CN205723858U - Set of cells - Google Patents

Abstract

The utility model provides a battery pack. The exterior body (32) of the laminated power storage assembly (2) has an embossed part (45) on at least one of the facing first exterior part (10) and second exterior part (20), and has an embossed part (45) through A plurality of electrode element chambers (42) are formed by heat-sealing around the embossed portion (45) to form convex portions. The battery pack (5) stacks and connects a plurality of the modules (2), and forms a space (70) for heat dissipation by utilizing the difference in thickness between the electrode element chamber (42) and the heat-sealed parts (52a, 52b). Furthermore, in the battery element chamber (42), the battery element (60) is connected to the metal foil inner exposed portion (14, 24), and the module 2) is connected to the metal foil outer exposed portion (16, 26).

Description

Battery

technical field

The utility model relates to a battery pack capable of light weight, high heat dissipation and space saving.

In addition, in this specification, the word "aluminum" is used to include Al and Al alloys, the word "copper" is used to include Cu and Cu alloys, and the word "nickel" is used to include Ni and Al alloys. The meaning of Ni alloy, the word "titanium" is used to include the meaning of Ti and Ti alloy. In addition, in this specification, the word "metal" is used in the meaning including a metal simple substance and an alloy.

Background technique

With the miniaturization and weight reduction of lithium-ion secondary batteries and lithium polymer secondary batteries used in hybrid vehicles, electric vehicle batteries, household or industrial stationary storage batteries, there are metal exteriors that have replaced the conventional ones, On the other hand, laminated exterior parts in which resin films are bonded to both sides of metal foil are often used. In addition, it is being considered to install electric double layer capacitors and lithium ion capacitors with laminated exterior parts in cars and buses.

In equipment that requires high energy, such as electric vehicles, in order to obtain a large amount of electric energy with a small volume, it is possible to stack power storage modules and connect them in series. However, during charging and discharging, heat generated by the internal resistance of the modules tends to accumulate. , so that high temperature is formed in the components, therefore, not only will accelerate the deterioration of the battery, reduce the performance of the battery, but also affect the safety of the battery. Therefore, in a battery pack in which a plurality of power storage modules are stacked, it has been proposed to provide a heat radiation member between the power storage modules to cool the modules (see Patent Documents 1 and 2).

In the battery pack described in Patent Document 1, a corrugated member is provided between the power storage modules as a heat dissipation member to form a cool air circulation space to obtain a heat dissipation effect. In addition, in the battery pack described in Patent Document 2, a pipe member through which coolant flows is arranged between the power storage modules, and a leaf spring is provided between the pipe member and the power storage modules to form a space for air cooling. , so as to obtain a high cooling effect by utilizing both liquid cooling and air cooling.

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2012-84551

Patent Document 2: Japanese Patent Laid-Open No. 2014-170697

Utility model content

However, the cooling methods described in Patent Documents 1 and 2 require bulky heat-dissipating components such as corrugated members, pipe members, and plate springs, as well as supply devices for cold air or cooling liquid. space. Therefore, even if the power storage module is reduced in size, it is difficult to reduce the size of the battery pack. In addition, the electricity storage module uses tabs to connect electrodes, which may cause heat generation from the connection position of the tabs, decrease in the sealing performance of the sealing part, and the like.

The utility model is made in view of the above technical background, and aims to provide a battery pack that does not increase in size, improves heat dissipation performance, and greatly reduces the risk of liquid leakage.

In order to achieve the above object, the utility model has the following constitutions.

(1) A battery pack characterized in that,

Laminated power storage modules have:

The first exterior member has a first heat-resistant resin layer laminated on one surface of the first metal foil and a first thermoplastic resin layer laminated on the other surface, and has a surface on the side of the first thermoplastic resin layer. an exposed portion inside the first metal foil where the first metal foil is exposed; a second exterior member that laminates a second heat-resistant resin layer on one surface of the second metal foil and a second thermoplastic resin layer on the other surface, On the surface of the second thermoplastic resin layer, there is a second metal foil inner exposed portion for the second metal foil to expose; a battery element, which has a positive electrode, a negative electrode, and a separator disposed therebetween,

At least one of the first exterior member and the second exterior member has an embossed portion in a region including the first metal foil inner exposed portion and the second metal foil inner exposed portion, by making the first outer covering member A thermoplastic resin layer faces the second thermoplastic resin layer of the second exterior member, and is surrounded by a heat-sealed portion formed by welding the first thermoplastic resin layer and the second thermoplastic resin layer, thereby forming a battery cell with a plurality of battery element chambers. An exterior body, wherein the cell element chamber is formed as a convex portion by the embossed portion, the first metal foil inner exposed portion and the second metal foil inner exposed portion face each other in the chamber, and the outer surface of the exterior body is formed for the first metal foil outer exposed portion where the first metal foil is exposed and the second metal foil outer exposed portion where the second metal foil is exposed,

For the battery element sealed into the battery element chamber together with the electrolyte, the positive electrode is connected to the inner exposed part of the first metal foil, and the negative electrode is connected to the inner exposed part of the second metal foil.

A plurality of the above-mentioned laminated power storage modules are stacked so that a space is formed above the heat-sealed portion, and the laminated power storage modules adjacent in the stacking direction are separated by the outer exposed portion of the first metal foil and the second metal foil. The outer exposed part is connected.

(2) In the battery pack of the preceding item (1), a plurality of laminated power storage modules are stacked such that the cell chamber and the heat-sealed portion overlap in the stacking direction of the laminated power storage modules.

(3) In the battery pack of the preceding item (1) or (2), a heat conductor is disposed between adjacent laminated power storage modules in the stacking direction.

(4) In the battery pack of the preceding item (1) or (2), the space serves as a cooling gas flow path.

(5) In the battery pack of the preceding item (1), the space and the battery element chamber are adjacent only in a direction perpendicular to the stacking direction of the laminated power storage modules.

(6) In the battery pack of the preceding item (2), the space is adjacent to the battery element chamber in both the stacking direction and the direction perpendicular to the stacking direction of the laminated power storage module. .

The effect of utility model

In the battery pack described in (1) above, the battery element chamber of the laminated power storage module is formed as a convex portion protruding to the outside of the exterior body, and therefore, a space is formed above the heat-sealed portion by stacking a plurality of modules. . The heat generated by the battery element is dissipated to the space, and the gas flows in the space to promote heat dissipation and cool the battery pack. The space is formed without using a heat dissipation member, and therefore, a cooling effect is obtained without enlarging the battery pack. 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 improved.

