KR102488346B1 - Battery pack - Google Patents

Abstract

In the exterior body 32 of the laminated power storage module 2, at least one of the first and second exterior materials 10 and 20 facing each other has an embossed portion 45, and the embossed portion 45 It has a plurality of electrode element chambers 42 that became convex portions by heat-sealing the periphery. The assembled battery 5 is formed by stacking and connecting a plurality of modules 2, and a space 70 for heat dissipation is formed by a difference in thickness between the electrode element chamber 42 and the heat-sealed portions 52a and 52b. has been In addition, in the battery element chamber 42, the battery element 60 conducts to the metal foil inner exposed parts 14 and 24, and the module 2 is connected through the metal foil outer exposed parts 16 and 26.

Description

Assembled battery {BATTERY PACK}

The present invention relates to an assembled battery with reduced weight, high heat dissipation, and space saving.

In addition, in this specification, the term "aluminum" is used to mean including Al and Al alloys, the term "copper" is used to mean including Cu and Cu alloys, and the term "nickel" is used to mean , Ni and Ni alloys are used, and the term "titanium" is used with the meaning including Ti and Ti alloys. In addition, in this specification, the term "metal" is used by the meaning which includes a simple metal and an alloy.

Lithium ion secondary batteries and lithium polymer secondary batteries used in batteries for hybrid vehicles and electric vehicles, and stationary storage batteries for household and industrial use are accompanied by miniaturization and weight reduction. Laminate packaging materials in which films are bonded are increasingly used. In addition, mounting of electric double layer capacitors and lithium ion capacitors using laminated exterior materials on automobiles and buses is being considered.

Devices that require high energy, such as electric vehicles, respond by stacking power storage modules and connecting them in series in order to obtain large amounts of electrical energy with a small volume. It is easy, and since the inside of the module becomes high temperature, not only the acceleration of battery deterioration and the decrease in performance are affected, but also the safety is affected. For this reason, in an assembled battery in which a plurality of power storage modules are stacked and arranged, it is 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 Literature 1, a corrugated material is interposed between power storage modules as a heat dissipation member to form a circulation space for cool air to obtain a heat dissipation effect. In addition, in the assembled battery described in Patent Document 2, a pipe member for distributing cooling liquid is disposed between the power storage module, and a plate spring is interposed between the pipe member and the power storage module. ) to form a space for air cooling, a high cooling effect is obtained by both liquid cooling and air cooling.

Japanese Unexamined Patent Publication No. 2012-84551 Japanese Patent Laid-Open No. 2014-170697

However, the cooling methods described in Patent Literatures 1 and 2 require bulky heat dissipation members such as corrugated materials, pipe members, and leaf springs, and further require a cooling air or cooling liquid supply device. occupies a large space. Therefore, even if the power storage module is miniaturized, it is difficult to miniaturize the assembled battery. In addition, since the power storage module connects electrodes using tab leads, there is a possibility that heat generation at the connection portion of the tab leads and a decrease in sealing performance of the sealing portion may occur.

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 and the risk of liquid leakage is significantly reduced without increasing the size.

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

[1] A laminate type 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 inside of the first metal foil is exposed on the surface on the side of the first thermoplastic resin layer. A second heat-resistant resin layer is laminated on one side of a first packaging material having a portion and a second metal foil, and a second thermoplastic resin layer is laminated on the other side, and the second metal foil is on the side of the second thermoplastic resin layer. A battery element having a second packaging material having an exposed second metal foil inner exposed portion, a positive electrode and a negative electrode, and a separator disposed between them,

At least one of the first packaging material and the second packaging material has an embossed portion in a region including the first metal foil inner exposed portion and the second metal foil inner exposed portion, and the first thermoplastic resin layer of the first packaging material and the second packaging material are The second thermoplastic resin layer faces each other, and the first thermoplastic resin layer and the second thermoplastic resin layer are fused together by being surrounded by the heat-sealed portion, so that the first metal foil inner exposed portion and the second metal foil inner exposed portion are in the room ( A first metal foil outer exposed portion in which a first metal foil is exposed on the outer surface of the exterior body, and an exterior body having a plurality of battery element chambers formed as convex portions by the embossed portion is formed, and A second metal foil outer exposed portion exposed to the second metal foil is formed,

In the battery element sealed together with the electrolyte in the battery element chamber, the positive electrode conducts to the first metal foil inner exposed portion and the negative electrode conducts to the second metal foil inner exposed portion,

A plurality of the laminated power storage modules are stacked in such a manner that a space is formed on the heat-sealed portion, and laminated power storage modules adjacent in the stacking direction are connected to the first metal foil outer exposed portion and the second metal foil outer exposed portion. Assembled battery to be.

[2] The assembled battery according to the preceding paragraph 1, wherein a plurality of laminated power storage modules are stacked so that the battery element chamber and the heat-sealed portion overlap each other in the stacking direction of the laminated power storage module.

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

[4] The assembled battery according to 1 or 2 above, wherein the space is a cooling gas passage.

[5] The assembled battery according to the preceding paragraph 1, wherein the space and the battery element chamber are adjacent only in a direction orthogonal to the stacking direction of the laminate type power storage module.

[6] The assembled battery according to the above 2, wherein the space and the battery element chamber are adjacent to each other in both directions of the stacking direction of the laminated power storage module and the direction orthogonal to the stacking direction.

In the assembled battery described in [1] above, since the battery element chamber of the laminated power storage module is formed as a convex portion protruding outward from the exterior body, a space is formed on the heat-sealed portion by stacking a plurality of modules. Heat generated from the battery elements is dissipated into the space, and the heat dissipation is accelerated by the flow of gas into the space, thereby cooling 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. In addition, since the surface area of the exterior body is increased by having a plurality of battery element chambers, the heat dissipation efficiency of each module is good.

In addition, in each laminate type power storage module, a plurality of battery elements conduct through the first metal foil and the second metal foil by the first metal foil inner exposed portion and the second inner exposed portion in the battery element chamber, and the laminate type power storage modules are connected to each other. Connected by the first metal foil outer exposed portion and the second metal foil outer exposed portion. In addition, the connection between the assembled battery and the external device is also performed 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 assembled battery do not have a tab lead. Therefore, since the first thermoplastic resin layer and the second thermoplastic resin layer are fused evenly in the portion in contact with the battery element chamber of the heat-sealing portion, the adhesion is high and the risk of liquid leakage is greatly reduced. In addition, by not using a tab lead, the heat sealing operation is simplified, and the weight and space saving of the assembled battery can be achieved.

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

Since the assembled battery described in the above [3] is arranged in a heat transfer body, a high cooling effect can be obtained.

In the assembled battery described in [4] above, heat dissipation is promoted by the flow of gas into the space.

In the assembled battery described in [5], heat generated in the battery element chamber is dissipated to an adjacent space in a direction orthogonal to the stacking direction of the laminated power storage module.

In the assembled battery described in [6] above, heat dissipation is promoted because the space and the battery element chamber are adjacent to each other in both directions of the stacking direction of the laminated power storage module and the direction orthogonal to the stacking direction.

