Battery modules and battery packs

Abstract

SOLUTION: To provide a battery module which includes a plurality of unit cells 32, a plurality of first connection members 33 and a plurality of second connection members 34, wherein the unit cell has an end face, a tab is provided on the end face, both the first connection member and the second connection member are flexible members, the first connection member has a first connection part, a second connection part and a bent part, both the first connection part and the second connection part have piece shapes, both ends of the bent part are connected to the first connection part and the second connection part, the plurality of unit cells are overlapped on each other, the first connection part connects the tabs of the two adjacent unit cells, the second connection member has a piece shape, the second connection member connects the second connection parts 332 of the two adjacent first connection members, and the second connection member, the first connection part and the second connection part are overlapped on the end face.EFFECT: When a unit cell is expanded, a first connection member and a second connection member can absorb expansion of the unit cell so as to more easily generate distortion, and stability of connection of the unit cells are guaranteed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present application relates to the technical field of lithium batteries, for example, battery modules and battery packs. [Background technology]

[0002] Pouch-type lithium-ion cells have a "breathing" effect in the free state during the charge and discharge process. Specifically, the cells undergo significant volume changes, and compared with the uncharged state, the lithium metal battery expands when fully charged. That is, due to the "breathing" effect of the cells, the cells expand, their thickness becomes uneven, and there is a slippage phenomenon between the cells, which causes deformation of the lithium metal battery and is unfavorable for the charge and discharge cycle. Therefore, it is necessary to apply a restraint force in the thickness direction of the cells to ensure the cycle. Summary of the Invention [Problem to be solved by the invention]

[0003] To increase the energy density of a battery, multiple cells are installed in a battery pack, and the cells are connected directly or in parallel via a printed circuit board (PCB). To prevent breakage of the tabs connecting the PCB, the cells are generally restrained on all four sides. However, the cells may slip due to the "deep breath" effect, which can lead to misalignment between the cells and the PCB. In severe cases, the PCB may break or the tab may tear off, resulting in the complete failure of the battery pack, making the battery pack unreliable and unsafe. [Means for solving the problem]

[0004] This application is a plurality of unit cells having end faces on which tabs are provided, and a plurality of first connection members and a plurality of second connection members, each of which is a flexible member; the first connecting member has a first connecting portion and a second connecting portion, each of which has a strip shape, and a bent portion whose both ends are connected to the first connecting portion and the second connecting portion, respectively; A battery module is provided in which a plurality of unit cells are stacked on top of each other, a first connection portion connects the tabs of two adjacent unit cells, a second connection member is strip-shaped and connects the second connection portions of two adjacent first connection members, and the second connection member, the first connection portion, and the second connection portion are stacked on the end faces of the unit cells.

[0005] The present application provides a battery pack including a case and a battery module disposed within the case, the side of the battery module abutting against the inner wall of the case. [Effects of the Invention]

