JP6611455B2 - Assembled battery - Google Patents

Description

  The present invention relates to an assembled battery that is reduced in weight, heat dissipation, and space saving.

  In this specification, the term “aluminum” is used to include Al and Al alloys, the term “copper” is used to include Cu and Cu alloys, and the term “nickel” includes Ni and The term “titanium” is used to include Ni alloys, and includes the meaning of Ti and Ti alloys. In this specification, the term “metal” is used to mean a single metal and an alloy.

  Lithium ion secondary batteries and lithium polymer secondary batteries used in hybrid and electric vehicle batteries, stationary storage batteries for home use or industrial use, have been used in the past due to the reduction in size and weight. Instead, a laminate exterior material in which a resin film is bonded to both surfaces of a metal foil is often used. In addition, mounting an electric double layer capacitor, a lithium ion capacitor, or the like using a laminate exterior material in an automobile or a bus is being studied.

Devices that require high energy, such as electric vehicles, can handle large amounts of electrical energy with a small volume by stacking power storage modules and connecting them in series. Since heat is likely to accumulate and the temperature inside the module becomes high, it not only promotes battery degradation and affects performance, but also affects safety. For this reason, in an assembled battery in which a plurality of power storage modules are stacked, it has been proposed to cool the modules by interposing a heat dissipation member between the power storage modules (see Patent Documents 1 and 2).
In the assembled battery described in Patent Document 1, a corrugated material is interposed between the power storage modules as a heat radiating member to form a cold air circulation space to obtain a heat radiating effect. In the assembled battery described in Patent Document 2, a tube member for circulating a coolant between the power storage modules is disposed, and a leaf spring is interposed between the tube member and the power storage module for air cooling. By forming the space, a high cooling effect is obtained by both liquid cooling and air cooling.

JP 2012-84551 A JP 2014-170697 A

  However, the cooling methods described in Patent Documents 1 and 2 require bulky heat-dissipating members such as corrugated materials, tube members, and leaf springs, and further require a cool air or coolant supply device. The cooling device takes up a large space. Therefore, it is difficult to reduce the size of the battery pack even if the power storage module is downsized. Furthermore, since the power storage module uses the tab lead to connect the electrodes, there is a possibility that heat is generated from the tab lead connecting portion and the sealing performance of the sealing portion is lowered.

  The present invention has been made in view of such a technical background, and an object of the present invention is to provide an assembled battery in which heat dissipation performance is improved without increasing the size and the risk of liquid leakage is greatly reduced.

  In order to achieve the above object, the present invention has the following configuration.

[1] A laminate type power storage module is
A first heat-resistant resin layer is laminated on one surface of the first metal foil, a first thermoplastic resin layer is laminated on the other surface, and the first metal foil is exposed on the surface on the first thermoplastic resin layer side. A first exterior material having an exposed portion inside the first metal foil, a second heat-resistant resin layer laminated on one surface of the second metal foil, and a second thermoplastic resin layer laminated on the other surface; A battery element having a second exterior material having a second metal foil inner exposed portion at which the second metal foil is exposed on the surface of the thermoplastic resin layer, and a positive electrode, a negative electrode, and a separator disposed between them; ,
At least one of the first exterior material and the second exterior material has an embossed portion in a region including the first metal foil inner exposed portion and the second metal foil inner exposed portion. The thermoplastic resin layer and the second thermoplastic resin layer of the second exterior material face each other, and are surrounded by a heat sealing portion where the first thermoplastic resin layer and the second thermoplastic resin layer are fused, thereby indoors. An exterior body having a plurality of battery element chambers facing the first metal foil inner exposed portion and the second metal foil inner exposed portion and having convex portions by the embossed portion is formed, and the first metal is formed on the outer surface of the exterior body. A first metal foil outer exposed portion where the foil is exposed and a second metal foil outer exposed portion where the second metal foil is exposed are formed,
The battery element enclosed with the electrolyte in the battery element chamber, the positive electrode is conductive to the first metal foil inner exposed portion and the negative electrode is conductive to the second metal foil inner exposed portion,
A plurality of the laminate-type power storage modules are stacked in such a manner that a space is formed on the heat sealing portion, and the laminate-type power storage modules adjacent in the stacking direction are the first metal foil outer exposed portion and the second metal foil exposed portion. A battery pack characterized by being connected with each other.

  [2] The assembled battery according to the item 1 above, wherein a plurality of laminated power storage modules are stacked so that the battery element chamber and the heat sealing portion overlap in the stacking direction of the laminated power storage modules.

  [3] The assembled battery according to the above item 1 or 2, wherein a heat transfer body is disposed between the laminated power storage modules adjacent in the stacking direction.

  In the assembled battery according to the above [1], the battery element chamber of the laminate-type energy storage module is formed as a protruding portion that protrudes to the outside of the exterior body, so that a space is formed on the heat sealing portion by stacking a plurality of modules. Is formed. The heat generated from the battery element is dissipated to the space, and further, the gas flows into the space to accelerate the heat dissipation and cool the assembled battery. Since the space is formed without using a heat radiating member, a cooling effect can be obtained without increasing the size of the assembled battery. Moreover, since the surface area of an exterior body becomes large by having several battery element chambers, the thermal radiation efficiency of each module is good.

  Furthermore, in each laminate-type power storage module, the plurality of battery elements are conducted through the first metal foil and the second metal foil through the first metal foil inner exposed portion and the second inner exposed portion in the battery element chamber, and the laminate type power storage module The first metal foil outer exposed portion and the second metal foil outer exposed portion are connected to each other. Further, the assembled battery and the external device are also connected by the first metal foil outer exposed portion and the second metal foil outer exposed portion. That is, the laminate-type power storage module and the assembled battery do not have tab leads. Accordingly, since the first thermoplastic resin layer and the second thermoplastic resin layer are fused together at the portion of the heat sealing portion that contacts the battery element chamber, the adhesiveness is high and the risk of liquid leakage is greatly reduced. . Furthermore, by not using the tab lead, the heat sealing work is simplified, and the weight and space saving of the assembled battery can be achieved.

  The assembled battery according to the above [2] has a high cooling effect because the electrode element chamber is adjacent to the space in both the stacking direction of the module and the direction orthogonal to the stacking direction, and the battery element chamber is in contact with the space in a larger area. Is obtained.

  Since the assembled battery according to [3] is exhausted by the heat transfer body, a high cooling effect is obtained.

It is a perspective view of one embodiment of a laminate type power storage module constituting the assembled battery of the present invention. It is the 1B-1B sectional view taken on the line in FIG. 1A. 1 is a perspective view of an embodiment of an assembled battery according to the present invention. It is the 2B-2B sectional view taken on the line in FIG. 2A. It is sectional drawing of a bare cell. It is sectional drawing of the other example of a shape of the electrode element chamber in a lamination-type electrical storage module. It is sectional drawing of the example of further another shape of the electrode element chamber in a lamination type electrical storage module. It is sectional drawing of other embodiment of the assembled battery concerning this invention. It is sectional drawing of other embodiment of the assembled battery concerning this invention. It is the elements on larger scale of FIG. 7A. It is the elements on larger scale of FIG. 7A.

  1A and 1B show an embodiment of a laminate-type energy storage module constituting the assembled battery of the present invention, and FIGS. 2A and 2B show an embodiment of an assembled battery using the laminate-type energy storage module.

