Battery module

Abstract

The present disclosure relates to a battery module. The battery module can have: a plurality of battery cells stacked in a first direction and each having an electrode tab extending in a second direction perpendicular to the first direction; and a guide member located on one side of the plurality of battery cells in the second direction and having a plurality of slits through which the electrode tabs of the plurality of battery cells pass, respectively. In each of the plurality of battery cells, the electrode tab passing through the slit can engage with the electrode tab of at least one other battery cell.

Description

Technical Field

[0001] The technology disclosed in this specification relates to battery modules. Background Technology

[0002] Japanese Patent Application Publication No. 2011-249243 discloses a battery module mounted on an electric vehicle. This battery module comprises multiple battery cells arranged in a stacked configuration and a busbar electrically connecting the multiple battery cells. Each of the multiple battery cells has an electrode tab, and the electrode tabs of the multiple battery cells are connected to the busbar. Summary of the Invention

[0003] The aforementioned battery module includes a busbar for connecting electrode tabs. The busbar is a rigid metal component and has a relatively large weight. Therefore, it is considered to achieve weight reduction of the battery module by omitting the busbar and directly connecting two or more electrode tabs. However, the busbar also serves to protect the relatively fragile electrode tabs. Therefore, if the busbar is easily omitted, there is a possibility of accidental deformation or damage to the electrode tabs. This specification provides a new technique for reducing the number of busbars in a battery module.

[0004] The technology disclosed in this specification is embodied in a battery module. The battery module may include: a plurality of battery cells stacked in a first direction and each having an electrode tab extending along a second direction perpendicular to the first direction; and a guide member located on one side of the plurality of battery cells in the second direction, having a plurality of slits through which the electrode tabs of the plurality of battery cells respectively pass. In each of the plurality of battery cells, the electrode tab passing through the slits can engage with the electrode tab of at least one other battery cell.

[0005] In the above configuration, the electrode tabs of multiple battery cells are guided by guide members with multiple slits. According to this configuration, even if the electrode tabs of two or more battery cells are directly joined without passing through a busbar, accidental deformation or damage to the electrode tabs can be prevented. Therefore, it is possible to reduce the number of busbars in the battery module and achieve a lighter battery module. Attached Figure Description

[0006] Referring to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below, wherein the same reference numerals denote the same elements, wherein:

[0007] Figure 1 A cross-sectional view of the battery module of Embodiment 1 is shown. Additionally, in... Figure 1 In the image, no shading was applied to the individual battery cells. Figures 2 to 4 The individual cells are also shown without shading.

[0008] Figure 2A diagram illustrating the manufacturing method of the battery module of Embodiment 1 is shown;

[0009] Figure 3 A cross-sectional view of the battery module of Embodiment 2 is shown;

[0010] Figure 4 A diagram illustrating the manufacturing method of the battery module of Embodiment 2 is shown; and

[0011] Figure 5 A diagram showing the tab engagement component and guide component in Embodiment 2 is provided. Detailed Implementation

[0012] In one embodiment of this technology, in at least one of a plurality of battery cells, the electrode tab through the slit can be engaged with the electrode tabs of three or more other battery cells. If the structure involves engaging many electrode tabs together, the time spent engaging the electrode tabs during battery module manufacturing can be reduced.

[0013] In one embodiment of this technology, in each of a plurality of battery cells, an electrode tab through a slit can be fused to the electrode tabs of at least one other battery cell. In this case, the plurality of electrode tabs can be joined together by ultrasonic welding.

[0014] Alternatively, the battery module may further include a tab engaging member mounted on the guide member. In this case, in each of the plurality of battery cells, the electrode tab through the slit can be held together with the electrode tabs of at least one other battery cell between the guide member and the tab engaging member. According to this configuration, during the manufacture of the battery module, the tab engaging member can be mounted on the guide member in a manner in which the electrode tabs of the plurality of battery cells are respectively inserted into the plurality of slits of the guide member, thereby enabling easy engagement of two or more electrode tabs.

[0015] In the above-described embodiments, the tab engaging member may also be mounted so as to be able to slide relative to the guide member. With this configuration, during the manufacture of the battery module, by mounting the tab engaging member relative to the guide member in a manner in which the electrode tabs of multiple battery cells are respectively inserted into multiple slits of the guide member, two or more electrode tabs can be easily engaged.

