Battery module

Abstract

The utility model provides a battery module. A battery module in which a plurality of battery cells stacked on each other are housed in a module case, the plurality of battery cells being electrically connected to each other via a bus bar, in which a first side surface portion and a planar second side surface portion, which are embossed surfaces that form a housing space inside the battery cells, are disposed so as to face a stacking direction, and in which the first side surface portion and the second side surface portion are disposed so as to face each other in a stacking direction. The battery module is provided with at least one first connecting part, the second side surfaces of the battery cells are provided with second side surfaces along which electrode leads are provided so as to protrude from the end parts of the battery cells in the width direction, and the first connecting part enables the second side surfaces of two adjacent battery cells to face each other, and enables the electrode leads to be connected with the busbar in a manner that the electrode leads are close to each other.

Description

Technical Field

[0001] The present disclosure relates to a battery module. Background Art

[0002] In the battery module described in Japanese Patent Application Laid-Open No. 2022-109732, a plurality of stacked battery cells and a plurality of bus bars electrically connecting the plurality of battery cells are housed in a housing.

[0003] In this battery module, the tips of electrode tabs extracted from a plurality of battery cells are connected so as to overlap one surface of a connected bus bar.

[0004] In the battery module described in Japanese Patent Application Laid-Open No. 2022-109732, a plurality of battery cells are stacked in the same orientation. Therefore, a plurality of electrode tabs are led out at intervals in the stacking direction and bent toward the connected busbars.

[0005] When the length of the busbar is shortened in the stacking direction in order to improve the space efficiency within the frame, there is a possibility that the bending angle of the electrode tab in the battery cell away from the busbar becomes larger, and the stress burden of the electrode tab in the connection part between the electrode tab and the busbar may increase due to the expansion of the battery cell caused by swelling of the battery module. Summary of the Invention

[0006] In consideration of the above facts, the present disclosure aims to provide a battery module that can improve the space efficiency within the module case and reduce the stress burden on the electrode leads at the connection between the electrode leads and the busbar.

[0007] The battery module of the first mode accommodates a plurality of battery cells stacked on each other in a module housing, and the plurality of battery cells are electrically connected to each other via a bus bar, wherein, in the battery cell, the embossed surface forming the internal accommodation space of the battery cell, i.e., the first side portion and the planar second side portion are arranged facing the stacking direction, and the electrode lead is provided protruding from the end of the width direction of the battery cell along the second side portion, and the battery module has at least one first connecting portion, which makes the second side portions of two adjacent battery cells face each other, so that the electrode leads are closely connected to the bus bar.

[0008] In the first embodiment of the battery module, a plurality of stacked battery cells are housed within a module housing. Furthermore, the plurality of battery cells are electrically connected via busbars. In the battery cell, the embossed surface (i.e., the first side surface) and the flat second side surface (i.e., the planar surface) forming the internal storage space of the battery cell are arranged facing the stacking direction, forming a so-called single-cup embossed structure. Furthermore, the battery cell has electrode leads protruding from the widthwise ends of the battery cell along the second side surface.

[0009] Here, the battery module has a first connection portion that connects the electrode leads to the busbar by arranging the second side surfaces of two adjacent battery cells facing each other, bringing the electrode leads into proximity. This first connection portion reduces the bending angle of the electrode leads toward the busbar, even when the length of the busbar is shortened along the stacking direction of the multiple battery cells. This reduces the stress on the electrode tabs. As a result, the busbar can be shortened, improving space efficiency within the module housing while reducing the stress on the electrode leads at the connection between the electrode tabs and the busbar.

[0010] In the battery module of the second aspect, in the first aspect, the first connecting portion brings the electrode leads having the same electrical polarity close to each other, thereby electrically connecting adjacent battery cells in parallel.

[0011] In the second embodiment of the battery module, the first connecting portion electrically connects electrode leads of the same electrical polarity. That is, adjacent battery cells are electrically connected in parallel via the first connecting portion. Therefore, the busbar can be shortened at the location where multiple adjacent battery cells are electrically connected in parallel, improving space efficiency within the module housing while reducing stress on the electrode leads at the connection between the electrode leads and the busbar.

[0012] The battery module of the third embodiment has, in the structure described in the second embodiment, at least one second connection portion, which electrically connects the two first connection portions 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, the two adjacent battery cells are arranged with the first side portions facing each other.