In the following description, the same reference numerals denote the same items, and redundant descriptions are omitted. Also, in the first exterior material and the second exterior material constituting the exterior body, when referring to a portion where the metal foil is exposed regardless of the exterior material and the formation position, it is generically referred to as a “metal foil exposed portion” and is placed in the electrode element chamber. The portion exposed and exposed is generally referred to as “metal foil inner exposed portion”, and the portion exposed on the outer surface of the exterior body is collectively referred to as “metal foil outer exposed portion”.
[Laminated power storage module]
The exterior body 32 of the laminate-type energy storage module 2 shown in FIGS. 1A and 1B is composed of the first exterior material 10 and the second exterior material 20, and nine battery element chambers 42 arranged in 3 rows × 3 rows. have. Each battery element chamber 42 is filled with a battery element 60 and an electrolyte.

  The first exterior material 10 is a laminate material in which a first heat-resistant resin layer 12 is laminated on one surface of a first metal foil 11 and a first thermoplastic resin layer 13 is laminated on the other surface. Nine embossed portions 45 having a square shape in plan view to be the battery element chamber 42 are formed by press molding. On the other hand, the second exterior material 20 is a laminate material in which the second heat-resistant resin layer 22 is laminated on one surface of the second metal foil 21 and the second thermoplastic resin layer 23 is laminated on the other surface. It is a flat sheet which does not have. In the exterior body 32, the first thermoplastic resin layer 13 of the first exterior material 10 and the second thermoplastic resin layer 23 of the second exterior material 20 face each other, and the first thermoplastic resin layer 13 around the embossed portion 45 The battery element chamber 42 for enclosing the battery element 60 and the electrolyte is formed by fusing the second thermoplastic resin layer 23 to form the heat sealing portions 52a and 52b. The battery element chamber 42 is formed as a convex portion protruding from the heat sealing portions 52a and 52b to the outside of the exterior body by the height of the embossed portion 45, and the module is thick in the battery element chamber 42. It is thin at 52a and 52b. Further, in the battery element chamber 42, a first metal foil inner exposed portion 14 is formed in which a part of the first thermoplastic resin layer 13 is removed to expose the first metal foil 11, and the second thermoplastic resin is formed. A portion of the layer 23 is removed to form a second metal foil inner exposed portion 24 where the second metal foil 21 is exposed.

  One side of the first exterior material 10 is extended from the heat sealing portion 52a to form the first flange 15 whose both surfaces are the outer surfaces of the exterior body 32, and the first metal foil outer exposed portion 16 where the first metal foil 11 is exposed. Is formed. On the other hand, on the opposite side of the first flange 15, the second exterior material 20 is extended from the heat sealing portion 52 a to form the second flange 25 whose both surfaces are the outer surfaces of the exterior body 32, and the second metal foil 21 is exposed. A second metal foil outer exposed portion 26 is formed. The first metal foil outer exposed portion 16 of the first flange 15 and the second metal foil outer metal foil exposed portion 26 of the second flange 25 are provided with three connection holes 17 and 27, respectively. Yes.

As shown in FIG. 3, the battery element 60 enclosed with the electrolyte in the battery element chamber 42 is a wound type in which a positive electrode 61, a separator 62, a negative electrode 63, and a separator 62 are laminated and this laminate is formed into a roll shape. It is a bare cell. The battery element 60 has the positive electrode 61 exposed as the uppermost layer and the negative electrode 63 exposed as the lowermost layer. In the battery element chamber 42, the positive electrode 61 of the battery element 60 contacts the first metal foil inner exposed portion 14 of the first exterior member 10 and is electrically connected, and the negative electrode 63 is the second metal of the second exterior member 20. The foil inner exposed portion 24 is in contact with and electrically connected. The first metal foil 11 is exposed at the first metal foil outer exposed portion 16 on the outer surface of the exterior body 32, and the second metal foil 21 is exposed at the second metal foil outer exposed portion 26 on the outer surface of the outer body 32. Therefore, the battery element 60 can be electrically connected to the outside through the first metal foil 10 and the second metal foil 20. That is, the first metal foil 11 is used as a positive electrode side conductive portion, and the second metal foil 21 of the second exterior material 20 is used as a negative electrode side conductive portion.
[Battery]
The assembled battery 5 shown in FIGS. 2A and 2B changes the direction of the four laminated energy storage modules 2 alternately so that the first flange 15 and the second flange 25 of the modules adjacent to each other in the stacking direction overlap. The battery element chambers 42 of the matching modules are stacked in an overlapping manner, and these are connected. That is, the four laminate-type energy storage modules 2 include the second metal foil outer exposed portion 26 of the second flange 25 of the uppermost first module and the first metal foil of the first flange 15 of the second module. The outer exposed portion 16 is connected to the connecting holes 27 and 17 by passing the connecting pins 35 made of a conductive material. Similarly, the second metal foil outer exposed portion 26 of the second layer module and the third layer The first metal foil outer exposed portion 16 of the module is connected, and the second metal foil outer exposed portion 26 of the third layer module and the first metal foil outer exposed portion 16 of the lowermost fourth layer module are connected. Has been. Further, a positive electrode pin 36 made of a conductive material is attached to the connection hole 17 of the first metal foil outer exposed portion 16 of the first layer module, and the connection of the second metal foil outer exposed portion 26 of the fourth layer is performed. A negative electrode pin 37 made of a conductive material is attached to the service hole 27. With the above connection, the four laminated power storage modules 2 are connected in series, and the positive electrode pin 36 and the negative electrode pin 37 can be used as electrode terminals of the assembled battery 5, and the electric wire 38 can be drawn out and connected to another device. .

  Since the laminate type power storage module 2 is thick in the battery element chamber 42 and thin in the heat sealing portions 52a and 52b, a space 70 is formed between adjacent laminate type power storage modules 2 in the stacking direction. That is, on the heat sealing portions 52a and 52b around the battery element chamber 42, a space 70 whose cross section is a square of (the width of the heat sealing portions 52a and 52b) × (the height of the embossed portion 45) is formed. The Since the heat sealing portions 52a and 52b always exist around the battery element chamber 42, all the battery element chambers 42 are in contact with the space 70 in the direction orthogonal to the stacking direction.

  In each laminated power storage module 2, the plurality of battery elements 60 are conducted through the first metal foil 11 and the second metal foil 21 through the first metal foil inner exposed portion 14 and the second inner exposed portion 24, and the laminated power storage module is used. The two can be connected by the first metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26. Furthermore, the assembled battery 5 and the external device are also connected by the first metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26. That is, the laminate-type power storage module 2 and the assembled battery 5 do not have tab leads. Therefore, the laminate-type energy storage module 2 has the adhesiveness because the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 are fused together so that the portions of the heat sealing portions 52a and 52b that are in contact with the battery element chamber 42 are fused. Is higher and a sealing property higher than that of the battery element chamber 42 from which the tab lead is drawn out is obtained, and the risk of liquid leakage is reduced. Furthermore, by not using the tab lead, the heat sealing work is simplified, and the assembled battery 5 can be reduced in weight and space.

  The assembled battery 5 is increased in capacity by connecting a plurality of laminate-type energy storage modules 2, but has a large amount of heat due to having a large number of battery elements 60. In the assembled battery 5, heat generated in the battery element 60 is dissipated into the space 70, and further, heat is dissipated by the gas flowing into the space 70 to be cooled. The space 70 is a heat dissipating space formed by stacking the laminate type power storage modules 2 and can exhibit heat dissipating performance without using a heat dissipating member such as a corrugated material, and can provide a cooling effect without increasing the size of the assembled battery. Can be obtained. Such cooling using the space 70 is an effect peculiar to a structure in which a plurality of laminated power storage modules 2 are stacked, and cannot be obtained by a single module. If the battery capacity of the entire module is the same, a plurality of battery elements and a plurality of battery element chambers enclosing them are provided rather than a module having one battery element and one battery element chamber enclosing it. The module has a higher heat dissipation efficiency because the surface area of the exterior body is larger.