1A is a perspective view of one embodiment of a laminate type power storage module constituting an assembled battery of the present invention.
1B is a cross-sectional view along line 1B-1B in FIG. 1A.
Fig. 2A is a perspective view of one embodiment of an assembled battery according to the present invention.
FIG. 2B is a cross-sectional view along line 2B-2B in FIG. 2A.
3 is a cross-sectional view of a bare cell;
Fig. 4 is a cross-sectional view of another shape example of an electrode element chamber in a laminated power storage module.
Fig. 5 is a cross-sectional view of another example of the shape of an electrode element chamber in a laminated power storage module.
Fig. 6 is a cross-sectional view of another embodiment of an assembled battery according to the present invention.
Fig. 7A is a cross-sectional view of another embodiment of an assembled battery according to the present invention.
Figure 7b is a partial enlarged view of Figure 7a.
Figure 7c is a partial enlarged view of Figure 7a.

1A and 1B show an embodiment of a laminated power storage module constituting the assembled battery of the present invention, and FIGS. 2A and 2B show an embodiment of an assembled battery using the laminated power storage module.

In the following description, like reference numerals denote the same thing, and overlapping descriptions are omitted. In addition, in the case where the metal foil is exposed regardless of the packaging material and the formation position in the first packaging material and the second packaging material constituting the packaging body, it is collectively referred to as a "metal foil exposed portion", and is included in the electrode element chamber. The portion exposed to the surface is generically referred to as "metal foil inner exposed portion", and the portion exposed to the outer surface of the exterior body is collectively referred to as "metal foil outer exposed portion".

[Laminate type storage module]

An exterior body 32 of the laminate type power storage module 2 shown in FIGS. 1A and 1B is composed of a first exterior material 10 and a second exterior material 20, and includes nine cells arranged in three rows x three rows. It has a battery element chamber 42. A battery element 60 and an electrolyte are sealed in each of the battery element chambers 42 .

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, and flat Nine embossed portions 45 in the form of a battery element chamber 42 in a plan view square are formed by press forming the sheet. On the other hand, the second exterior material 20 is a laminate material in which a second heat-resistant resin layer 22 is laminated on one side of the second metal foil 21 and a second thermoplastic resin layer 23 is laminated on the other side, It is a flat sheet having no embossed portion. 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 embossed portion 45 A battery element chamber 42 in which the battery element 60 and the electrolyte are sealed by fusing the surrounding first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 to form heat-sealed portions 52a and 52b. ) is formed. The battery element chamber 42 is formed as a convex portion protruding from the heat-sealed parts 52a and 52b to the outside of the exterior body by the height of the embossed part 45, and the thickness of the module is the battery element chamber 42 It is thick at , and thin at the heat sealing portions 52a and 52b. In addition, in the battery element chamber 42, a portion of the first thermoplastic resin layer 13 is removed to form a first metal foil inner exposed portion 14 exposed to the first metal foil 11, and a second thermoplastic resin layer 13 is formed. A part of the resin 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 directed from the heat-sealing portion 52a, and both sides become the first flange 15 serving as the outer surface of the exterior body 32, and the first metal foil 11 is exposed. A metal foil outer exposed portion 16 is formed. On the other hand, on the opposite side of the first flange 15, the second exterior material 20 is directed from the heat-sealed portion 52a, and both sides become the second flange 25 serving as the outer surface of the exterior body 32, The second metal foil outer exposed portion 26 where the two metal foils 21 are exposed is formed. In addition, in 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, three connecting holes 17 and 27, respectively is perforated.

As shown in FIG. 3, the battery element 60 enclosed with the electrolyte in the battery element chamber 42 is composed of a positive electrode 61, a separator 62, a negative electrode 63, and a separator 62 stacked together. , It is a wound type bare cell in which this laminate is formed in a roll shape. In the battery element 60, the positive electrode 61 is exposed as the uppermost layer and the negative electrode 63 is exposed as the lowermost layer. Within the battery element chamber 42, the positive electrode 61 of the battery element 60 electrically conducts by contacting the first metal foil inner exposed portion 14 of the first casing 10, and the negative electrode 63 2 It is in contact with the exposed part 24 inside the second metal foil of the exterior material 20 and is electrically conducting. The first metal foil 11 is exposed at the outer surface of the first metal foil 16 exposed on the outer surface of the enclosure 32, and the second metal foil 21 is exposed on the outer surface of the second metal foil 32. Since it is exposed at 26, the battery element 60 can obtain electrical conduction with 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 conductive portion on the positive electrode side, and the second metal foil 21 of the second packaging material 20 is used as a conductive portion on the negative electrode side.

[Assembly Battery]

In the assembled battery 5 shown in FIGS. 2A and 2B, four laminated power storage modules 2 are alternately arranged so that the first flanges 15 and the second flanges 25 of adjacent modules in the stacking direction overlap. By changing the direction, battery element chambers 42 of neighboring modules are stacked in an overlapping manner, and they are connected. That is, the four laminated power storage modules 2 are composed of the outer exposed portion 26 of the second metal foil of the second flange 25 of the first-layer module, which is the uppermost layer, and the first flange 15 of the second-tier module. 1. The metal foil outer exposed portion 16 is connected by passing a connecting pin 35 made of a conductive material through the connecting holes 27 and 17, and similarly, the second metal foil outer exposed portion of the second layer module ( 26) and the first metal foil outer exposed portion 16 of the third layer module are connected, and the second metal foil outer exposed portion 26 of the third layer module and the first metal foil outer exposed portion of the fourth layer module ( 16) are connected. Further, a positive electrode pin 36 made of a conductive material is attached to the connecting hole 17 of the first metal foil outer exposed portion 16 of the first layer module, and the fourth layer second metal foil outer exposed portion 26 A pin 37 for a negative electrode made of a conductive material is attached to the hole 27 for connection. By the above connection, the four laminated power storage modules 2 are connected in series, and the pin 36 for the positive electrode and the pin 37 for the negative electrode are used as electrode terminals of the assembled battery 5, and the electric wire 938 is connected. It can be withdrawn and connected to other devices.

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

In each laminated power storage module 2, the plurality of battery elements 60 are formed by the first metal foil inner exposed portion 14 and the second inner exposed portion 24 by the first metal foil 11 and the second metal foil ( 21), and the laminated power storage modules 2 can be connected to each other by the first metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26. In addition, the connection between the assembled battery 5 and the external device is also performed by the 1st metal foil outer exposed part 16 and the 2nd metal foil outer exposed part 26. That is, the laminated power storage module 2 and assembled battery 5 do not have tab leads. Therefore, in the laminated power storage module 2, the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 are evenly fused to each other at the portions of the heat-sealed portions 52a and 52b in contact with the battery element chamber 42, Because of this, adhesion is high, sealing performance higher than that of the battery element chamber 42 from which the tab lead is drawn out can be obtained, and the risk of liquid leakage is reduced. In addition, by not using a tab lead, the heat sealing operation is simplified, and the weight and space saving of the assembled battery 5 can be achieved.

