemical Co., Ltd.) as a negative electrode material and polyvinylidene fluoride resin (KF # 1100, Kureha Chemical Co., Ltd.) as a binder are mixed at a weight ratio of 95: 5. Then, N-methyl-2-pyrrolidinone was added as a solvent to prepare a paste mixture.
This mixture was applied to both sides of a copper foil serving as a current collector. This was dried and rolled, and then cut into a predetermined shape to produce a sheet-like negative electrode. The end portion of the negative electrode also includes an uncoated portion that becomes a lead terminal for connection to the negative electrode terminal.

Production of electrode body:
A plurality of pairs of the produced negative electrode and positive electrode were laminated so as to face each other with a polyolefin-based separator interposed therebetween, so that a laminated electrode body as shown in FIG. Except for the surface on which the lead terminals are formed, the upper and lower separators of the positive electrode were joined so as to wrap the positive electrode by applying heat to the end portions. Further, the negative electrode current collector which is the lowermost part of the laminated electrode body was formed with d2 shown in FIG. 2 (b) larger, and metal lithium was stuck on the lower surface of the laminated electrode body. The bonded portion of the metallic lithium was bent so as to face the laminated end face, and the metallic lithium was brought into contact with the edge of the negative electrode current collector on the laminated end face of the laminated electrode body.
The positive lead terminals were bundled and connected, and the negative lead terminals were bundled and connected.

Device fabrication:
The positive electrode lead terminal of the laminated electrode body was connected to the positive electrode terminal, and the negative electrode lead terminal was connected to the negative electrode terminal. These were inserted into a hard container, and a nonaqueous electrolytic solution containing lithium salt was injected so that the laminated electrode body was sufficiently immersed (FIGS. 3B and 3C). Thereafter, vacuuming was performed.
It was left to stand in a dry atmosphere for several days, the non-aqueous electrolyte was impregnated inside the laminated electrode body, and lithium ions were preoccluded in the negative electrode of the laminated electrode body.
Then, a lid was attached to the hard container, the laminated electrode body was pressed in the laminating direction, the whole was inserted into a laminated package serving as an element container, and evacuation was performed. Thereafter, the opening portion of the laminate package was hermetically sealed by heat sealing in a state where each one end side of the positive electrode terminal and the negative electrode terminal was outside the container. In this way, a power storage element was produced (see FIG. 1).

  In addition, you may perform preliminary occlusion of lithium ion in the state which attached the cover body to the hard container and sealed with the laminate package. In that case, pre-occlusion can be performed in an air atmosphere, and the cost can be reduced.

  As mentioned above, although this invention was demonstrated based on the typical Example, this invention can have various aspects other than having mentioned above.

  Dissolution of pre-occlusion metal lithium in a storage element using a laminated electrode body in which a positive electrode capable of occluding and releasing anions and a negative electrode capable of occluding and releasing lithium ions are alternately laminated with a separator interposed therebetween. In addition, the production efficiency can be improved by smoothly and quickly preliminarily storing lithium ions in the negative electrode, and the internal resistance can be reduced to improve the quality stability.

It is sectional drawing which shows 1st Embodiment of the electrical storage element by this invention. It is sectional drawing and a top view of the laminated electrode body accommodated in the electrical storage element by this invention. It is the principal part top view and sectional drawing of 1st Embodiment of the electrical storage element by this invention. It is sectional drawing which shows 2nd Embodiment of the electrical storage element by this invention. It is a principal part top view which shows 3rd Embodiment of the electrical storage element by this invention. It is a principal part top view which shows 4th Embodiment of the electrical storage element by this invention, and its sectional drawing. It is principal part sectional drawing which shows the structural example of the conventional electrical storage element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Power storage element 11, 51, 61 Hard container 13, 63 Lid 15 Element container 17 Fixture 20 Stacked electrode body 21 Positive electrode 211 Positive electrode material 212 Positive electrode collector 213 Lead terminal (positive electrode)
22 Separator 23 Negative electrode 231 Negative electrode material 232 Negative electrode current collector 233 Lead terminal (negative electrode)
24 Nonaqueous Electrolytic Solution 31 Positive Electrode Terminal 33 Negative Electrode Terminal 40 Conductive Support Body 42 Metal Lithium 44 Connection Lead 45, 46 Connection Lead 51a, 51b, 51c Projection 62 Isolation Wall

Claims (6)

A positive electrode material capable of occluding and releasing anions was attached on a sheet-like positive electrode current collector, and a negative electrode material capable of occluding and releasing lithium ions was attached on a sheet-like negative electrode current collector. A negative electrode is alternately laminated in the vertical direction with a separator interposed therebetween, a non-aqueous electrolyte containing a lithium salt, and the negative electrode current collector electrically connected to the lithium ion. In a power storage device comprising metal lithium for preliminarily occlusion in the negative electrode and an element container of a soft package in which the laminated electrode body is hermetically housed together with the non-aqueous electrolyte,
Metal lithium conductively connected to the negative electrode current collector is disposed facing the laminated end faces on the left and right sides of the laminated electrode body,
The laminated electrode body and the metallic lithium are housed together with the non-aqueous electrolyte in a box-shaped shape holding jig whose upper side is open at the bottom, and the laminated electrode body is formed of the shape retaining jig. Pressed from above in the stacking direction by the lower surface of the lid covering the opening,
The inner wall of the shape retaining jig is formed with a protrusion protruding toward the laminated end face of the laminated electrode body, and the metallic lithium faces the laminated end face at a portion where the protrusion is not formed. By being arranged, even after the metallic lithium is dissolved by the non-aqueous electrolyte, the laminated electrode body is held in place by the protrusions,
The shape retaining jig and the lid are hermetically housed in the element container;
A power storage element.   2. The laminated electrode body according to claim 1, wherein the laminated electrode body is disposed between the end surface on the side where the metallic lithium is not disposed and the inner wall surface of the shape retaining jig in the shape retaining jig covered with the lid. An electricity storage element characterized in that the non-aqueous electrolyte is filled, and the non-aqueous electrolyte is accommodated in the shape retention jig in a larger amount than the multilayer electrode body is impregnated.   3. The power storage device according to claim 1, wherein each of the negative electrode current collector of the multilayer electrode body and the separator are in contact with lithium metal disposed on a side surface of the shape retaining jig.   4. The lead terminal drawn from each of the positive electrode current collectors is connected to the positive electrode terminal, the lead terminal drawn from each of the negative electrode current collectors is connected to the negative electrode terminal, and the shape retaining jig and the lid body A power storage element, wherein the positive electrode terminal and the negative electrode terminal are formed in accordance with a joint shape.   5. The power storage device according to claim 1, further comprising: a fixture that holds the lid and the shape-retaining jig in a pressed state. In any one of Claims 1-5, the isolation wall which partitions off the internal space of the said shape-retaining jig is provided, and it arrange | positions in each area | region partitioned by the said isolation wall on the lamination | stacking end surface of the said lamination electrode body. An electrical storage element characterized in that said metallic lithium and said non-aqueous electrolyte are respectively accommodated, each positive electrode of each said laminated electrode body is connected to each other, and each negative electrode is connected to each other.

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