In addition, in each laminated power storage module, the plurality of battery elements are electrically connected through the first metal foil and the second metal foil through the first metal foil inner exposed part and the second inner exposed part in the battery element chamber, and the laminated The type electric storage components are connected to each other by using the outer exposed portion of the first metal foil and the outer exposed portion of the second metal foil. Furthermore, the connection between the battery pack and the external equipment is also performed through the exposed portion outside the first metal foil and the exposed portion outside the second metal foil. That is, the laminated power storage module and the battery pack do not have tabs. Therefore, since the first thermoplastic resin layer and the second thermoplastic resin layer are welded together in the heat-sealed portion connected to the battery element chamber, the adhesiveness is improved, and the risk of liquid leakage is greatly reduced. Furthermore, since tabs are not used, the heat-sealing operation is simple, and the weight and space of the battery pack can be reduced.

In the battery pack described in (2) above, the electrode element chamber is adjacent to the space in both the stacking direction of the module and the direction perpendicular to the stacking direction, and the battery element chamber can contact the space with a larger area. , a high cooling effect can be obtained.

In the battery pack described in (3) above, since the heat conductor dissipates heat, a high cooling effect can be obtained.

In the battery pack described in (4) above, since the gas flows in the space, heat dissipation can be promoted.

In the battery pack described in (5) above, heat generated in the battery element chamber is dissipated to a space adjacent thereto in a direction perpendicular to the stacking direction of the laminated power storage modules.

In the battery pack described in (6) above, the space is adjacent to the battery element chamber in both the stacking direction and the direction perpendicular to the stacking direction of the laminated power storage modules, thereby facilitating heat dissipation.

Description of drawings

Fig. 1A is a perspective view of an embodiment of a laminated power storage module constituting the battery pack of the present invention.

Fig. 1B is a cross-sectional view along line 1B-1B in Fig. 1A.

Fig. 2A is a perspective view of an embodiment of the battery pack of the present invention.

Fig. 2B is a cross-sectional view along line 2B-2B in Fig. 2A.

Fig. 3 is a 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 electricity storage module.

Fig. 5 is a cross-sectional view of another shape example of an electrode element chamber in a laminated electricity storage module.

Fig. 6 is a cross-sectional view of another embodiment of the battery pack of the present invention.

Fig. 7A is a cross-sectional view of another embodiment of the battery pack of the present invention.

Fig. 7B is a partially enlarged view of Fig. 7A.

Fig. 7C is a partially enlarged view of Fig. 7A.

Explanation of reference signs

2, 2a, 2b, 2c, 2d... Laminated power storage modules

5, 6, 7... battery pack

10...First exterior parts

11...The first metal foil

12...First heat-resistant resin layer

13...First thermoplastic resin layer

14...the inner exposed portion of the first metal foil

15...first flange

16, 18... The outer exposed portion of the first metal foil

20…Second exterior parts

21...second metal foil

22...Second heat-resistant resin layer

23...Second thermoplastic resin layer

24...Exposed part of the inner side of the second metal foil

25…Second flange

26, 28... The outer exposed part of the second metal foil

32, 33, 80, 82…Exterior body

42, 82, 83a, 83b battery element room

45, 46... Embossing department

52a, 52b...Heat sealing part

60…single battery (battery element)

61…Positive pole

62...Separator

63…Negative pole

70, 71... space

75...Heat conductor.

detailed description

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

In the following description, the same reference numerals denote the same items, and repeated descriptions are omitted. In addition, among the first exterior member and the second exterior member constituting the exterior body, regardless of the exterior member and the formation position, when referring to the portion where the metal foil is exposed, it is collectively referred to as the "metal foil exposed part", and will face the electrode element chamber. The exposed parts are collectively referred to as "metal foil inner exposed parts", and the parts exposed to the outer surface of the exterior body are collectively referred to as "metal foil outer exposed parts".

Laminated power storage module

The exterior body 32 of the laminated power storage module 2 shown in FIGS. 1A and 1B is composed of the first exterior material 10 and the second exterior material 20 , and has nine cell chambers 42 arranged in 3 rows×3 columns. A battery element 60 and an electrolyte are enclosed in each of the battery element chambers 42 .

The first exterior member 10 is a laminate 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. The sheet is formed by press forming to form nine embossed portions 45 that constitute the battery element chamber 42 and are square in plan view. On the other hand, the second exterior material 20 is a laminate 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. Flat sheet without embossing. 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 and the second thermoplastic resin layer 13 around the embossed part 45 The two thermoplastic resin layers 23 are welded to form the heat-sealed portions 52a, 52b, thereby forming the battery element chamber 42 for enclosing the battery element 60 and the electrolyte. The battery element chamber 42 is formed as a protrusion protruding from the heat-sealed parts 52a and 52b to the outside of the exterior body at a height equal to that of the embossed part 45. The portions 52a, 52b are thin. In addition, in the battery element chamber 42, the first metal foil inner exposed portion 14 where the first metal foil 11 is exposed is formed by removing a part of the first thermoplastic resin layer 13, and a part of the second thermoplastic resin layer 23 is removed. The second metal foil inner exposed portion 24 through which the second metal foil 21 is exposed.

One side of the first exterior member 10 is formed as a first flange 15, which extends outward from the heat-sealed portion 52a. The exposed first metal foil outer portion 16 of the foil 11 is exposed. On the other hand, a second flange 25 is formed on the side opposite to the first flange 15. The second flange 25 is the second exterior member 20 extending outward from the heat-sealed portion 52a, and the two surfaces constitute the exterior body. 32 is formed with a second metal foil outer exposed portion 26 where the second metal foil 21 is exposed. In addition, three connection holes 17 , 27 are punched on 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 .

As shown in FIG. 3 , the battery element 60 enclosed in the battery element chamber 42 together with the electrolyte is a rewinding type unit cell, and a positive electrode 61, a separator 62, a negative electrode 63, and a separator 62 are laminated, and the laminate is Form into rolls. 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. In the battery element chamber 42 , the positive electrode 61 of the battery element 60 is in contact with the exposed portion 14 inside the first metal foil of the first exterior member 10 for electrical conduction, and the negative electrode 63 is in contact with the exposed portion 24 inside the second metal foil of the second exterior member 20 And conduction. The first metal foil 11 is exposed at the first metal foil outer exposed portion 16 on the outer surface of the outer casing 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 casing 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 serves as the positive electrode-side conduction portion, and the second metal foil 21 of the second exterior material 20 serves as the negative electrode-side conduction portion.

Battery

In the battery pack 5 shown in FIGS. 2A and 2B , four laminated power storage modules 2 are stacked and connected in such a manner that the first flanges 15 and the first flanges 15 of adjacent modules in the stacking direction The second flanges 25 alternately change directions while overlapping, and overlap the battery element chambers 42 of adjacent modules. That is, among the four laminated power storage modules 2, the second metal foil outer exposed portion 26 of the second flange 25 of the first module on the uppermost layer and the second metal foil exposed portion 26 of the first flange 15 of the second module are A metal foil outer exposure 16 is connected by inserting a connection pin 35 made of a conductive material into the connection holes 27, 17. Similarly, the second metal foil outer exposure 26 and the third layer of the assembly are connected. The outer exposed parts 16 of the first metal foils of the components of the first layer are connected, and the second exposed parts 26 of the outer metal foils of the components of the third layer are connected with the exposed parts 16 of the first metal foils of the lowermost component of the fourth layer. . In addition, a positive electrode pin 36 made of a conductive material is installed in the connection hole 17 of the first metal foil outer exposed portion 16 of the first layer assembly, and the connection of the second metal foil outer exposed portion 26 of the fourth layer is A negative electrode pin 37 made of a conductive material is installed in the hole 27 . Through the connection as described above, four laminated power storage modules 2 are connected in series, the positive pin 36 and the negative pin 37 are used as electrode terminals of the battery pack 5, and the electric wire 38 can be drawn out to connect to other equipment.