[0013] In the battery module of the third embodiment, there is a second connection portion in which two first connection portions are electrically connected in series via a busbar. In addition, 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, the two adjacent battery cells are arranged so that the first side portions, which serve as embossed surfaces, face each other. Therefore, a gap corresponding to the thickness of the embossed surfaces of the two adjacent battery cells is provided between the two first connection portions. Therefore, the length of the busbar constituting the second connection portion can be designed according to the thickness of the embossed surfaces of the two adjacent battery cells, making the design easy.

[0014] In the battery module according to a fourth aspect, in the first aspect or the second aspect, the electrode lead protrudes from a center position in a height direction of the battery cell.

[0015] In the fourth embodiment of the battery module, the electrode leads of each battery cell protrude from the ends of the battery cell in the width direction and the center of the height direction. Therefore, the position of the electrode leads within the module housing remains unchanged whether the battery cell is positioned horizontally or vertically inverted in the width direction. Thus, for example, when two electrode leads of different electrical polarities are connected closely to the busbar, the orientation of one of the two adjacent battery cells can be reversed horizontally in the width direction, so that their second side faces face each other. Alternatively, when two electrode leads of the same electrical polarity are connected closely to the busbar, the orientation of one of the two adjacent battery cells can be reversed vertically in the height direction, so that their second side faces face each other. In other words, in the fourth embodiment, the orientation of the battery cells can be freely changed within the module housing, allowing multiple battery cells to be connected in a space-efficient manner. Consequently, the battery module has a highly versatile structure, making it easy to modify the design based on space efficiency within the module housing.

[0016] As described above, in the battery module according to the present disclosure, it is possible to improve the space efficiency within the module case and reduce the stress burden on the electrode leads at the connection portion between the electrode leads and the bus bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Exemplary embodiments of the present disclosure will be described in detail based on the following drawings, in which:

[0018] Figure 1 It is a schematic plan view showing the main parts of a vehicle to which the battery pack according to the embodiment is applied.

[0019] Figure 2 It is a schematic perspective view of a battery module according to the embodiment.

[0020] Figure 3 It is a plan view of the battery module according to the embodiment with the upper cover of the module case removed.

[0021] Figure 4 This is a schematic diagram of battery cells housed in a battery module as viewed from the thickness direction.

[0022] Figure 5 It is a partially enlarged schematic plan view showing a state where a plurality of battery cells are housed in a module case.

[0023] Figure 6 A modified example of the method for stacking a plurality of battery cells according to the embodiment is shown. Figure 5 Corresponding top view. DETAILED DESCRIPTION

[0024] Below, refer to Figures 1 to 5, illustrating an embodiment of the present disclosure.

[0025] (Overall Structure of Vehicle 100)

[0026] Figure 1 1 is a schematic plan view showing the main parts of a vehicle 100 to which the battery pack 10 according to the embodiment is applied. Figure 1 As shown, vehicle 100 is an electric vehicle (BEV: battery electric vehicle) with a battery pack 10 mounted under the floor. Arrows UP, FR, and LH in the various figures indicate the upper side in the vehicle's vertical direction, the front side in the vehicle's longitudinal direction, and the left side in the vehicle's width direction, respectively. When describing directions using the terms front, back, left, right, up, and down, unless otherwise specified, these refer to the front and back directions in the vehicle's longitudinal direction, the left and right directions in the vehicle's width direction, and the top and bottom directions in the vehicle's vertical direction.

[0027] As an example, vehicle 100 of this embodiment includes a DC / DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 disposed toward the front of the vehicle relative to battery pack 10. Furthermore, a motor 108, a gearbox 110, an inverter 112, and a charger 114 are disposed toward the rear of the vehicle relative to battery pack 10.

[0028] The DC current output from battery pack 10 is voltage-regulated by DC / DC converter 102 and then supplied to electric compressor 104, PTC heater 106, inverter 112, etc. Furthermore, by supplying power to motor 108 via inverter 112, the rear wheels rotate, causing vehicle 100 to travel.

[0029] A charging port 116 is provided on the right side of the rear portion of the vehicle 100 . By connecting a charging plug of an external charging device (not shown) to the charging port 116 , electric power can be stored in the battery pack 10 via the on-board charger 114 .

