Laminate type battery

Abstract

To provide a laminate type battery in which the difference in resistance between one side and the other side with the center of the side as the boundary is suppressed.SOLUTION: A laminate type battery includes an electrode body, a side member arranged on the side of the electrode body, and a laminate film covering the electrode body and a part of the side member, and the side member is arranged in a position offset to one side with respect to the center of the side in the longitudinal direction of the side, and when the side on which the side member is offset with respect to the center in the longitudinal direction of the side is defined as the offset side and the other side is defined as the non-offset side, the volume of the side member located on the offset side of the side is equal to the volume of the side member located on the non-offset side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a laminate-type battery. [Background technology]

[0002] 2. Description of the Related Art Conventionally, laminate type batteries have been used which include an electrode body, a side member such as a terminal, and a laminate film which covers the electrode body and a portion of the side member.

[0003] For example, Patent Document 1 discloses a battery in which a terminal on one side surface is disposed offset to one side with respect to the center of the side surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-283611 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally, laminated type batteries have been used that include an electrode body, a side member such as a terminal, and a laminate film that covers a part of the electrode body and the side member. In this laminated type battery, the side member may be disposed at a position offset to one side with respect to the center of the side in the longitudinal direction of the side. However, in an electrode body in which the side member is biased to one side of the side surface, a difference in resistance may occur between the side where the side member is biased (biased side) and the other side (non-biased side) across the center of the side surface.

[0006] The present disclosure has been made in consideration of the above-mentioned circumstances, and has an object to provide a laminate-type battery in which the difference in resistance between one side and the other side across the center of the side surface is suppressed. [Means for solving the problem]

[0007] Means for solving the above problems include the following aspects. <1> An electrode body, A side member disposed on a side surface of the electrode body, A laminate film covering the electrode body and a part of the side member, The side member is disposed at a position offset to one side with respect to the center of the side surface in the longitudinal direction of the side surface, When one side where the side member is offset with respect to the center in the longitudinal direction of the side surface is defined as the uneven side and the other side is defined as the non-uneven side, the side member has equal volumes of the side member located on the uneven side and the side member located on the non-uneven side on the side surface, a laminate battery. <2> The laminate battery according to <1>, wherein the side member has a shape in which the thickness continuously decreases from the non-uneven side toward the uneven side. <3> The laminate battery according to <1>, wherein the side member has holes formed in a region on the uneven side with the center of the side surface as a boundary.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide a laminate battery in which the difference in resistance between one side and the other side with the center of the side surface as a boundary is suppressed.

Brief Description of the Drawings

[0009] [Figure 1] It is a schematic perspective view showing an electrode body and a side member in a laminate battery according to an embodiment of the present disclosure. [Diagram 2] (A) is a schematic side view of the laminate battery shown in FIG. 1 as viewed from the side surface direction, and (B) is a schematic side view of another aspect of the laminate battery according to the embodiment of the present disclosure as viewed from the side surface direction. [Diagram 3] It is a schematic plan view showing a main part of a vehicle. [Figure 4] It is a schematic perspective view of a battery module. [Diagram 5]FIG. 2 is a plan view of the battery module with the top cover removed. [Figure 6] 3 is a schematic diagram of a battery cell accommodated in a battery module as viewed from the thickness direction. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment that is an example of the present disclosure will be described below. These descriptions are for illustrating the embodiment and are not intended to limit the scope of the invention.

[0011] <Laminated battery> A laminated battery according to an embodiment of the present disclosure is a laminated battery comprising an electrode body, a side member arranged on a side of the electrode body, and a laminate film covering the electrode body and a portion of the side member, wherein the side member is arranged in a position offset to one side with respect to the center of the side in the longitudinal direction of the side. When one side on which the side member is offset relative to the center in the longitudinal direction of the side surface is defined as the offset side, and the other side is defined as the non-offset side, the volume of the side member located on the offset side of the side surface is equal to the volume of the side member located on the non-offset side.