In the above-mentioned laminated power storage module 2, the thickness of the module is thicker at the cell element chamber 42 and thinner at the heat-sealed parts 52a, 52b, so that a gap is formed between the laminated power storage modules 2 adjacent in the stacking direction. Space 70. That is, on the heat-sealed portions 52a, 52b around the battery element chamber 42, a space 70 having a quadrilateral cross section of (width of the heat-sealed portions 52a, 52b)×(height of the embossed portion 45) is formed. The heat-sealed portions 52a and 52b must necessarily exist around the battery element chambers 42, so all the battery element chambers 42 contact the space 70 in a direction perpendicular to the stacking direction.

In each laminated power storage assembly 2, a plurality of battery elements 60 are electrically connected via 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 type The power storage components 2 can be connected with each other by using the first exposed portion 16 outside the metal foil and the exposed portion 26 outside the second metal foil. In addition, the connection between the battery pack 5 and external equipment is also performed through the first metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26 . That is, the laminated power storage module 2 and the battery pack 5 do not have tabs. Therefore, in the laminated power storage module 2, the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 are all welded at the parts of the heat-sealed parts 52a and 52b that are connected to the battery element chamber 42, so that the adhesiveness is improved. Well, higher airtightness can be obtained than the battery element chamber 42 from which the tab is drawn, and the risk of liquid leakage can be reduced. Furthermore, since tabs are not used, the heat-sealing operation is simple, and the weight and space of the battery pack 5 can be reduced.

The battery pack 5 achieves high capacity by connecting a plurality of laminated power storage modules 2 , but generates a large amount of heat due to the presence of a plurality of battery elements 60 . In the battery pack 5 , the heat generated by the battery elements 60 is released into the space 70 , and the gas flowing into the space 70 is used to promote heat dissipation for cooling. The space 70 is a heat dissipation space formed by stacking the laminated power storage modules 2. The heat dissipation performance can be exhibited without using a heat dissipation member such as a corrugated member, and the battery pack can be obtained without increasing the size of the battery pack. cooling effect. Cooling by using such a space 70 is particularly effective in a structure in which a plurality of laminated power storage modules 2 are stacked, which cannot be obtained with a single module. Also, if the battery capacity of the entire module is the same, compared to a module having one battery element and one battery element chamber enclosing the battery element, there are multiple battery elements and multiple battery element chambers enclosing the battery element therein. The surface area of the component outer body is large, and the heat dissipation efficiency is high.

The cooling effect is enhanced by blowing forced air to the space 70, and can be further enhanced by blowing cold air. However, even without forced air supply, natural convection will also occur when the difference in heat generation produces a temperature difference in the battery pack 5 , so that a corresponding cooling effect can also be obtained.

The condition for forming a space in the battery pack is that the outer surface of the exterior body has protrusions by forming the battery element chamber by the embossed portion. However, the form of the embossed portion and the electrode element chamber is not limited to the embodiments shown in FIGS. 2A and 2B , as long as the embossed portion is formed on at least one of the first exterior material and the second exterior material constituting the exterior body. If so, the 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-sealed portion is of course set to a size that can ensure the airtightness of the battery element chamber, but in order to expand the space for heat dissipation, the size of the heat-sealed portion can be increased to a larger size size.

4 and 5 show examples of other embodiments of the embossed portion and the battery element chamber. In addition, in both figures, the illustration of 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 omitted, and the inner exposed portion of the first metal foil and the second metal foil are formed in the chamber facing the chamber. The exposed portion inside the foil and the encapsulation of the battery element 60 are the same as those of the above-mentioned laminated power storage module 2 .

The exterior body 80 of FIG. 4 has embossed parts 45 and 46 on both the first exterior material 10 and the second exterior material 20 , and these embossed parts 45 and 46 face each other to form one electrode element chamber 81 . The exterior body 82 of FIG. 5 is the same as the exterior body 80 described above, and has embossed parts 45 and 46 on both the first exterior material 10 and the second exterior material 20, and each embossed part 45 and 46 is directed toward the opposite member. The electrode element chambers 83a and 83b are formed by forming flat portions. Since the outer casings 80, 82 have the embossed parts 45, 46 on both surfaces in the thickness direction, when the modules including these outer casings 80, 82 are stacked, spaces are formed on both surfaces of the module.

In addition, the arrangement of the space can be changed according to the lamination method of the laminated power storage modules.

In the battery pack 6 shown in FIG. 6 , the laminated power storage modules 2 are stacked in shifted positions every other layer, and the battery element chamber 42 of one module 2 is arranged. The center overlaps with the intersection of the heat-sealed portions 52a, 52b of the adjacent modules 2 in the stacking direction. The shift amount is 1/2 of the distance between the battery element chambers 42 . By shifting the positions of the laminated power storage modules 2 as described above, the battery element chambers 42 are arranged in a zigzag pattern in the stacking direction. In addition, due to the staggering of the laminated power storage modules 2, the positions of the connection holes 17, 27 of adjacent modules will be staggered, so the widths of the first flange 15 and the second flange 25 are changed to make the connection holes 17, 27 27 counterpoints. Therefore, strictly speaking, the shape of the laminated power storage module 2 shown in FIG. 6 is different from that of the laminated power storage module 2 shown in FIGS. 1A to 2B , but the same drawings are used for simplicity of explanation and illustration mark. Similar to the battery pack 5, in the battery pack 6, four laminated power storage modules 2 are connected in series by connecting pins 35, and the positive electrode pin 36 of the module mounted on the first layer is connected to the pin 36 mounted on the fourth layer. The negative electrode pin 37 of the assembly is used as an electrode terminal of the battery pack 6 .

With the above-mentioned stacked structure, the spaces 71 are also formed in a zigzag shape in the stacking direction, and the spaces 71 are formed directly above and directly below the battery element chambers 42 of the laminated power storage modules 2 of each layer. The size of the space 71 is the same as the space 70 of the above-mentioned battery pack 5, with respect to the electrode element chamber 42 of the battery pack 5, it is only adjacent to the space 70 in the direction perpendicular to the stacking direction, and the electrode element chamber of the battery pack 6 42 is adjacent to the space 71 in both the stacking direction and the direction perpendicular to the stacking direction. Therefore, the cooling efficiency can be improved by bringing the battery element chamber 42 into contact with the space 71 over a larger area.