[0016] (Example 1)

[0017] Reference Figure 1 and Figure 2The battery module 10 of this embodiment will now be described. The battery module 10 of this embodiment can, for example, be mounted in a vehicle. The vehicle is, for example, a battery electric vehicle (BEV). However, the vehicle is not limited to a BEV; it can also be other types of electric vehicles such as a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV). The battery module 10 is capable of supplying power to the motors that drive the wheels of the vehicle.

[0018] like Figure 1 As shown, the battery module 10 includes multiple battery cells 12, a housing 16, a pair of covers 18 and 19, a pair of guide components 20, and a pair of electrode terminals 22 and 24.

[0019] Each battery cell 12 is configured as a rechargeable and dischargeable secondary battery cell. The secondary battery cell is, for example, a lithium-ion battery cell. Each battery cell 12 has a flat shape. Each battery cell 12 is, for example, a pouch-type (also called a laminated type) battery cell. Each battery cell 12 has an elongated shape. Multiple battery cells 12 are stacked along the thickness direction of the battery cell 12.

[0020] Here, in the accompanying drawings, the thickness direction (also referred to as the stacking direction) of the battery cell 12 is represented by direction D1, and the length direction of the battery cell 12 perpendicular to the thickness direction is represented by direction D2. Therefore, the thickness direction (stacking direction) is an example of the "first direction" of this technology, and the length direction is an example of the "second direction" of this technology.

[0021] Multiple battery cells 12 are housed within a housing 16. The housing 16 has a first end 16a and a second end 16b. The housing 16 extends cylindrically from the first end 16a to the second end 16b along the length direction D2 of the battery cells 12. Thus, the housing 16 surrounds the multiple battery cells 12. Each end 16a, 16b of the housing 16 has an opening 17a, 17b. A cover 18 covering the opening 17a is provided at the first end 16a of the housing 16.

[0022] A pair of electrode terminals 22, 24 are provided on the cover 18 at the first end 16a of the housing 16. Each electrode terminal 22, 24 is a curved plate-shaped component. Each electrode terminal 22, 24 is made of a conductor such as metal. Each electrode terminal 22, 24 protrudes outward from the cover 18. Each electrode terminal 22, 24 extends from the inside of the cover 18 (i.e., the electrode tab side) toward the outside of the cover 19. Each electrode terminal 22, 24 penetrates the cover 18. The pair of electrode terminals 22, 24 are the positive terminal 22 and the negative terminal 24 of the battery module 10. Each electrode terminal 22, 24 is electrically connected to a plurality of battery cells 12. A cover 19 covering the opening 17b is provided at the second end 16b of the housing 16. In addition, the housing 16 and the pair of covers 18, 19 are made of insulating materials such as resin.

[0023] Each battery cell 12 has a pair of electrode tabs 14. The pair of electrode tabs 14 are located at both ends of the battery cell 12 along the length direction D2. Each pair of electrode tabs 14 is a sheet-like component and is made of a conductive material such as metal. Each electrode tab 14 draws power from the interior of the battery cell 12 to the outside. Each electrode tab 14 of the multiple battery cells 12 protrudes from the housing 16 along the length direction through openings 17a or 17b. The multiple electrode tabs 14 are covered by a pair of caps 18 and 19 located at both ends 16a and 16b of the housing 16. Thus, the multiple electrode tabs 14 protruding from the openings 17a and 17b of the housing 16 are protected.

[0024] As an example, the plurality of battery cells 12 have four pairs of battery cells 12. Each pair of battery cells 12 is adjacent to each other and connected in parallel via electrode tabs 14. The four pairs of battery cells 12 are connected in series via electrode tabs 14. Among the four pairs of battery cells 12, the pair of battery cells 12 located at one end in the stacking direction (thickness direction D1 of the battery cell 12) is connected to one of the pair of electrode terminals 22, 24. Among the four pairs of battery cells 12, the pair of battery cells 12 located at the other end in the stacking direction (D1) is connected to the other pair of electrode terminals 22, 24.