[0030] The arrangement and structure of the components comprising vehicle 100 are not limited to the above-described configuration. For example, the present invention may also be applied to a hybrid vehicle (HV) or a plug-in hybrid electric vehicle (PHEV) equipped with an engine. Furthermore, in this embodiment, a rear-wheel drive vehicle is configured with motor 108 mounted at the rear of the vehicle. However, this is not limiting. A front-wheel drive vehicle may also be configured with motor 108 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, a vehicle may also be configured with in-wheel motors at each wheel.

[0031] Here, the battery pack 10 is configured to include a plurality of battery modules 11. In this embodiment, as an example, ten battery modules 11 are provided. Specifically, five battery modules 11 are arranged in the vehicle longitudinal direction on the right side of the vehicle 100, and five battery modules 11 are arranged in the vehicle longitudinal direction on the left side of the vehicle 100. Furthermore, the battery modules 11 are electrically connected.

[0032] Figure 2 1 is a schematic three-dimensional diagram of the battery module 11. Figure 2 As shown, the battery module 11 includes a module housing 16 that forms an outer shell. The module housing 16 is formed into a generally rectangular parallelepiped shape with the vehicle width direction as the longitudinal direction. Furthermore, the module housing 16 is made of an aluminum alloy. For example, the module housing 16 is formed by laser welding or other methods by joining aluminum die-casting to the two ends of an aluminum alloy extrusion.

[0033] 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, described later, is connected to the connector 14. In addition, bus bars 30 (see FIG. 1 ) are welded to both ends of the battery module 11 in the vehicle width direction. Figure 4 ).

[0034] The battery module 11 has a vehicle widthwise length MW of, for example, 350 mm to 600 mm, a vehicle longitudinal length ML of, for example, 150 mm to 250 mm, and a vehicle vertical height MH of, for example, 80 mm to 110 mm.

[0035] Figure 3 FIG. 1 is a top view of the battery module 11 with the upper cover removed. Figure 3 As shown, battery cells 20 serving as batteries are housed within the module housing 16. As an example, multiple battery cells 20 are housed in an aligned (stacked) state within the module housing 16. In this embodiment, 24 battery cells 20 are aligned in the vehicle front-to-rear direction and bonded to each other.

[0036] In addition, for easy understanding, Figures 3 to 5 In each figure, the direction indicated by the arrow W is set as the width direction of the battery cell 20, the direction indicated by the arrow H is set as the height direction (up and down direction) of the battery cell 20, and the direction indicated by the arrow D is set as the thickness direction of the battery cell 20.

[0037] The width direction of the battery case 22 described below coincides with the width direction W of the battery cell 20 . The height direction of the battery case 22 coincides with the height direction H of the battery cell 20 . The thickness direction of the battery case 22 coincides with the thickness direction D of the battery cell 20 .

[0038] A flexible printed circuit (FPC) 21 is placed above the battery cell 20. The FPC 21 is formed in a strip shape with its length extending across the width of the vehicle. Thermistors 23 are located at each end of the FPC 21. The thermistors 23 are not bonded to the battery cell 20 and are instead pressed toward the battery cell 20 by the upper cover of the battery module 11.

[0039] Furthermore, one or more cushioning materials (not shown) are housed within the module case 16. For example, the cushioning materials are elastically deformable thin plate-like members, arranged between adjacent battery cells 20 with the arrangement of the battery cells 20 oriented in the thickness direction. In this embodiment, cushioning materials are placed at both longitudinal ends and the longitudinal center of the module case 16, as an example.

[0040] Figure 4 This is a schematic diagram of the battery cell 20 housed in the battery module 11 as viewed from the thickness direction D. Figure 4 As shown, the battery cell 20 is formed into a rectangular plate with the width direction W as the longitudinal direction, and includes a battery case 22 forming an outer shell. The battery case 22 houses an electrode assembly 40. The electrode assembly 40 is composed of a stack of a positive electrode, a negative electrode, and a separator. In this embodiment, the battery case 22 is formed of a laminate film, and the electrode assembly 40 is sealed by the laminate film.

[0041] With respect to the battery case 22, embossing is performed on at least one side in the thickness direction of the battery case 22. By performing the embossing, a concave receiving portion 221 for internally receiving the electrode body 40 and an outer end portion 223 provided on the outside of the receiving portion 221 are formed on the side. In addition, the battery case 22 can adopt both a single-cup embossing structure in which embossing is performed at one location and a double-cup embossing structure in which embossing is performed at two locations. In the present embodiment, the single-cup embossing structure is a drawing depth of about 8 mm to 10 mm. Therefore, with respect to the battery case 22, the first side portion 22A on one side in the thickness direction is set as an embossed surface to which embossing is performed, and the second side portion 22B on the other side in the thickness direction (refer to Figure 5 ) becomes a non-embossed surface that has not been embossed.

