TWI699925B - Battery - Google Patents

Abstract

The exterior body 32 of the laminated power storage module 2 has an embossed portion 45 on at least one of the opposing first exterior material 10 and the second exterior material 20, and the surroundings of the embossed portion 45 are heat-sealed There may be a plurality of electrode element chambers 42 that become convex portions. In the battery pack 5, a plurality of layers of the aforementioned modules 2 are laminated and connected, and a space 70 for heat dissipation is formed by the difference in thickness between the electrode element chamber 42 and the heat-sealed portions 52a and 52b. Furthermore, the battery element 60 in the aforementioned battery element chamber 42 is connected to the metal foil inner exposed portions 14 and 24, and the modules 2 are connected by the metal foil outer exposed portions 16, 26.

Description

Battery

The present invention relates to a battery pack with light weight, high heat release and space saving.

In addition, in the present invention, the meaning of "aluminum" includes Al and Al alloys, the meaning of "copper" includes Cu and Cu alloys, and the meaning of "nickel" includes Ni and Ni alloys, and the meaning of "titanium" Meaning, it includes Ti and Ti alloys. In addition, in the present invention, the meaning of "metal" includes single metals and alloys.

In recent years, lithium-ion storage batteries or lithium polymer storage batteries used in batteries for hybrid or electric vehicles, household or industrial stationary storage batteries have been miniaturized and lightened, and metal foils are laminated with resin films on both sides. The use of laminated exterior materials to replace traditional metal exterior materials is increasing. In addition, it is currently studying the use of laminated exterior materials such as electric double layer capacitors and lithium ion capacitors to be mounted on cars or buses.

For electric vehicles, etc., in order to enable devices that must have high energy to obtain high energy with a small volume, the power storage modules can be stacked and connected in-line as a response. However, during charging and discharging, the internal resistance of the modules tends to accumulate heat. The high temperature inside the module will not only promote battery degradation, affect performance, but also affect safety. Therefore, there have been proposals to store a heat-radiating element between the power storage modules to cool the modules (refer to the special Li literature 1, 2).

In the battery pack described in Patent Document 1, a corrugated material as a heat radiating element is placed between the storage modules to form a circulation space for cold air to obtain a heat radiating effect. In addition, in the battery pack described in Patent Document 2, a tube element for circulating cooling liquid is arranged between the storage modules, and a leaf spring is interposed between the tube element and the storage module to form a space for air cooling. A higher cooling effect is obtained by both liquid cooling and air cooling.

【Prior Technical Literature】 【Patent Literature】

[Patent Document 1] JP 2012-84551 A

[Patent Document 2] JP 2014-170697 A

However, the cooling methods described in Patent Documents 1 and 2 must have high-volume heat-radiating elements such as corrugated materials, tube elements, and leaf springs, and further must have a supply device for supplying cold air or cooling liquid. These cooling devices occupy a large part of the battery pack. space. Therefore, even if the miniaturization of the power storage module is to be achieved, it is difficult to miniaturize the battery pack. Furthermore, since the power storage module uses tabs to connect the electrodes, there is a possibility of heat generation from the connection position of the tabs or a decrease in the tightness of the sealing portion.

In view of the above technical background, the purpose of the present invention is to provide a battery pack that can have high heat release performance without being large-sized, and can greatly reduce the risk of liquid leakage.

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

[1] A battery pack characterized by being laminated by a plurality of laminated power storage modules, the laminated power storage module having a first exterior material, a second exterior material, and battery elements; An exterior material is an area layer on one side of the first metal foil with a first heat-resistant resin layer, an area layer on the other side with a first thermoplastic resin layer, and the surface on the side of the first thermoplastic resin layer has an exposed first The inner exposed part of the first metal foil of a metal foil; the aforementioned second exterior material is a second heat-resistant resin layer on one side of the second metal foil, and a second thermoplastic resin layer on the other side, The surface on the side of the second thermoplastic resin layer has an exposed portion inside the second metal foil exposing the second metal foil; the battery element has a positive electrode and a negative electrode, and a separator disposed between them; the first outer At least one of the packaging material and the second outer packaging material has an embossed portion in the area including the exposed part inside the first metal foil and the exposed part inside the second metal foil. The first heat of the first outer packaging material The plastic resin layer is opposed to the second thermoplastic resin layer of the second exterior material, and surrounds the heat-sealed portion of the first thermoplastic resin layer and the second thermoplastic resin layer after fusion, the exposed portion inside the first metal foil and the first The inner exposed parts of the two metal foils face the room, forming a plurality of battery element chamber exterior bodies having protrusions formed by the embossed parts, and the outer surface of the exterior body is formed with a first exposing the first metal foil The outside exposed part of the metal foil and the outside exposed part of the second metal foil where the second metal foil is exposed; The battery element enclosed in the battery element compartment together with the electrolyte has the positive electrode connected to the exposed part of the first metal foil and the negative electrode connected to the exposed part of the second metal foil; and the battery pack is composed of a plurality of the aforementioned laminated power storage modules. The heat-sealed portion is laminated under a state where a space is formed, and the laminated storage modules adjacent in the laminating direction are connected between the first metal foil outer exposed portion and the second metal foil outer exposed portion.

[2] The battery pack as described in the preceding paragraph 1, wherein the battery element chamber and the heat-sealed portion are overlapped in the stacking direction of the laminated power storage module to laminate a plurality of laminated power storage modules.

[3] The battery pack as described in item 1 or 2, wherein a heat transfer body is arranged between adjacent laminated storage modules in the stacking direction.

[4] The battery pack described in item 1 or 2, wherein the space is a cooling gas flow path.

[5] The battery pack described in the preceding paragraph 1, wherein the space and the battery element compartment are adjacent only in a direction orthogonal to the stacking direction of the laminated power storage module.

[6] The battery pack as described in the preceding paragraph 2, wherein the space is adjacent to the battery element compartment in two directions of the stacking direction of the laminated power storage module and the direction orthogonal to the stacking direction.

The battery pack described in the above [1], since the battery element compartment of the laminated power storage module is formed as a convex portion protruding from the outer side of the outer body, it can be heated by the lamination of plural modules. A space is formed on the sealing part. The heat generated by the battery elements dissipates heat to the aforementioned space, and further the heat dissipation can be promoted by the gas flowing in the aforementioned space, thereby cooling the battery pack. The aforementioned space is formed without the use of heat-radiating elements, so the battery pack does not need to be enlarged to obtain the cooling effect. this In addition, the surface area of the exterior body can be increased by having a plurality of battery element chambers, so that the heat dissipation efficiency of each module is excellent.

Furthermore, in each laminated power storage module, the plurality of battery elements are 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 of the battery element chamber, and the laminate The type storage modules are connected to each other by the first metal foil outer exposed part and the second metal foil outer exposed part. Furthermore, the connection between the battery pack and the external device is also performed through the first metal foil outer exposed part and the second metal foil outer exposed part. That is, the laminated power storage module and the battery pack do not have tabs. Therefore, the part of the heat-sealed part that contacts the battery element chamber is completely fused with the first thermoplastic resin layer and the second thermoplastic resin layer, thus sealing Very high performance, which can greatly reduce the risk of liquid leakage. Furthermore, since no tabs are used, the heat-sealing operation is simplified, and the battery pack can be reduced in weight and space.