[0025] Each guide member 20 is a plate-shaped component and is made of an insulating material, such as resin. A pair of guide members 20 are located on opposite sides of the plurality of battery cells 12 along the length direction D2. Each guide member 20 has a plurality of slits 20s. The opening surface of each slit 20s has a rectangular shape. Each slit 20s penetrates the guide member 20 along the length direction D2 of the battery cell 12. The dimension of the battery cell 12 in the thickness direction D1 at each slit 20s is larger than the dimension of the battery module 10 in the thickness direction D1 of each electrode tab 14. The corresponding electrode tab 14 passes through each slit 20s. That is, each electrode tab 14 extends through the guide member 20 along the length direction D2.

[0026] In each of the plurality of battery cells 12, the electrode tab 14 through the slit 20s is joined to the electrode tab 14 of at least another battery cell 12. Specifically, in a portion of the plurality of battery cells 12, the electrode tab 14 through the slit 20s is joined to the electrode tab 14 of three other battery cells 12. Furthermore, in another portion of the plurality of battery cells 12, the electrode tab 14 through the slit 20s is joined to the electrode tab 14 of another battery cell 12. The plurality of electrode tabs 14 are joined together, for example, by ultrasonic welding. The number of electrode tabs 14 joined together is not limited to two or four, but may also be three or five or more.

[0027] In other words, the battery module 10 has one or more joints JP where at least two or more electrode tabs 14 are joined together. The joining of multiple electrode tabs 14 is not limited to ultrasonic welding. For example, the joining of multiple electrode tabs 14 can also be performed by laser welding. Alternatively, multiple electrode tabs 14 can also be joined via other components such as adhesive materials, welding materials, connecting components (e.g., wires, etc.).

[0028] In the battery module 10 of this embodiment, the electrode tabs 14 of multiple battery cells 12 are each guided by a guide member 20 having multiple slits 20s. With this configuration, even if the electrode tabs 14 of two or more battery cells 12 are directly joined without passing through a busbar, accidental deformation or damage to the electrode tabs 14 can be suppressed. Therefore, the number of busbars in the battery module 10 can be reduced, and the battery module 10 can be made lighter.

[0029] Furthermore, in this embodiment, in a portion of the multiple battery cells 12, the electrode tabs 14 of the battery cell 12 passing through the slit 20s are joined with the electrode tabs 14 of the other three battery cells 12. As a structure in which many electrode tabs 14 are joined together, the workload of joining the electrode tabs 14 during battery module manufacturing can be reduced.

[0030] refer to Figure 2 This is an example illustrating the manufacturing method of battery module 10. First, as... Figure 2 As shown, a plurality of battery cells 12 and a pair of guide members 20 are prepared to be housed within a housing 16. The guide members 20 are then positioned at both ends 16a and 16b of the housing 16. The pair of guide members 20 are then positioned such that the electrode tabs 14 of the plurality of battery cells 12 are inserted into the slits 20s of the guide members 20. The electrode tabs 14 passing through the slits 20s and at least one other electrode tab 14 are then gathered together and joined by ultrasonic welding. At this time, two or more gathered electrode tabs 14 are clamped by a welding head 50 and an anvil 52 for ultrasonic welding, and welding is performed using ultrasonic vibration energy from the welding head 50. Furthermore, excess portions of the joined electrode tabs 14 can be cut off. Then, the joint portions JP of two pairs of electrode tabs 14 located at both ends in the stacking direction of the plurality of pairs of electrode tabs 14 on the first end 16a side of the housing 16 are respectively connected to electrode terminals 22 and 24. Finally, as... Figure 1 As shown, a pair of covers 18 and 19 are installed at both ends 16a and 16b of the housing 16.

[0031] Thus, battery module 10 is manufactured. According to this manufacturing method, even if the electrode tabs 14 of two or more battery cells 12 are directly joined without passing through a busbar, accidental deformation or damage to the electrode tabs 14 can be prevented. Therefore, the number of busbars in battery module 10 can be reduced, and the battery module 10 can be made lighter.

[0032] Furthermore, although not limited to this, in the battery module 10, the junction JP of each pair of battery cells 12 can also be connected to the vehicle's battery management system (BMS), which is not shown. In this case, the BMS can detect the potential of each pair of battery cells 12.