[0042] The upper end of the battery case 22 is bent, and the corners are chamfered to form a substantially trapezoidal shape. Furthermore, the upper end of the battery case 22 is bent, and a fixing tape 24 is wrapped around the upper end of the battery case 22 in the width direction.

[0043] Here, the battery cell 20 includes an electrode lead 26 protruding 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 22B constituting the non-embossed surface of the battery cell 20.

[0044] The electrode lead 26 consists of a positive electrode lead 26A that protrudes from one end of the battery cell 20 in the width direction W, and a negative electrode lead 26B that protrudes from the other end of the battery cell 20 in the width direction W. The positive electrode lead 26A is connected to the positive electrode current collector (not shown) of the electrode body 40 inside the battery case 22. The negative electrode lead 26B is connected to the negative electrode current collector (not shown) of the electrode body 40 inside the battery case 22.

[0045] In addition, as an example, the electrode lead 26 protrudes from the center of the battery cell 20 in the height direction H. Therefore, the battery cell 20 has a structure in which the position of the electrode lead 26 in the module case 16 does not change when the battery cell 20 is in a position in which the width direction W is reversed left and right, or when the battery cell 20 is in a position in which the height direction H is reversed up and down.

[0046] The electrode lead 26 of each battery cell is connected via a welding portion 50 (see Figure 5 ) are electrically joined to a bus bar 30, described later. The electrode lead 26 is connected to wiring external to the battery module 11 via the bus bar 30. A known welding method can be appropriately used to weld the electrode lead 26 and the bus bar 30. In one example of this embodiment, the electrode lead 26 and the bus bar 30 are joined by laser welding.

[0047] 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 mm to 900 mm, or 1000 mm or greater. The length CW2 of the region housing the electrode assembly is, for example, 500 mm to 520 mm, 600 mm to 700 mm, 700 mm to 800 mm, 800 mm to 900 mm, or 1000 mm or greater. The height CH of the battery cell 20 is, for example, 80 mm to 110 mm, or 110 mm to 140 mm. Furthermore, the thickness of the battery cell 20 is, for example, 5.0 mm to 7.0 mm, 7.0 mm to 9.0 mm, or 9.0 mm to 11.0 mm. The height TH of the terminal 26 is, for example, 40 mm to 50 mm, 50 mm to 60 mm, or 60 mm to 70 mm.

[0048] Hereinafter, for convenience of description, one end portion of the battery cell 20 in the height direction H is referred to as an upper end portion 20A, and the other end portion of the battery cell 20 in the height direction H is referred to as a lower end portion 20B.

[0049] Figure 5 1 is a partially enlarged schematic top view showing a state where a plurality of battery cells 20 are housed in a module case 16. Figure 5 As shown, within the module case 16, the ends 261 of the electrode leads 26 protrude from the ends of the stacked battery cells 20 in the width direction W. Furthermore, a plurality of bus bars 30 are disposed on one side and the other side of the battery cells 20 in the width direction W.

[0050] In addition, for ease of explanation, Figure 5 The diagram shows a state where spaces are provided between adjacent battery cells 20 , but in reality, the stacked battery cells 20 are constrained to each other with a buffer material interposed therebetween or directly in contact with each other while applying a predetermined constraining pressure along the stacking direction (thickness direction D).

[0051] The width direction W of the battery cell 20 is defined as the plate thickness direction, and the bus bar 30 extends along the stacking direction (thickness direction D) of the battery cell 20. The bus bar 30 is also provided with a groove-shaped through-hole 32 that penetrates the bus bar 30 in the plate thickness direction.

[0052] The electrode leads 26 protruding from the ends of the battery cells 20 in the width direction W are inserted into the through-holes 32 of the bus bar 30. The ends 261 protruding from the through-holes 32 are folded back toward the bus bar 30 and overlap the surface of the bus bar 30. The bus bar 30 is provided with a first connecting portion 30A that electrically connects adjacent battery cells in parallel, and a second connecting portion 30B that electrically connects two first connecting portions 30A in series.

[0053] (Regarding the method of stacking battery cells)

[0054] like Figure 5 As shown, as an example, a plurality of stacked battery cells are electrically connected in parallel to form a parallel stack 20PC within the module case 16. In this embodiment, two adjacent battery cells form one parallel stack 20PC.