  The cooling effect is enhanced by forcibly blowing air into the space 70 and further enhanced by sending cool air. However, even if the air is not forcibly blown, natural convection occurs when a temperature difference occurs in the assembled battery 5 due to heat generation, so that a corresponding cooling effect is obtained.

  In order to form a space in the assembled battery, it is a condition that the battery element chamber is formed by an embossed portion and has a convex portion on the outer surface of the exterior body. However, the form of the embossed portion and the electrode element chamber is not limited to the embodiment shown in FIGS. 2A and 2B, and at least one of the first exterior material and the second exterior body constituting the exterior body is embossed. If the portion is formed, a convex portion can be formed on the outer surface of the exterior body. In addition, the distance between the battery element chambers, that is, the width of the heat sealing portion is naturally set to a dimension that can ensure the sealing of the battery element chamber. It is free to make the stop dimension larger than that.

  4 and 5 show other embodiments of the embossed portion and the battery element chamber. In these figures, the laminated structure of the first exterior member 10 and the second exterior member 20 and the internal structure of the battery element chamber are not shown, but the first metal foil inner exposed portion and the The two-metal foil inner exposed portion is formed and the battery element 60 is enclosed, which is the same as the laminate type power storage module 2.

  In the exterior body 80 of FIG. 4, both the first exterior material 10 and the second exterior material 20 have embossed portions 45 and 46, and these embossed portions 45 and 46 face each other to form one electrode element chamber 81. ing. In the exterior body 82 of FIG. 5, both the first exterior material 10 and the second exterior material 20 have embossed portions 45 and 46, as in the case of the exterior body 80. Electrode element chambers 83a and 83b are formed facing the flat portion of the material. Since the exterior bodies 80 and 82 have the embossed portions 45 and 46 on both surfaces in the thickness direction, when modules having these exterior bodies 80 and 82 are stacked, spaces are formed on both surfaces of the module.

  Further, the arrangement of the spaces can be changed depending on the lamination mode of the laminate type power storage module.

  The assembled battery 6 shown in FIG. 6 is formed by laminating the laminated power storage modules 2 with the positions shifted every other layer, and the center of the battery element chamber 42 of one module 2 is adjacent to each other in the stacking direction. It arrange | positions so that it may overlap with the intersection of 52a, 52b. The shift amount is ½ of the distance between the battery element chambers 42. By thus shifting the position of the laminate-type power storage module 2, the battery element chambers 42 are arranged in a staggered manner in the stacking direction. Since the positions of the connection holes 17 and 27 of the adjacent modules are shifted by shifting the laminate type power storage module 2, the positions of the connection holes 17 and 27 are changed by changing the widths of the first flange 15 and the second flange 25. Aligning. Therefore, the shape of the laminate type power storage module 2 shown in FIG. 6 is not strictly the same as that of the laminate type power storage module 2 shown in FIGS. 1A to 2B, but the same reference numerals are used for the sake of simplicity of explanation and illustration. Used. As in the assembled battery 5, the assembled battery 6 includes four laminated storage modules 2 connected in series by connecting pins 35, and a positive electrode pin 36 and a fourth layer module attached to the first layer module. The negative electrode pin 37 attached to is used as the electrode terminal of the battery pack 6.

  With the stacked structure described above, the spaces 71 are also formed in a zigzag pattern in the stacking direction, and the spaces 71 are formed immediately below and directly below the battery element chamber 42 of the laminate-type power storage module 2 of each layer. The space 71 has the same dimensions as the space 70 of the assembled battery 5, but the electrode element chamber 42 of the assembled battery 5 is adjacent to the space 70 only in a direction orthogonal to the stacking direction, whereas the assembled battery 6 The electrode element chamber 42 is adjacent to the space 71 in both the stacking direction and the direction orthogonal to the stacking direction. Thus, cooling efficiency can be improved by making the battery element chamber 42 contact the space 71 with a larger area.

  In the assembled battery 6 in which the electrode element chambers 42 and the spaces 71 are arranged in a staggered manner as described above, the size relationship between the electrode element chambers 42 and the heat sealing portions 52a and 52b is restricted in order to achieve a staggered arrangement. Never happen. When the electrode element chamber 42 and the heat sealing portions 52a and 52b have the same size, a space having the same size as the electrode element chamber 42 is formed. When the electrode element chamber 42 is larger than the heat sealing portions 52a and 52b, a part of the electrode element chamber 42 overlaps in the stacking direction, but a space is formed. Conversely, when the electrode element chamber 42 is smaller than the heat sealing portions 52a and 52b, the heat sealing portions 52a and 52b partially overlap in the stacking direction, but the lower electrode element chamber 42 is the upper heat sealing portion. Since 52a and 52b are supported, it does not occur that the upper electrode element chamber 42 is filled in the space to block the space. In either case, a space corresponding to the dimensions of the heat sealing portions 52a and 52b is formed.

Furthermore, as another means for enhancing the cooling effect, there is a method of interposing a heat transfer body 75 between the laminate type power storage modules 2. In the assembled battery 6 of FIG. 5, the cooling effect is enhanced by interposing a metal plate as the heat transfer body 75 and exhausting heat to the metal plate. The material of the heat transfer body 75 is preferably aluminum or copper having a high thermal conductivity, and a cooling device can be connected to the heat transfer body 75 to enhance the cooling effect.
[Other forms of laminated storage module and battery pack]
The laminate-type energy storage module constituting the assembled battery is required to have a metal foil outside exposed portion on the outer surface of the exterior body, but the formation position thereof is not limited. The outer metal exposed portion is a portion for obtaining electrical continuity between modules and electrical continuity between the assembled battery and the outside, and these electrical continuity is also possible in the outer metal foil exposed portion provided other than the flange.

  Laminated power storage modules 2a, 2b, 2c, and 2d constituting the battery pack 7 having the four-layer structure shown in FIGS. 7A to 7C are different from the laminate power storage module 2 constituting the battery pack 6 in the battery element chamber 42. It is common that the positive electrode 61 of the battery element 60 is electrically connected to the first metal foil inner exposed portion 14 and the negative electrode 63 is electrically connected to the second metal foil inner exposed portion 24. The formation position of the metal foil outer exposed portion where the metal foil is exposed on the outer surface of the metal foil is different. Further, it is common to the assembled battery 6 that the four laminated storage modules 2a, 2b, 2c, and 2d are stacked in such a manner that the battery element chambers 42 and the spaces 71 are positioned in a staggered manner in the stacking direction. .

  In the first-layer laminated power storage module 2 a, the first metal foil outer exposed portion 16 is formed on the first flange 15. Further, as shown in FIG. 7B, the second metal foil outer exposed portion 28 is formed on the surface opposite to the second metal foil inner exposed portion 24, that is, the bottom surface of the battery element chamber 42. The second metal foil outer exposed portion 28 has the second metal foil 21 exposed by removing the second heat-resistant resin layer 22 of the second exterior material 20.