In the battery pack 6 in which the electrode element chambers 42 and the spaces 71 are arranged in a staggered manner as described above, since they are arranged in a staggered manner, the size relationship between the electrode element chambers 42 and the heat-sealed portions 52a, 52b is not affected. limit. When the electrode element chamber 42 and the heat-sealed portions 52 a and 52 b 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-sealed portions 52a and 52b, parts of the electrode element chamber 42 overlap in the stacking direction, but a space is formed. Conversely, when the electrode element chamber 42 is smaller than the heat seal portions 52a, 52b, the heat seal portions 52a, 52b partially overlap in the stacking direction, but the electrode element chamber 42 of the lower layer supports the heat seal portions 52a, 52b of the upper layer, so This does not cause the electrode element chamber 42 of the upper layer to enter the space and fill the space. In any case, a space corresponding to the size of the heat-sealed portions 52a, 52b can be formed.

In addition, as another means for enhancing the cooling effect, there is a method of providing a heat conductor 75 between the laminated power storage modules 2 . In the battery pack 6 in FIG. 6 , a metal plate is sandwiched as a heat conductor 75 to dissipate heat from the metal plate to improve the cooling effect. The material of the heat conductor 75 is preferably aluminum or copper with high thermal conductivity, and a cooling device can also be connected to the heat conductor 75 to improve the cooling effect.

Other Embodiments of Laminated Electric Storage Module and Battery Pack

The laminated power storage module constituting the battery pack is conditioned to have a metal foil outer exposed portion on the outer surface of the exterior body, but the formation position is not limited. The outer metal exposed part is a part that achieves the conduction between the components and the battery pack and the outside, and these conduction can also be realized at the outer metal foil exposed part provided outside the flange.

The same points between the laminated power storage modules 2a, 2b, 2c, and 2d constituting the battery pack 7 having a four-layer structure shown in FIGS. 7A to 7C and the laminated power storage module 2 constituting the battery pack 6 are: In the battery element chamber 42, the positive electrode 61 of the battery element 60 is connected to the exposed part 14 inside the first metal foil, and the negative electrode 63 is connected to the exposed part 24 inside the second metal foil. The formation position of the metal foil outer exposed portion that exposes the metal foil on the outer surface of the metal foil is also different. In addition, the four laminated power storage modules 2a, 2b, 2c, and 2d are stacked so that the battery element chambers 42 and the spaces 71 are arranged in a zigzag pattern in the stacking direction, similarly to the battery pack 6 .

In the laminated power storage module 2 a of the first uppermost layer, the first metal foil outer exposed portion 16 is formed on the first flange 15 . Furthermore, 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, on the bottom surface of the battery element chamber 42 . In the second metal foil outer exposed portion 28 , the second metal foil 21 is exposed by removing the second heat-resistant resin layer 22 of the second exterior member 20 .

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

In the laminated power storage module 2d of the fourth lowest layer, as shown in FIG. 7C , the first metal foil outer exposed portion 18 is formed on the surface opposite to the first metal foil inner exposed portion 14, that is, the battery element chamber. 42 on top. In the first metal foil outer exposed portion 18 , the first heat-resistant resin layer 12 of the first exterior material 10 is removed to expose the first metal foil 11 . In addition, the second metal foil outer exposed portion 26 is formed on the second flange 25 .

In the above-mentioned battery pack 7, the four laminated power storage modules 2a, 2b, 2c, and 2d of the above-mentioned three types are laminated with a heat conductor 75 made of a conductive material interposed therebetween, and sandwiched by jigs (not shown). Holding this laminated body, the heat conductor 75 is brought into close contact with the laminated type electricity storage modules 2a, 2b, and 2c to be assembled. 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 conductor 75 . The heat conductor 75 is an electric conductor, and therefore, the battery elements 60 of each layer are connected in series via the first metal foil 10 and the second metal foil 20 . In addition, the power supply to external equipment utilizes the first metal foil outer exposed portion 16 of the first flange 15 of the uppermost laminated module 2a and the second flange of the lowermost laminated power storage module 2c. The second metal foil outer exposed portion 26 of 25 is realized, and the pin 36 for the positive electrode and the pin 37 for the negative electrode are attached to them.

As described above, by providing the metal foil externally exposed portion at the contact portion of the stacked laminated electricity storage modules, the connection of the laminated electricity storage modules can be realized without using a connecting member. In addition, the battery pack 7 includes a heat conductor 75 for the purpose of improving the cooling effect, and the heat conductor 75 is used as a conductive part, but the heat conductor 75 may not be sandwiched and the exposed parts of the metal foils may directly contact And get conduction.

Materials and Forming of the First Exterior Part and the Second Exterior Part

In the first exterior member 10, the first heat-resistant resin layer 12 is adhered to one surface of the first metal foil 11 via a first adhesive layer, and the first thermoplastic resin layer is adhered to the other surface via a second adhesive layer. Resin layer 13. 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, 18 are formed by removing the first thermoplastic resin layer 13 corresponding to the surface to be formed. and the second adhesive layer or by removing the first heat-resistant resin layer 12 and the first adhesive. Moreover, when forming the embossed part 45 by press forming, after forming a metal exposure part, press forming is performed.

In the second exterior member 20, the second heat-resistant resin layer 22 is adhered to one surface of the second metal foil 21 via a third adhesive layer, and the second thermoplastic resin layer is adhered to the other surface via a fourth adhesive layer. resin layer 23 . Same as the first exterior member 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 is formed by corresponding to the The formed surface is formed by removing the second thermoplastic resin layer 23 and the fourth adhesive layer, or removing the second heat-resistant resin layer 22 and the third adhesive layer.

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

The preferred material of the first metal foil 11 is soft aluminum foil, and the thickness is preferably 20 μm˜150 μm. From the viewpoint of formability and cost, a soft aluminum foil of 30 μm to 80 μm is particularly preferable. On the other hand, the preferred material of the second metal foil 21 is soft or hard aluminum foil, stainless steel foil, nickel foil, copper foil, titanium foil. The preferred thickness of these foils is 10 μm to 150 μm, and from the viewpoint of impact resistance, bending resistance, and cost, it is preferably 15 μm to 100 μm.