The assembled battery 5 has a high capacity by connecting a plurality of laminated power storage modules 2, but since it has a large number of battery elements 60, the amount of heat generated is also large. In the assembled battery 5, the heat generated in the battery element 60 is dissipated to the space 70, and the flow of gas in the space 70 promotes heat dissipation and cools. The space 70 is a heat dissipation space formed by stacking the laminated power storage modules 2, and can exhibit heat dissipation performance without using a heat dissipation member such as a corrugated material, and can achieve a cooling effect without increasing the size of the assembled battery. You can get it. Cooling using such a space 70 is an effect specific to a structure in which a plurality of laminated power storage modules 2 are stacked, and cannot be obtained with a single module. In addition, if the battery capacity of the entire module is the same, a module having a plurality of battery elements and a plurality of battery element chambers for sealing them is better than a module having one battery element and one battery element chamber for sealing it. Since the surface area is large, the heat dissipation efficiency is good.

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

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 shapes of the embossed portion and the electrode element chamber are not limited to the embodiments shown in FIGS. 2A and 2B, and the embossed portion is formed on at least one of the first and second exterior materials constituting the exterior body. If there is, a convex part can be formed on the outer surface of an exterior body. In addition, it is natural that the distance between the battery element chambers, that is, the width of the heat-sealing part is set to a dimension that can secure the airtightness of the battery element chamber. Enlarging is free.

4 and 5 show examples of other forms of the embossed portion and the battery element chamber. In these drawings, the laminated structure of the first packaging material 10 and the second packaging material 20 and the internal structure of the battery element chamber are not shown, but facing the room, the first metal foil inner exposed portion and the second It is the same as in the laminate type power storage module 2 in which the battery element 60 is sealed while the metal foil inner exposed portion is formed.

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. and forms one electrode element chamber 81. In the exterior body 82 of FIG. 5, like the exterior body 80, both the first exterior material 10 and the second exterior material 20 have embossed portions 45 and 46, but each M The bosses 45 and 46 form electrode element chambers 83a and 83b facing the flat portion of the mating material. Since the exterior bodies 80 and 82 have 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 sides of the modules. .

In addition, the layout of the space can be changed by the stacking mode of the laminated power storage module.

In the assembled battery 6 shown in Fig. 6, the laminated power storage modules 2 are stacked with the above-mentioned laminated power storage modules 2 shifted layer by layer, and the centers of the battery element chambers 42 of one module 2 are adjacent to each other in the stacking direction. It is arrange|positioned so that it may overlap with the intersection of the heat-sealing parts 52a, 52b of the module 2 which does. The amount of shift is 1/2 of the distance between the battery element chambers 42 . By shifting the positions of the laminated power storage modules 2 in this way, the battery element chambers 42 are arranged in a zigzag shape in the stacking direction. In addition, since the positions of the connecting holes 17 and 27 of adjacent modules are shifted by shifting the laminated power storage module 2, the widths of the first flange 15 and the second flange 25 are changed. Thus, positioning of the connecting holes 17 and 27 is performed. Therefore, although the shape of the laminated power storage module 2 shown in FIG. 6 is not the same as the laminated power storage module 2 shown in FIGS. are using In the assembled battery 6, like the assembled battery 5, four laminated power storage modules 2 are connected in series by connection pins 35, and a positive electrode pin ( 36) and the negative electrode pin 37 provided in the fourth-layer module are used as electrode terminals of the assembled battery 6.

With the above laminated structure, the space 71 is also formed in a zigzag shape in the stacking direction, and the space 71 is directly below and immediately below the battery element chamber 42 of the laminated power storage module 2 of each layer. is formed The space 71 has the same dimensions as the space 70 of the assembled battery 5 described above, but the electrode element chamber 42 of the assembled battery 5 is adjacent to the space 70 only in the direction orthogonal to the stacking direction. In contrast, the electrode element chamber 42 of the assembled battery 6 adjoins the space 71 in both directions of the stacking direction and the direction orthogonal to the stacking direction. In this way, cooling efficiency can be increased by allowing the battery element chamber 42 to contact the space 71 with a larger area.

As described above, in the assembled battery 6 in which the electrode element chamber 42 and the space 71 are arranged in a zigzag pattern, the electrode element chamber 42 and the heat sealing portions 52a and 52b are arranged in a zigzag pattern. The size relationship of the dimensions of is not regulated. When the electrode element chamber 42 and the heat sealing portions 52a and 52b have the same dimensions, a space having the same dimensions 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, part of the heat-sealing portions 52a and 52b overlap in the stacking direction, but the lower electrode element chamber 42 is the upper layer. Since the heat-sealing portions 52a and 52b are supported, it does not occur that the space is filled with the upper electrode element chamber 42 and the space is blocked. In either case, a space corresponding to the dimensions of the heat-sealing portions 52a and 52b is formed.

In addition, as another means of enhancing the cooling effect, there is a method of interposing a heat transfer body 75 between the laminated power storage modules 2 . In the assembled battery 6 of FIG. 6 , the cooling effect is enhanced by arranging the heat transfer body 75 on the metal plate with the metal plate interposed therebetween. The material of the heating element 75 is preferably aluminum or copper having high thermal conductivity, and a cooling effect may be enhanced by connecting a cooling device to the heating element 75.

[Other Forms of Laminated Power Storage Modules and Assembled Batteries]

Laminate type power storage modules constituting assembled batteries are required to have a metal foil outer exposed portion on the outer surface of the exterior body, but their formation positions are not limited. The outer metal exposed portion is a portion that obtains conduction between the modules and conduction between the assembled battery and the outside, and conduction thereof is possible even at the outer metal foil exposed portion provided other than the flange.

The laminated power storage modules 2a, 2b, 2c, and 2d constituting the assembled battery 7 of the four-layer structure shown in FIGS. In the battery element chamber 42, the positive electrode 61 of the battery element 60 conducts to the first metal foil inner exposed portion 14, and the negative electrode 63 conducts to the second metal foil inner exposed portion 24. Although what is being done is common, the formation position of the metal foil outer exposed part exposed by the metal foil on the outer surface of the exterior body 33 differs depending on the lamination position. In addition, four laminated power storage modules 2a, 2b, 2c, and 2d are stacked in such a manner that the battery element chamber 42 and the space 71 are positioned in a zigzag shape in the stacking direction. are in common

In the first-layer laminated power storage module 2a of the uppermost layer, 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. In the second metal foil exposed portion 28, the second metal foil 21 is exposed by removing the second heat-resistant resin layer 22 of the second exterior material 20.

As shown in FIG. 7C , in the intermediate second 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. In the first metal foil exposed portion 18, the first metal foil 11 is exposed by removing the first heat-resistant resin layer 12 of the first exterior material 10. As shown in FIG. 7B, the second metal foil outer exposed portion 28 is formed on the opposite side of the metal foil inner exposed portion 24, that is, on the bottom surface of the battery element chamber 42. In the second metal foil exposed portion 28, the second metal foil 21 is exposed by removing the second heat-resistant resin layer 22 of the second exterior material 20.

As shown in FIG. 7C, in the fourth layer of the lowermost laminated power storage module 2d, 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. It is formed on the top surface of (42). In the first metal foil exposed portion 18, the first metal foil 11 is exposed by removing the first heat-resistant resin layer 12 of the first exterior material 10. In addition, the second metal foil outer exposed portion 26 is formed on the second flange 25 .

