Battery module

Abstract

To provide a battery module that can reduce stress burden of an electrode lead in a connection part between the electrode lead and a bus bar while increasing the space efficiency in a module case.SOLUTION: In a battery module 11, a plurality of battery cells 20 stacked on each other are accommodated in a module case 16 and the battery cells are electrically connected to each other through a bus bar 30. In the battery cell, a first side surface part 22A, which is an embossed surface forming an accommodation space inside the battery cell, and a second side surface part 22B in a planar shape are disposed facing each other in a stacking direction. An electrode lead 26 is provided projecting from an end part of the battery cell in a width direction along the second side surface art 22B. The second side surface parts 22B of the adjacent battery cells are disposed facing each other and with their electrode leads put close to each other, at least one first connection part 30A connected to the bus bar is provided.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a battery module. [Background technology]

[0002] In the battery module described in Patent Document 1 below, a housing contains a plurality of stacked battery cells and a plurality of bus bars that electrically connect the plurality of battery cells to each other. In this battery module, the tips of electrode tabs drawn out from the plurality of battery cells are connected so as to be stacked on one side of the bus bar to be connected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-109732 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery module described in Patent Document 1, multiple battery cells are stacked in the same orientation, so that multiple electrode tabs are drawn out at intervals in the stacking direction and bent towards the bus bar to which they are connected.

[0005] If the length of the bus bar is shortened in the stacking direction to improve the space efficiency inside the housing, the bending angle of the electrode tab in the battery cell far from the bus bar will become large, and there is a risk that the stress burden on the electrode tab at the connection between the electrode tab and the bus bar will increase due to factors such as expansion of the battery cell when the battery module swells.

[0006] In consideration of the above, an object of the present invention is to provide a battery module that can increase the space efficiency within a module case while reducing the stress burden on the electrode leads at the connection portions between the electrode leads and bus bars. [Means for solving the problem]

[0007] A first aspect of the battery module is a battery module in which a plurality of battery cells stacked on top of each other are housed within a module case and the plurality of battery cells are electrically connected to each other via a bus bar. In the battery module, a first side portion which is an embossed surface that forms the internal storage space of the battery cell and a planar second side portion are arranged facing each other in the stacking direction, and an electrode lead is provided protruding from an end of the battery cell in the width direction along the second side portion. The second side portions of two adjacent battery cells are arranged facing each other, and at least one first connection portion is provided in which the electrode leads are brought close to each other and connected to the bus bar.

[0008] In the battery module of the first aspect, a plurality of battery cells stacked on top of each other are housed in a module case. The plurality of battery cells are electrically connected to each other via bus bars. The battery cells are arranged such that a first side portion, which is an embossed surface that forms the internal storage space of the battery cell, and a planar second side portion face each other in the stacking direction, forming a so-called single-cup embossed structure. The battery cells have electrode leads that protrude from the widthwise ends of the battery cells along the second side portion.

[0009] Here, the battery module has a first connection portion in which the electrode leads of two adjacent battery cells are brought into close proximity and connected to the bus bar by arranging the second side portions of the two adjacent battery cells facing each other. In this first connection portion, the electrode leads of the adjacent battery cells are brought into close proximity, and even if the length of the bus bar is shortened along the stacking direction of the multiple battery cells, the bending angle of the electrode lead toward the connecting bus bar can be reduced, thereby reducing the stress burden on the electrode tab. As a result, it is possible to shorten the bus bar, and while increasing the space efficiency within the module case, the stress burden on the electrode lead at the connection portion between the electrode tab and the bus bar can be reduced.

[0010] A battery module of a second aspect is based on the first aspect, and the first connection portion brings the electrode leads having the same electrical polarity into close proximity, electrically connecting the adjacent battery cells in parallel.

[0011] In the battery module of the second aspect, the first connection portion electrically connects the electrode leads having the same electrical polarity to each other. That is, adjacent battery cells are electrically connected in parallel via the first connection portion. This makes it possible to shorten the bus bar at the portion where adjacent battery cells are electrically connected in parallel, thereby improving the space efficiency within the module case and reducing the stress load on the electrode lead at the connection portion between the electrode lead and the bus bar.