[0012] If the side surface member is disposed in a position offset to one side with respect to the center of the side surface in the longitudinal direction of the side surface (i.e., a position offset from the center of the side surface), the volume of the side surface member will be relatively large on the side where the side surface member is offset (the offset side) across the center of the side surface, and the volume of the side surface member will be relatively small on the other side (the non-offset side).As a result, the offset side where the volume of the side surface member is relatively large will have low resistance, whereas the non-offset side where the volume of the side surface member is relatively small will have high resistance, i.e., a difference in resistance will occur between the offset side and the non-offset side of the side surface.

[0013] In contrast, in the laminated battery according to the embodiment of the present disclosure, the volume of the maldistribution side and the volume of the non-maldistribution side of the side surface member are equal across the center of the side surface, which makes it possible to suppress the resistance of one side being larger than that of the non-maldistribution side of the side surface, and therefore makes it possible to suppress the difference in resistance between the maldistribution side and the non-maldistribution side of the side surface.

[0014] Hereinafter, a laminate type battery according to an embodiment of the present disclosure will be specifically described with reference to the drawings. The drawings shown below are schematic diagrams, and the size and shape of each part are appropriately exaggerated to make them easier to understand.

[0015] First aspect Fig. 1 is a schematic perspective view showing an electrode body and a side member of a laminated battery according to a first aspect of an embodiment of the present disclosure. Fig. 2(A) is a schematic side view of the laminated battery shown in Fig. 1 as seen from a side direction (the direction of the surface on which the side member is arranged, the Z direction in Figs. 1 and 2).

[0016] 1, the electrode body 4 in the laminated battery according to the first embodiment has terminals 26, as an example of side surface members, arranged on each of a pair of side surfaces 4A. Note that on the side surface 4A of the electrode body 4, there are two regions 41A and 42A in which the terminal 26 is not arranged, on both sides of the terminal 26 in the longitudinal direction (arrow X direction) of the side surface 4A. The terminal 26 is disposed at a position offset to one side (offset to the right in FIGS. 1 and 2(A)) with respect to the center Lc1 of the side 4A in the longitudinal direction (arrow X direction) of the side 4A of the electrode body 4. In the present disclosure, the side where the side member 26 is offset with respect to the center Lc1 in the longitudinal direction (arrow X direction) of the side 4A is referred to as the "offset side", and the other side is referred to as the "non-offset side". On the side surface 4A of the electrode body 4, a region 42A where the terminals 26 are not arranged on the side (unevenly distributed side) where the terminals 26 are unevenly arranged has a smaller area than the other side (non-unevenly distributed side), and a region 41A on the non-unevenly distributed side has a larger area than a region 42A on the unevenly distributed side. Note that, hereinafter, of the two regions on the side surface of the electrode body where no side surface member is arranged, the region with the larger area is referred to as the "wide region" and the region with the smaller area is referred to as the "narrow region."

[0017] In the laminated battery according to the first embodiment, as shown in Fig. 2(A), a laminate film 28 is disposed so as to cover the electrode body 4 and a part of the terminal 26. The laminate film 28 is disposed so as to cover the entire surface of the electrode body 4, and the entire area of ​​the side surface 4A of the electrode body 4 where the terminal 26 is not provided is covered with the laminate film 28 (therefore, the electrode body 4 covered with the laminate film 28 is shown by a dotted line in Fig. 2(A)). The laminate film 28 is disposed with respect to the terminal 26 so as to cover a part of each of the upper surface 26B, one side surface 26C, the lower surface 26D, and the other side surface 26E of the terminal 26, more specifically, the area on the electrode body 4 side on these four surfaces. Therefore, the entire outer surface 26A of the terminal 26, as well as the upper surface 26B, one side surface 26C, the lower surface 26D, and the area of ​​the other side surface 26E opposite the electrode body 4 are not covered by the laminate film 28 and are exposed.