[0055] In the parallel stack 20PC, two adjacent battery cells 20 are arranged with their non-embossed second side surfaces 22B facing each other. Therefore, in the parallel stack 20PC, the electrode leads 26 are drawn out to the busbar 30 side in a close proximity at the ends in the width direction W.

[0056] In addition, in the parallel stack 20PC, the orientation of one of the two adjacent battery cells 20 is reversed 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 are opposite in the stacking direction (in the vertical direction). Figure 5Therefore, in the parallel stack 20PC, on one side and the other side in the width direction W, the electrode leads having the same electrical polarity (positive or negative) are close to each other.

[0057] The two electrode leads 26 that are adjacent to each other on one side and the other side in the width direction W of the parallel stack 20PC are folded back toward the bus bar 30 through the through-holes 32 of the bus bar 30, and overlap with the surface of the bus bar 30. The overlapping portions of the two electrode leads 26 are bonded to the surface of the bus bar 30 by welds 50.

[0058] The two parallel stacks 20PC arranged in the stacking direction are electrically connected in series via the second connecting portion 30B of the bus bar 30 extending in the stacking direction between the two parallel stacks 20PC. In other words, the second connecting portion 30B electrically connects the two first connecting portions 30A in series.

[0059] To the side of the second connecting portion 30B, a battery cell 20 connected to one of the two first connecting portions 30A and a battery cell 20 connected to the other of the two first connecting portions 30A are adjacent. These two adjacent battery cells 20 are arranged with their first side surfaces 22A, which serve as embossed surfaces, facing each other. Therefore, a gap corresponding to the thickness of the embossed surfaces of the two adjacent battery cells 20 is provided between the two first connecting portions 30A. Therefore, the length of the busbar 30 constituting the second connecting portion 30A is set in accordance with the thickness of the embossed surfaces of the two adjacent battery cells 20.

[0060] (Function and effect)

[0061] As described above, in the battery module 11 according to the embodiment, a plurality of battery cells 20 are stacked within the module housing 16. Furthermore, the plurality of battery cells 20 are electrically connected to each other via the busbar 30. The battery cells 20 have a first side surface 22A (embossed surface) and a flat second side surface 22B (planar surface) that define the internal storage space of the battery cells 20, arranged facing the stacking direction, forming a so-called single-cup embossed structure. Furthermore, the battery cells 20 have electrode leads 26 that protrude from the ends of the battery cells 20 in the width direction W along the second side surface 22B.

[0062] Here, the battery module 11 has a first connection portion 30A that connects the electrode leads 26 to the bus bar 30 by arranging the second side surfaces 22B of two adjacent battery cells 20 facing each other. This first connection portion 30A reduces the bending angle of the electrode leads 26 toward the connected bus bar 30, even when the electrode leads 26 of adjacent battery cells 20 are brought into proximity and the length of the bus bar 30 is shortened along the stacking direction of the multiple battery cells 20. This reduces the stress on the electrode leads 26. As a result, the bus bar can be shortened, improving space efficiency within the module case while also reducing the stress on the electrode leads 26 at the connection between the electrode tabs and the bus bar.

[0063] Furthermore, in this embodiment, the first connecting portion 30A electrically connects the electrode leads 26 of the same electrical polarity. That is, adjacent battery cells 20 are electrically connected in parallel via the first connecting portion 30A. Therefore, the busbar 30 can be shortened at the location where the adjacent battery cells 20 are electrically connected in parallel, improving space efficiency within the module housing while reducing stress on the electrode leads 26 at the connection between the busbar 30 and the electrode leads.

[0064] Furthermore, in this embodiment, a second connection portion 30B is provided that electrically connects the two first connection portions 30A in series via the busbar 30. Furthermore, between the battery cell 20 connected to one of the two first connection portions 30A and the battery cell 20 connected to the other of the two first connection portions 30A, the two adjacent battery cells 20 are arranged with their first side surfaces 22A, which serve as embossed surfaces, facing each other. Therefore, a gap corresponding to the thickness of the embossed surfaces of the two adjacent battery cells 20 is provided between the two first connection portions 30A. Therefore, the length of the busbar 30 constituting the second connection portion 30B can be designed based on the thickness of the embossed surfaces of the two adjacent battery cells 20, making design easier.