  As shown in FIG. 7C, in the middle second layer and third layer laminated power storage modules 2b and 2c, the first metal foil outer exposed portion 18 is the surface opposite to the first metal foil inner exposed portion 14, that is, It is formed on the top surface of the battery element chamber 42. The first metal foil outer exposed portion 18 has the first metal foil 11 exposed by removing the first heat-resistant resin layer 12 of the first exterior material 10. Further, as shown in FIG. 7B, the second metal foil outer exposed portion 28 is formed on the opposite surface of the two metal foil inner exposed portion 24, that is, the bottom surface of the battery element chamber 42. The second metal foil outer exposed portion 28 has the second metal foil 21 exposed by removing the second heat-resistant resin layer 22 of the second exterior material 20.

  As shown in FIG. 7C, in the lowermost fourth-layer laminated power storage module 2 d, the first metal foil outer exposed portion 18 is the surface opposite to the first metal foil inner exposed portion 14, that is, the battery element chamber 42. It is formed on the top surface. The first metal foil outer exposed portion 18 has the first metal foil 11 exposed by removing the first heat-resistant resin layer 12 of the first exterior material 10. The second metal foil outer exposed portion 26 is formed on the second flange 25.

  The assembled battery 7 is laminated by sandwiching a heat transfer body 75 made of a conductive material between the three types and four types of laminate type power storage modules 2a, 2b, 2c, and 2d, and the laminated body is a jig (not shown). ) Between the heat transfer body 75 and the laminate type power storage modules 2a, 2b, 2c. In this assembled state, the first metal foil outer exposed portion 18 and the second metal foil exposed portion 28 formed on the outer surface of the battery element chamber 42 are in contact with the heat transfer body 75. Since the heat transfer body 75 is a conductor, the battery elements 60 of each layer are connected in series via the first metal foil 10 and the second metal foil 20. The external device is energized with the first metal foil externally exposed portion 16 of the first flange 15 of the uppermost laminate module 2a and the second metal foil of the second flange 25 of the lowermost laminate type power storage module 2c. The outer exposed portion 26 bears, and a positive electrode pin 36 and a negative electrode pin 37 are attached thereto.

As described above, by providing the exposed portion of the metal foil at the contact portion of the laminated laminate type electricity storage module, the laminate type electricity storage module can be connected without using a connection member. The assembled battery 7 has a heat transfer body 75 interposed for the purpose of improving the cooling effect, and uses the heat transfer body 75 as a conductive portion. However, the metal foil externally exposed portion without the heat transfer body 75 being interposed. It is also possible to obtain continuity by directly contacting each other.
[Materials and molding of first and second exterior materials]
The first exterior material 10 has a first heat-resistant resin layer 12 bonded to one surface of a first metal foil 11 via a first adhesive layer, and a first thermoplastic resin via a second adhesive layer to the other surface. A resin layer 13 is bonded. The first metal foil inner exposed portion 14 is formed by removing the first thermoplastic resin layer 13 and the second adhesive layer, and the first metal foil outer exposed portions 16 and 18 are formed according to the surface to be formed. It is formed by removing the thermoplastic resin layer 13 and the second adhesive layer, or the first heat-resistant resin layer 12 and the first adhesive. Moreover, when forming the embossed part 45 by press molding, after forming a metal exposure part, press molding is performed.

  The second exterior material 20 has a second heat-resistant resin layer 22 bonded to one surface of the second metal foil 21 via a third adhesive layer, and a second thermoplastic resin via a fourth adhesive layer to the other surface. A resin layer 23 is bonded. Similar to the first exterior material 20, the second metal foil inner exposed portion 24 is formed by removing the second thermoplastic resin layer 23 and the fourth adhesive layer, and the second metal foil outer exposed portions 26 and 28 are formed. Depending on the surface to be formed, the second thermoplastic resin layer 23 and the fourth adhesive layer, or the second heat resistant resin layer 22 and the third adhesive layer are removed.

  1B, 2B, 6, 7B, and 7C omit illustration of the first adhesive layer, the second adhesive layer, the third adhesive layer, and the fourth adhesive layer.

  A preferable material of the first metal foil 11 is a soft aluminum foil, and a thickness of 20 to 150 μm is preferable. In terms of formability and cost, a soft aluminum foil having a thickness of 30 to 80 μm is particularly preferable. On the other hand, preferred materials for the second metal foil 21 are soft or hard aluminum foil, stainless steel foil, nickel foil, copper foil, and titanium foil. The preferable thickness of these foils is 10 to 150 μm, and 15 to 100 μm is preferable in terms of impact resistance, bending resistance, and cost.

  In addition, the first metal foil 11 and the second metal foil 21 may be plated foil or clad foil. For example, as the second metal foil 21, a plated foil obtained by applying nickel plating to copper, or a clad foil made of stainless steel and nickel can be used.

Furthermore, it is preferable that a chemical conversion film is formed on at least the surface of the first metal foil layer 11 and the second metal foil layer 21 on the side where the metal foil exposed portions 14, 16, 24, 26 are present. The chemical conversion film is a film formed by performing a chemical conversion treatment on the surface of the metal foil, and by performing such a chemical conversion treatment, the metal foil surface is sufficiently corroded by the contents (electrolyte, etc.). In addition, even when the module is manufactured, the exposed portion serving as an electrical extraction window can be prevented from being discolored or deteriorated even when an electrolyte is attached, and the influence of corrosion due to moisture in the atmosphere can be reduced. Although the chemical conversion treatment layer itself has almost no electrical conductivity, the coating thickness is very small, so there is almost no current resistance. For example, the chemical conversion treatment is performed on the metal foil by performing the following treatment. That is, on the surface of the metal foil that has been degreased,
1) phosphoric acid;
Chromic acid,
An aqueous solution of a mixture comprising at least one compound selected from the group consisting of a metal salt of fluoride and a non-metal salt of fluoride; 2) phosphoric acid;
At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins;
An aqueous solution of a mixture comprising at least one compound selected from the group consisting of chromic acid and a chromium (III) salt, 3) phosphoric acid,
At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins;
At least one compound selected from the group consisting of chromic acid and a chromium (III) salt;
An aqueous solution of a mixture comprising at least one compound selected from the group consisting of a metal salt of fluoride and a nonmetal salt of fluoride, and coating the surface of the metal foil with any one of the above aqueous solutions 1) to 3) After the process, chemical conversion treatment is performed by drying.

The conversion coating, chromium coating weight preferably is 0.1mg ^{/ m 2} ~50mg ^/ m 2 as a (per one surface), in particular ^2mg / ^{m 2 ~20mg} / m ² preferred.

  As the heat-resistant resin constituting the first heat-resistant resin layer 12 and the second heat-resistant resin layer 22, a heat-resistant resin that does not melt at the heat seal temperature when heat-sealing the exterior material is used. As the heat-resistant resin, it is preferable to use a heat-resistant resin having a melting point higher by 10 ° C. or higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layers 13 and 23, and a melting point higher by 20 ° C. or higher than the melting point of the thermoplastic resin. It is particularly preferable to use a heat-resistant resin having For example, stretched films such as a polyethylene naphthalate film, a polybutylene naphthalate film, and a polycarbonate film are preferable in addition to a polyester film and a polyamide film. The thickness is preferably in the range of 9 to 50 μm.

  As the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23, at least one thermoplastic resin selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers is used. An unstretched film is preferred, and the thickness is preferably in the range of 20 to 80 μm.