[0018] The terminal 26 has a shape in which the thickness is continuously reduced toward the side where the terminal 26 is unevenly arranged, that is, from the non-uniformly distributed side toward the unevenly distributed side. In other words, the thickness of the terminal 26 is continuously reduced from the larger area (wide area) 41A side toward the smaller area (narrow area) 42A side of the two regions 41A and 42A where the terminal 26 is not arranged on the side surface 4A of the electrode body 4. The thickness of the terminal 26 means the length in the Y direction in Figs. 1 and 2(A). With this configuration, the terminal 26 has a configuration in which the volume of the region 261 on the non-uniformly distributed side and the volume of the region 262 on the unevenly distributed side are equal to each other with respect to the center Lc1 of the side surface 4A.

[0019] As described above, the laminated battery shown in FIG. 1 and FIG. 2(A) is configured such that the volume of the maldistribution side and the volume of the non-maldistribution side of the side surface member are equal across the center of the side surface, and the difference in resistance between the maldistribution side and the non-maldistribution side of the side surface can be suppressed.

[0020] 1 and 2(A) show an embodiment in which the terminal 26 has a shape in which the thickness continuously decreases from the non-uniform distribution side to the uniform distribution side. However, this is not limited to this embodiment, and for example, the side member may have a shape in which the thickness gradually decreases from the non-uniform distribution side to the uniform distribution side.

[0021] Second aspect FIG. 2(B) is a schematic side view of a laminated battery according to a second aspect of the embodiment of the present disclosure, as viewed from the side direction (the direction of the surface on which the side member is disposed, the Z direction in FIG. 2). The laminated battery of the second embodiment has the same configuration as the laminated battery of the first embodiment except for the terminals as an example of side surface members, so a detailed description thereof will be omitted here.

[0022] 2(B), the electrode body 4 in the laminated battery according to the second embodiment has terminals 27, as an example of side surface members, arranged on each of a pair of side surfaces 4A. Note that on the side surface 4A of the electrode body 4, there are two regions 41A and 42A in which the terminal 27 is not arranged, on both sides of the terminal 27 in the longitudinal direction (arrow X direction) of the side surface 4A. The terminal 27 is disposed at a position offset to one side (offset to the right in FIG. 2(B)) with respect to the center Lc1 of the side 4A in the longitudinal direction (arrow X direction) of the side 4A of the electrode body 4. In this disclosure, the side where the side member 27 is offset with respect to the center Lc1 in the longitudinal direction (arrow X direction) of the side 4A is referred to as the "offset side", and the other side is referred to as the "non-offset side". On the side 4A of the electrode body 4, the area 42A where the terminals 27 are not arranged on the side (unevenly distributed side) where the terminals 27 are unevenly arranged is narrower in area than the other side (non-unevenly distributed side), and the area 41A on the non-unevenly distributed side is wider in area than the area 42A on the unevenly distributed side.

[0023] Then, five holes 270 are formed in a region 272 on the eccentric side of the terminal 27, with the center Lc1 of the side surface 4A as the boundary. Since the holes 270 are hollow, the region of the holes 270 is not included in the volume of the terminal 27. Since the holes 270 that are not included in the volume of the terminal 27 are formed in the region 272 on the eccentric side of the terminal 27, the volume of the region 272 on the eccentric side of the terminal 27 is reduced. As a result, the volume of the region 271 on the non-eccentric side and the volume of the region 272 on the eccentric side, with the center Lc1 of the side surface 4A as the boundary, are configured to be equal to each other.

[0024] As described above, the laminated battery shown in FIG. 2(B) is configured such that the volume of the maldistribution side and the volume of the non-maldistribution side of the side surface member are equal across the center of the side surface, thereby making it possible to suppress the difference in resistance between the maldistribution side and the non-maldistribution side of the side surface.

[0025] 2(B) shows an embodiment in which five circular holes 270 are formed. However, this is not limiting, and the shape of the holes and the number of holes can be freely changed.

[0026] Next, a battery module, a battery pack, and a vehicle having a laminated battery according to an embodiment of the present disclosure will be described with reference to the drawings.