In the battery pack described in [2] above, the battery element compartment is adjacent to the space in two directions, the stacking direction of the modules and the direction perpendicular to the stacking direction, so that the battery element compartment can have more area and space contact , So it can get extremely high cooling effect.

The battery pack described in [3] above is a heat transfer body that dissipates heat, so it can obtain extremely high cooling effects.

The battery pack described in [4] above promotes heat generation by flowing gas in the space.

In the battery pack described in [5] above, the heat generated in the battery element compartment radiates heat in a space adjacent to the direction orthogonal to the stacking direction of the aforementioned laminated power storage module.

In the battery pack described in [6] above, the space is adjacent to the battery element chamber in the stacking direction and the direction perpendicular to the stacking direction of the laminated power storage module, thereby promoting heat release.

2, 2a, 2b, 2c, 2d‧‧‧Laminated storage module

5, 6, 7‧‧‧Battery pack

10‧‧‧The first exterior material

11‧‧‧The first metal foil

12‧‧‧The first heat-resistant resin layer

13‧‧‧The first thermoplastic resin layer

14‧‧‧Inside exposed part of the first metal foil

15‧‧‧First flange

16, 18‧‧‧Exposed outside part of the first metal foil

20‧‧‧Second exterior material

21‧‧‧Second metal foil

22‧‧‧Second heat-resistant resin layer

23‧‧‧The second thermoplastic resin layer

24‧‧‧Second metal foil inside exposed part

25‧‧‧Second flange

26、28‧‧‧Exposed outside part of the second metal foil

32, 33, 80, 82‧‧‧Exterior body

42, 82, 83a, 83b‧‧‧Battery element room

45、46‧‧‧Embossed part

52a, 52b‧‧‧Heat seal

60‧‧‧Bare cell (battery element)

61‧‧‧Positive

62‧‧‧Partition

63‧‧‧Negative pole

70、71‧‧‧Space

75‧‧‧Heat transfer body

[Fig. 1A] A perspective view of one embodiment of the laminated power storage module constituting the battery pack of the present invention.

[Figure 1B] Sectional view of line 1B-1B in Figure 1A.

[Fig. 2A] An oblique view of an embodiment of the battery pack of the present invention.

[Figure 2B] The cross-sectional view of line 2B-2B in Figure 2A.

[Figure 3] Sectional view of bare cell.

[Figure 4] A cross-sectional view of another example of the shape of the electrode element chamber in the laminated power storage module.

[Figure 5] A cross-sectional view of another example of the shape of the electrode element chamber in the laminated power storage module.

[Figure 6] A cross-sectional view of another embodiment of the battery pack of the present invention.

[FIG. 7A] A cross-sectional view of another embodiment of the battery pack of the present invention.

[Figure 7B] Partial enlarged view of Figure 7A.

[Figure 7C] Partial enlarged view of Figure 7A.

FIGS. 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 aforementioned laminated power storage module.

In the following description, the same symbols denote the same ones, so repeated descriptions are omitted. In addition, in the first exterior material and the second exterior material constituting the exterior body, regardless of the exterior material and the formation position, the The exposed parts of the metal foil are collectively referred to as "metal foil exposed parts", the exposed parts facing the electrode element chamber are collectively referred to as "metal foil exposed parts", and the parts exposed on the outside of the exterior body are collectively called "metal foil exposed parts".

〔Laminated Power Storage Module〕

The exterior material 32 of the laminated 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 has 9 pieces arranged in 3 rows x 3 rows的 battery element room 42. The battery element 60 and electrolyte are enclosed in each battery element chamber 42 described above.

The aforementioned first exterior material 10 is a laminate of the area layer first heat-resistant resin layer 12 on one side of the first metal foil 11 and the first thermoplastic resin layer 13 on the other side. The flat material is stamped It is shaped to form nine embossed portions 45 that are square in plan view of the battery element chamber 42. On the other hand, the second exterior material 20 is a laminate of the area layer second heat-resistant resin layer 22 on one side of the second metal foil 21 and the second thermoplastic resin layer 23 on the other side. Plane material without embossing. The aforementioned exterior body 32 is formed by making 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 aligning the first thermoplastic resin layer around the embossed portion 45 The thermoplastic resin layer 13 and the second thermoplastic resin layer 23 are fused to form heat-sealed portions 52a and 52b, thereby forming a battery element chamber 42 in which the battery element 60 and the electrolyte are enclosed. The aforementioned battery element chamber 42 is formed as a convex portion protruding from the outer side of the outer body, and its height is only from the heat-sealed portion 52a, 52b to the embossed portion 45. The thickness of the module is thicker in the battery element chamber 42 , It becomes thinner at the heat-sealed parts 52a and 52b. In addition, the battery element chamber 42 is formed with a first metal foil inside exposed portion 14 where a part of the first thermoplastic resin layer 13 is removed to expose the first metal foil 11, and a part of the second thermoplastic resin layer 23 is removed to expose The second metal foil 21 is exposed Two exposed parts 24 inside the metal foil.

One side of the first exterior material 10 is extended from the heat-sealed portion 52a, and both sides become the outer surface of the exterior body 32 and become the first flange 15 to form the first metal foil outer exposed portion 16 exposing the first metal foil 11. On the other hand, the opposing sides of the first flange 15 are the two surfaces of the second exterior material 20 that extend from the heat-sealed portion 52a to become the exterior surfaces of the exterior body 32, and become the second flange 25, forming the exposed second The second metal foil outer exposed portion 26 of the metal foil 21. In addition, the first metal foil outer exposed portion 16 of the first flange 15 and the second metal foil outer metal foil exposed portion 26 of the second flange 25 are respectively provided with three connection holes 17 and 27.

The battery element 60 enclosed in the aforementioned battery element chamber 42 together with electrolyte, as shown in FIG. 3, is a stack of positive electrode 61, separator 62, negative electrode 63, and separator 6, and the laminate is formed into a roller-shaped winding type Bare battery. In the aforementioned 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 first metal foil inner exposed portion 14 of the first exterior material 10 to be electrically connected, and the negative electrode 63 is connected to the second metal foil of the second exterior material 20. The inside exposed portion 24 is in contact and electrically conductive. Since the aforementioned first metal foil 11 is exposed on the first metal foil outer exposed portion 16 on the outer surface of the outer body 32, and the second metal foil 21 is exposed on the second metal foil outer exposed portion 26 on the outer surface of the outer body 32, Therefore, the battery element 60 is electrically connected to the outside through the first metal foil 10 and the second metal foil 20. That is, the first metal foil 11 is used as the positive electrode side conduction portion, and the second metal foil 21 of the second exterior material 20 is used as the negative electrode side conduction portion.