The first adhesive layer and the third adhesive layer are preferably a two-component curable polyester polyurethane-based or polyether polyurethane-based adhesive, and the second adhesive layer and the fourth adhesive layer are polyolefin-based considering electrolyte resistance. The adhesive is preferred. Preferred application of the respective adhesive is 1 to 5 g / ^{m 2.}

  The method for forming the exposed metal foil portion in the first exterior material 10 and the second exterior material 20 is not limited at all. For example, in the process of laminating a metal foil and a resin layer by a dry laminating method, an adhesive is applied using a gravure roll engraved with a portion to which no adhesive is attached, and an adhesive uncoated portion is formed, and the metal foil and After the resin layers are bonded together, the resin layer on the adhesive-unapplied portion is cut out to expose the metal foil. The 1st exterior material 10 and the 2nd exterior material 20 which are used for the lamination type electrical storage module 2 of the said embodiment have metal foil exposed part 14, 16, 24, 26 in the surface at the side of a thermoplastic resin layer. Therefore, the first metal foil 11 and the first thermoplastic resin layer 13, the second metal foil 21 and the second thermoplastic resin layer 23 are bonded together by the above method, and the metal foil exposed portions 14, 16, and 24 are bonded together. , 26 are formed. On the other hand, since there is no exposed metal portion on the surface of the heat-resistant resin layer side, the first metal foil 11 and the first heat-resistant resin layer 12, and the second metal foil 21 and the second heat-resistant resin layer 22 are well-known bonding methods. Paste together.

  When the metal foil outer exposed portion is formed on the first heat-resistant resin layer 12 and / or the second heat-resistant resin layer 22 side surface of the first exterior material 10 and / or the second exterior material 20, After the first metal foil 11 and the first heat-resistant resin layer 12, the second metal foil 21 and the second heat-resistant resin layer 22 are bonded together, the resin layer is removed.

  Further, as shown in FIG. 1A and the like, when the embossed portion 45 is formed by press molding on the first exterior material 10, press forming is performed after the metal exposed portion is formed. In the molding of the first exterior material 10 in the illustrated example, the first metal foil inner exposed portion 14 is press-molded with a molding die including a male die in contact with the top surface, a female die into which the male die is inserted, and a pressing die. In the case where an embossed portion is formed on the second exterior material 20, press molding is performed in the same manner.

In addition, if the first exterior material 10 is cut to a dimension that slightly protrudes the two sides without the first flange from the second exterior material 20 and the protruding portion is bent after heat sealing, the first metal on the cut end face is obtained. Contact between the foil 11 and the second metal foil 21 can be prevented. The second exterior material 20 may be bent with the dimensions of the first exterior material 10 and the second exterior material 10 reversed.
[Battery element structure and materials]
The laminated power storage modules 2, 2 a, 2 b, 2 c, 2 d use bare cells as the battery elements 60. Details of the bare cell and the electrolyte encapsulated with the bare cell are as follows.
(Bare cell)
A bare cell as the battery element 60 includes a positive electrode 61, a separator 62, and a negative electrode 63. The form of the cell is not limited to the wound type shown in FIG. As another form of the bare cell, the positive electrode and the negative electrode are cut to the size of the cell, and each foil is combined with a separator, and a plurality of layers are alternately stacked. A laminate type in which electrical members are joined by ultrasonic waves can be exemplified.

  The positive electrode 61 is preferably composed of a current collector and a positive electrode active material, and a metal foil is generally used for the current collector. As the metal foil, a hard or soft aluminum foil having a thickness of 7 to 50 μm is preferably used, and the portion in contact with the metal exposed portion 14 preferably has no active material. The composition of the positive electrode active material layer is not particularly limited. For example, PVDF (polyvinylidene fluoride), SBR (styrene butadiene rubber), CMC (carboxymethyl cellulose sodium salt, etc.), PAN (polyacrylonitrile), linear It is formed of a mixed composition obtained by adding a lithium salt (for example, lithium cobaltate, lithium nickelate, lithium iron phosphate, lithium manganate, etc.) to a binder such as a type polysaccharide. The thickness of the positive electrode active material layer is preferably set to 2 μm to 300 μm. The positive electrode active material layer may further contain a conductive auxiliary agent such as carbon black or CNT (carbon nanotube).

  Furthermore, it is preferable to use a binder between the current collector and the positive electrode active material in order to improve adhesion. Although the said binder is not specifically limited, For example, the layer formed with PVDF, SBR, CMC, PAN, a linear polysaccharide etc. is mentioned. In order to improve the electrical conductivity between the current collector and the positive electrode active material layer, a conductive additive such as carbon black or CNT (carbon nanotube) may be further added to the binder layer. The thickness of the binder layer is preferably set to 0.2 μm to 10 μm. By making a binder layer 10 micrometers or less, the increase in the internal resistance of the bare cell by the binder which does not have electroconductivity can be suppressed as much as possible.

  The negative electrode 63 is preferably composed of a current collector and a negative electrode active material, and a metal foil is generally used for the current collector. As the metal foil, a copper foil having a thickness of 7 to 50 μm is preferably used, and aluminum foil, titanium foil, and stainless steel foil can be used. Further, like the positive electrode, it is preferable that the portion in contact with the metal exposed portion 24 has no active material. Although the composition of the negative electrode active material layer is not particularly limited, for example, a binder such as PVDF, SBR, CMC, PAN, linear polysaccharide, and the like (for example, graphite, lithium titanate, Si series) Alloy, tin-based alloy, etc.). The thickness of the negative electrode active material layer is preferably set to 1 μm to 300 μm. The negative electrode active material layer may further contain a conductive additive such as carbon black or CNT (carbon nanotube).

  Furthermore, it is preferable to use a binder between the current collector and the negative electrode active material in order to improve adhesion. Although the said binder is not specifically limited, For example, the layer formed by PVDF, SBR, CMC, and PAN is mentioned. The binder layer may further contain a conductive auxiliary agent such as carbon black or CNT in order to improve the conductivity between the current collector and the negative electrode active material layer. The thickness of the binder layer is preferably set to 0.2 μm to 10 μm. By making the said binder layer 10 micrometers or less, the increase in the internal resistance of the bare cell by the binder which does not have electroconductivity can be suppressed as much as possible.

  When laminating the binder layer and the positive electrode active material layer on the current collector (metal foil) constituting the positive electrode 61, the composition of each layer is sequentially applied to the metal foil and dried. The same applies when the binder layer and the negative electrode active material layer are laminated on the current collector (metal foil) constituting the negative electrode 63.

  The separator 62 is not particularly limited. For example, a polyethylene separator, a polypropylene separator, a separator formed of a multilayer film composed of a polyethylene film and a polypropylene film, or a resin separator made of a ceramic. For example, a separator composed of a wet or dry porous film coated with a heat-resistant inorganic material such as The thickness of the separator 62 is preferably set to 5 μm to 50 μm.

  Furthermore, preferred materials when the laminate type electricity storage module of the present invention is an electric double layer capacitor are as follows.