[0012] The battery module of the third aspect has at least one second connection portion in which two of the first connection portions are electrically connected in series via the bus bar, and between the battery cell connected to one of the two first connection portions and the battery cell connected to the other of the two first connection portions, two adjacent battery cells are arranged with their first side portions facing each other.

[0013] In the battery module of the third aspect, the two first connection parts have a second connection part electrically connected in series via a bus bar. In addition, between a battery cell connected to one of the two first connection parts and a battery cell connected to the other of the two first connection parts, two adjacent battery cells are arranged with their first side portions, which are embossed surfaces, facing each other. Therefore, a gap is provided between the two first connection parts according to the thickness of the embossed surfaces of the two adjacent battery cells. Therefore, the length of the bus bar constituting the second connection part can be designed according to the thickness of the embossed surfaces of the two adjacent battery cells, making the design easier.

[0014] A battery module of a fourth aspect is the battery module of the first or second aspect, wherein the electrode leads protrude from a central position in a height direction of the battery cells.

[0015] In the battery module of the fourth aspect, the electrode lead of each battery cell protrudes from the end of the battery cell in the width direction and the center position in the height direction. Therefore, even if the battery cell is inverted in the width direction or the height direction, the position of the electrode lead in the module case does not change. As a result, when two electrode leads with different electrical polarities are brought close to each other and connected to a bus bar, for example, the orientation of one of the two adjacent battery cells is inverted left and right in the width direction and the second side portions of each battery cell are faced to each other. Also, when two electrode leads with the same electrical polarity are brought close to each other and connected to a bus bar, the orientation of one of the two adjacent battery cells is inverted up and down in the height direction and the second side portions of each battery cell are faced to each other. In other words, in the fourth aspect, the orientation of the battery cell can be freely changed in the module case, and multiple battery cells can be connected to each other in a manner with high space efficiency. Therefore, the battery module has a highly versatile structure, and it is easy to change the design considering the space efficiency in the module case. Effect of the Invention

[0016] As described above, in the battery module according to the present invention, it is possible to improve the space efficiency within the module case, while reducing the stress burden on the electrode leads at the connection portions between the electrode leads and the bus bars. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic plan view showing a main part of a vehicle to which a battery pack according to an embodiment is applied; [Diagram 2] FIG. 1 is a schematic perspective view of a battery module according to an embodiment. [Diagram 3] FIG. 2 is a plan view of the battery module according to the embodiment with the top lid of the module case removed. [Figure 4] 3 is a schematic diagram of a battery cell accommodated in a battery module as viewed from the thickness direction. FIG. [Diagram 5] 4 is a schematic plan view showing, in a partially enlarged manner, a state in which a plurality of battery cells are housed in a module case. FIG. [Figure 6] 6 is a plan view corresponding to FIG. 5, showing a modified example of a method for stacking a plurality of battery cells according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, one embodiment of the present invention will be described with reference to FIGS.

[0019] (Overall configuration of vehicle 100) Fig. 1 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. 1, the vehicle 100 is an electric vehicle (BEV: Battery Electric Vehicle) in which the battery pack 10 is mounted under the floor. Note that arrows UP and FR in each drawing indicate the battery pack 10 mounted under the floor. The arrows L and LH 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 the directions of front, rear, left, right, top and bottom are used in the description, they refer to the front and rear in the vehicle longitudinal direction, the left and right in the vehicle width direction, and the top and bottom in the vehicle vertical direction, unless otherwise specified.

[0020] 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.

[0021] 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.

[0022] 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 device (not shown) to the charging port 116, power can be stored in the battery pack 10 via the on-board charger 114.

[0023] 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.

[0024] Here, the battery pack 10 is configured to include a plurality of battery modules 11. In the embodiment, as an example, ten battery modules 11 are provided. Specifically, five battery modules 11 are arranged in the vehicle front-rear direction on the right side of the vehicle 100, and five battery modules 11 are arranged in the vehicle front-rear direction on the left side of the vehicle 100. In addition, each battery module 11 is electrically connected.