〔Battery pack〕

The battery pack 5 shown in Fig. 2A and Fig. 2B is formed by connecting 4 laminated power storage modules 2. The four laminated power storage modules 2 are overlapped with the first flange 15 and the second flange 25 of the adjacent modules in the stacking direction to change to different directions, and the battery element compartment 42 of the adjacent modules is Layers of overlapping states. That is, four laminated power storage modules 2, the uppermost layer of the first layer of the second flange 25 of the second metal foil outer exposed portion 26 and the second layer of the first flange 15 of the module The outside exposed 16 of the first metal foil is connected to the connection holes 27 and 17 by the connecting pins 35 made of conductive material. Similarly, the outside exposed part 26 of the second metal foil of the second layer module is connected to the third layer The first metal foil outer exposed portion 16 of the module of the third layer is connected, and the second metal foil outer exposed portion 26 of the third layer module is connected with the first metal foil outer exposed portion 16 of the fourth layer of the lowest layer. In addition, the connection hole 17 of the first metal foil outer exposed portion 16 of the first layer module is attached with a positive electrode plug 36 made of a conductive material, and the fourth layer is connected to the second metal foil outer exposed portion 26 The hole 27 is attached with a negative pin 37 made of a conductive material. Through the above-mentioned connection, the four laminated power storage modules 2 are connected in series, and the positive electrode pins 36 and the negative electrode pins 37 serve as the electrode terminals of the battery pack 5, and the wires 38 can be pulled out to connect to other devices.

In the aforementioned laminated power storage module 2, since the thickness of the module is thicker in the battery element chamber 42 and thinner at the heat-sealed portions 52a, 52b, it is between adjacent laminated power storage modules 2 in the stacking direction There is a space 70. That is, the heat-sealed portions 52a and 52b around the battery element chamber 42 are formed with a space 70 having a quadrangular cross-section (width of the heat-sealed portions 52a and 52b) x (height of the embossed portion 45). Since the heat-sealed portions 52a and 52b must exist around the battery element chamber 42 described above, all the battery element chambers 42 are connected to the space 70 in a direction orthogonal to the stacking direction.

In each laminated power storage module 2, a plurality of battery elements 60 are passed through the first metal foil 11 and the second metal foil through the first metal foil inner exposed portion 14 and the second inner exposed portion 24 The second metal foil 21 is conductive, and the laminated power storage modules 2 are connected to each other by the first metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26. Furthermore, the connection between the battery pack 5 and the external device 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, the laminated power storage module 2 completely fuses the first thermoplastic resin layer 13 and the second thermoplastic resin layer 23 at the portions where the heat-sealed portions 52a and 52b contact the battery element chamber 42, so that the sealing performance is extremely high. Compared with the battery element chamber 42 where the tabs are pulled out, it can obtain higher airtightness and reduce the risk of liquid leakage. Furthermore, by not using tabs, the heat sealing operation can be simplified, and the weight and space of the battery pack 5 can be reduced.

Although the aforementioned battery pack 5 is connected to a plurality of laminated power storage modules 2 to increase the capacity, the large number of battery elements 60 also generates a large amount of heat. In the aforementioned battery pack 5, the heat generated by the battery element 60 is radiated to the aforementioned space 70, and further, by the gas flowing in the aforementioned space 70, the heat can be promoted and cooled. The aforementioned space 70 is a heat radiating space formed by the stacking of laminated power storage modules 2. It does not require the use of heat radiating elements such as corrugated materials to exhibit heat radiation performance, and the cooling effect can be obtained without increasing the size of the battery pack . The unique effect of the structure obtained by laminating a plurality of laminated power storage modules 2 of the cooling system using such a space 70 cannot be obtained by a single module. In addition, if the battery capacity of the entire module is the same, compared to a module with one battery element and one battery element compartment enclosed in it, a module with multiple battery elements and multiple battery element compartments enclosed in it , The surface area of the exterior body is larger, so it has a good heat release efficiency.

The cooling effect can be increased when forced air is sent to the aforementioned space 70, and can be further increased when cold air is blown. However, even if the air is not forced, the temperature in the battery pack 5 will be generated due to heat Poor, natural convection can occur, so the corresponding cooling effect can also be obtained.

The condition for forming a space in the battery pack is that the battery element compartment is formed by embossing and the outer surface of the exterior body has a convex portion. However, the embossed portion and the battery element chamber are not limited to the implementation shown in Figures 2A and 2B, as long as at least one of the first exterior material and the second exterior material constituting the exterior body is formed with pressure Convexes can be formed on the outer surface of the exterior body. In addition, although the distance between the battery element compartments, that is, the width of the heat-sealed part, is set to ensure the airtightness of the battery element compartment, it is natural that the size of the heat-sealed part can be set freely to increase the space for heat dissipation. Bigger.

4 and 5 show examples of other types of embossed parts and battery element chambers. In addition, in these figures, although the laminated structure of the first exterior material 10 and the second exterior material 20 and the internal structure of the battery element compartment are omitted from the drawings, they form the inside exposed portion of the first metal foil facing the room and the second The exposed portion inside the metal foil and the battery element 60 are also enclosed at the same time, which are the same as the laminated power storage module 2 described above.

The exterior body 80 of FIG. 4 has embossed portions 45, 46 on both the first exterior material 10 and the second exterior material 20. These embossed portions 45, 46 are opposed to each other to form one Electrode element chamber 81. The exterior body 82 of FIG. 5 is the same as the aforementioned exterior body 80. Both the first exterior material 10 and the second exterior material 20 have embossed portions 45 and 46, but the individual embossed portions 45, 46 is opposed to the flat part of the corresponding material to form battery element chambers 83a and 83b. Since the aforementioned exterior bodies 80 and 82 have embossed portions 45 and 46 on both sides in the thickness direction, modules with these exterior bodies 80 and 82 can form spaces on both sides of the modules when they are laminated.

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

In the battery pack 6 shown in FIG. 6, the aforementioned laminated power storage modules 2 are shifted to a position separated by one layer and stacked, and the center of the battery element chamber 42 of one module 2 is arranged to be adjacent to the module 2 in the stacking direction The intersections of the heat-sealed portions 52a and 52b overlap. The offset is 1/2 of the distance between the battery element compartments 42. By shifting the position of the laminated power storage module 2 in this way, the battery element chamber 42 can be arranged in a zigzag shape in the stacking direction. In addition, when the laminated power storage module 2 shifts, the positions of the connection holes 17 and 27 of adjacent modules will shift. Therefore, the width of the first flange 15 and the second flange 25 can be changed. The positions of connection holes 17, 27 are aligned. Therefore, the shape of the laminated power storage module 2 shown in FIG. 6 is strictly different from that of the laminated power storage module 2 shown in FIGS. 1A to 2B, but it is used for the sake of concise description and illustration. Same symbol. The aforementioned battery pack 6, which is the same as the aforementioned battery pack 5, consists of four laminated power storage modules 2 connected in series by connecting pins 35. The positive electrode pins 36 and the fourth layer attached to the first layer module The negative pin 37 attached to the module of the layer serves as the electrode terminal of the battery pack 6.

With the above-mentioned layered structure, the space 71 is also formed in a zigzag shape in the layering direction, and the space 71 is formed directly below and directly below the battery element chamber 42 of the laminated power storage module 2 of each layer. Although the aforementioned space 71 is the same size as the space 70 of the battery pack 5, the electrode element chamber 42 of the battery pack 5 is only adjacent to the space 70 in the direction perpendicular to the stacking direction. The electrode element chamber 42 of the battery pack 6 It is adjacent to the space 71 in both the stacking direction and the direction perpendicular to the stacking direction. In this way, the battery element chamber 42 will have more area in contact with the space 71, so that the cooling efficiency can be improved.