The current collector of the positive electrode 61 and the current collector of the negative electrode 63 are preferably hard aluminum foil having a thickness of 7 to 50 μm. The positive electrode active material and the negative electrode active material are preferably carbon black or CNT (carbon nanotube). The separator is preferably a porous polycellulose film having a thickness of 5 μm to 100 μm or a nonwoven fabric having a thickness of 5 μm to 100 μm.
(Electrolytes)
The electrolyte encapsulated together with the battery element is not particularly limited, but at least one selected from the group consisting of water, ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and dimethoxyethane. And an electrolyte containing a lithium salt. The lithium salt is not particularly limited, and examples thereof include lithium hexafluorophosphate, lithium tetrafluoroborate, and quaternary ammonium tetrafluoroborate. Examples of the quaternary ammonium salt include tetramethylammonium salt. Moreover, what the above-mentioned electrolyte gelatinized with PVDF, PEO (polyethylene oxide), etc. may be used.
[Lamination-type power storage module and assembled battery manufacturing method]
The laminated power storage modules 2, 2a, 2b, 2c, and 2d can be manufactured by the following steps.
(1) The first metal foil inner exposed portion 14, the first metal foil outer exposed portion 16 or the first metal foil exposed portion 18, and the embossed portion 45 are formed at the required positions by the method described above. The exterior material 10 is produced. Moreover, the 2nd exterior material 20 in which the 2nd metal foil inner side exposed part 24, the 2nd metal foil outer side exposed part 26, or the 2nd metal foil outer side exposed part 28 was formed in the required position is produced.
(2) The first exterior material 10 is placed so that the first thermoplastic resin layer 13 is on top, and the positive electrode of the battery element 60 is placed on the first metal foil inner exposed part 14 in each embossed part 45 that becomes the battery element chamber 42. The battery element 60 is loaded so that 61 contacts, and an electrolyte is injected using a syringe or the like.
(3) Assembling the exterior bodies 32 and 33 by aligning the second exterior material 20 so that the second metal foil inner exposed portion 24 of the second exterior material 20 is in contact with the negative electrode 63 of the battery element 60. . In this assembled state, the first flange 15 extends from the end of the second exterior member 20 and the second flange 25 extends from the end of the first exterior member 10, and the first metal foil outer exposure 16 and the first The two-metal foil outer exposed portion 26 is exposed on the outer surfaces of the exterior bodies 32 and 33.
(4) The heat sealing part 52a is formed using the heated hot plate.
(6) Preliminary charging is performed by connecting a clip to the first metal foil outer exposed portion 16 of the first flange 15 and the second metal foil outer exposed portion 26 of the second flange 25, and put in a constant temperature bath at 100 ° C. for 8 hours. Degas.
(7) The battery element 60 and the electrolyte are enclosed in the battery element chamber 42 by heat-sealing the unsealed part with a hot plate heated under reduced pressure to form the heat-sealed portion 52b.
(8) The connection holes 17 and 27 are made in the first metal foil outer exposed portion 16 of the first flange 15 and the second metal foil outer exposed portion 26 of the second flange 25.

  The above manufacturing method is merely an example, and is not particularly limited to such a manufacturing method.

  The produced laminate type power storage modules 2, 2a, 2b, 2c, and 2d are laminated by laminating a required number or by interposing a heat transfer body 75, and connecting adjacent modules in the laminating direction by the method described above. Assemble the battery. The number of stacks in the assembled battery of the present invention is arbitrary.

  The use of the assembled battery according to the present invention is not limited, but the power source for automobiles, bicycles, two-wheeled vehicles, trains, airplanes, ships, etc. that require electricity, specifically, the capacity of hybrid vehicles, electric vehicles, industrial / household storage batteries, etc. Lithium secondary battery (lithium ion battery, lithium polymer battery, etc.) module, solid battery module, lithium ion capacitor module for the same use, and electric double layer capacitor module for the same use.

Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.
<Example 1>
Four laminate-type modules 2 shown in FIGS. 1A and 1B were produced, and an assembled battery 5 shown in FIGS. 2A and 2B was produced.

  The first metal foil 11 was a soft aluminum foil having a thickness of 40 μm of A8079 classified by JIS H4160, and was subjected to chemical conversion treatment on both sides. The first heat resistant resin layer 12 is a biaxially stretched polyamide film having a thickness of 25 μm. The first thermoplastic resin layer 13 is an unstretched polypropylene film having a thickness of 40 μm. The second metal foil 21 was a soft SUS304 stainless steel foil having a thickness of 20 μm, and was subjected to chemical conversion treatment on both sides. The second heat resistant resin layer 22 is a biaxially stretched polyester film having a thickness of 12 μm. The second thermoplastic resin layer 23 is an unstretched polypropylene film having a thickness of 40 μm.

Moreover, the dimension of the 1st metal foil inner side exposed part 14 and the 2nd metal foil inner side exposed part 24 is 30 mm x 30 mm, and the dimension of the 1st metal foil outer side exposed part 16 and the 2nd metal foil outer side exposed part 26 is 20 mm x. 200 mm.
(First exterior material)
The first heat-resistant resin layer 12 was bonded to one surface of the first metal foil 11 by a dry lamination method with a two-part curable polyester polyurethane adhesive having a coating thickness of 3 μm, and cured in a 50 ° C. aging furnace for 3 days. Next, when the two-component curing type olefin adhesive having a coating thickness of 2 μm is applied to the opposite surface of the first metal foil 11 to a coating thickness of 2 μm by the dry laminating method, nine first metal foils are applied. Adhesive uncoated portions corresponding to the dimensions and positions of the inner exposed portion 14 and one first metal foil outer exposed portion 16 were formed, and the first thermoplastic resin layer 13 was bonded. After pasting, it was cured in an aging furnace at 40 ° C. for 3 days.

  After curing, the first thermoplastic resin layer 13 on the adhesive-unapplied portion is removed by cutting with a laser blade, and the first metal foil inside exposed portion 14 and the first metal foil outside exposed where the first metal foil 11 is exposed. Part 16 was formed.

Next, using a molding die composed of a 40 mm square male mold, female mold, and pressing mold, press molding with a depth of 4 mm is performed in such a manner that the top surface of the male mold is in contact with the first metal foil inner exposed portion 14. An embossed portion to be the element chamber 42 was formed. Further, the periphery was trimmed to obtain the first exterior material 10. The planar dimension of the first exterior material 10 is 140 mm × 160 mm.
(Second exterior material)
The second heat-resistant resin layer 22 was bonded to one surface of the second metal foil 21 with a two-part curable polyester polyurethane adhesive having a coating thickness of 3 μm by a dry laminating method and cured in a 50 ° C. aging furnace for 3 days. Next, nine second metal foils are applied to the opposite surface of the second metal foil 21 when a two-component curing type olefin-based adhesive having a coating thickness of 2 μm is applied to a coating thickness of 2 μm by a dry laminating method. An adhesive uncoated portion corresponding to the size and position of the inner exposed portion 24 and one second metal foil outer exposed portion 26 was formed, and the second thermoplastic resin layer 23 was bonded. After pasting, it was cured in an aging furnace at 40 ° C. for 3 days.

After curing, the second thermoplastic resin layer 23 on the adhesive-unapplied portion is removed by cutting with a laser blade, and the second metal foil inner exposed portion 24 and the second metal foil outer exposed portion where the second metal foil 21 is exposed. Part 26 was formed. Further, the periphery was trimmed to obtain a second exterior material 20. The planar size of the second exterior material 20 is 150 mm × 160 mm, which is larger than the first exterior material 10.
(Electrode element)
As the electrode element 60, a bare cell was manufactured using the following materials.