The assembled battery 7 is stacked with a heat transfer member 75 made of a conductive material sandwiched between the four laminated power storage modules 2a, 2b, 2c, and 2d of the three types, and the laminate is formed with a jig ( (not shown), and the heat transfer body 75 and the laminated power storage modules 2a, 2b, and 2c are brought into close contact to form an assembly. In this assembled state, the first metal foil outer exposed portion 18 and the second metal foil outer 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 element 75 is a conductor, the battery elements 60 of each layer are connected in series through the first metal foil 10 and the second metal foil 20 . In addition, the current with the external device is connected to the outer exposed portion 16 of the first metal foil of the first flange 15 of the laminated module 2a on the uppermost layer and the second flange 25 of the laminated power storage module 2c on the lowermost layer. ), and the pin 36 for positive electrode and the pin 37 for negative electrode are attached to them.

As described above, the laminated power storage modules can be connected without using a connecting member by providing the external exposed portion of the metal foil at the contact portion of the stacked laminated power storage modules. In addition, the assembled battery 7 uses the heat transfer body 75 as a conductive part with the heat transfer body 75 interposed therebetween for the purpose of improving the cooling effect. Conduction can also be obtained by making the exposed parts directly contact each other.

[Material and Molding of First Exterior Material and Second Exterior Material]

In the first packaging material 10, a first heat-resistant resin layer 12 is bonded to one side of a first metal foil 11 via a first adhesive layer, and a first thermoplastic resin layer 12 is bonded to the other side via a second adhesive layer. The stratum 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 portion 16, 18 is formed in accordance with the surface to be formed, the first It is formed by removing the thermoplastic resin layer 13 and the 2nd adhesive layer, or the 1st heat resistant resin layer 12 and the 1st adhesive agent. In addition, when forming the embossed part 45 by press molding, press molding is performed after forming a metal exposed part.

In the second exterior material 20, the second heat-resistant resin layer 22 is bonded to one side of the second metal foil 21 through the third adhesive layer, and the second thermoplastic resin layer 22 is bonded to the other side through the fourth adhesive layer. The stratum 23 is bonded. Like 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 portion 26, 28, Depending on the surface to be formed, it is formed by removing the second thermoplastic resin layer 23 and the fourth adhesive layer or the second heat-resistant resin layer 22 and the third adhesive layer.

In addition, in FIGS. 1B, 2B, 6, 7B, and 7C, illustration of the first adhesive layer, the second adhesive layer, the third adhesive layer, and the fourth adhesive layer is omitted.

A preferable material for the first metal foil 11 is a soft aluminum foil, and the thickness is preferably 20 μm to 150 μm. In terms of formability and cost, a soft aluminum foil of 30 µm to 80 µm is particularly preferred. 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 preferred thickness of these foils is 10 µm to 150 µm, and is preferably 15 µm to 100 µm from the viewpoints of impact resistance, bending resistance, and cost.

In addition, as the first metal foil 11 and the second metal foil 21, plating foil or clad foil may also be used. For example, as the second metal foil 21, a plated foil in which copper is plated with nickel, or a clad foil of stainless steel and nickel can be used.

In addition, it is preferable that a chemical conversion film is formed on the surface of the first metal foil layer 11 and the second metal foil layer 21 at least on the side where the metal foil exposed portions 14, 16, 24, 26 exist. The chemical conversion film is a film formed by subjecting the surface of the metal foil to chemical conversion treatment, and such a chemical conversion treatment can sufficiently prevent corrosion of the surface of the metal foil by the contents (electrolyte, etc.). Even the exposed portion serving as the extraction window of the module does not discolor or deteriorate even when electrolyte adheres to the module during fabrication, and the effect of corrosion due to moisture in the air or the like can be reduced. Although the converted layer itself has almost no conductivity, there is almost no conduction resistance because the coating film thickness is extremely small. For example, chemical conversion treatment is performed on metal foil by performing the following treatment. That is, on the surface of the metal foil subjected to degreasing treatment,

1) phosphoric acid;

chromic acid,

An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts of fluorides and non-metal salts of fluorides.

2) phosphoric acid;

At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins, and phenolic resins;

Aqueous solution of a mixture containing at least one compound selected from the group consisting of chromic acid and chromium (III) salts

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 chromium (III) salt;

An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts of fluorides and non-metal salts of fluorides.

Chemical conversion treatment is performed by drying after apply|coating the aqueous solution of any one of said 1)-3) to the surface of metal foil.

The chemical conversion film preferably has a chromium adhesion amount (per side) of 0.1 mg/m 2 to 50 mg/m 2 , particularly preferably 2 mg/m 2 to 20 mg/m 2 .

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-sealing temperature at the time of heat-sealing the packaging material is used. As the heat-resistant resin, it is preferable to use a heat-resistant resin having a melting point higher than the melting point of the thermoplastic resin constituting the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 by 10° C. or more, and the melting point of the thermoplastic resin It is particularly preferable to use a heat-resistant resin having a melting point higher than 20°C or higher. For example, a stretched film such as a polyethylene naphthalate film, a polybutylene naphthalate film, or a polycarbonate film other than a polyester film or a polyamide film is preferable. Further, the thickness is preferably in the range of 9 μm 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-based copolymers, acid-modified products thereof, and ionomers An unstretched film made of is preferable, and the thickness is preferably in the range of 20 μm to 80 μm.

The first adhesive layer and the third adhesive layer are preferably two-component curing polyester polyurethane or polyether polyurethane adhesives, and the second adhesive layer and the fourth adhesive layer are preferably polyolefin adhesives in consideration of electrolyte resistance. A preferred application of each adhesive is 1 g/m 2 to 5 g/m 2 .

The method of forming the metal foil exposed portion in the first exterior material 10 and the second exterior material 20 is not limited at all. For example, in the step of bonding the metal foil and the resin layer by the dry lamination method, the adhesive is applied using a gravure roll in which the portion to which the adhesive is not adhered is carved to form an adhesive unapplied portion, and the metal foil and the resin layer are bonded. After printing, the resin layer on the adhesive uncoated portion is excised to expose the metal foil. The first packaging material 10 and the second packaging material 20 used in the laminated power storage module 2 of the above embodiment have metal foil exposed portions 14, 16, 24, and 26 on the surface on the thermoplastic resin layer side. Since there is, the 1st metal foil 11 and the 1st thermoplastic resin layer 13, and the 2nd metal foil 21 and the 2nd thermoplastic resin layer 23 are pasted together by the above-mentioned method, and after bonding, the metal foil exposed part 14 , 16, 24, 26). On the other hand, since there is no metal exposed portion on the surface on the side of the heat-resistant resin layer, 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. Attached by the attachment method.

In the case of forming the outer exposed portion of the metal foil on the surface of the first packaging material 10 and/or the second packaging material 20 on the side of the first heat-resistant resin layer 12 and/or the second heat-resistant resin layer 22, After bonding the 1st metal foil 11 and the 1st heat resistant resin layer 12, and the 2nd metal foil 21 and the 2nd heat resistant resin layer 22 together by the above-mentioned method, the resin layer is removed.