[0027] (Overall configuration of vehicle 100) Fig. 3 is a schematic plan view showing a main part of a vehicle 100 to which a battery pack 10 according to an embodiment is applied. As shown in Fig. 3, the vehicle 100 is an electric vehicle (BEV: Battery Electric Vehicle) in which the battery pack 10 is mounted under the floor. Note that the arrows UP, FR, and LH in each figure indicate the upper side in the vehicle vertical direction, the front side in the vehicle longitudinal direction, and the left side in the vehicle width direction, respectively. When describing using the front-rear, left-right, up-down directions, they refer to the front-rear in the vehicle longitudinal direction, the left-right in the vehicle width direction, and the up-down in the vehicle vertical direction, unless otherwise specified.

[0028] As an example, in the vehicle 100 of this embodiment, a DC / DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 are disposed on the vehicle front side of the battery pack 10. In addition, a motor 108, a gear box 110, an inverter 112, and a charger 114 are disposed on the vehicle rear side of the battery pack 10.

[0029] The direct current output from the battery pack 10 has its voltage adjusted by a DC / DC converter 102, and is then supplied to an electric compressor 104, a PTC heater 106, an inverter 112, etc. In addition, power is supplied to a motor 108 via the inverter 112, causing the rear wheels to rotate and causing the vehicle 100 to run.

[0030] A charging port 116 is provided on the right side at the rear of the vehicle 100, and by connecting a charging plug of an external charging facility (not shown) to the charging port 116, power can be stored in the battery pack 10 via the charger 114.

[0031] The arrangement and structure of each component constituting the vehicle 100 are not limited to the above-mentioned configuration. For example, the present invention may be applied to a hybrid vehicle (HV: Hybrid Vehicle) equipped with an engine or a plug-in hybrid vehicle (PHEV: Plug-in Hybrid Electric Vehicle). In addition, in the present embodiment, the vehicle is a rear-wheel drive vehicle in which the motor 108 is mounted at the rear of the vehicle, but the present invention is not limited to this. The vehicle may be a front-wheel drive vehicle in which the motor 108 is mounted at the front of the vehicle, or a pair of motors 108 may be mounted at the front and rear of the vehicle. Furthermore, the vehicle may be equipped with an in-wheel motor on each wheel.

[0032] Here, the battery pack 10 is configured to include a plurality of battery modules 11. As an example in this embodiment, ten battery modules 11 are provided. Specifically, five battery modules 11 are arranged on the right side of the vehicle 100 in the vehicle front-rear direction, and five battery modules 11 are arranged on the left side of the vehicle 100 in the vehicle front-rear direction. In addition, each battery module 11 is electrically connected.

[0033] Fig. 4 is a schematic perspective view of the battery module 11. As shown in Fig. 4, the battery module 11 is formed in a substantially rectangular parallelepiped shape with the vehicle width direction as the longitudinal direction. The outer shell of the battery module 11 is formed of an aluminum alloy. For example, the outer shell of the battery module 11 is formed by joining aluminum die castings to both ends of an aluminum alloy extrusion material by laser welding or the like.

[0034] A pair of voltage terminals 12 and a connector 14 are provided at both ends of the battery module 11 in the vehicle width direction. A flexible printed circuit board 22, which will be described later, is connected to the connector 14. In addition, bus bars (not shown) are welded to both ends of the battery module 11 in the vehicle width direction.

[0035] The length MW of the battery module 11 in the vehicle width direction is, for example, 350 mm to 600 mm, the length ML in the vehicle front-rear direction is, for example, 150 mm to 250 mm, and the height MH in the vehicle up-down direction is, for example, 80 mm to 110 mm.

[0036] Fig. 5 is a plan view of the battery module 11 with the top cover removed. As shown in Fig. 5, a plurality of battery cells 20 are housed in an arranged state inside the battery module 11. In this embodiment, as an example, 24 battery cells 20 are arranged in the front-rear direction of the vehicle and bonded to one another.