In the battery pack 6 in which the electrode element chamber 42 and the space 71 are arranged in a zigzag shape as described above, it is not necessary to restrict the size relationship between the electrode element chamber 42 and the heat seal portions 52a and 52b for the zigzag arrangement. The electrode element chamber 42 and the heat-sealed portions 52a, 52b are When the size is the same, a space of the same size as the electrode element chamber 42 will be formed. When the electrode element chamber 42 is larger than the heat seal portions 52a and 52b, a space that partially overlaps with the electrode element chamber 42 in the stacking direction is formed. Conversely, the electrode element chamber 42 is smaller than the heat-sealed portions 52a and 52b. Although the heat-sealed portions 52a and 52b partially overlap in the stacking direction, the electrode element chamber 42 in the lower layer supports the heat-sealed portions 52a and 52b in the upper layer. Therefore, the upper electrode element chamber 42 fills the space and blocks the space. In any case, a space corresponding to the size of the heat-sealed portions 52a and 52b can be formed.

Furthermore, as another means for improving the cooling effect, there is a method of interposing the heat transfer body 75 between the laminated power storage devices 2. In the battery pack 6 of FIG. 6, a metal plate serving as a heat transfer body 75 is inserted therein, and the cooling effect can be improved by dissipating heat from the metal plate. The material of the aforementioned heat transfer body 75 is preferably aluminum or copper with high thermal conductivity, and the heat transfer body 75 can also be connected with a cooling device to improve the cooling effect.

〔Other types of laminated storage modules and battery packs〕

Although the condition for the laminated power storage module constituting the battery pack is to have an exposed portion of the metal foil on the outer surface of the exterior body, there is no limitation on the position where it is formed. The outer metal exposed part is the part that allows the module to be connected and the battery pack to the outside. The outer metal foil exposed part provided outside the flange can also make it conductive.

The laminated power storage modules 2a, 2b, 2c, and 2d constituting the battery pack 7 of the 4-layer structure shown in FIGS. 7A to 7C are shared in the battery element compartment 42 with the laminated power storage module 2 constituting the battery pack 6 The positive electrode 61 of the battery element 60 is connected to the inside exposed part 14 of the first metal foil, and the negative electrode 63 is connected to the inside exposed part 24 of the second metal foil. However, according to the stacking position, the outside of the metal foil exposed on the outer surface of the outer body 33 is exposed. The formation position of the Ministry will different. In addition, the four laminated power storage modules 2a, 2b, 2c, and 2d are laminated with the battery element chamber 42 and the space 71 in a zigzag position in the stacking direction to be common to the battery pack 6.

The first layer of the laminated power storage module 2 a of the uppermost layer is formed on the first flange 15 with the first metal foil outer exposed portion 16. In addition, 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. The aforementioned second metal foil outer exposed portion 28 is obtained by removing the second heat-resistant resin layer 22 of the second exterior material 20 to expose the second metal foil 21.

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

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

The aforementioned battery pack 7 is based on the above-mentioned 3 types of 4 laminated storage modules 2a, A heat transfer body 75 made of a conductive material is sandwiched between 2b, 2c, and 2d. The laminate is clamped by a jig (not shown) to make the heat transfer body 75 and the laminated power storage module 2a , 2b, 2c are tightly assembled, thus 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 transfer body 75. Since the aforementioned heat transfer body 75 is a conductor, the battery elements 60 of each layer are connected in series by the first metal foil 10 and the second metal foil 20. In addition, the energization with the external device is provided by the first flange 15 of the uppermost laminated power storage module 2a with the first metal foil outer exposed portion 16 and the lowermost laminated power storage module 2c with the second protrusion The outer exposed portion 26 of the second metal foil of the rim 25 bears, and these are attached with a positive electrode plug 36 and a negative electrode plug 37.

As described above, by providing the exposed portion of the metal foil at the contact portion of the laminated power storage module that has already been laminated, it is possible to contact the laminated power storage module without using a connecting element. In addition, although the battery pack 7 interposes the heat transfer body 75 for the purpose of improving the cooling effect, and uses the heat transfer body 75 as a conductive part, the heat transfer body 75 is not interposed and the exposed portions of the metal foil directly contact each other to obtain electrical conduction. .

[Material and forming of the first exterior material and the second exterior material]

In the first exterior material 10, one side of the first metal foil 11 is bonded to the first heat-resistant resin layer 12 through the first adhesive layer, and the other side is bonded to the first thermoplastic through the second adhesive layer The resin layer 13 is bonded together. The first metal foil inner exposed portion 14 is formed by removing the first thermoplastic resin layer 13 and the second adhesive layer. The first metal foil outer exposed portions 16, 18 are formed by removing the first thermoplastic resin according to the formed surface The layer 13 and the second adhesive layer are formed by removing the first heat-resistant resin layer 12 and the first adhesive. In addition, when forming the embossed part 45 by press forming, press forming is performed after the metal exposed part is formed.

For the second exterior material 20, one side of the second metal foil 21 is bonded to the second heat-resistant resin layer 22 through the third adhesive layer, and the other side is bonded to the fourth adhesive layer and the second thermoplastic The resin layer 23 is bonded together. Same as the first exterior material 20, the second metal foil inner exposed portion 24 is formed by removing the second thermoplastic resin layer 23 and the fourth adhesive layer, and the second metal foil outer exposed portions 26, 28 are formed accordingly On the surface, the second thermoplastic resin layer 23 and the fourth adhesive layer are removed, or the second heat-resistant resin layer 22 and the third adhesive layer are removed.

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

The preferred material of the aforementioned first metal foil 11 is a soft aluminum foil with a thickness of 20 μm to 150 μm . From the standpoint of formability and cost, a soft aluminum foil of 30 μm to 80 μm is particularly preferred. On the other hand, the preferred material for the second metal foil 21 is 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 from the viewpoint of impact resistance, bending resistance, and cost, 15 μm to 100 μm is preferred.

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

Furthermore, it is preferable that the first metal foil layer 11 and the second metal foil layer 21 have a chemical conversion film formed on at least the side where the metal foil exposed portions 14, 16, 24, and 26 exist. The aforementioned chemical conversion film is a film formed by applying chemical conversion treatment on the surface of the metal foil. By applying such a chemical conversion treatment, the metal foil surface can be sufficiently prevented from being corroded by the contents (electrolyte, etc.) even if it becomes an electrical extraction window. The exposed part will not be attached to the electrolyte when the module is made. Discoloration or deterioration due to aging, and can also reduce the influence of corrosion caused by moisture in the atmosphere. Although the conductivity of the chemical conversion layer itself is close to zero, since the thickness of the coating film is extremely small, the conduction resistance is also close to zero. For example, by performing the following treatment, a chemical conversion treatment can be applied to the metal foil. That is, the surface of the metal foil subjected to the degreasing treatment is coated with an aqueous solution of any one of the following 1) to 3) and then dried to perform a chemical conversion treatment.

1) An aqueous solution containing a mixture of phosphoric acid, chromic acid, and at least one compound selected from the group of fluoride metal salts and fluoride non-metal salts; 2) containing phosphoric acid, selected from acrylic resins, chitosan An aqueous solution of a mixture of at least one resin in the group of Chitosan derivative resins and phenol resins, and at least one compound selected from the group of chromic acid and chromium (III) salt; 3) Contains phosphoric acid, at least one resin selected from the group of acrylic resins, chitosan derivative resins, and phenol resins, at least one compound selected from the group of chromic acid and chromium (III) salts, and selected An aqueous solution of a mixture of at least one compound from the group of fluoride metal salts and fluoride non-metal salts.