In the case of forming the embossed portion 45 by press molding on the first packaging material 10 as shown in FIG. 1A and the like, press forming is performed after forming the metal exposed portion. In the molding of the first exterior material 10 of the illustrated example, the first metal foil inner exposed portion 14 is pressed with a molding mold consisting of a male mold in contact with the cloth surface, a female mold with a male mold inserted, and a pressing mold to mold In the case of forming the embossed portion on the second packaging material 20, press molding is similarly performed.

In addition, when the first exterior material 10 is cut to a size that slightly protrudes from the second exterior material 20 on the two sides without the first flange, and the protruding portion is bent after heat sealing, the first metal foil on the cut end surface Contact between (11) and the second metal foil 21 can be prevented. The second packaging material 20 may be bent by reversing the dimensions of the first packaging material 10 and the second packaging material 10 .

[Structure and Materials of Battery Elements]

The laminate type power storage modules 2 , 2a , 2b , 2c , and 2d use a bare cell as a battery element 60 . Details of the bare cell and the electrolyte encapsulated together with the bare cell are as follows.

(bare cell)

A bare cell as the battery element 60 is composed of a positive electrode 61 , a separator 62 , and a negative electrode 63 . The shape of the cell is not limited to the winding type of FIG. 3 . As another type of bare cell, a positive electrode and a negative electrode are cut to the size of the cell, and a plurality of layers are alternately laminated as a combination of a separator in each foil, and a current collector of a positive electrode and a collector of a negative electrode A laminated type bonded 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 μm to 50 μm is preferably used, and it is preferable that there is no active material at a location in contact with the metal exposed portion 14. The composition of the positive electrode active material layer is not particularly limited. For example, PVDF (polyvinylidene fluoride), SBR (styrene butadiene rubber), CMC (carboxymethylcellulose sodium salt, etc.), PAN (polyacrylonitrile) , a linear polysaccharide or the like, and a mixed composition in which a lithium salt (eg, lithium cobaltate, lithium nickelate, lithium iron phosphate, lithium manganate, etc.) is added. 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 additive such as carbon black or CNT (carbon nanotube).

In addition, it is preferable to use a binder between the current collector and the positive electrode active material in order to increase adhesion. The binder is not particularly limited, but examples thereof include a layer formed of PVDF, SBR, CMC, PAN, linear polysaccharide or the like. In order to improve 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 setting the thickness of the binder layer to 10 μm or less, increase in the internal resistance of the bare cell due to the non-conductive binder 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 as the current collector. As the metal foil, copper foil having a thickness of 7 μm to 50 μm is preferably used, and other aluminum foils, titanium foils, and stainless steel foils can be used. Also, like the positive electrode, it is preferable that there is no active material at a location in contact with the metal exposed portion 24 . The composition of the negative electrode active material layer is not particularly limited, but, for example, PVDF, SBR, CMC, PAN, a binder such as a linear polysaccharide, additives (eg, graphite, lithium titanate, Si-based alloy, tin-based alloy, etc.) is added to form a mixed composition or the like. 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).

In addition, it is preferable to use a binder between the current collector and the negative electrode active material in order to increase adhesion. The binder is not particularly limited, but examples include a layer formed of PVDF, SBR, CMC, or PAN. A conductive auxiliary agent such as carbon black or CNT may be further added to the binder layer in order to improve 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 setting the thickness of the binder layer to 10 µm or less, an increase in internal resistance of the bare cell due to the non-conductive binder can be suppressed as much as possible.

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

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

In addition, the preferred materials for the case where the laminate type power storage module of the present invention is an electric double layer capacitor are as follows.

The current collectors of the positive electrode 61 and the negative electrode 63 are preferably hard aluminum foils 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.

(electrolyte)

In addition, the electrolyte to be sealed together with the battery element is not particularly limited, but at least one solvent 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. Examples of the lithium salt include, but are not limited to, lithium hexafluorophosphate, lithium tetrafluoroborate, and quaternary ammonium tetrafluoroboric acid. As said quaternary ammonium salt, tetramethylammonium salt etc. are mentioned, for example. Alternatively, a gelated electrolyte of PVDF, PEO (polyethylene oxide), or the like may be used.

[Method of manufacturing laminated power storage module and assembled battery]

The laminate type power storage modules 2, 2a, 2b, 2c, and 2d can be manufactured by the following process.

(1) By the method described above, 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 provided at the desired location. The formed first exterior material 10 is manufactured. In addition, the second exterior material 20 in which the second metal foil inner exposed portion 24, the second metal foil outer exposed portion 26, or the second metal foil outer exposed portion 28 is formed is manufactured at a required position.

(2) Place the first packaging material 10 with the first thermoplastic resin layer 13 on top, and place the battery on the first metal foil inner exposed portion 14 in each embossed portion 45 that becomes the battery element chamber 42. The battery element 60 is charged so that the positive electrode 61 of the element 60 contacts, and electrolyte is injected using a syringe or the like.

(3) The second packaging material 20 is overlapped while positioning so that the second metal foil inner exposed portion 24 of the second packaging material 20 contacts the negative electrode 63 of the battery element 60, and the packaging body 32 , 33). In this assembled state, the first flange 15 extends from the end of the second exterior material 20, and the second flange 25 extends from the end of the first exterior material 10. The metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26 are exposed to the outer surfaces of the exterior bodies 32 and 33 .

(4) A heat-sealing portion 52a is formed using a heated hot plate.

(6) 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 to perform preliminary charging, and a constant temperature bath at 100 ° C. for 8 hours to degas.

(7) The battery element 60 and the electrolyte are sealed in the battery element chamber 42 by heat-sealing the unsealed portion with a heated hot plate under reduced pressure to form a heat-sealed portion 52b.

(8) Connection holes 17 and 27 are drilled 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 only an example thereof, and is not particularly limited to such a manufacturing method.

The fabricated laminated power storage modules 2, 2a, 2b, 2c, and 2d are stacked in a required number or stacked with the heat transfer body 75 interposed therebetween, and adjacent modules in the stacking direction are connected by the above-described method. and assemble the battery. In the assembled battery of the present invention, the number of layers is arbitrary.

The use of the assembled battery according to the present invention is not limited, but is a power source for automobiles, bicycles, two-wheeled vehicles, trains, airplanes, ships, etc. that require electricity, specifically, lithium secondary batteries with high capacity such as hybrid vehicles, electric vehicles, and industrial/home storage batteries. It can be used for battery (lithium ion battery, lithium polymer battery, etc.) module, solid battery module, lithium ion capacitor module for the same purpose, and electric double layer capacitor module for the same purpose as above.

[Example]

Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.

<Example 1>

Four laminated modules 2 shown in FIGS. 1A and 1B were fabricated, and a battery pack 5 shown in FIGS. 2A and 2B was fabricated.

The first metal foil 11 is a soft aluminum foil with a thickness of 40 µm and A8079 classified as JIS H4160, and chemical conversion treatment was performed on both surfaces. 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 is a stainless steel foil made of soft SUS304 with a thickness of 20 μm, and chemical conversion treatment is performed on both surfaces of both surfaces. 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 with a thickness of 40 μm.