[0006] The beneficial effects of the present application are as follows: by installing a plurality of first connecting members and second connecting members, the cells are connected to each other solely by the first connecting members, and the combination of the first connecting members and the second connecting members replaces the original integrated PCB board; when the cells expand, the first connecting members and the second connecting members can more easily absorb the expansion of the cells, preventing the tabs from being torn and the first connecting members and the second connecting members from being separated from the tabs of the cells, ensuring the stability of the connection between the cells and preventing disconnections within the battery module; by overlapping the second connecting members, the first connecting parts, and the second connecting parts on the end faces of the cells, the overall shape of the battery module can be close to a rectangular parallelepiped, and both the first connecting members and the second connecting members are flexible; thus, the external restraint structural members provide restraint for the six sides of the battery module, reducing the slippage phenomenon during the expansion of the cells, reducing deformation of the battery module, and improving the reliability and safety of the battery module. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating a state in which a cell and a first connecting member are connected according to some embodiments of the present application. [Figure 2] 2 is a schematic diagram showing a state in which a cell and a first connecting member are connected according to some embodiments of the present application. FIG. [Figure 3] 3 is a schematic diagram showing a state in which a cell and a first connecting member are connected according to some embodiments of the present application. FIG. [Figure 4] 1 is a schematic diagram illustrating a connection between a cell, a first connecting member, and a second connecting member according to some embodiments of the present application. [Figure 5] 2 is a schematic diagram showing a state in which a cell, a first connecting member, and a second connecting member are connected according to some embodiments of the present application; FIG. [Figure 6] 1 is a schematic diagram of a battery module according to some implementations of the present application; [Figure 7] 1 is a schematic diagram showing a state in which a cell and a first connecting member are connected according to some other embodiments of the present application. FIG. [Figure 8] 10 is a schematic diagram 2 showing a state in which a cell and a first connecting member are connected according to some other embodiments of the present application. FIG. [Figure 9] 3 is a schematic diagram showing a state in which a cell and a first connecting member are connected according to some other embodiments of the present application. FIG. [Figure 10] 10A to 10C are schematic diagrams illustrating a state in which a cell, a first connecting member, and a second connecting member are connected together according to some other embodiments of the present application. [Figure 11] 1 is a schematic diagram of a battery module according to some other embodiments of the present application. [Figure 12] 1 is a cross-sectional schematic diagram of a battery pack according to some embodiments of the present application. [Figure 13] 1 is an exploded schematic diagram of a battery pack according to some implementations of the present application. [Figure 14] 1 is a schematic diagram of a battery pack according to some implementations of the present application (one bonding plate is not shown). FIG. [Figure 15] 1 is a schematic diagram of a second buffer member according to some embodiments of the present application. FIG. [Figure 16] 1 is a schematic diagram of a case and a partition plate according to some embodiments of the present application (one of which is not shown as a joining plate); [Figure 17] FIG. 2 is a structural diagram of a tab in some implementations of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the description of this application, unless otherwise clearly specified or limited, the terms "coupled," "connected," and "fixed" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or integration, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, internal communication between two elements, or an interaction between two elements. Those skilled in the art can understand the specific meaning of the terms used in this application depending on the specific situation.

[0009] As shown in FIGS. 6 and 11 (some reference numerals refer to FIGS. 1 to 5 and 7 to 10 ), the battery module 3 according to the present application includes a plurality of cells 32, a plurality of first connecting members 33, and a plurality of second connecting members 34. The cells 32 have end faces on which tabs 322 are provided. The first connecting members 33 and the second connecting members 34 are both flexible members, i.e., the first connecting members 33 and the second connecting members 34 are both flexible and can be distorted when subjected to pressure. The first connecting member 33 includes a first connecting portion 331, a second connecting portion 332, a third connecting portion 333, a fourth connecting portion 334, a fifth connecting portion 335, a fifth connecting portion 336, a sixth connecting portion 337, a sixth connecting portion 338, a sixth connecting portion 339, a sixth connecting portion 339, a sixth connecting portion 339, a sixth connecting portion 331, a fifth connecting portion 332, a sixth connecting portion 333, a sixth connecting portion 334, a sixth connecting portion 335, a sixth connecting portion 336, a sixth connecting portion 337, a sixth connecting portion 338, a sixth connecting portion 339 ... The second connecting member 34 has two connection portions 332 and a bending portion 333, and the first connection portion 331 and the second connection portion 332 are both strip-shaped, and both ends of the bending portion 333 are connected to the first connection portion 331 and the second connection portion 332, respectively, and the multiple single cells 32 are arranged stacked on top of each other, and the first connection portion 331 connects the tabs 322 of two adjacent single cells 32, and the second connecting member 34 is strip-shaped and connects the second connection portions 332 of two adjacent first connecting members 33, and the second connecting member 34, the first connection portion 331 and the second connection portion 332 are stacked on the end faces of the single cells 32.