[0037] A flexible printed circuit (FPC) 22 is disposed on the battery cells 20. The flexible printed circuit 22 is formed in a strip shape with the vehicle width direction as the longitudinal direction, and a thermistor 24 is provided on each of both ends of the flexible printed circuit 22. The thermistor 24 is not bonded to the battery cells 20, and is configured to be pressed towards the battery cells 20 by the upper lid of the battery module 11.

[0038] One or more cushioning materials (not shown) are housed inside the battery module 11. For example, the cushioning materials are elastically deformable thin plate-like members, and are arranged between adjacent battery cells 20 with the arrangement direction of the battery cells 20 being the thickness direction. As an example in this embodiment, cushioning materials are arranged at both ends of the battery module 11 in the longitudinal direction and in the central portion in the longitudinal direction.

[0039] Fig. 6 is a schematic diagram of a battery cell 20 housed in a battery module 11, viewed from the thickness direction. As shown in Fig. 6, the battery cell 20 is formed in a substantially rectangular plate shape, and houses an electrode body (not shown) inside. The electrode body is configured by laminating a positive electrode, a negative electrode, and a separator, and is sealed with a laminate film 28.

[0040] In this embodiment, as an example, the housing portion for the electrode body is formed by folding and pasting an embossed sheet-like laminate film 28. Note that although both a single cup embossed structure in which embossing is performed at one place and a double cup embossed structure in which embossing is performed at two places can be adopted, the present embodiment adopts a single cup embossed structure with a drawing depth of about 8 mm to 10 mm.

[0041] The upper ends of the battery cells 20 at both ends in the longitudinal direction are bent to form corners. The upper end of the battery cells 20 is also bent, and a fixing tape 30 is wound around the upper end of the battery cells 20 along the longitudinal direction.

[0042] Here, terminals (tabs) 26 are provided at both longitudinal ends of the battery cell 20. In this embodiment, as an example, the terminals 26 are provided at positions offset downward from the vertical center of the battery cell 20. The terminals 26 are joined to a bus bar (not shown) by laser welding or the like.

[0043] The length CW1 of the battery cell 20 in the vehicle width direction is, for example, 530 mm to 600 mm, 600 mm to 700 mm, 700 mm to 800 mm, 800 to 900 mm, 1000 mm or more, the length CW2 of the region in which the electrode body is housed is, for example, 500 mm to 520 mm, 600 mm to 700 mm, 700 mm to 800 mm, 800 to 900 mm, 1000 mm or more, and the height CH of the battery cell 20 is, for example, 80 mm to 110 mm, 110 mm to 140 mm. The thickness of the battery cell 20 is 5.0 mm to 7.0 mm, 7.0 mm to 9.0 mm, 9.0 mm to 11.0 mm, and the height TH of the terminal 26 is 40 mm to 50 mm, 50 mm to 60 mm, 60 mm to 70 mm. [Explanation of symbols]

[0044] 4 electrode body, 10 battery pack, 11 battery module, 12 voltage terminal, 14 connector, 20 battery cell, 22 flexible printed circuit board, 24 thermistor, 26, 27 terminal, 28 laminate film, 30 fixing tape, 41A, 42A area, 100 vehicle, 102 converter, 104 electric compressor, 106 heater, 108 motor, 110 gear box, 112 inverter, 114 charger, 116 charging port, 261, 262, 271, 272 area, 270 hole

Claims

1. An electrode body; A side member disposed on a side surface of the electrode body; a laminate film covering the electrode body and a portion of the side surface member, The side surface member is disposed at a position offset to one side with respect to the center of the side surface in the longitudinal direction of the side surface, a laminated battery in which, when one side of the side member where the side member is biased relative to the center in the longitudinal direction of the side surface is defined as an eccentric side and the other side is defined as a non-eccentric side, a volume of the side member located on the eccentric side of the side surface is equal to a volume of the side member located on the non-eccentric side.

2. The laminate type battery according to claim 1 , wherein the side surface member has a shape such that a thickness thereof continuously decreases from the non-uniform distribution side toward the uneven distribution side.

3. The laminated battery according to claim 1 , wherein the side surface member has a hole formed in an area on the uneven distribution side with the center of the side surface as a boundary.

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