In addition, the dimensions of the first metal foil inner exposed portion 14 and the second metal foil inner exposed portion 24 are 30 mm × 30 mm, and the first metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26 The dimensions of are 20 mm × 200 mm.

(First Exterior Material)

On one side of the first metal foil 11, the first heat-resistant resin layer 12 was bonded to one side of the first metal foil 11 with a two-component curing polyester polyurethane adhesive having a coating thickness of 3 μm by the dry lamination method, and the first heat-resistant resin layer 12 was applied in an aging furnace at 50 ° C. was cured for 3 days. Next, on the opposite side of the first metal foil 11, by the dry lamination method, when a two-component curing type olefinic adhesive having a coating thickness of 2 μm is applied to a coating thickness of 2 μm, nine first metal foil inner exposed parts (14) and an adhesive uncoated portion corresponding to the size and position of the first metal foil outer exposed portion 16 was formed, and the first thermoplastic resin layer 13 was pasted. After bonding, it was cured for 3 days in an aging furnace at 40°C.

After curing, the first thermoplastic resin layer 13 on the adhesive uncoated portion is cut and removed with a laser blade, and the first metal foil inner exposed portion 14 and the first metal foil outer portion exposed by the first metal foil 11 are removed. An exposed portion 16 was formed.

Next, using a 40 mm square male, female, and press mold, press molding is performed with a depth of 4 mm in an aspect in contact with the first metal foil inner exposed portion 14 on the top surface of the male, battery element The embossed part used as the yarn 42 was formed. Furthermore, the periphery was trimmed and the 1st packaging material 10 was obtained. The plane dimension of this 1st packaging material 10 is 140 mm x 160 mm.

(Second Exterior Material)

On one side of the second metal foil 21, the second heat-resistant resin layer 22 was pasted with a two-component curing type polyester polyurethane adhesive having a coating thickness of 3 μm by the dry lamination method, and the second heat-resistant resin layer 22 was applied in an aging furnace at 50° C. for 3 days. He was cured. Next, on the opposite side of the second metal foil 21, by the dry lamination method, when a two-component curing type olefin-based adhesive having a coating thickness of 2 μm is applied at a coating thickness of 2 μm, nine second metal foil inner exposed parts (24) and one second thermoplastic resin layer 23 were bonded by forming an adhesive uncoated portion corresponding to the size and position of the second metal foil outer exposed portion 26. After bonding, it was cured for 3 days in an aging furnace at 40°C.

After curing, the second thermoplastic resin layer 23 on the non-adhesive portion is cut and removed with a laser blade, and the second metal foil inner exposed portion 24 and the second metal foil outer exposed portion 26 exposed by the second metal foil 21 are exposed. ) was formed. Further, the periphery was trimmed to obtain the second exterior material 20. The planar dimension of this second packaging material 20 is 150 mm x 160 mm, which is larger than that of the first packaging material 10 .

(electrode element)

As the electrode element 60, a bare cell was fabricated using the following materials.

The current collector of the positive electrode 61 is a hard aluminum foil of A1100 classified as 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 as JIS H3100, and has a thickness of 15 μm and a width of 200 mm. The positive electrode active material layer forming paste contains 60 parts by mass of a positive electrode active material containing lithium cobaltate as a main component, 10 parts by mass of PVDF as a binder and electrolyte retaining agent, 5 parts by mass of acetylene black (conductive material), N-methyl-2-pyrroly It is a paste obtained by kneading and dispersing 25 parts by mass of money (organic solvent). The paste for forming a negative electrode active material is 57 parts by mass of a negative electrode active material containing carbon powder as a main component, 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, acetylene black (conductive It is a paste obtained by kneading and dispersing 3 parts by mass and 25 parts by mass of N-methyl-2-pyrrolidone (organic solvent). The binder liquid is a binder liquid obtained by dissolving PVDF 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 solution in which lithium hexafluorophosphate (LiPF ₆ ) is dissolved at a concentration of 1 mol/ℓ in a mixed solvent in which ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) are mixed in equal volume ratios. .

The positive electrode 61 was manufactured by the following process. First, a binder liquid 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 after drying of 0.5 μm. Next, a liquid paste for the positive electrode active material layer was applied to the surface of the binder layer, dried at 100° C. for 30 minutes, followed by hot pressing to obtain a density of 4.8 g/cm 3 and a thickness after drying. A 120 μm positive electrode active material layer was formed. Further, it was cut into a coil shape with a width of 35 mm by making a width.

The negative electrode 63 was manufactured by the following process. First, a binder liquid 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 after drying of 0.5 μm. Next, a paste for the negative electrode active material layer solution was applied to the surface of the binder layer, dried at 100° C. for 30 minutes, followed by hot pressing to form a negative electrode active material layer having a density of 1.5 g/cm 3 and a thickness after drying of 20.1 μm. did Further, it was cut into a coil shape with a width of 35 mm by making a width.

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 laminated and wound in the order of slightly shifting each other, A bare cell with a thickness of 4 mm and a square of 38 mm was manufactured by pressing and crushing so that the positive electrode 61 was exposed on the surface and the negative electrode 63 was exposed on the opposite surface.

(Assembly of laminate type power storage module and assembled battery)

(1) The first packaging material 10 is placed so that the first thermoplastic resin layer 13 is on top, and the first metal foil inner exposed portion 14 in each embossed portion 45 forming the battery element chamber 42 is The battery element 60 was loaded so that the positive electrode 61 of the battery element 60 came into contact with it, and the electrolyte was injected using a syringe or the like.

(2) The second packaging material 20 is overlapped while being positioned so that the second metal foil inner exposed portion 24 of the second packaging material 20 contacts the negative electrode 63 of the battery element 60, and the packaging body 32 ) to assemble. In this assembled state, the first flange 15 extends from the end of the second exterior material 20, and the second flange 25 extends from the end of the first exterior material 10, and the first metal foil is exposed outside ( 16) and the second metal foil outer exposed portion 26 are exposed to the outer surface of the exterior body 32.

(3) It heat-sealed for 3 seconds at a pressure of 0.3 MPa using a hot plate heated to about 200°C to form a hot-sealed portion 52a. The width of the heat sealing portion 52a between the embossed portions 45 is 5 mm.

(4) Clips are 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 until a battery voltage of 4.2V is generated. After charging, the battery element chamber 42 was degassed by putting it in a thermostat at 100°C for 8 hours.

(5) The unsealed portion was heat-sealed with a hot plate heated to about 200° C. under a reduced pressure of 86 kPa to form a heat-sealed portion 52b, thereby sealing the battery element 60 and the electrolyte in the battery element chamber 42. . The width of the heat sealing portion 52b between the embossed portions 45 is 5 mm.

(6) As a countermeasure against short circuit, 25 μm is applied to the edge of the first casing material 10 on the side of the second flange 25 and the edge of the second casing material 20 on the side of the first flange 15. The adhesive tape was attached and the first metal foil 11 and the second metal foil 21 exposed on the cross section were coated. In addition, as for the other two sides, the protruding second packaging material 20 was bent toward the first packaging material 10 side, and insulation measures were taken and side surface strength reinforcement was performed. 2A shows a state before bending.