For the aforementioned chemical conversion film, the chromium adhesion amount (per single side) is preferably 0.1 mg/m ² to 50 mg/m ^{2 and particularly} preferably 2 mg/m ² to 20 mg/m ² .

The heat-resistant resin constituting the first heat-resistant resin layer 12 and the second heat-resistant resin layer 22 is a heat-resistant resin that does not melt due to the heat-sealing temperature when a heat-sealed exterior material is used. The aforementioned heat-resistant resin is preferably 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 more than 10°C. The heat-resistant resin whose melting point is higher than 20°C is particularly preferred. For example, in addition to polyester films and polyamide films, stretched films such as polyethylene naphthalate film, polybutylene naphthalate, and polycarbonate film are preferred. In addition, the thickness is preferably in the range of 9 μm to 50 μm .

The aforementioned first thermoplastic resin layer 13 and second thermoplastic resin layer 23 are preferably at least one selected from the group consisting of polyethylene, polypropylene, olefin copolymers, and acid denatured substances and ionomers. The thickness of the unstretched film made of the thermoplastic resin is preferably in the range of 20 μm ~80 μm .

The first adhesive layer and the third adhesive layer are preferably two-component curing type polyester polyurethane or polyether polyurethane adhesives. The second adhesive layer and the fourth adhesive layer are made of polyolefin in consideration of electrolyte resistance. The adhesive is better. The preferred coating of individual adhesives is 1g/m ² ~5g/m ² .

The method of forming the metal foil exposed portions of the aforementioned first exterior material 10 and second exterior material 20 is not limited. For example, in the step of bonding the metal foil and the resin layer by the dry lamination method, an engraved gravure roll is used to coat the adhesive on the part where the adhesive is not attached to form an uncoated part of the adhesive. The metal foil and the resin After the layer is laminated, the resin layer on the uncoated part of the adhesive is removed to expose the metal foil. As the first exterior used in the laminated storage module 2 of the above-mentioned embodiment The material 10 and the second exterior material 20 have metal foil exposed portions 14, 16, 24, 26 on the thermoplastic resin layer side, so the first metal foil 11 and the first thermoplastic resin The layer 13, the second metal foil 21, and the second thermoplastic resin layer 23 are bonded together, and the metal exposed portions 14, 16, 24, and 26 are formed after bonding. 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 and the first heat-resistant resin layer 12, the second metal foil 21 and the second heat-resistant resin layer 22 are made by conventional Known fitting means.

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

In addition, as shown in FIG. 1A etc., when the first exterior material 10 is press-formed to form the embossed portion 45, press-forming is performed after the metal exposed portion is formed. In the forming of the first exterior material 10 shown in the figure, the forming mold is formed by the male type contacting the top surface of the inner exposed portion 14 of the first metal foil, the female type inserted by the male type, and the pressurized type Stamping and forming. When the second exterior material 20 forms the embossed portion, press forming is also performed in the same manner.

In addition, first cut the first exterior material 10 to such a size that the two sides without the first flange slightly protrude from the second exterior material 20. When the protruding part is heat-sealed and bends, it can be prevented from being cut. The contact between the first metal foil 11 and the second metal foil 21 on the end surface. The size of the first exterior material 10 and the second exterior material 10 can also be reversed, and the second exterior material 20 can be bent.

〔Structure and materials of battery elements〕

The aforementioned laminated storage modules 2, 2a, 2b, 2c, and 2d use bare cells as Battery element 60. The details of the aforementioned bare cell and the electrolyte enclosed with the bare cell are as follows.

(Bare cell)

The bare cell as the battery element 60 is composed of a positive electrode 61, a separator 62, and a negative electrode 63. The type of the aforementioned bare cell is not limited to the winding type of FIG. 3. Other types of bare cells can be exemplified as the positive electrode and the negative electrode are divided into the size of the bare cell, and individual foils and separators are combined alternately and multiple layers, each current collector of the positive electrode, and each negative electrode The current collector is a laminated type with ultrasonic bonding.

The positive electrode 61 is preferably composed of a current collector and a positive electrode active material, and the current collector generally uses metal foil. The metal foil preferably uses hard or soft aluminum foil with a thickness of 7 μm-50 μm. It is preferable that there is no active material at the position in contact with the metal exposed portion 14. The composition of the aforementioned positive active material layer is not limited. For example, PVDF (polyvinylidene fluoride), SBR (styrene butadiene rubber), CMC (carboxymethyl cellulose sodium salt, etc.), PAN (polyacrylonitrile), direct It is formed by adding a mixed composition of lithium salt (for example, lithium cobaltate, lithium nickelate, lithium iron phosphate, lithium manganate, etc.) to an adhesive such as chain polysaccharides. The thickness of the aforementioned positive electrode active material layer is preferably set to 2 μm to 300 μm. The aforementioned positive electrode active material layer may further contain conductive auxiliary agents such as carbon fiber, carbon black, CNT (carbon nanotube), etc.

Furthermore, in order to improve adhesion between the aforementioned current collector and the positive electrode active material, it is preferable to use an adhesive. The aforementioned adhesive is not particularly limited, and examples thereof include layers formed of PVDF, SBR, CMC, PAN, linear polysaccharides, and the like. For the aforementioned adhesive 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 and CNT (carbon nanotube) may be further added. The thickness of the aforementioned adhesive layer is preferably set at 0.2 μm to 10 μm . When the adhesive layer is 10 μm or less, the increase in the internal resistance of the bare cell caused by the non-conductive adhesive 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 the current collector generally uses metal foil. The metal foil preferably uses copper foil with a thickness of 7 μm -50 μm , and other aluminum foil, titanium foil, and stainless steel foil can also be used. In addition, as with the positive electrode, it is preferable that no active material is present at the position in contact with the metal exposed portion 24. The composition of the aforementioned negative electrode active material layer is not particularly limited, but it can be achieved, for example, by adding additives (e.g., graphite, lithium titanate, graphite, lithium titanate, etc.) to adhesives such as PVDF, SBR, CMC, PAN, and linear polysaccharides. Si-based alloys, tin-based alloys, etc.) are formed of mixed compositions. The thickness of the aforementioned negative electrode active material layer is preferably set to 1 μm to 300 μm . The aforementioned negative electrode active material layer may further contain conductive auxiliary agents such as carbon black and CNT (carbon nanotube).

Furthermore, in order to improve adhesion between the current collector and the negative electrode active material, it is better to use an adhesive. Although the aforementioned adhesive is not particularly limited, for example, a layer formed of PVDF, SBR, CMC, and PAN can be mentioned. In order to improve the conductivity between the current collector and the negative electrode active material layer, the aforementioned adhesive layer may further add conductive auxiliary agents such as carbon black and CNT (carbon nanotube). The thickness of the aforementioned adhesive layer is preferably set at 0.2 μm to 10 μm . When the adhesive layer is 10 μm or less, the increase in the internal resistance of the bare cell caused by the non-conductive adhesive can be suppressed as much as possible.

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

Although the aforementioned separator 62 is not particularly limited, for example, a separator made of polyethylene, a separator made of polypropylene, a separator made of multiple layers of polyethylene film and polypropylene film, or the like The resin separator is a separator made of a wet or dry porous film formed by coating silicate and other heat-resistant inorganic substances. The thickness of the aforementioned spacer 62 is preferably set to 5 μm -50 μm .