[0033] (Example 2)

[0034] Reference Figures 3-5 The battery module 110 of this embodiment will be described below. Figures 3-5 As shown, the battery module 110 does not have covers 18 and 19, but has a pair of electrode engagement members 118 and 119. The pair of electrode engagement members 118 and 119 are respectively mounted on a pair of guide members 20 of the battery module 110. In this respect, the battery module 110 of this embodiment differs from the battery module 10 of Embodiment 1. Other configurations of the battery module 110 can be configured in the same way as the battery module 10 of Embodiment 1.

[0035] A pair of tab engaging components 118 and 119 are components for engaging multiple battery cells 12. Each tab engaging component 118 and 119 is made of an insulating material such as resin. Each tab engaging component 118 and 119 has a cuboid shape. As an example, each tab engaging component 118 and 119 has a fitting groove 118a and 119a that can fit into a guide member 20. Each tab engaging component 118 and 119 is fixed to the guide member 20 by fitting the guide member 20 into the fitting groove 118a and 119a. Each fitting groove 118a and 119a extends along the thickness direction D1 of the battery cell 12. Each tab engaging component 118 and 119 is mounted relative to the guide member 20 in a manner that allows it to slide along the thickness direction D1 of the battery cell 12.

[0036] Main reference Figure 5 The details of the fitting groove 119a of the tab engagement component 119 will be explained. For example... Figure 5As shown, the fitting groove 119a extends from one end 119e of the battery cell 12 in the tab engagement member 119 along the thickness direction D1 to the other end 119f of the battery cell 12 in the tab engagement member 119 along the thickness direction D1. The cross-section of the fitting groove 119a has a certain area. Here, the cross-sectional area refers to the area of ​​the cross-section cut in a plane perpendicular to the thickness direction D1 of the battery cell 12. The fitting groove 119a opens toward the battery cell 12 at the end face 119c of the tab engagement member 119. The width dimension of the fitting groove 119a at the end face 119c is smaller than the width dimension at the bottom face 119d of the fitting groove 119a. Here, the width dimension refers to the dimension at the bottom face 119d of the fitting groove 119a in the direction D3 perpendicular to the thickness direction D1 and the long side direction D2 of the battery cell 12. The fitting groove 118a of the tab engagement member 118 may also have the same configuration as the fitting groove 119a of the tab engagement member 119.

[0037] like Figure 3 As shown, in each of the plurality of battery cells 12, the electrode tab 14 passing through the slit 20s of the guide member 20 is held together with the electrode tabs 14 of at least one other battery cell 12 between the guide member 20 and the tab engagement members 118, 119. With this configuration, when manufacturing the battery module 110, by mounting the tab engagement members 118, 119 to the guide member 20 in a state where the electrode tabs 14 of the plurality of battery cells 12 are respectively inserted into the plurality of slits 20s of the guide member 20, two or more electrode tabs 14 can be easily engaged.

[0038] Similar to the cover 18 in Embodiment 1, a pair of electrode terminals 22, 24 are mounted on the tab engagement member 118. In each of the plurality of battery cells 12 on the tab engagement member 118 side, the electrode tab 14 passing through the slit 20s of the guide member 20, together with the electrode tabs 14 of at least one other battery cell 12, is held between the electrode terminals 22, 24 of the guide member 20 and the tab engagement member 118. Thus, by mounting the tab engagement member 118 to the guide member 20, it is possible to engage two or more electrode tabs 14, and the engagement of the two or more electrode tabs 14 with the respective electrode terminals 22, 24 can be easily implemented.

[0039] Furthermore, in this embodiment, a pair of tab engaging components 118 and 119 cover the openings 17a and 17b at both ends 16a and 16b of the housing 16. That is, each tab engaging component 118 and 119 functions as a cover for the housing 16.

[0040] Furthermore, in the battery module 110 of this embodiment, the electrode tabs 14 of the plurality of battery cells 12 are also guided by guide members 20 having a plurality of slits 20s. According to this configuration, even if the electrode tabs 14 of two or more battery cells 12 are directly joined without passing through a busbar, accidental deformation or damage to the electrode tabs 14 can be suppressed. Thus, the number of busbars in the battery module 110 can be reduced, and the battery module 110 can be made lighter.