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

In addition, it is preferable to form a chemical conversion coating on at least the side where the metal foil exposed portions 14 , 16 , 24 , and 26 are present on the first metal foil layer 11 and the second metal foil layer 21 . The chemical conversion coating is a coating formed by performing a chemical conversion treatment on the surface of the metal foil. By performing such a chemical conversion treatment, the corrosion of the metal foil surface by the contents (electrolyte, etc.) can be sufficiently prevented. The exposed part of the window is taken out, and the electrolyte is attached when the module is manufactured, so there will be no discoloration or deterioration, and the influence of corrosion such as moisture in the atmosphere can be reduced. The chemical conversion treatment layer itself basically has no conductivity, the thickness of the coating film is extremely small, and basically has no conduction resistance. For example, the chemical conversion treatment is given to the metal foil by performing the following treatment. That is, on the surface of the metal foil that has been degreased, apply any one of the aqueous solutions in the following 1) to 3) to the surface of the metal foil, dry it, and implement chemical conversion treatment

1) an aqueous solution comprising phosphoric acid, chromic acid, and a mixture of at least one compound selected from the group consisting of metal salts of fluorides and non-metallic salts of fluorides;

2) Contains phosphoric acid, at least one resin selected from the group consisting of acrylic resins, chitosan derivative resins, and phenolic resins, and at least one resin selected from the group consisting of chromic acid and chromium (III) salts. an aqueous solution of a mixture of compounds;

3) Contains phosphoric acid, at least one resin selected from the group consisting of acrylic resins, chitosan derivative resins, and phenolic resins, and at least one resin selected from the group consisting of chromic acid and chromium (III) salts. Aqueous solution of a mixture of a compound and at least one compound selected from the group consisting of metal salts of fluorides and non-metallic salts of fluorides

The chemical conversion coating preferably has a chromium adhesion amount (per one surface) 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 when heat-sealing the exterior 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. Heat-resistant resin with a temperature higher than 20°C. For example, stretched films such as polyethylene naphthalate films, polybutylene naphthalate films, and polycarbonate films are preferable besides polyester films and polyamide films. In addition, the thickness is preferably in the range of 9 μm to 50 μm.

The first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 are preferably formed of at least one thermoplastic resin selected from polyethylene, polypropylene, olefin-based copolymers, their acid-modified products, and ionomers. The thickness of the unstretched film is preferably in the range of 20 μm to 80 μm.

The first adhesive layer and the third adhesive layer are preferably two-liquid curing type polyester polyurethane or polyether polyurethane adhesives, and the second adhesive layer and the fourth adhesive layer take electrolyte resistance into consideration. On the other hand, polyolefin-based adhesives are preferable. The preferable coating 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 part 10 and the second exterior part 20 is not limited in any way. For example, in the process of bonding a metal foil and a resin layer using dry lamination, an adhesive is applied using a gravure roll in which the portion where the adhesive is not attached is engraved to form an adhesive-uncoated After bonding the metal foil and the resin layer, the resin layer above the adhesive-uncoated portion is cut off to expose the metal foil. The first exterior material 10 and the second exterior material 20 used in the laminated power storage module 2 of the above-mentioned embodiment have the metal foil exposed parts 14, 16, 24, 26 on the thermoplastic resin layer side, and the above-mentioned The first metal foil 11 and the first thermoplastic resin layer 13 , and the second metal foil 21 and the second thermoplastic resin layer 23 are bonded by hand, and after bonding, the metal foil exposed portions 14 , 16 , 24 , and 26 are formed. On the other hand, since there is no exposed metal portion on the side of the heat-resistant resin layer, the first metal foil 11, the first heat-resistant resin layer 12, and the second metal foil 21 can be bonded in a known manner. and the second heat-resistant resin layer 22 .

In addition, when the metal foil outer exposed portion is formed on the surface of the first exterior material 10 on the side of the first heat-resistant resin layer 12 and/or on the surface of the second exterior material 20 on the side of the second heat-resistant resin layer 22 , after bonding 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 by the above-mentioned method, the resin layer is removed.

Moreover, as shown in FIG. 1A etc., when press-forming the 1st exterior material 10 and forming the embossed part 45, press-forming is performed after forming a metal exposure part. In the molding of the first exterior member 10 of the illustrated example, press molding is performed by using a molding die consisting of a male die, a female die, and a pressing die, wherein the male die allows the inner exposed portion 14 of the first metal foil to contact the top surface, and the female die For male mold insertion. In the case of forming the embossed portion on the second exterior material 20, press molding is also performed in the same manner.

In addition, the first exterior member 10 is cut to such a size that the two sides without the first flange protrude a little from the second exterior member 20, and if the protruding part is heat-sealed and then bent, it is possible to prevent the second A metal foil 11 and a second metal foil 21 are in contact at the cut end faces. Alternatively, the dimensions of the first exterior material 10 and the second exterior material 20 may be reversed, and the second exterior material 20 may be bent.

Construction and materials of battery elements

Single cells are used as battery elements 60 in the laminated power storage modules 2 , 2 a , 2 b , 2 c , and 2 d. Details of the single cell and the electrolyte enclosed with the single cell are as follows.

(single battery)

A single battery as a battery element 60 is composed of a positive electrode 61 , a separator 62 , and a negative electrode 63 . Embodiments of the battery cell are not limited to the rolled-back type of FIG. 3 . As another embodiment of a single battery, a stacked type can be exemplified, that is, a positive electrode and a negative electrode are cut into the size of a battery cell, and a separator sheet is combined for each foil to form a stack, and a plurality of them are alternately stacked, and the positive electrode is bonded by ultrasonic waves. between the current collectors of the negative electrode and between the current collectors of the negative electrode.

The positive electrode 61 is preferably composed of a current collector and a positive electrode active material, and metal foil is generally used for the current collector. The metal foil is preferably hard or soft aluminum foil with a thickness of 7 μm to 50 μm, 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, and it is composed of, for example, PVDF (polyvinylidene fluoride), SBR (styrene butadiene rubber), CMC (sodium carboxymethyl cellulose, etc.), PAN (polyacrylonitrile ), linear polysaccharides and other binders with lithium salts (for example, lithium cobaltate, lithium nickelate, lithium iron phosphate, lithium manganate, etc.) 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 conductive auxiliary agents such as carbon black and 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 improve adhesion. The binder is not particularly limited, and examples thereof include layers made of PVDF, SBR, CMC, PAN, linear polysaccharides, and the like. In the binder layer, in order to improve the conductivity between the current collector and the positive electrode active material layer, a conductive auxiliary agent such as carbon black or CNT (carbon nanotube) may be further added. The thickness of the adhesive layer is preferably set to 0.2 μm to 10 μm. By setting the adhesive layer to be 10 μm or less, it is possible to suppress as much as possible an increase in the internal resistance of a unit cell formed of a non-conductive adhesive.

The negative electrode 63 is preferably composed of a current collector and a negative electrode active material, and metal foil is generally used for the current collector. As the metal foil, copper foil having a thickness of 7 μm to 50 μm is preferably used, and aluminum foil, titanium foil, and stainless steel foil can also be used. In addition, similarly to the positive electrode, it is preferable that no active material is in contact with the metal exposed portion 24 . The composition of the negative electrode active material layer is not particularly limited, for example, by adding additives (for example, graphite, lithium titanate, Si-based Alloys, tin-based alloys, etc.) mixed compositions, 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 conductive auxiliary agents such as carbon black and 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 improve the adhesion. The binder is not particularly limited, and examples thereof include layers made of PVDF, SBR, CMC, and PAN. In the binder layer, in order to improve the conductivity between the current collector and the negative electrode active material layer, a conductive auxiliary agent such as carbon black or CNT may be further added. The thickness of the adhesive layer is preferably set to 0.2 μm to 10 μm. By making the adhesive layer have a thickness of 10 μm or less, it is possible to suppress as much as possible an increase in the internal resistance of a unit cell formed of a non-conductive adhesive.