(7) Three connection holes 17 and 27 were drilled 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 laminated power storage modules 2 were produced.

(8) As shown in FIGS. 2A and 2B, the four laminated modules 2 are alternately oriented so that the first flanges 15 and the second flanges 25 of adjacent modules in the stacking direction overlap. changed and laminated.

(9) Connect the four laminated modules 2 in series with connecting pins 35, attach the pins 36 for positive electrodes to the outer exposed portion 16 of the first metal foil on the uppermost layer, and attach the pins 36 to the lowermost layer. A negative electrode pin 37 was attached to the outer exposed portion 26 of the metal foil. Through the above steps, the assembled battery 5 was produced.

The assembled battery 5 is formed in a space 70 having a square cross section of (width of the heat-sealing portion 52a: 5 mm) x (height of the embossed portion: 4 mm) on the heat-sealing portion 52a. ) is formed, and a space having a rectangular cross section of (width of hot sealing portion 52b 5 mm) x (height of embossed portion 4 mm) is formed on the hot sealing portion 52b.

<Comparative Example 1>

Comparative Example 1 is an assembled battery in which four laminated power storage modules having a different structure from Example 1 are stacked.

In addition, in the laminated power storage module 2 of Example 1, nine battery elements 60 are sealed in each battery element chamber 42, and metal foil exposed portions are formed on the inner and outer surfaces of the exterior body to form a tab lead. Conductivity with the battery element 60 is obtained without using it. Regarding these laminated power storage modules 2, in the laminated module of Comparative Example 1, one battery element is sealed in one battery element chamber, and the capacity equivalent to that of nine battery elements in Example 1 is obtained. The size of the battery element was increased so that In addition, the exterior body of the laminated module of Comparative Example 1 has no metal foil exposed portion on the inside or outside, and is a module that is drawn out to the exterior body by connecting a tab lead to a battery element.

(exterior body)

The packaging material includes a portion having an embossed portion corresponding to the battery element chamber corresponding to the first packaging material 10 of Example 1 and a flat portion covering the opening of the embossed portion corresponding to the second packaging material 20 of Example 1 It is made of one whole. The exterior body is formed by folding the exterior material in two and bending it. The material constituting the exterior material is that the metal foil is a soft aluminum foil (A8021 soft aluminum foil classified as JIS H4160) with a thickness of 40 μm, the heat-resistant resin layer is a biaxially stretched polyamide film with a thickness of 25 μm, and the thermoplastic resin layer is It is a polypropylene film with a thickness of 40 μm.

The exterior material is a heat-resistant resin layer bonded to the entire surface of one side of the metal foil through a polyester urethane-based adhesive having an application amount of 3 g/m2, and a polyolefin-based adhesive having an application amount of 2 g/m 2 over the entire surface of the metal foil. It was produced by pasting together the thermoplastic resin layers and subsequently curing them in a 40°C thermostat for 3 days. The exterior material does not have an exposed portion of the metal foil, and the entire aluminum foil is covered with a resin layer.

Press molding was performed on the exterior material to form an embossed portion having a size of 115 mm × 115 mm × 4 mm in height, and trimming was performed in anticipation of the dimensions of the flat portion and the planned portion of the heat-sealing 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 formed by exposing 5 mm of one end side in the longitudinal 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, and both sides of the aluminum foil are exposed. 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 sandwiched and adhered by means of a heat seal.

The negative electrode tab lead is formed by exposing 5 mm of one end side of a nickel foil having a length of 40 mm, a width of 3 mm, and a thickness of 100 μm in the longitudinal direction, and both sides of the nickel foil having a length of 10 mm, a width of 5 mm, and a thickness of 50 μm. An insulating film made of a maleic acid-modified polypropylene film (melting point: 140° C., MFR: 3.0 g/10 min.) was pinched and bonded by means of a heat seal, and produced.

The ends of the positive electrode tab lead were bonded to the positive electrode of the battery element, and the negative electrode tab lead was bonded to the negative electrode, and the tips of the positive electrode tab lead and the negative electrode tab lead were pulled out from the same side of the battery element.

(Assembly of laminate type power storage module and assembled battery)

(1) The exterior material is previously marked with a ruler or the like to mark the bending position.

(2) The battery element is loaded into the embossed portion of the exterior material, positioned so that the insulating film of the tab lead is loaded on the heat-sealed portion predetermined portion, and the exterior material is bent at the marked position to form a flat portion into the embossed portion put on

(3) With respect to the two sides including the side from which the tab lead is taken out, it was sandwiched at a pressure of 0.3 MPa using a hot plate heated to 200 ° C. and heat-sealed for 3 seconds.

(4) 45 ml of the same electrolyte as in Example 1 was injected into the syringe from the unsealed side, and temporary filling and degassing were performed in the same manner as in Example 1.

(5) Under a reduced pressure of 0.086 MPa in a discharged state of 3.0 V, the unsealed side was held at a pressure of 0.3 MPa using a hot plate heated to 200 ° C., and heat-sealed for 3 seconds, and the battery element and electrolyte were sealed in the battery element chamber. sealed.

Through the above steps, four laminated power storage modules were fabricated.

(6) Four laminated modules were stacked and connected in series to assemble an assembled battery.

<evaluation>

The battery packs 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 at 16.8 V, charging and discharging at 1 C (charging in 1 hour, discharging in 1 hour) was repeated 100 times at room temperature at 18°C, and the voltage and capacity when fully charged again were measured. In addition, the temperatures of the fully charged battery when discharged at 1C and discharged at 0.2C were measured with a temperature sensor, and an average value was obtained. The temperature measurement position is the center of the 3rd layer module in both Example 1 and Comparative Example 1, Example 1 is the central part of the outer surface of the embossed part in the center of 3 rows x 3 rows, and Comparative Example 1 is the central part of the embossed part.

[Table 1]

As shown in Table 1, Example 1 and Comparative Example 1 showed no difference in battery capacity, and the same result was obtained even when charging and discharging were repeated for 100 cycles. In addition, with respect to the calorific value during discharge, it was confirmed that the assembled battery of Example 1 suppressed heat generation and had a high heat dissipation effect, compared to Comparative Example 1 at 1C discharge time and 0.2C discharge time.

This application accompanies the claim of priority of Japanese Patent Application No. 2015-83102 of the Japanese patent application for which it applied on April 15, 2015, The content of the disclosure constitutes a part of this application as it is.

The terms and expressions used herein are used for purposes of description and not to be construed as limiting, and are not intended to exclude any equivalents of the features shown and described herein, but within the claimed scope of the present invention. It should be recognized that variations are also permissible.