[0010] A plurality of first connection members 33 and second connection members 34 are provided, and two of the single cells 32 are individually connected to each other using the first connection portions 331, and the second connection portions 332 of the first connection members 33 are further connected using the second connection members 34, thereby replacing the integrated PCB. In this embodiment, when the cells 32 expand, the first connecting member 33 and the second connecting member 34 can absorb the expansion of the cells 32 so that distortion occurs more easily, preventing the tabs 322 from being torn and the first connecting member 33 and the second connecting member 34 from being separated from the tabs 322 of the cells 32. This ensures stable connections between the cells 32 and prevents disconnections within the battery module 3. By overlapping the second connecting member 34, the first connecting portion 331, and the second connecting portion 332 on the end faces of the cells 32, the overall shape of the battery module 3 can be made closer to a rectangular parallelepiped. Furthermore, the first connecting member 33 and the second connecting member 34 are both flexible. In this way, the external restraint structural member provides a restraint to the six sides of the battery module 3, reducing the sliding phenomenon that occurs during the expansion of the cells 32, reducing deformation of the battery module 3, and improving the reliability and safety of the battery module 3.

[0011] In this embodiment, the first connecting member 33 and the second connecting member 34 are both nickel pieces, and the first connecting member 33 forms a first connecting portion 331, a bent portion 333 and a second connecting portion 332 after being bent.

[0012] In this embodiment, the first connecting members 33 and the second connecting members 34 are made of nickel pieces, thereby reducing the weight of the battery module 3 and achieving a lightweight design.

[0013] 6 and 11, the battery module 3 includes a support member 35, and the battery cell 32 has a main body portion 323 and a sealing edge portion 321. The thickness of the main body portion 323 is greater than the thickness of the sealing edge portion 321. The support member 35 is provided between the sealing edge portions 321 of two adjacent battery cells 32. The support member 35 abuts against the side of the sealing edge portion 321, and the side of some of the support members 35 abuts against the first connecting member 33 and the second connecting member 34, while the side of some of the support members 35 abuts against the second connecting member 34 alone. In this embodiment, the cells 32 are pouch-type batteries, and the sealing edge portion 321 is a sealing edge of an aluminum laminate film, which is a structure unique to pouch-type batteries. When the support member 35 is provided, the support member 35 fills the gap between the sealing edge portions 321 of two adjacent cells 32, thereby reducing distortion of the sealing edge portion 321. The support member 35 also provides support to the first connecting member 33 and the second connecting member 34, reducing the degree of bending of the first connecting portion 331, the second connecting portion 332 and the second connecting member 34, thereby improving the reliability of the battery module 3.

[0014] In this embodiment, the support member 35 is a flexible support block. The cells 32 expand and change volume during charging and discharging. By making the support member 35 a flexible support block and making the support member 35 flexible, it can be understood that the support member 35 can absorb strain of the cells 32 to a certain extent, reduce deformation of the battery module 3, and improve the reliability and safety of the battery module 3. For example, the support member 35 may be an ethylene-vinyl acetate copolymer (EVA copolymer) foam.

[0015] 6 and 11, the hardness of the support members 35 located on both sides of the battery module 3 may be greater than the hardness of the support member 35 located at the center of the battery module 3, and the support members 35 located on both sides of the battery module 3 can directly contact the external restraining structural members and restrict the position of the single cells 32.

[0016] A first buffer member 36, which is strip-shaped, is provided between two adjacent cells 32. The provision of the first buffer member 36 also absorbs strain from the cells 32, reduces deformation of the battery module 3, and improves the reliability and safety of the battery module 3. The first buffer member 36 may be EVA foam.