[0025] Fig. 2 is a schematic perspective view of the battery module 11. As shown in Fig. 2, the battery module 11 includes a module case 16 that forms an outer shell. The module case 16 is formed in a substantially rectangular parallelepiped shape with the vehicle width direction as the longitudinal direction. The module case 16 is made of an aluminum alloy. For example, the module case 16 is formed by joining aluminum die castings to both ends of an aluminum alloy extrusion material by laser welding or the like.

[0026] 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 21, which will be described later, is connected to the connector 14. In addition, bus bars 30 (see FIG. 4) are welded to both ends of the battery module 11 in the vehicle width direction.

[0027] 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.

[0028] Fig. 3 is a plan view of the battery module 11 with the top cover removed. As shown in Fig. 3, battery cells 20 as batteries are housed inside the module case 16. As an example, a plurality of battery cells 20 are housed in an arranged (stacked) state inside the module case 16. In this embodiment, 24 battery cells 20 are arranged in the front-rear direction of the vehicle and bonded to one another.

[0029] For ease of understanding, in each of Figures 3 to 5, the direction indicated by arrow W is the width direction of battery cell 20, the direction indicated by arrow H is the height direction (up and down direction) of battery cell 20, and the direction indicated by arrow D is the thickness direction of battery cell 20. The width direction of the battery case 22, which will be described later, coincides with the width direction W of the battery cells 20. The height direction of the battery case 22 coincides with the height direction H of the battery cells 20. The thickness direction of the battery case 22 coincides with the thickness direction D of the battery cells 20.

[0030] On the battery cell 20, a flexible printed circuit board (FPC) is The flexible printed circuit board 21 is formed in a strip shape with its longitudinal direction aligned with the vehicle width direction, and a thermistor 23 is provided at each end of the flexible printed circuit board 21. The thermistor 23 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.

[0031] Furthermore, one or more cushioning materials (not shown) are housed inside the module case 16. 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 module case 16 in the longitudinal direction and in the central portion in the longitudinal direction.

[0032] 4 is a schematic diagram of a battery cell 20 housed in a battery module 11, as viewed from a thickness direction D. As shown in FIG. 4, the battery cell 20 is formed in a long rectangular plate shape with the width direction W as the longitudinal direction, and includes a battery case 22 forming an outer shell. An electrode body 40 is housed inside the battery case 22. The electrode body 40 includes a positive electrode and a negative electrode. and a separator are laminated together. In this embodiment, the battery case 22 is made of a laminate film, and the electrode body 40 is sealed by the laminate film.

[0033] The battery case 22 is embossed on at least one side in the thickness direction of the battery case 22. By the embossing, a concave housing portion 221 in which the electrode body 40 is housed and an outer end portion 223 provided on the outside of the housing portion 221 are formed on the side. The battery case 22 may adopt both a single cup embossed structure in which one portion is embossed and a double cup embossed structure in which two portions are embossed, but the present embodiment adopts a single cup embossed structure with a drawing depth of about 8 mm to 10 mm. Therefore, the battery case 22 has a first side portion 22A on one side in the thickness direction that is an embossed surface that has been embossed, and a second side portion 22B (see FIG. 5) on the other side in the thickness direction that is a non-embossed surface that has not been embossed.

[0034] The upper end of the battery case 22 in the width direction is bent and the corners are chamfered to form a generally trapezoidal shape. In addition, the upper end of the battery case 22 is bent, and a fixing tape 24 is wound around the upper end of the battery case 22 along the width direction.

[0035] Here, the battery cell 20 is equipped with an electrode lead 26 that protrudes from an end of the battery cell 20 (battery case 22) in the width direction W. Since the battery cell 20 has a single-cup embossed structure, the electrode lead 26 extends along the second side surface portion 22B that constitutes the non-embossed surface of the battery cell 20.