[0065] In this embodiment, the electrode leads 26 of each battery cell 20 protrude from the ends of the battery cell 20 in the width direction W and from the center in the height direction H. Therefore, the position of the electrode leads 26 within the module case 16 remains unchanged whether the battery cell 20 is positioned horizontally in the width direction W or vertically in the height direction H. Thus, for example, when two electrode leads 26 of different electrical polarities are connected closely to the bus bar 30, the orientation of one of the two adjacent battery cells 20 can be reversed horizontally in the width direction W, so that their second side faces 22B face each other. Alternatively, when two electrode leads 26 of the same electrical polarity are connected closely to the bus bar 30, the orientation of one of the two adjacent battery cells 20 can be reversed vertically in the height direction H, so that their second side faces 22B face each other. In other words, in this embodiment, the orientation of the battery cells 20 can be freely changed within the module case 16, allowing multiple battery cells 20 to be connected in a space-efficient manner. Therefore, the battery module 11 has a highly versatile structure, and its design can be easily modified in consideration of the space efficiency within the module case 16 .

[0066] The above describes one embodiment, but the present disclosure can be implemented with various modifications within the scope of the present disclosure. The scope of the present disclosure is of course not limited to the above embodiment. The following describes a modification that can be replaced or combined with the structure of the above embodiment.

[0067] (Regarding a Modification of the Battery Cell Stacking Method)

[0068] In the above embodiment, two adjacent battery cells 20 are electrically connected in parallel via the first connecting portion 30A. However, Figure 6 As shown, three or more battery cells 20 are electrically connected in parallel via the first connecting portion 30A.

[0069] exist Figure 6 In the embodiment, the first battery cell 201, the second battery cell 202, the third battery cell 203, and the fourth battery cell 204 are electrically connected in parallel via the first connecting portion 30A to form a parallel stack 200PC. The structures of the first to fourth battery cells 201 to 204 are identical to the battery cell 20 of the above-described embodiment, so identical components are denoted by identical reference numerals and detailed descriptions are omitted.

[0070] The first battery cell 201 and the second battery cell 202 are arranged along the stacking direction (in Figure 6The first battery cell 201 and the second battery cell 202 are arranged so that their second side surfaces 22B, which are non-embossed surfaces, face each other. The second battery cell 202 is arranged in a vertically reversed position relative to the first battery cell 201 in the height direction H.

[0071] The third battery cell 203 is arranged adjacent to the first battery cell 201. The third battery cell 203 is arranged such that the second side surface 22B, which is the non-embossed surface, faces the first side surface 22A, which is the embossed surface of the first battery cell 201. The fourth battery cell 204 is arranged adjacent to the second battery cell 202. The fourth battery cell 204 is arranged such that the second side surface 22B, which is the non-embossed surface, faces the first side surface 22A, which is the embossed surface of the second battery cell 202.

[0072] Even in the parallel stack 200PC described above, the length of the bus bar 30 can be shortened while reducing the stress burden on the electrode leads 26 at the portion where the adjacent battery cells 20 are electrically connected in parallel.

[0073] In addition, in the above embodiment, two adjacent battery cells 20 are electrically connected in parallel via the first connecting portion 30A, but the present invention is not limited thereto. Alternatively, two adjacent battery cells 20 may be electrically connected in series via the first connecting portion 30A. In other words, two electrode leads 26 having different electrical polarities may be brought into close proximity to electrically connect adjacent battery cells 20 in series.

Claims

1. A battery module, comprising a plurality of battery cells stacked on top of each other in a module housing, wherein the plurality of battery cells are electrically connected to each other via bus bars, characterized in that: In the battery cell, the embossed surface forming the internal storage space of the battery cell, i.e., the first side surface, and the planar second side surface are arranged facing the stacking direction, and the electrode lead is provided along the second side surface so as to protrude from the end portion in the width direction of the battery cell. The battery module includes at least one first connecting portion, wherein the second side surfaces of two adjacent battery cells are arranged to face each other and the electrode leads are connected to the bus bar in close proximity.

2. The battery module according to claim 1, wherein: The first connecting portion brings the electrode leads having the same electrical polarity closer together to electrically connect the adjacent battery cells in parallel.

3. The battery module according to claim 2, characterized in that The battery module has at least one second connection portion, the second connection portion electrically connecting the two first connection portions in series via the bus bar. Between the battery cell connected to one of the two first connecting portions and the battery cell connected to the other of the two first connecting portions, two adjacent battery cells are arranged with the first side surfaces facing each other.

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

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