In the case where 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 applied 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 .

The separator 62 is not particularly limited, and examples thereof include a separator made of polyethylene, a separator made of polypropylene, a separator made of a laminated film formed of a polyethylene film and a polypropylene film, or a separator made of such a resin. Separator sheets made of wet or dry porous films coated with heat-resistant inorganic materials such as ceramics on the sheet, etc. The thickness of the separator 62 is preferably set to 5 μm to 50 μm.

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

The current collector of the positive electrode 61 and the current collector of the negative electrode 63 are preferably hard aluminum foils with 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 with a thickness of 5 μm to 100 μm, a nonwoven fabric with a thickness of 5 μm to 100 μm, or the like.

(electrolyte)

In addition, the electrolyte enclosed with the battery element is not particularly limited, and examples include electrolytes selected from water, ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and dimethoxy At least one of ethane as the solvent and lithium salt as the electrolyte. 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 and the like. In addition, as the above-mentioned electrolyte, one gelled with PVDF, PEO (polyethylene oxide), or the like can be used.

Laminated electric storage module and method of manufacturing battery pack

The laminated power storage modules 2, 2a, 2b, 2c, and 2d can be manufactured by the following steps.

(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 formed at desired positions. An exterior piece 10 . 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 at a desired position is manufactured.

(2) Place the first exterior member 10 in such a way that the first thermoplastic resin layer 13 goes up that the positive electrode 61 of the battery element 60 and the inner side of the first metal foil in each embossed portion 45 constituting the battery element chamber 42 are exposed. The battery element 60 is loaded in such a manner that the parts 14 are in contact with each other, and the electrolyte is injected using a syringe or the like.

(3) Align the second exterior member 20 and overlap them so that the second metal foil inner exposed portion 24 of the second exterior member 20 is in contact with the negative electrode 63 of the battery element 60, and assemble the exterior body 32, 33. In this assembled state, the first flange 15 protrudes from the end of the second exterior member 20, the second flange 25 protrudes from the end of the first exterior member 10, the first metal foil outer exposed portion 16 and the second The outer exposed portions 26 of the two metal foils are exposed on the outer surfaces of the outer casings 32 , 33 .

(4) The heat-sealed portion 52a is formed using a heated hot plate.

(6) Connect the electric 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 pre-charge it, and put it into a constant temperature bath at 100°C 8 hours and exhaust.

(7) Under a reduced pressure environment, the unsealed portion is heat-sealed with a heated hot plate to form the heat-sealed portion 52b, thereby sealing the battery element 60 and the electrolyte in the battery element chamber 42 .

(8) Holes 17 and 27 for connection 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-mentioned production method is merely an example, and in particular such a production method should not be limited.

A desired number of manufactured laminated power storage modules 2, 2a, 2b, 2c, 2d are stacked, or a desired number of manufactured laminated power storage modules 2, 2, 2a, 2b, 2c, and 2d are stacked, and the above-mentioned method is used to connect adjacent modules in the stacking direction to assemble a battery pack. The number of laminations in the battery pack of the present invention is arbitrary.

The use of the battery pack of the present utility model is not limited, and can be used for power sources such as automobiles, bicycles, motorcycles, trains, airplanes, ships, etc., which need electricity. Specifically, it can be used for hybrid vehicles, electric vehicles, industrial-household batteries Large-capacity lithium secondary battery (lithium-ion battery, lithium polymer battery, etc.) components, solid-state battery components, lithium-ion capacitor components for the same purpose, and electric double-layer capacitor components for the same purpose.

Example

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

(Example 1)

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

The first metal foil 11 is a soft aluminum foil having a thickness of 40 μm and A8079 classified in accordance with JIS H4160, and chemical conversion treatment was performed on both surfaces. The first heat-resistant resin layer 12 is a biaxially stretched polyamide film with 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 soft SUS304 stainless steel foil with a thickness of 20 μm, and chemical conversion treatment was performed on both surfaces. The second heat-resistant resin layer 22 is a biaxially stretched polyester film with a thickness of 12 μm. The second thermoplastic resin layer 23 is an unstretched polypropylene film having 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 30mm×30mm, and the dimensions of the first metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26 are 20mm×200mm.

(first exterior part)

On one side of the first metal foil 11, the first heat-resistant resin layer 12 is bonded with a two-component curing type polyester polyurethane adhesive with a coating thickness of 3 μm by dry lamination, and aged at 50 ° C. Furnace aging for 3 days. Next, on the reverse side of the first metal foil 11, a two-component curing type olefin-based adhesive is applied by dry lamination so that when the coating thickness is 2 μm, nine first metal foils are formed. The first thermoplastic resin layer 13 is bonded to the metal foil inner exposed portion 14 and the adhesive unapplied portion corresponding in size and position to one first metal foil outer exposed portion 16 . After bonding, it was aged for 3 days in an aging oven at 40°C.

After curing, use a laser cutter to cut off the first thermoplastic resin layer 13 on the uncoated portion of the adhesive to form the first metal foil inner exposed portion 14 and the first metal foil exposed portion 11 for the first metal foil 11 to expose. The outer exposed portion 16 of the metal foil.

Next, use a 40mm square forming mold consisting of a male mold, a female mold, and a pressing mold, so that the top surface of the male mold is in contact with the first metal foil inner exposed portion 14, and press molding with a pressing depth of 4mm is carried out. An embossed portion constituting the battery element chamber 42 is formed. Then, the first exterior material 10 is obtained by trimming around. The planar size of the first exterior material 10 is 140 mm×160 mm.

(Second Exterior)

On one side of the second metal foil 21, the second heat-resistant resin layer 22 is adhered to the second heat-resistant resin layer 22 with a two-component curing type polyester polyurethane adhesive with a coating thickness of 3 μm by dry lamination, and aged at 50° C. Furnace aging for 3 days. Next, on the reverse side of the second metal foil 21, a two-component curing type olefin-based adhesive is applied by dry lamination so that when the coating thickness is 2 μm, nine second metal foils are formed. The second thermoplastic resin layer 23 is bonded to the inner exposed portion 24 and the adhesive uncoated portion corresponding in size and position to the one second metal foil outer exposed portion 26 . After bonding, it was aged for 3 days in an aging oven at 40°C.