[0036] The electrode lead 26 is composed of a positive electrode lead 26A protruding from one end of the battery cell 20 in the width direction W, and a negative electrode lead 26B protruding from the other end of the battery cell 20 in the width direction W. The positive electrode lead 26A is connected to a positive electrode current collector (not shown) of the electrode body 40 inside the battery case 22. The negative electrode lead 26B is connected to a negative electrode current collector (not shown) of the electrode body 40 inside the battery case 22.

[0037] Also, as an example, the electrode lead 26 protrudes from the center position in the height direction H of the battery cell 20. Therefore, the position of the electrode lead 26 within the module case 16 does not change even if the battery cell 20 is inverted left to right in the width direction W or up to down in the height direction H.

[0038] The electrode lead 26 of each battery cell is electrically joined to a bus bar 30 (described later) via a welded portion 50 (see FIG. 5). The electrode lead 26 is connected to external wiring of the battery module 11 via the bus bar 30. Although any known welding method can be appropriately used to weld the electrode lead 26 to the bus bar 30, in one example of the present embodiment, the electrode lead 26 and the bus bar 30 are joined by laser welding.

[0039] 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.

[0040] For ease of explanation, one end of the battery cell 20 in the height direction H will be referred to as the upper end 20A, and the other end of the battery cell 20 in the height direction H will be referred to as the lower end 20B.

[0041] Fig. 5 is a schematic plan view showing, in a partially enlarged manner, a state in which multiple battery cells 20 are housed in a module case 16. As shown in Fig. 5, in the module case 16, ends 261 of electrode leads 26 protrude from ends in the width direction W of the multiple battery cells 20 that are stacked on top of each other. In addition, multiple bus bars 30 are arranged on both sides of the battery cells 20 in the width direction W.

[0042] For ease of explanation, FIG. 5 illustrates a state in which adjacent battery cells 20 are spaced apart; however, in reality, the stacked battery cells 20 are in contact with each other either directly or via a cushioning material, and are constrained to each other with a predetermined confining pressure applied along the stacking direction (thickness direction D).

[0043] The busbar 30 has a thickness direction that is the width direction W of the battery cells 20, and extends along the stacking direction (thickness direction D) of the battery cells 20. In addition, the busbar 30 has a slot-shaped through hole 32 formed therein that penetrates the busbar 30 in the thickness direction.

[0044] The electrode leads 26 protruding from the ends of the battery cells 20 in the width direction W are inserted into through holes 32 of the bus bar 30, and the ends 261 protruding from the through holes 32 are folded back towards the bus bar 30 and overlapped on the surface of the bus bar 30. The bus bar 30 is provided with first connection portions 30A that electrically connect adjacent battery cells in parallel, and second connection portions 30B that electrically connect the two first connection portions 30A in series.

[0045] (About the stacking method of battery cells) 5, as an example, a plurality of stacked battery cells are electrically connected in parallel to form a parallel stack body 20PC inside the module case 16. In this embodiment, one parallel stack body 20PC is formed by two adjacent battery cells.

[0046] In the parallel stack 20PC, two adjacent battery cells 20 are arranged with the second side surface portions 22B, which are non-embossed surfaces, facing each other. Therefore, in the parallel stack 20PC, the electrode leads 26 are drawn out to the bus bar 30 side in close proximity to each other at the ends in the width direction W.

[0047] In the parallel stack 20PC, one of two adjacent battery cells 20 is inverted up and down in the height direction H. Therefore, the upper end 20A of one battery cell 20 and the lower end 20B of the other battery cell 20 face each other in the stacking direction (thickness direction D in FIG. 5). For this reason, in the parallel stack 20PC, electrode leads with the same electrical polarity (positive or negative) are adjacent to each other on one side and the other side in the width direction W.

[0048] Two electrode leads 26 adjacent to each other on one side and the other side in the width direction W of the parallel laminate 20PC have ends 261 that pass through the through holes 32 of the bus bar 30 folded back toward the bus bar 30 and overlapped on the surface of the bus bar 30. On the surface of the bus bar 30, the overlapping portions of the two electrode leads 26 are joined by a welded portion 50.