Furthermore, when the laminated 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 system of the negative electrode 63 are preferably hard aluminum foils with a thickness of 7-50 μm . The positive electrode active material and the negative electrode active material are preferably carbon black or CNT (carbon nanotube). The thickness of the separator system 5 μ m ~ 100 μ m of a porous film of polyethylene or cellulose thickness of 5 μ m ~ 100 μ m preferably of non-woven fabric and the like.

(Electrolyte)

In addition, the electrolyte enclosed with the battery elements is not particularly limited, but it can be exemplified as: containing selected from water, ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and ethylene carbonate At least one solvent in the group of dimethyl ethoxide and an electrolyte containing lithium salt. The aforementioned lithium salt is not particularly limited, but examples thereof include lithium hexafluorophosphate, lithium tetrafluoroborate, and quaternary ammonium tetrafluoroborate. Examples of the aforementioned quaternary ammonium salt include tetramethylammonium salt and the like. In addition, the aforementioned electrolyte may be obtained by gelation of PVDF, PEO (polyethylene oxide), etc.

[Manufacturing method of laminated power storage module and battery pack]

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

(1) The first exterior material 10 is produced by the method described previously. The first exterior material 10 is formed with a first metal foil inside exposed portion 14 and a first metal foil outside exposed at a desired position The portion 16 or the first metal foil exposed portion 18 and the embossed portion 45. In addition, a second exterior material 20 is produced, and the second exterior material 20 is formed with a second metal foil inside exposed portion 24, a second metal foil outside exposed portion 26, or a second metal foil outside exposed portion 28 at desired positions.

(2) Place the first exterior material 10 so that the first thermoplastic resin layer 13 faces upward, so that the first metal foil inner exposed portion 14 in each embossed portion 45 of the battery element chamber 42 and the positive electrode of the battery element 60 The battery element 60 is filled in contact with 61, and the electrolyte is injected using a syringe or the like.

(3) The second exterior material 20 is superimposed on one side of the second exterior material 20 where the second metal foil inside exposed portion 24 of the second exterior material 20 is in contact with the negative electrode 63 of the battery element 60, and the exterior bodies 32 and 33 are assembled. In this assembled state, the first flange 15 extends from the end of the second exterior material 20, and at the same time the second flange 25 extends from the end of the first exterior material 10, so that the first The metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26 are exposed on the outer surfaces of 32 and 33.

(4) A heated hot plate is used to form the heat-sealed portion 52a.

(6) Tighten the first metal foil outer exposed part 16 of the first flange 15 and the second metal foil outer exposed part 26 of the second flange 25 with a clamp for pre-charging, and put it in a constant temperature bath at 100°C for 8 hours Perform gas exhaust.

(7) The unsealed portion is heat-sealed with a heated hot plate under reduced pressure 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 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-mentioned manufacturing method is only one example, and is not particularly limited to such a manufacturing method.

The produced laminated storage modules 2, 2a, 2b, 2c, 2d are laminated in the required number, or the heat transfer body 75 is interposed and laminated. By the above method, the adjacent modules can be connected in the laminated direction , Assemble the battery pack. The number of layers of the battery pack of the present invention is arbitrary.

The use of the battery pack of the present invention is not limited. It can be used as a power source for cars, bicycles, two-wheelers, trams, airplanes, ships, etc. that require electricity. Specifically, it can be used in hybrid vehicles, electric vehicles, and industrial applications. Large-capacity lithium secondary battery (lithium ion battery, lithium polymer battery, etc.) modules, solid battery modules, lithium ion capacitor modules for the same purpose, and electric double layer capacitor modules for the same purpose as household storage batteries.

[Example]

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

<Example 1>

Make four laminated modules 2 shown in Figs. 1A and 1B, and make the battery pack 5 shown in Figs. 2A and 2B.

The first metal foil 11 is a soft aluminum foil with a thickness of 40 μm classified as A8079 by JIS H4160, and chemical conversion treatment is applied to both sides. 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 SUS 304 stainless steel foil with a thickness of 20 μm, and chemical conversion treatment is applied to 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 size of the first metal foil inner exposed portion 14 and the second metal foil inner exposed portion 24 is 30 mm×30 mm, and the size of the first metal foil outer exposed portion 16 and the second metal foil outer exposed portion 26 is 20 mm×200 mm.

(The first exterior material)

One side of the first metal foil 11 is laminated with the first heat-resistant resin layer 12 with a 2-liquid hardening polyester polyurethane adhesive with a thickness of 3 μm by dry lamination, and aging at 50°C The furnace was cured for 3 days. Next, the opposite surface of the aforementioned first metal foil 11 is laminated with the first thermoplastic resin layer 13 with a 2-liquid hardening olefin-based adhesive with a thickness of 2 μm by a dry lamination method. When the adhesive is coated with a coating thickness of 2 μm , the size and position of the 9 first metal foil inner exposed portions 14 and 1 first metal foil outer exposed portion 16 are formed to form an adhesive uncoated portion And fit. After bonding, use a 40℃ aging furnace to cure for 3 days.

After curing, the first thermoplastic resin layer 13 on the uncoated part of the adhesive is cut and removed with a laser knife to form the first metal foil inside exposed part 14 and the first metal foil exposed outside. Part 16

Next, using a 40mm-angle male, female, and pressurized mold, press and mold a battery with a depth of 4mm so that the top surface of the male is in contact with the exposed portion 14 of the first metal foil. The embossed part of the element chamber 42. And further cut the periphery to obtain the first exterior material 10. The plane size of the first exterior material 10 is 140mm×160mm.

(Second exterior material)

One side of the second metal foil 21 is laminated with the second heat-resistant resin layer 22 by a dry lamination method with a 2-component curing type polyester polyurethane adhesive with a thickness of 3μm, and used at 50°C Cured in the furnace for 3 days. Next, the opposite surface of the second metal foil 21 is laminated with the second thermoplastic resin layer 23 by applying a two-liquid curing olefin-based adhesive with a thickness of 2 μm by a dry lamination method, and the adhesive When the coating is applied with a coating thickness of 2 μm, the sizes and positions of the nine second metal foil inner exposed portions 24 and one second metal foil outer exposed portion 26 form an adhesive uncoated portion and are bonded together. After bonding, use a 40℃ aging furnace to cure for 3 days.

After curing, the second thermoplastic resin layer 23 on the uncoated part of the adhesive is cut and removed with a laser knife to form the second metal foil inner exposed part 24 and the second metal foil exposed outside the second metal foil 21部26. And further cut the periphery to obtain the second exterior material 20. The plane size of the second exterior material 20 is 150 mm×160 mm, which is larger than the first exterior material 10.

(Electrode element)

The electrode element 60 is a bare cell made of the following materials.