After curing, use a laser cutter to cut off and remove the second thermoplastic resin layer 23 on the uncoated portion of the adhesive to form the second metal foil inner exposed portion 24 and the second metal foil exposed portion 21 for the second metal foil 21. Metal foil outer exposed portion 26 . Then, trim the four sides to obtain the second exterior material 20 . The planar size of the second exterior material 20 is 150 mm×160 mm, which is larger than that of the first exterior material 10 .

(electrode components)

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

The current collector of the positive electrode 61 is a hard aluminum foil of A1100 classified according to JIS H4160, having 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, with a thickness of 15 μm and a width of 200 mm. The paste for forming the positive electrode active material layer is obtained by kneading 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, and 5 parts by mass of acetylene black (conductive material). 25 parts by mass of N-methyl-2-pyrrolidone (organic solvent) and disperse the obtained paste. The paste for forming the negative electrode active material is obtained by kneading 57 parts by mass of the negative electrode active material mainly composed of carbon powder, 5 parts by mass of PVDF as a binder and electrolyte retaining agent, and a copolymer of hexafluoropropylene and maleic anhydride. 10 parts by mass, 3 parts by mass of acetylene black (conductive material), and 25 parts by mass of N-methyl-2-pyrrolidone (organic solvent) were dispersed in the obtained paste. The binder liquid is 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 lithium hexafluorophosphate dissolved at a concentration of 1 mole/liter in a mixed solvent obtained by mixing ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in an equal volume ratio. (LiPF6) the resulting solution.

The positive electrode 61 is manufactured through the following steps. 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 with a thickness of 0.5 μm after drying. Next, apply a positive electrode active material layer liquid paste on the surface of the adhesive layer, dry it at 100°C for 30 minutes, and then perform hot pressing to form a density of 4.8g/cm ³ and a thickness after drying. A positive electrode active material layer of 120 μm. Then, this was cut into a coil shape with a width of 35 mm through a width-imparting step.

The negative electrode 63 is produced through the following steps. First, a binder liquid was applied to one 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, apply a negative electrode active material layer liquid paste on the surface of the adhesive layer, dry it at 100° C. for 30 minutes, and then perform hot pressing to form a density of 1.5 g/cm ³ and a thickness after drying. The negative electrode active material layer is 20.1 μm. Then, this was cut into a coil shape with a width of 35 mm through a width-imparting step.

Next, in the order of negative electrode 63 (current collector-negative electrode active material layer)/separator 62/(positive electrode active material layer-current collector) positive electrode 61/separator, they are stacked in a manner that gradually shifts a little from each other, Winding was performed, and crushing was performed so that the positive electrode 61 was exposed on one side and the negative electrode 63 was exposed on the reverse side, to produce a 38 mm square single cell with a thickness of 4 mm.

(Assembly of laminated power storage modules and battery packs)

(1) Place the first exterior member 10 with the first thermoplastic resin layer 13 going up so that the positive electrode 61 of the battery element 60 is in contact with the inside of the first metal foil in each embossed portion 45 for forming the battery element chamber 42. In such a manner that the exposed portion 14 is in contact, the battery element 60 is loaded, and the electrolyte is injected using a syringe or the like.

(2) The outer case 32 is assembled by aligning and overlapping the second outer case 20 so that the second metal foil inner exposed portion 24 of the second outer case 20 contacts the negative electrode 63 of the battery element 60 . In this assembled state, the first flange 15 protrudes from the end of the second outer covering part 20, and the second flange 25 protrudes from the end of the first outer covering part 10, the first metal foil outer exposure 16 and the second outer covering part 10 are exposed. The outer exposed portions 26 of the two metal foils are exposed on the outer surface of the exterior body 32 .

(3) Using a hot plate heated to about 200° C., heat-seal for 3 seconds at a pressure of 0.3 MPa to form the heat-sealed portion 52 a. The width of the heat-sealed part 52a between the embossed parts 45 was 5 mm.

(4) Connect an electric 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, charge until a battery voltage of 4.2V is generated, and put it in 100°C 8 hours, do the exhaust in the battery element chamber 42.

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

(6) As a countermeasure against short circuit, the end edge of the first exterior material 10 on the side of the second flange 25 and the end edge of the second exterior material 20 on the side of the first flange 15 are pasted with a 25 μm adhesive tape to cover the end faces. The exposed first metal foil 11 and second metal foil 21 . In addition, on the other two sides, the protruding second exterior material 20 is bent toward the first exterior material 10 side to form a countermeasure against insulation and strengthen the strength of the side surface. In addition, FIG. 2A shows the state before bending.

(7) Three connection holes 17 , 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 .

Through the above steps, four laminated power storage modules 2 were fabricated.

(8) With reference to Fig. 2A and Fig. 2B, with the mode that the first flange 15 and the second flange 25 of the adjacent assembly in stacking direction coincide, change the direction of 4 laminated assemblies 2, make They are different from each other and stack them.

(9) Use the connecting pin 35 to connect four laminated modules 2 in series, install the positive electrode pin 36 on the first metal foil outer exposed portion 16 of the uppermost layer, and install the positive electrode pin 36 on the second metal foil outer exposed portion of the lowermost layer. 26 is installed with pin 37 for negative pole. The battery pack 5 is fabricated through the above steps.

The battery pack 5 forms a quadrilateral space 70 with a cross-section of (the width of the heat-sealed portion 52a 5mm)×(the height of the embossed portion 4mm) on the heat-sealed portion 52a, and forms a cross-sectional space 70 on the heat-sealed portion 52b of ( The quadrilateral space of the width|variety 5mm of the heat-seal part 52b) x (height 4mm of an embossing part).

(comparative example 1)

Comparative Example 1 is a battery pack in which four laminated power storage modules different in structure from Example 1 were laminated.

In addition, in the laminated power storage module 2 of Example 1, the nine battery elements 60 are respectively enclosed in each battery element chamber 42, and metal foil exposed parts are formed on the inner surface and the outer surface of the exterior body, so that it can be assembled without using tabs. Conduction with the battery element 60 is realized. Compared with this laminated power storage module 2, in the laminated module of Comparative Example 1, one battery element is enclosed in one battery element chamber, and the capacity equal to that of the nine battery elements of Example 1 is increased. The size of the battery element is increased. In addition, in the laminated module of Comparative Example 1, the exterior body has no metal foil exposed parts on the inside and outside, and the tab is connected to the battery element and the tab is drawn out of the exterior body.

(external body)

Among the exterior parts, corresponding to the first exterior part 10 of Example 1, there is a part of the embossed part constituting the battery element chamber, and corresponding to the second exterior part 20 of Example 1, there is a portion to block the embossed part. The flat portion of the opening is integral. The exterior body is formed by folding the exterior member into double layers. The material constituting the exterior part is a soft aluminum foil with a thickness of 40 μm (soft aluminum foil A8021 classified according to JIS H4160) if it is a metal foil, and a biaxially drawn aluminum foil with a thickness of 25 μm if it is a heat-resistant resin layer. Stretched polyamide film, if it is a thermoplastic resin layer, it is a polypropylene film with a thickness of 40 μm.