The current collector of the positive electrode 61 is a hard aluminum foil of A1100 classified by JIS H4160, and has a thickness of 15 μm and a width of 500 mm. The current collector of the negative electrode 63 is a hard copper foil of C1100R classified according to JIS H3100, and has a thickness of 15 μm and a width of 200 mm. The paste for forming a positive electrode active material layer is 60 parts by mass of a positive electrode active material mainly composed of lithium cobaltate, 10 parts by mass of PVDF as a binder and electrolyte retaining agent, 5 parts by mass of acetylene black (conductive material), N-methyl- A paste in which 25 parts by mass of 2-pyrrolidone (organic solvent) is kneaded and dispersed. The negative electrode active material forming paste includes 57 parts by mass of a negative electrode active material mainly composed of carbon powder, 5 parts by mass of PVDF as a binder and electrolyte retaining agent, 10 parts by mass of a copolymer of hexafluoropropylene and maleic anhydride, A paste in which 3 parts by mass of acetylene black (conductive material) and 25 parts by mass of N-methyl-2-pyrrolidone (organic solvent) are kneaded and dispersed. The binder liquid is a binder liquid in which PVDF is dissolved in a solvent (dimethylformamide). The separator 62 is a porous wet separator having a width of 38 mm and a thickness of 8 μm. The electrolyte is a mixed solvent containing ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in an equal volume ratio, and lithium hexafluorophosphate (LiPF ₆ ) is dissolved at a concentration of 1 mol / L. Solution.

The positive electrode 61 was produced by the following steps. First, a binder solution was applied to the entire surface of the current collector and dried at 100 ° C. for 30 seconds to form a binder layer having a thickness of 0.5 μm after drying. Next, a positive electrode active material layer liquid paste is applied to the surface of the binder layer, dried at 100 ° C. for 30 minutes, and then hot pressed to a density of 4.8 g / cm ³ and a thickness after drying of 120 μm. A positive electrode active material layer was formed. Furthermore, it cut | judged in the coil shape of 35 mm width by width insertion.

The negative electrode 63 was produced by the following process. First, a binder solution was applied to one side of the current collector and dried at 100 ° C. for 30 seconds to form a binder layer having a thickness of 0.5 μm after drying. Next, the negative electrode active material layer liquid paste is applied to the surface of the binder layer, dried at 100 ° C. for 30 minutes, and then hot pressed to a density of 1.5 g / cm ³ and a dried thickness of 20. A 1 μm negative electrode active material layer was formed. Furthermore, it cut | judged in the coil shape of 35 mm width by width insertion.

Next, the negative electrode 63 (current collector-negative electrode active material layer) / separator 62 / (positive electrode active material layer-current collector) positive electrode 61 / separator are sequentially stacked and wound one by one. A bare cell having a size of 38 mm square and a thickness of 4 mm was produced by crushing so that the positive electrode 61 was exposed on the opposite side and the negative electrode 63 was exposed on the opposite side.
(Assembly of laminated storage module and battery pack)
(1) The first exterior material 10 is placed with the first thermoplastic resin layer 13 on top, and the battery element 60 is placed on the first metal foil inner exposed part 14 in each embossed part 45 forming the battery element chamber 42. The battery element 60 was loaded so that the positive electrode 61 was in contact, and the electrolyte was injected using a syringe or the like.
(2) The exterior body 32 is assembled by overlapping the second exterior material 20 while aligning so that the second metal foil inner exposed portion 24 of the second exterior material 20 contacts the negative electrode 63 of the battery element 60. In this assembled state, the first flange 15 extends from the end of the second exterior member 20 and the second flange 25 extends from the end of the first exterior member 10, and the first metal foil outer exposure 16 and the first The two-metal foil outer exposed portion 26 is exposed on the outer surface of the exterior body 32.
(3) Using a hot plate heated to about 200 ° C., heat sealing was performed at a pressure of 0.3 MPa for 3 seconds to form a heat sealing portion 52a. The width of the heat sealing portion 52a between the embossed portions 45 is 5 mm.
(4) A clip is connected to the first metal foil outer exposed portion 16 of the first flange 15 and the second metal foil outer exposed portion 26 of the second flange 25, and charging is performed until a battery voltage of 4.2 V is generated. The battery element chamber 42 was degassed by placing it in a constant temperature bath at 0 ° C. for 8 hours.
(5) The battery element 60 and the electrolyte are placed in the battery element chamber 42 by heat-sealing the unsealed part with a hot plate heated to about 200 ° C. under reduced pressure of 86 kPa to form the heat-sealed part 52b. Enclosed. The width of the heat sealing portion 52b between the embossed portions 45 is 5 mm.
(6) As a measure against short circuit, a 25 μm adhesive tape is applied to the edge of the first exterior member 10 on the second flange 25 side and the edge of the second exterior member 20 on the first flange 15 side, and exposed to the end face. One metal foil 11 and second metal foil 21 were coated. Furthermore, the second exterior material 20 that protruded from the other two sides was bent toward the first exterior material 10 to take insulation measures and to strengthen the side. FIG. 2A shows a state before bending.
(7) Three connection holes 17 and 27 were made in the first metal foil outer exposed portion 16 of the first flange 15 and the second metal foil outer exposed portion 26 of the second flange 25.

Through the above steps, four laminate-type energy storage modules 2 were produced.
(8) As shown in FIGS. 2A and 2B, the four laminated modules 2 are alternately changed in direction so that the first flange 15 and the second flange 25 of the modules adjacent to each other in the stacking direction overlap each other. And laminated.
(9) Four laminated modules 2 are connected in series with connection pins 35, and positive electrode pins 36 are attached to the uppermost first metal foil outer exposed portion 16, and the lowermost second metal foil outer exposed portion is attached. 26, a negative electrode pin 37 was attached. The assembled battery 5 was produced through the above steps.

In the assembled battery 5, a space 70 having a cross section of a quadrangle of (a width 5 mm of the heat sealing portion 52a) × (a height of the embossed portion 4 mm) is formed on the heat sealing portion 52a. Further, a space having a cross section of a quadrangle of (the width of the heat sealing portion 52b is 5 mm) × (the height of the embossed portion is 4 mm) is formed.
<Comparative example 1>
Comparative Example 1 is an assembled battery in which four laminated power storage modules having a different structure from that of Example 1 are stacked.

Further, in the laminate type power storage module 2 of Example 1, nine battery elements 60 are enclosed in the respective battery element chambers 42, metal foil exposed portions are formed on the inner surface and the outer surface of the outer package, and tab leads are not used. Electrical connection with the battery element 60 is obtained. In contrast to the laminate-type energy storage module 2, the laminate-type module of Comparative Example 1 has one battery element enclosed in one battery element chamber, and has the same capacity as the nine battery elements of Example 1. The size of the battery element was increased as shown. Further, the outer package of the laminate type module of Comparative Example 1 is a module that does not have a metal foil exposed portion on the inner side or the outer side, is connected to the battery element with a tab lead, and is drawn out to the outer package.
(Exterior body)
The exterior material closes the opening of the embossed portion corresponding to the second exterior material 20 of Example 1 and the portion having the embossed portion that becomes the battery element chamber corresponding to the first exterior material 10 of Example 1. The flat part is integrated. The exterior body is formed by folding the exterior material in half. The material constituting the exterior material is a soft aluminum foil having a thickness of 40 μm (A8021 soft aluminum foil classified according to JIS H4160), and a heat-resistant resin layer is a biaxially stretched polyamide film having a thickness of 25 μm. The thermoplastic resin layer is a polypropylene film having a thickness of 40 μm.

The exterior material has a heat-resistant resin layer bonded to the whole of one surface of the metal foil via a polyester urethane-based adhesive with a coating amount of 3 g / m ^2, and the coating amount of ² g / m is applied to the entire other surface. The thermoplastic resin layer was bonded through a polyolefin adhesive having m ² and then cured in a thermostatic bath at 40 ° C. for 3 days. The said exterior material does not have a metal foil exposed part, and the whole aluminum foil is coat | covered with the resin layer.