[0049] The two parallel laminates 20PC arranged in the stacking direction are electrically connected in series via the second connection portion 30B of the bus bar 30 extending in the stacking direction between the two parallel laminates 20PC. In other words, the second connection portion 30B electrically connects the two first connection portions 30A in series.

[0050] On the side of the second connection portion 30B, a battery cell 20 connected to one of the two first connection portions 30A and a battery cell 20 connected to the other of the two first connection portions 30A are adjacent to each other. The two adjacent battery cells 20 are arranged with their first side surface portions 22A, which are embossed surfaces, facing each other. Therefore, a gap is provided between the two first connection portions 30A according to the thickness of the embossed surfaces of the two adjacent battery cells 20. Therefore, the length of the bus bar 30 constituting the second connection portion 30A is set corresponding to the thickness of the embossed surfaces of the two adjacent battery cells 20.

[0051] (Action and Effects) As described above, in the battery module 11 according to the embodiment, a plurality of battery cells 20 stacked on top of each other are housed in the module case 16. The plurality of battery cells 20 are electrically connected to each other via the bus bars 30. The battery cells 20 have a so-called single-cup embossed structure in which a first side surface portion 22A, which is an embossed surface that forms the internal storage space of the battery cell 20, and a planar second side surface portion 22B are arranged facing each other in the stacking direction. The battery cells 20 have electrode leads 26 that are provided so as to protrude from the ends of the battery cells 20 in the width direction W along the second side surface portion 22B.

[0052] Here, the battery module 11 has a first connection portion 30A in which the electrode leads 26 of two adjacent battery cells 20 are brought into close proximity to each other and connected to the bus bar 30 by arranging the second side surface portions 22B of two adjacent battery cells 20 facing each other. In this first connection portion 30A, the electrode leads 26 of the adjacent battery cells 20 are brought into close proximity to each other, and even if the length of the bus bar 30 is shortened along the stacking direction of the multiple battery cells 20, the bending angle of the electrode lead 26 toward the connecting bus bar 30 side can be reduced, and the stress burden on the electrode lead 26 can be reduced. As a result, the bus bar can be shortened, and the space efficiency inside the module case can be improved while the stress burden on the electrode lead 26 at the connection portion between the electrode tab and the bus bar can be reduced.

[0053] Furthermore, in this embodiment, the first connection portion 30A electrically connects the electrode leads 26 having the same electrical polarity to each other. That is, adjacent battery cells 20 are electrically connected in parallel via the first connection portion 30A. This makes it possible to shorten the bus bar 30 at the location where adjacent battery cells 20 are electrically connected in parallel to increase the space efficiency within the module case, while reducing the stress load on the electrode lead at the connection portion between the electrode lead 26 and the bus bar 30.

[0054] Furthermore, in this embodiment, the two first connection parts 30A have a second connection part 30B electrically connected in series via the bus bar 30. Between the battery cell 20 connected to one of the two first connection parts 30A and the battery cell 20 connected to the other of the two first connection parts 30A, the two adjacent battery cells 20 are arranged with their first side surface parts 22A, which are embossed surfaces, facing each other. Therefore, a gap is provided between the two first connection parts 30A according to the thickness of the embossed surfaces of the two adjacent battery cells 20. Therefore, the length of the bus bar 30 constituting the second connection part 30B can be designed according to the thickness of the embossed surfaces of the two adjacent battery cells 20, making the design easier.

[0055] In this embodiment, the electrode lead 26 of each battery cell 20 protrudes from the end of the battery cell 20 in the width direction W and from the center position in the height direction H. Therefore, even if the battery cell 20 is inverted left and right in the width direction W or up and down in the height direction H, the position of the electrode lead 26 in the module case 16 does not change. As a result, for example, when two electrode leads 26 with different electrical polarities are brought close to each other and connected to the bus bar 30, the orientation of one of the two adjacent battery cells 20 may be inverted left and right in the width direction W, and the second side surface portions 22B of each battery cell 20 may be opposed to each other. Also, for example, when two electrode leads 26 with the same electrical polarity are brought close to each other and connected to the bus bar 30, the orientation of one of the two adjacent battery cells 20 may be inverted up and down in the height direction H, and the second side surface portions 22B of each battery cell 20 may be opposed to each other. In other words, in this embodiment, the orientation of the battery cell 20 can be freely changed in the module case 16, and multiple battery cells 20 can be connected to each other in a highly space-efficient manner. Therefore, the battery module 11 has a highly versatile structure, and the design can be easily modified to take into account the space efficiency inside the module case 16.