[0041] Here is an example illustrating the manufacturing method of battery module 110. First, as... Figure 4 As shown, a plurality of battery cells 12 and a pair of guide members 20 are prepared to be housed within a housing 16. Next, the guide members 20 are respectively positioned at both ends 16a and 16b of the housing 16. At this time, the pair of guide members 20 are respectively positioned such that the electrode tabs 14 of the plurality of battery cells 12 are inserted into the corresponding slits 20s of the guide members 20. Next, each electrode tab engaging member 118, 119 is slidably moved relative to its corresponding guide member 20 for installation. At this time, with the electrode tabs 14 of the plurality of battery cells 12 inserted into the slits 20s, the electrode tab engaging members 118, 119 are respectively installed onto the guide members 20.

[0042] The tab engagement member 118 starts from the starting position opposite to the guide member 20 (reference). Figure 4 The electrode engagement component 118 is slid to the mounting position of the guide component 20 (see reference). Figure 3 As a result, by sliding the tab engaging members 118 and 119, for each of the plurality of battery cells 12, the electrode tab 14 is bent so that it overlaps with the electrode tabs 14 of the other adjacent battery cells 12. With the tab engaging members 118 and 119 in the mounting position, the folded plurality of electrode tabs 14 are held between the guide member 20 and the tab engaging members 118 and 119. Thus, the plurality of electrode tabs 14 are engaged. In addition, a pair of electrode terminals 22 and 24 are mounted on the tab engaging member 118. With the tab engaging member 118 in the mounting position, the pair of electrode terminals 22 and 24 respectively contact the engagement portion JP of the corresponding plurality of electrode tabs 14.

[0043] Thus, battery module 110 is manufactured. In the above-described manufacturing method, each tab engaging member 118, 119 is slidably mounted relative to guide member 20. According to this configuration, when manufacturing battery module 110, by sliding the tab engaging members 118, 119 relative to guide member 20 while inserting the electrode tabs 114 of multiple battery cells 12 into the multiple slits 20s of guide member 20, two or more electrode tabs 14 can be easily engaged.

[0044] In this embodiment, two battery cells 12 connected in parallel are connected in series. Among the four battery cells 12, the length of the electrode tab 14 at one end of the battery cell 12 located in the thickness direction D1 (the length of the battery cell 12 in the length direction D2) is smaller than the length of the electrode tab 14 of the other three battery cells 12. This configuration prevents the electrode tab 14 from protruding from the guide member 20 when the tab engaging parts 118 and 119 are mounted onto the guide member 20.

[0045] The battery module 10 of Embodiment 1 may have only one of the pair of covers 18 and 19. In another variation, the battery module 10 may not have covers 18 and 19.

[0046] Battery modules 10 and 110 in embodiments 1 and 2 may not have electrode terminals 22 and 24. In this case, external electrical components that are electrically connected to battery modules 10 and 110 can be directly connected to one or more joints JP provided in battery modules 10 and 110.

Claims

1. A battery module, comprising: Multiple battery cells are stacked in a first direction and each has an electrode tab extending in a second direction perpendicular to the first direction; as well as The guiding component is located on one side of the plurality of battery cells in the second direction and has a plurality of slits through which the electrode tabs of the plurality of battery cells pass respectively; In each of the plurality of battery cells, the electrode tab through the slit is engaged with the electrode tab of at least one other battery cell.

2. The battery module according to claim 1, wherein, In at least one of the plurality of battery cells, the electrode tab through the slit is engaged with the electrode tabs of three or more other battery cells.

3. The battery module according to claim 1 or 2, wherein, In each of the plurality of battery cells, the electrode tab through the slit is fused to the electrode tab of at least one other battery cell.

4. The battery module according to claim 1 or 2, wherein, The battery module also includes a tab engagement component mounted on the guide component. In each of the plurality of battery cells, the electrode tab through the slit is held together with the electrode tabs of at least one other battery cell between the guide member and the tab engagement member.

5. The battery module according to claim 4, wherein, The tab engagement component is mounted to be able to slide relative to the guide component.

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