The exterior material was press-molded to form an embossed portion of 115 mm × 115 mm × height 4 mm, and trimmed in anticipation of the dimensions of the flat portion and the heat sealed portion planned portion.
(Battery element and tab lead)
The battery element was manufactured using the same material as in Example 1 so that the outer shape was 110 mm square.

  The positive electrode tab lead is exposed to 5 mm on one end side in the length direction of a soft aluminum foil (A1050 soft aluminum foil classified by JIS H4000) having a length of 30 mm, a width of 3 mm, and a thickness of 100 μm. An insulating film made of a maleic anhydride-modified polypropylene film (melting point: 140 ° C., MFR: 3.0 g / 10 min) having a length of 10 mm, a width of 5 mm, and a thickness of 50 μm was prepared by heat sealing.

  The negative electrode tab lead is exposed to 5 mm on one end side in the length direction of a nickel foil having a length of 40 mm, a width of 3 mm, and a thickness of 100 μm, and maleic anhydride having a length of 10 mm, a width of 5 mm, and a thickness of 50 μm on both surfaces of the nickel foil. An insulating film made of a modified polypropylene film (melting point: 140 ° C., MFR: 3.0 g / 10 min) was produced by being sandwiched by heat sealing.

The end of the positive electrode tab lead was joined to the positive electrode of the battery element and the negative electrode tab lead was joined to the negative electrode, and the tips of the positive electrode tab lead and the negative electrode tab lead were drawn from the same side of the battery element.
(Assembly of laminated storage module and battery pack)
(1) The exterior material is marked in advance with a ruler or the like.
(2) The battery element is loaded in the embossed portion of the outer packaging material, aligned so that the insulating film of the tab lead is placed on the heat sealing portion planned portion, and the outer packaging material is bent at the marked position to fold the flat portion. It was put on the embossed part.
(3) Two sides including the side from which the tab lead was pulled out were heat sealed for 3 seconds by sandwiching them at a pressure of 0.3 MPa using a hot plate heated to 200 ° C.
(4) From the unsealed side, 45 mL of the same electrolyte as in Example 1 was injected with a syringe, and temporary charging and degassing were performed in the same manner as in Example 1.
(5) The battery was heat sealed for 3 seconds with a pressure of 0.3 MPa using a hot plate heated to 200 ° C. under a reduced pressure of 0.086 MPa in a discharge state of 3.0 V. The battery element and the electrolyte were enclosed in the element chamber.

Through the above steps, four laminate type power storage modules were produced.
(6) Four laminated modules were stacked and connected in series to assemble an assembled battery.
<Evaluation>
The assembled batteries of Example 1 and Comparative Example 1 obtained as described above were evaluated based on the following evaluation method. The evaluation results are shown in Table 1.

  After the assembled battery was fully charged to 16.8 V, 1C charge / discharge (charge in 1 hour, discharge in 1 hour) was repeated 100 times at room temperature of 18 ° C., and the voltage and capacity when fully charged again were measured. In addition, when the fully charged battery was discharged at 1 C, the temperature at the time of 0.2 C discharge was measured with a temperature sensor, and an average value was obtained. The temperature measurement position is the center of the third-layer module in both Example 1 and Comparative Example 1, Example 1 is the center of the outer surface of the embossed part in the center of 3 rows × 3 rows, and Comparative Example 1 is the embossed part. Central part.

表１の通り、実施例１と比較例１とは電池容量に違いは見られず、１００サイクルの充放電を繰り返しても同じ結果となった。また、放電時の発熱量については、１Ｃ放電時も０．２放電時も比較例１に対し実施例１の組電池は発熱が抑えられ、放熱効果が高いことを確認した。

As shown in Table 1, there was no difference in battery capacity between Example 1 and Comparative Example 1, and the same result was obtained even after 100 cycles of charge / discharge. Moreover, about the emitted-heat amount at the time of discharge, it confirmed that the assembled battery of Example 1 suppressed heat_generation | fever compared with the comparative example 1 at the time of 1C discharge and 0.2 discharge, and the heat dissipation effect was high.

  The laminate type electricity storage module of the present invention can be suitably used as various power sources.

2, 2 a, 2 b, 2 c, 2 d, laminated power storage modules 5, 6, 7, assembled battery 10, first exterior material 11, first metal foil 12, first heat-resistant resin layer 13, first thermoplastic resin layer DESCRIPTION OF SYMBOLS 14 ... 1st metal foil inner side exposed part 15 ... 1st flange 16, 18 ... 1st metal foil outer side exposed part 20 ... 2nd exterior material 21 ... 2nd metal foil 22 ... 2nd heat resistant resin layer 23 ... 2nd heat Plastic resin layer 24 ... second metal foil inner exposed part 25 ... second flange 26, 28 ... second metal foil outer exposed part 32, 33, 80, 82 ... exterior body 42, 82, 83a, 83b battery element chamber 45, 46 ... Embossed parts 52a, 52b ... Heat sealing part 60 ... Bare cell (battery element)
61 ... Positive electrode 62 ... Separator 63 ... Negative electrode 70, 71 ... Space 75 ... Heat transfer body

Claims (3)

Laminate power storage module
A first heat-resistant resin layer is laminated on one surface of the first metal foil, a first thermoplastic resin layer is laminated on the other surface, and the first metal foil is exposed on the surface on the first thermoplastic resin layer side. A first exterior material having an exposed portion inside the first metal foil, a second heat-resistant resin layer laminated on one surface of the second metal foil, and a second thermoplastic resin layer laminated on the other surface; A battery element having a second exterior material having a second metal foil inner exposed portion at which the second metal foil is exposed on the surface of the thermoplastic resin layer, and a positive electrode, a negative electrode, and a separator disposed between them; ,
At least one of the first exterior material and the second exterior material has an embossed portion in a region including the first metal foil inner exposed portion and the second metal foil inner exposed portion. The thermoplastic resin layer and the second thermoplastic resin layer of the second exterior material face each other, and are surrounded by a heat sealing portion where the first thermoplastic resin layer and the second thermoplastic resin layer are fused, thereby indoors. the first metal foil inner exposed portion and the second metal foil inner exposed portion faces, outer body having a plurality of battery element chamber has been made a convex portion is formed by the embossed portions, said outer body, said first outer package A first flange extending from the heat-sealed portion and having both sides become the outer surface of the exterior body, a first metal foil outer exposed portion is formed on the first flange, and the first metal foil is exposed; A connection hole is drilled in the first metal foil outer exposed portion, and the second One side of the dressing is extended from the heat-sealed portion to form a second flange whose both surfaces become the outer surface of the exterior body, and a second metal foil outer exposed portion is formed in which the second metal foil is exposed to the second flange, Furthermore, a connection hole is drilled in the second metal foil outer exposed portion,
The battery element enclosed with the electrolyte in the battery element chamber, the positive electrode is conductive to the first metal foil inner exposed portion and the negative electrode is conductive to the second metal foil inner exposed portion,
A plurality of the laminate type power storage modules are stacked in such a manner that a space is formed on the heat sealing portion, and the laminate type power storage modules adjacent in the stacking direction are exposed to the first metal foil outer exposed portion and the second metal foil outer exposed. The battery pack is characterized by being electrically connected to each other through a connection pin that passes through each connection hole .   2. The assembled battery according to claim 1, wherein a plurality of laminated power storage modules are stacked so that the battery element chamber and the heat sealing portion overlap in the stacking direction of the stacked power storage modules.   The assembled battery according to claim 1 or 2, wherein a heat transfer body is disposed between adjacent laminated power storage modules in the stacking direction.

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