The outer cover is produced by bonding a heat-resistant resin layer to the entire one surface of the metal foil with a polyester-urethane-based adhesive having a coating amount of 3 g/m ² , and bonding the heat-resistant resin layer to the other surface of the metal foil. The entire thermoplastic resin layer was bonded with a polyolefin-based adhesive having a coating amount of 2 g/m ² , followed by aging in a constant temperature bath at 40° C. 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.

The exterior material was subjected to press molding to form an embossed part of 115 mm x 115 mm x 4 mm in height, and trimmed to estimate the dimensions of the flat part and the part to be heat-sealed.

(battery elements and tabs)

The battery element was fabricated using the same material as in Example 1 to form a quadrilateral with a side length of 110 mm.

The production method of the positive electrode tab is to expose 5 mm on one end side of the length direction of a soft aluminum foil (A1050 soft aluminum foil classified according to JIS H4000) with a length of 30 mm, a width of 3 mm, and a thickness of 100 μm. An insulating film formed of a maleic anhydride-modified polypropylene film (melting point 140° C., MFR 3.0 g/10 minutes) with a length of 10 mm, a width of 5 mm, and a thickness of 50 μm was heat-sealed on both sides of the aluminum foil.

Negative pole lugs are made in such a way that the nickel foil with a length of 40 mm, a width of 3 mm, and a thickness of 100 μm is exposed to 5 mm at one end side in the longitudinal direction, and the nickel foil is heat-sealed on both sides of the nickel foil with a length of An insulating film formed of a maleic anhydride-modified polypropylene film (melting point: 140° C., MFR: 3.0 g/10 minutes) having a width of 10 mm, a width of 5 mm, and a thickness of 50 μm.

The positive pole of the battery element is joined to the end of the positive pole tab and the negative pole is joined to the negative pole, and the tops of the positive pole tab and the negative pole tab are drawn from the same side of the battery element.

(Assembly of laminated power storage modules and battery packs)

(1) The exterior part is marked with a ruler or the like to mark the bending position in advance.

(2) Load the battery element into the embossed part of the outer case, align the tabs with the insulating film placed on the part to be heat-sealed, and bend the outer part at the position where the mark is formed to make it flat. Partially covering the embossed part.

(3) With regard to two sides including the side from which the tabs are drawn, heat-sealing is performed for 3 seconds by sandwiching them with a pressure of 0.3 MPa using a hot plate heated to 200°C.

(4) Using a syringe, inject 45 mL of the same electrolyte as in Example 1 into the unsealed side, and perform pre-charging and exhaust in the same manner as in Example 1.

(5) Under the discharge state of 3.0V, and under the decompression condition of 0.086MPa, using a hot plate heated to 200°C, with a pressure of 0.3MPa, heat seal the unsealed side for 3 seconds, thereby A battery element and an electrolyte are enclosed in the battery element chamber.

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

(6) Four laminated modules are stacked and connected in series to assemble a battery pack.

evaluate

The battery packs of Example 1 and Comparative Example 1 treated as above were evaluated based on the following evaluation methods. The evaluation results are shown in Table 1.

After fully charging the battery pack to 16.8V, repeat 100 times of 1C charge and discharge (1 hour charge, 1 hour discharge) at room temperature of 18°C, and measure the voltage and capacity when fully charged again. In addition, when a fully charged battery is discharged at 1C, the temperature at the time of discharging at 0.2C is measured with a temperature sensor, and the average value is calculated. The temperature measurement position is in 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 x 3 columns, and Comparative Example 1 is the embossed part. of the central part.

【Table 1】

As shown in Table 1, there was no difference in battery capacity between Example 1 and Comparative Example 1, and the result was the same even when 100 cycles of charging and discharging were repeated. In addition, it was confirmed that, compared with Comparative Example 1, the battery pack of Example 1 can suppress the heat generation during discharge regardless of whether it is 1C discharge or 0.2C discharge, and the heat dissipation effect is good.

This application claims the priority of Japanese Patent Application No. 2015-83102 filed on April 15, 2015, and the content described therein directly constitutes a part of the content of this application.

It must be recognized that the words and expressions used in this article are for illustration and cannot be used as a limiting interpretation. Any equivalents of the technical features suggested and described in this article are not excluded. Various modifications can be made within the scope of protection of the technical solutions described in the claims of the utility model.

Industrial availability

The laminated power storage assembly of the utility model can be well used as various power sources.

Claims (6)

1. A battery pack, characterized in that, The laminated power storage module includes: a first exterior material in which a first heat-resistant resin layer is laminated on one surface of a first metal foil; a first thermoplastic resin layer is laminated on the other surface; A surface on the side of the thermoplastic resin layer has an exposed portion inside the first metal foil that exposes the first metal foil; The other side is laminated with a second thermoplastic resin layer, and has a second metal foil inner exposed portion exposing the second metal foil on the side of the second thermoplastic resin layer; a battery element having a positive electrode, a negative electrode, and a configuration the separator between the two, At least one of the first exterior member and the second exterior member has an embossed portion in a region including the first metal foil inner exposed portion and the second metal foil inner exposed portion, so that the first outer covering member The thermoplastic resin layer faces the second thermoplastic resin layer of the second exterior member, and is surrounded by a heat-sealed portion obtained by fusing the first thermoplastic resin layer and the second thermoplastic resin layer, thereby forming an exterior body having a plurality of battery element chambers , the battery element chamber is formed as a convex portion by the embossed portion, the first metal foil inner exposed portion and the second metal foil inner exposed portion face each other in the chamber, and the outer surface of the outer casing is formed such that the first a first metal foil outer exposed portion exposing the metal foil and a second metal foil outer exposed portion exposing the second metal foil, The battery element sealed into the battery element chamber together with the electrolyte, its positive electrode is connected to the inner exposed part of the first metal foil, and its negative electrode is connected to the inner exposed part of the second metal foil. A plurality of the above-mentioned laminated power storage modules are stacked so as to form a space above the heat-sealed part, and the laminated power storage modules adjacent in the stacking direction are separated by the outer exposed part of the first metal foil and the second metal foil. The outer exposed part is connected. 2. The battery pack according to claim 1, wherein: A plurality of laminated power storage modules are stacked so that the cell chamber and the heat-sealed portion overlap in the stacking direction of the laminated power storage modules. 3. The battery pack according to claim 1 or 2, wherein: In the stacking direction, heat conductors are arranged between adjacent laminated power storage modules. 4. The battery pack according to claim 1 or 2, wherein, The space is a cooling gas flow path. 5. The battery pack according to claim 1, wherein: The space and the battery element chamber are adjacent only in a direction perpendicular to the lamination direction of the laminated electricity storage modules. 6. The battery pack according to claim 2, wherein: The space is adjacent to the battery element chamber in both the stacking direction and the direction perpendicular to the stacking direction of the laminated power storage module.