[0017] As shown in Figure 17, the tab 322 of the battery 32 has a third connection portion 3221 and a fourth connection portion 3222, and the fourth connection portion 3222 of the tab 322 is connected to the battery core inside the battery 32 by the third connection portion of the tab 322, and the third connection portion 3221 and the fourth connection portion 3222 are both strip-shaped, and the fourth connection portion 3222 is connected perpendicularly to the third connection portion 3221, that is, the strip-shaped tab 322 is bent 90 degrees to form the third connection portion 3221 and the fourth connection portion 3222, and the fourth connection portion 3222 is parallel to the end face of the battery 32, and the fourth connection portion 3222 is connected to the first connection portion 331. By making the fourth connection portion 3222 parallel to the end face of the battery 32 and connecting the fourth connection portion 3222 to the first connection portion 331, it is possible to avoid bending the connection position between the tab 322 and the first connection member 33, reduce the difficulty of connecting the tab 322 and the first connection member 33 and the impact of bending on the connection effect, and improve the reliability of the connection between the tab 322 and the first connection member 33.

[0018] In this embodiment, the first connecting portion 331 and the tab 322 are connected by welding, and the second connecting portion 332 and the second connecting member 34 are also connected by welding. Ultrasonic welding or other welding methods such as laser welding may be used.

[0019] The cell 32 typically has two tabs 322, one of which is a positive electrode and the other is a negative electrode. The two tabs 322 of the cell 32 shown in Figures 1 to 6 are located on the same side of the cell 32, and are referred to as single-side tab-withdrawn batteries, with the tabs 322 of the single-side tab-withdrawn batteries extending from the same end face of the cell 32. The two tabs 322 of the cell 32 shown in Figures 7 to 11 are located on both sides of the cell 32, and are referred to as double-side tab-withdrawn batteries, with the tabs 322 of the double-side tab-withdrawn batteries extending from both end faces of the cell 32.

[0020] Referring to FIGS. 1 to 6, for a single-side tab-draw type battery, the battery module 3 can be produced by the following steps.

[0021] In step 101, referring to FIG. 1, the (positive electrode) tab 322 of one battery cell 32 (one-side tab pull-out battery) and the (negative electrode) tab 322 of another battery cell 32 are connected and combined using a first connecting member 33 (nickel piece) by ultrasonic welding.

[0022] In step 102, referring to FIG. 2 and taking into account FIG. 1, the tabs 322 of the two cells 32 (one-side tab-pulled batteries) are bent 90 degrees, the two cells 32 (one-side tab-pulled batteries) are stacked together, and one first buffer member 36 is inserted between the two cells 32 (one-side tab-pulled batteries). Then, the first connecting member 33 (nickel piece) is bent 90 degrees to make the first connecting member 33 L-shaped, and a battery combination is formed in this step.

[0023] In step 103, referring to FIG. 3, stack multiple battery combinations as shown in FIG. 2, ensuring that one first buffer member 36 is placed between every two single cells 32 (single-side tab pull-out type batteries).

[0024] In step 104, referring to FIG. 4 and taking into account FIG. 3, in accordance with the design requirements for series and parallel connection of the circuits within the battery module 3, the battery combination shown in FIG. 2 is connected using the second connecting member 34, and the second connecting member 34 (nickel piece) and the second connecting portion 332 of the first connecting member 33 (nickel piece) are connected by ultrasonic welding.

[0025] In step 105, referring to Figure 5 and taking into account Figure 4, the excess portion of the first connecting member 33 (nickel piece) is cut off, and the first connecting member 33 (nickel piece) is then continued to bend 90 degrees to form the bent portion 333 of the first connecting member 33, at which time the first connecting portion 331 and the second connecting portion 332 of the first connecting member 33 are overlapped.

[0026] In step 106, referring to FIG. 6 and taking into account FIG. 5, the support members 35 are filled into the gaps between the cells 32.

[0027] Referring to FIGS. 7 to 11, for a double-tab withdrawn battery, the battery module 3 can be produced by the following steps.

[0028] In step 201, referring to FIG. 7, the (positive electrode) tab 322 and the (negative electrode) tab 322 of the cell 32 (a double-tab withdrawn battery) are ultrasonically welded to two first connecting members 33 (nickel pieces), respectively.