[0056] Although one embodiment has been described above, the present invention can be implemented with various modifications without departing from the spirit of the present invention. Of course, the scope of the present invention is not limited to the above embodiment. Below, we will explain modified examples that can be substituted or combined with the configuration of the above embodiment.

[0057] (Modifications to the battery cell stacking method) In the above embodiment, two adjacent battery cells 20 are electrically connected in parallel via the first connection portion 30A. However, as shown in FIG. 6, three or more battery cells 20 may be electrically connected in parallel via the first connection portion 30A.

[0058] 6, a first battery cell 201, a second battery cell 202, a third battery cell 203, and a fourth battery cell 204 are electrically connected in parallel via a first connection portion 30A to form a parallel stack body 200PC. Note that the configurations of the first battery cell 201 to the fourth battery cell 204 are the same as those of the battery cell 20 in the above embodiment, so the same components are denoted by the same reference numerals and detailed description will be omitted.

[0059] The first battery cell 201 and the second battery cell 202 are adjacent to each other along the stacking direction (thickness direction D in FIG. 6). The first battery cell 201 and the second battery cell 202 are arranged with the second side surface portions 22B, which are non-embossed surfaces, facing each other. The second battery cell 202 is arranged in an orientation in which it is upside down in the height direction H with respect to the first battery cell 201.

[0060] The third battery cell 203 is disposed adjacent to the first battery cell 201. The third battery cell 203 is disposed with the second side surface portion 22B, which is the non-embossed surface, facing the first side surface portion 22A, which is the embossed surface of the first battery cell 201. The fourth battery cell 204 is disposed adjacent to the second battery cell 202. The fourth battery cell 204 is disposed with the second side surface portion 22B, which is the non-embossed surface, facing the first side surface portion 22A, which is the embossed surface of the second battery cell 202.

[0061] In the parallel stack 200PC described above, the length of the bus bar 30 can also be shortened while reducing the stress load on the electrode leads 26 at the locations where adjacent battery cells 20 are electrically connected in parallel.

[0062] In the above embodiment, two adjacent battery cells 20 are electrically connected in parallel via the first connection portion 30A, but the present invention is not limited to this. Two adjacent battery cells 20 may be electrically connected in series via the first connection portion 30A. That is, two electrode leads 26 with different electrical polarities may be brought close to each other, and the adjacent battery cells 20 may be electrically connected in series. [Explanation of symbols]

[0063] 11 Battery module 16 Module case (case) 20 Battery Cells 22A 1st side part 22B 2nd side part 26 Electrode Lead

Claims

1. A battery module in which a plurality of stacked battery cells are housed in a module case and the plurality of battery cells are electrically connected to each other via bus bars, The battery cell is arranged such that a first side surface portion, which is an embossed surface that forms an internal storage space of the battery cell, and a planar second side surface portion face each other in the stacking direction, and an electrode lead is provided to protrude from an end portion in a width direction of the battery cell along the second side surface portion, the second side surface portions of two adjacent battery cells are arranged to face each other, and the electrode leads are brought close to each other and connected to the bus bar, and at least one first connection portion is provided. Battery module.

2. the first connection portion brings the electrode leads having the same electrical polarity into close proximity and electrically connects the adjacent battery cells in parallel; The battery module according to claim 1 .

3. At least one second connection portion is electrically connected in series between two of the first connection portions via the bus bar, Between the battery cell connected to one of the two first connection parts and the battery cell connected to the other of the two first connection parts, two adjacent battery cells are arranged with the first side surface portions facing each other. The battery module according to claim 2 .

4. The electrode lead protrudes from a center position in a height direction of the battery cell. The battery module according to claim 1 or 2.

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