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

2, 2a, 2b, 2c, 2d: laminate type power storage module
5, 6, 7: set battery
10: first exterior material
11: first metal foil
12: first heat-resistant resin layer
13: first thermoplastic resin layer
14: first metal foil inner exposed portion
15: first flange
16, 18: first metal foil outer exposed portion
20: second exterior material
21: second metal foil
22: second heat-resistant resin layer
23: second thermoplastic resin layer
24: second metal foil inner exposed portion
25: second flange
26, 28: second metal foil outer exposed portion
32, 33, 80, 82: exterior body
42, 82, 83a, 83b: battery element chamber
45, 46: embossing part
52a, 52b: heat sealing part
60: bare cell (battery element)
61: positive electrode
62: separator
63 negative electrode
70, 71: space
75: heating element

Claims (12)

A laminated 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 inside of the first metal foil is exposed on the surface on the side of the first thermoplastic resin layer. A second heat-resistant resin layer is laminated on one side of a first packaging material having a portion and a second metal foil, and a second thermoplastic resin layer is laminated on the other side, and the second metal foil is on the side of the second thermoplastic resin layer. A battery element having a second packaging material having an exposed second metal foil inner exposed portion, a positive electrode and a negative electrode, and a separator disposed between them,
At least one of the first packaging material and the second packaging material has an embossed portion in a region including the first metal foil inner exposed portion and the second metal foil inner exposed portion, and the first thermoplastic resin layer of the first packaging material and the second packaging material are separated. The second thermoplastic resin layer faces each other, and the first thermoplastic resin layer and the second thermoplastic resin layer are surrounded by the heat-sealed portion that is fused, so that the first metal foil inner exposed portion and the second metal foil inner exposed portion face the room, An exterior body having a plurality of battery element chambers in which convex portions are formed by the embossed portion is formed, and in the exterior body, one side of the first exterior material extends from the heat-sealed portion, and both sides are the outer surface of the exterior body. A first metal foil outer exposed portion formed of a flange and exposed to the first metal foil is formed on the first flange, and a connection hole is drilled in the first metal foil outer exposed portion, and one side of the second exterior material is heat-sealed. A second metal foil externally exposed portion is formed on the second flange, and the second metal foil externally exposed portion is formed on the second flange and is connected to the second metal foil externally exposed portion. A dragon hole is drilled,
In the battery element sealed together with the electrolyte in the battery element chamber, the positive electrode conducts to the first metal foil inner exposed portion and the negative electrode conducts to the second metal foil inner exposed portion,
A plurality of the laminated power storage modules are stacked in such a way that a space is formed on the heat-sealed portion, and the laminated power storage modules adjacent in the stacking direction have a first metal foil outer exposed portion and a second metal foil outer exposed portion respectively connecting holes. An assembled battery characterized in that it is electrically connected through a connecting pin passed therethrough. According to claim 1,
An assembled battery characterized in that a plurality of laminated power storage modules are stacked so that the battery element chamber and the heat-sealed portion overlap each other in the stacking direction of the laminated power storage modules. According to claim 1 or 2,
An assembled battery characterized in that a heating element is disposed between adjacent laminated power storage modules in the stacking direction. According to claim 1 or 2,
An assembled battery characterized in that the space is a cooling gas passage. According to claim 1,
An assembled battery characterized in that the space and the battery element chamber adjoin only in a direction orthogonal to the stacking direction of the laminate type power storage module. According to claim 2,
An assembled battery characterized in that the space and the battery element chamber are adjacent to each other in both directions of the lamination direction of the laminated power storage module and a direction orthogonal to the lamination direction. A laminated 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 inside of the first metal foil is exposed on the surface on the side of the first thermoplastic resin layer. A second heat-resistant resin layer is laminated on one side of a first packaging material having a portion and a second metal foil, and a second thermoplastic resin layer is laminated on the other side, and the second metal foil is on the side of the second thermoplastic resin layer. A battery element having a second packaging material having an exposed second metal foil inner exposed portion, a positive electrode and a negative electrode, and a separator disposed between them,
At least one of the first packaging material and the second packaging material has an embossed portion in a region including the first metal foil inner exposed portion and the second metal foil inner exposed portion, and the first thermoplastic resin layer of the first packaging material and the second packaging material are separated. The second thermoplastic resin layer faces each other, and the first thermoplastic resin layer and the second thermoplastic resin layer are surrounded by the fused heat-sealed portion, so that the first metal foil inner exposed portion and the second metal foil inner exposed portion face the room, An exterior body having a plurality of cell element chambers in which convex portions are formed by the embossed portion is formed, and on the outer surface of the exterior body, the first metal foil exposed portion of the first metal foil and the second metal foil exposed portion of the second metal foil are formed. An outer exposed portion is formed,
In the battery element sealed together with the electrolyte in the battery element chamber, the positive electrode conducts to the first metal foil inner exposed portion and the negative electrode conducts to the second metal foil inner exposed portion,
A plurality of the laminated power storage modules are stacked in such a way that a space is formed on the heat-sealed portion, and laminated power storage modules adjacent in the stacking direction are connected to a first metal foil outer exposed portion and a second metal foil outer exposed portion,
An assembled battery characterized in that the space and the battery element chamber adjoin only in a direction orthogonal to the stacking direction of the laminate type power storage module. According to claim 7
An assembled battery characterized in that a heating element is disposed between adjacent laminated power storage modules in the stacking direction. According to claim 7 or 8
An assembled battery characterized in that the space is a cooling gas passage. A laminated 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 inside of the first metal foil is exposed on the surface on the side of the first thermoplastic resin layer. A second heat-resistant resin layer is laminated on one side of a first packaging material having a portion and a second metal foil, and a second thermoplastic resin layer is laminated on the other side, and the second metal foil is on the side of the second thermoplastic resin layer. A battery element having a second packaging material having an exposed second metal foil inner exposed portion, a positive electrode and a negative electrode, and a separator disposed between them,
At least one of the first packaging material and the second packaging material has an embossed portion in a region including the first metal foil inner exposed portion and the second metal foil inner exposed portion, and the first thermoplastic resin layer of the first packaging material and the second packaging material are separated. The second thermoplastic resin layer faces each other, and the first thermoplastic resin layer and the second thermoplastic resin layer are surrounded by the fused heat-sealed portion, so that the first metal foil inner exposed portion and the second metal foil inner exposed portion face the room, An exterior body having a plurality of cell element chambers in which convex portions are formed by the embossed portion is formed, and on the outer surface of the exterior body, the first metal foil exposed portion of the first metal foil and the second metal foil exposed portion of the second metal foil are formed. An outer exposed portion is formed,
In the battery element sealed together with the electrolyte in the battery element chamber, the positive electrode conducts to the first metal foil inner exposed portion and the negative electrode conducts to the second metal foil inner exposed portion,
A plurality of the laminated power storage modules are stacked in such a way that a space is formed on the heat-sealed portion, and laminated power storage modules adjacent in the stacking direction are connected to a first metal foil outer exposed portion and a second metal foil outer exposed portion,
In the lamination direction of the laminated power storage modules, a plurality of laminated power storage modules are stacked so that the battery element chamber and the heat seal portion overlap each other;
An assembled battery characterized in that the space and the battery element chamber are adjacent to each other in both directions of the lamination direction of the laminated power storage module and a direction orthogonal to the lamination direction. According to claim 10
An assembled battery characterized in that a heating element is disposed between adjacent laminated power storage modules in the stacking direction. According to claim 10 or 11
An assembled battery characterized in that the space is a cooling gas passage.

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