The current collector system of the positive electrode 61 is classified as A1100 hard aluminum foil by JIS H4160, with a thickness of 15 μm and a width of 500 mm. The current collector system of the negative electrode 63 is classified as C1100R hard copper foil by JIS H3100, with a thickness of 15 μm and a width of 200 mm. The positive electrode active material layer formation slurry is composed of 60 parts by mass of positive electrode active material with lithium cobalt oxide as the main component, 10 parts by mass of PVDF as an adhesive and electrolyte retaining agent, 5 parts by mass of acetylene black (conductive material), N-form 25 parts by mass of methyl-2-pyrrolidone (organic solvent) is kneaded and dispersed into a paste. The slurry for forming negative electrode active material is 57 parts by weight of negative electrode active material with carbon powder as the main component, 5 parts by weight of PVDF as an adhesive and electrolyte retaining agent, 10 parts by weight of copolymer of hexafluoropropylene and maleic anhydride, and acetylene black (Conductive material) 3 parts by mass and 25 parts by mass of N-methyl-2-pyrrolidone (organic solvent) are kneaded and dispersed into a paste. Then, the solvent (dimethylformamide) is used to dissolve PVDF into the adhesive liquid. The separator 62 is a porous wet separator with a width of 38 mm and a thickness of 8 μm. The electrolyte is a mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in equal volume ratios. Lithium hexafluorophosphate (LiPF ₆ ) is dissolved to a concentration of 1 mol/ The solution of L.

The aforementioned positive electrode 61 is produced by the following steps. First, the adhesive was applied to the entire surface of one side of the current collector and dried at 100°C for 30 seconds to form an adhesive layer with a thickness of 0.5 μm after drying. Then, the liquid slurry for the positive electrode active material layer was coated on the surface of the aforementioned adhesive layer, dried at 100°C for 30 seconds, and then hot stamped to form a positive electrode active material layer with a density of 4.8 g/cm ³ and a dried thickness of 120 μm . Furthermore, it was cut into a 35mm wide coil shape by putting it in the frame.

The aforementioned negative electrode 63 is produced by the following steps. First, the adhesive was applied on one side of the current collector and dried at 100°C for 30 seconds to form an adhesive layer with a thickness of 0.5 μm after drying. Next, the liquid slurry for the negative electrode active material layer was coated on the surface of the aforementioned adhesive layer, dried at 100°C for 30 seconds, and then heated and pressed to form a density of 1.5 g/cm ³ and a thickness of 20.1 μm after drying. Negative active material layer. Furthermore, it was cut into a 35mm wide coil shape by putting it in the frame.

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 slowly layered and wound in order to make one The positive electrode 61 was exposed on the side on the side, and the negative electrode 63 was exposed on the opposite side and squashed to produce a bare cell with a square of 38 mm and a thickness of 4 mm.

(Assembly of laminated storage modules and battery packs)

(1) Place the first exterior material 10 with the first thermoplastic resin layer 13 facing upwards, so that the first metal foil inner exposed portion 14 in each embossed portion 45 forming the battery element chamber 42 and the positive electrode of the battery element 60 The battery element 60 is filled in contact with 61, and the electrolyte is injected using a syringe or the like.

(2) The position where one side of the second exterior material 20 is in contact with the second metal foil inside exposed portion 24 of the second exterior material 20 and the negative electrode 63 of the battery element 60 is superimposed, and the exterior body 32 is assembled. 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 The foil outer exposed portion 16 and the second metal foil outer exposed portion 26 are exposed on the outer surface of the exterior body 32.

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

(4) Tighten 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 with a clamp, charge until the battery voltage of 4.2V is generated, and release Enter a constant temperature bath at 100°C for 8 hours to exhaust the gas in the battery element chamber 42.

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

(6) The short-circuit countermeasure is to stick a 25 μm adhesive tape on the edge of the second flange 25 side of the first exterior material 10 and the edge of the first flange 15 side of the second exterior material 20, Cover the first metal foil 11 and the second metal foil 21 with the exposed end faces. Furthermore, the second exterior material 20 protruding on the other two sides is bent to the side of the first exterior material 10 to perform insulation countermeasures and strengthen the side surfaces. In addition, FIG. 2A shows the state before bending.

(7) Three 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.

Through the above steps, 4 laminated power storage modules are produced.

(8) Referring to FIGS. 2A and 2B, the first flange 15 and the second flange 25 of the adjacent modules of the four laminated power storage modules 2 in the stacking direction are overlapped and changed to be stacked in different directions.

(9) The four laminated power storage modules 2 are connected in line by connecting pins 35, the outer exposed portion 16 of the first metal foil of the uppermost layer is attached with a pin 36 for positive electrode, and the outer exposed portion of the second metal foil of the lowermost layer 26 has a negative pin 36 attached. Through the above steps, the battery pack 5 is produced.

In the aforementioned battery pack 5, the heat-sealed portion 52a is formed with a quadrangular space 70 with a cross-section (width of the heat-sealed portion 52a: 5mm) x (height of the embossed portion: 4mm), and the heat-sealed portion 52b has a cross-section of ( The heat-sealed portion 52b has a quadrangular space of 5mm in width)×(4mm in height of the embossed portion).

<Comparative Example 1>

Comparative Example 1 is a battery pack composed of 4 laminated power storage modules with a different structure from that of Example 1.

In addition, in the laminated power storage module 2 of Example 1, 9 battery elements 60 are individually enclosed in the battery element chamber 42, and metal foil exposed portions are formed on the inner and outer surfaces of the exterior body. The battery can be obtained without using tabs. The element 60 is turned on. In contrast to this laminated power storage module 2, the laminated power storage module of Comparative Example 1 has one battery element enclosed in one battery element compartment in order to obtain the same capacity as that of Example 1’s 9 battery elements , The size of the battery element is larger. In addition, the exterior body of the laminated power storage module of Comparative Example 1 does not have metal foil exposed portions on the inside and outside, but connects the battery elements to the tabs and pulls the tabs out of the mold outside the exterior body. group.

(Exterior body)

The exterior material corresponds to the first exterior material 10 of Example 1 having a portion that becomes the embossed portion of the battery element chamber, and the second exterior material 20 corresponding to Example 1 has a flat surface that closes the opening of the aforementioned embossed portion Partially formed. The exterior system is formed by folding the aforementioned exterior material twice. The material constituting the aforementioned exterior material, the metal foil is a soft aluminum foil with a thickness of 40μm (a soft aluminum foil classified as A8021 in JIS H4160, the heat-resistant resin layer is a biaxially stretched polyamide film with a thickness of 25μm, and the thermoplastic resin layer is a thickness of 40μm Polypropylene film.

The aforementioned exterior material is on the entire surface of one side of the metal foil, and is bonded to the heat-resistant resin layer via a polyester urethane adhesive with a coating amount of 3 g/m ² , and the other side The entire surface of the surface is made by bonding a polyolefin-based adhesive with a coating amount of 2 g/m ² and a thermoplastic resin layer, and then curing it in a thermostat at 40°C for 3 days. The aforementioned exterior material does not have a metal foil exposed portion, and the entire aluminum foil is covered with a resin layer.

The aforementioned exterior material is stamped and formed to form an embossed part of 115mm×115mm×4mm in height, and the size of the flat part and the predetermined part of the heat-sealed part are reserved for cutting.

(Battery elements and contacts)

The battery element was made with the same material as in Example 1 and the outer shape was 110mm square.

The positive electrode tab is exposed at 5mm of one end in the longitudinal direction of a soft aluminum foil with a length of 30mm, a width of 3mm and a thickness of 100μm (soft aluminum foil of A1050 classified by JIS H4000), and is heat-sealed to make the length 10mm and width 5mm , Maleic anhydride modified polypropylene film with a thickness of 50μm (melting point 140℃, MFR 3.0g/1 0 points) The insulating film is made by sandwiching both sides of the aluminum foil.

The negative electrode tab is exposed at one end of the nickel foil with a length of 40 mm, a width of 3 mm, and a thickness of 100 μm by 5 mm, and a maleic anhydride denatured polypropylene film of 10 mm in length, 5 mm in width and 50 μm in thickness is heat-sealed ( Melting point is 140℃, MFR is 3.0g/10 minutes) The insulating film is made by sandwiching both sides of the nickel foil.

Join the positive electrode and the end of the positive electrode tab of the aforementioned battery element, and join the negative electrode and the negative electrode tab at the same time, and pull out the ends of the positive electrode tab and the negative electrode tab on the same side of the battery element.

(Assembly of laminated storage modules and battery packs)

(1) For exterior materials, mark the folding position with a ruler in advance.

(2) Load the battery elements into the embossed part of the aforementioned exterior material, mount the insulating film of the tab on the predetermined part of the heat-sealed part, align the position, and bend the exterior material at the marked position. Cover the embossed part on the flat surface.

(3) For the two sides including the side where the tabs are pulled out, use a hot plate heated to 200°C to clamp them at a pressure of 0.3 MPa for 3 seconds to heat seal them.

(4) Using a syringe from the unsealed side, inject 45 mL of the same electrolyte as in Example 1, and perform pseudo charging and exhaust by the same method as in Example 1.

(5) Under a discharge state of 3.0V and a reduced pressure of 0.086MPa, use a hot plate heated to 200°C to clamp the unsealed edge at a pressure of 0.3MPa for 3 seconds to heat-seal the battery elements. And the electrolyte is enclosed in the battery element compartment.

Through the above steps, 4 laminated power storage modules were produced.

(6) The four laminated power storage modules are stacked and connected in line to assemble the battery pack.

<Assessment>

The battery packs of Example 1 and Comparative Example 1 obtained above were evaluated based on the following evaluation method. 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 18°C room temperature, and measure the voltage and capacity when fully charged again. In addition, use a temperature sensor to measure the temperature of a fully charged battery at 1C discharge and 0.2C discharge, and calculate the average value. Example 1 and Comparative Example 1 are at the same temperature measurement position, both are at the center of the third layer of the module. Example 1 is at the center of the outer surface of the embossed part in the center of 3 rows x 3 rows. Comparative Example 1 is In the center of the embossing section.

As shown in Table 1, there is no difference in battery capacity between Example 1 and Comparative Example 1, and the results obtained by repeating 100 times of charge and discharge are also the same. In addition, regarding the calorific value during discharge, it can be confirmed that the battery pack of Example 1 can suppress heat generation and has a higher heat release effect than that of Comparative Example 1, regardless of whether it is 1C discharge or 0.2 discharge.

This application is accompanied by a Japanese patent application filed on April 15, 2015. The priority claim of the petition No. 2015-83102, the disclosure of which directly constitutes a part of this application.

The terms and descriptions used here are used to describe the embodiments of the present invention, but the present invention is not limited to these. Any equivalent of the characteristic items disclosed and described in the present invention should not be excluded, and various modifications within the scope of the present invention should also be understood as acceptable.

[Possibility of industrial use]

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

2, 2a, 2b, 2c, 2d‧‧‧Laminated storage module

5, 6, 7‧‧‧Battery pack

10‧‧‧The first exterior material

11‧‧‧The first metal foil

12‧‧‧The first heat-resistant resin layer

13‧‧‧The first thermoplastic resin layer

14‧‧‧Inside exposed part of the first metal foil

15‧‧‧First flange

16, 18‧‧‧Exposed outside part of the first metal foil

20‧‧‧Second exterior material

21‧‧‧Second metal foil

22‧‧‧Second heat-resistant resin layer

23‧‧‧The second thermoplastic resin layer

24‧‧‧Second metal foil inside exposed part

25‧‧‧Second flange

26、28‧‧‧Exposed outside part of the second metal foil

32, 33, 80, 82‧‧‧Exterior body

42, 82, 83a, 83b‧‧‧Battery element room

45、46‧‧‧Embossed part

52a, 52b‧‧‧Heat seal

60‧‧‧Bare cell (battery element)

61‧‧‧Positive

62‧‧‧Partition

63‧‧‧Negative pole

70、71‧‧‧Space

75‧‧‧Heat transfer body

Claims (6)

A battery pack characterized in that it is formed by laminating a plurality of laminated power storage modules, the laminated power storage module having a first exterior material, a second exterior material, and battery elements; the first exterior The material is the area layer first heat-resistant resin layer on one side of the first metal foil, the area layer first thermoplastic resin layer on the other side, and the surface on the side of the first thermoplastic resin layer has the first metal foil exposed The inner exposed part of the first metal foil; the second exterior material is a second heat-resistant resin layer with an area layer on one side of the second metal foil, a second thermoplastic resin layer on the other side with an area layer, the second The surface on the side of the thermoplastic resin layer has an exposed portion inside the second metal foil exposing the second metal foil; the battery element has a positive electrode and a negative electrode, and a separator arranged between them; the first exterior material and At least one of the second exterior materials has an embossed portion in the area including the first metal foil inside exposed part and the second metal foil inside exposed part, by the first thermoplastic resin layer of the first exterior material Opposite the second thermoplastic resin layer of the second exterior material, and surround the heat-sealed portion of the first thermoplastic resin layer and the second thermoplastic resin layer after fusion, the exposed portion inside the first metal foil, and the second metal foil The exposed inner part faces the room and forms a plurality of battery element compartment exterior bodies having convex parts formed by the embossed parts, and the exterior body is one side of the first exterior material extending from the heat-sealed part , Both sides become the outer surface of the exterior body and become the first flange, and the first metal foil outer exposed part is formed on the first flange, and the first metal foil outer exposed part is further penetrated and connected With the cavity, one side of the aforementioned second exterior material is extended from the heat-sealed part, and both sides become the exterior surface of the exterior body and become the second flange, The second flange is formed with a second metal foil outer exposed part exposing the second metal foil, and a connection hole is further perforated in the second metal foil outer exposed part; the battery element in the battery element chamber is sealed together with the electrolyte, The positive electrode is connected to the exposed part of the inner side of the first metal foil, and the negative electrode is connected to the exposed part of the second metal foil; and the above-mentioned battery pack is laminated with a plurality of the aforementioned laminated power storage modules forming a space on the heat-sealed part, The laminated power storage modules adjacent to each other in the stacking direction are electrically connected to the first metal foil outer exposed part and the second metal foil outer exposed part through connection pins in connection holes, respectively. The battery pack described in the first item of the scope of patent application, in which the battery element chamber and the heat-sealed part are overlapped in the stacking direction of the laminated power storage module to laminate a plurality of laminated power storage modules. The battery pack described in item 1 or 2 of the scope of patent application, in which a heat transfer body is arranged between adjacent laminated storage modules in the stacking direction. The battery pack described in item 1 or 2 of the scope of patent application, wherein the aforementioned space is a cooling gas flow path. The battery pack described in the first item of the scope of patent application, wherein the space and the battery element compartment are only adjacent in a direction orthogonal to the stacking direction of the laminated power storage module. In the battery pack described in the second item of the patent application, the space is adjacent to the battery element compartment in two directions of the stacking direction and the stacking direction of the laminated power storage module.

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