[0029] In step 202, referring to FIG. 8 and taking into account FIG. 7, the tab 322 is bent 90 degrees.

[0030] In step 203, referring to FIG. 9 and taking into account FIG. 8, the first connecting member 33 (nickel piece) is bent by 90°.

[0031] In step 204, referring to FIG. 10, a plurality of combinations of the cells 32 (double-tab draw-out type batteries) and first connecting members 33 shown in FIG. 9 are stacked, one first buffer member 36 is inserted between every two cells 32 (double-tab draw-out type batteries), the grooves of the tabs 322 of the cells 32 are filled and flattened up to the ultrasonic welding points of the tabs 322, and then, according to the design requirements for series and parallel connection of the circuits within the battery module 3, the plurality of cells 32 (double-tab draw-out type batteries) are connected using second connecting members 34 (nickel pieces).

[0032] In step 205, referring to FIG. 11 and taking into account FIG. 10, the first connecting member 33 (nickel piece) is bent by 90 degrees, and at this time, the first connecting portion 331 and the second connecting portion 332 of the first connecting member 33 are overlapped.

[0033] 12 to 16, this embodiment further provides a battery pack including a case 1 and a battery module 3 according to any of the embodiments, where the battery module 3 is disposed within the case 1, with the side of the battery module 3 abutting against the inner wall of the case 1. The case 1 in this embodiment is the restraining structure mentioned in the embodiment, and the battery module 3 has a rectangular parallelepiped outer shape, which can reduce the difficulty in designing the restraining structure; that is, the battery module 3 is restrained using a planar structure within the case, thereby reducing the difficulty in designing the battery pack and reducing costs.

[0034] The battery pack further includes a lead wire 210 and a second cushioning member 2. The case 1 is provided with a current output base 13. The battery module 3 has a power transmission side 31 (the power transmission side 31 is formed by joining and combining end faces of multiple cells 32). The second connecting member 34 of the battery module 3 is provided on the power transmission side 31. Both ends of the lead wire 210 are connected to the current output base 13 and the second connecting member 34, respectively. The second cushioning member 2 is provided between the power transmission side 31 and the inner wall of the case 1. The second cushioning member 2 absorbs expansion of the cells 32, thereby reducing pressure on the lead wire and improving the reliability of the battery pack. The second cushioning member 2 may be EVA foam.

[0035] A wiring groove 21 is provided in the second buffer member 2, and the lead wire 210 is provided in the wiring groove 21. The provision of the wiring groove 21 further reduces the pressure on the lead wire 210 when the cell 32 collides, thereby improving the reliability of the battery pack.

[0036] 15, the second cushioning member 2 is further provided with a lightening hole 22. The provision of the lightening hole 22 reduces the weight of the second cushioning member 2, thereby reducing the weight of the entire battery pack and enabling a lightweight battery pack design.

[0037] A plurality of battery modules 3 are provided within the case 1, and as shown in Fig. 16, the case 1 is further provided with a plurality of partition plates 12, which are fixed to the inner wall of the case 1, and are provided between two adjacent battery modules 3, and the partition plates 12 abut against the sides of the battery modules 3. By providing the partition plates 12, the partition plates 12 divide the space within the case 1, individually restrain each battery module 3, and prevent direct contact between the battery modules 3, thereby enhancing the restraining effect on the battery modules 3 and improving the reliability of the battery pack.

[0038] In this embodiment, the case 1 has a rectangular parallelepiped shape, and is formed by joining six joining plates 11 to enclose the case 1, and the partition plates 12 are fixed and connected to the corresponding joining plates 11, respectively. [Explanation of symbols]

[0039] 1···Case, 11···Joint plate, 12···Partition plate, 13···Current output base, 2... second buffer member, 21... wiring groove, 210... lead wire, 22... lightening hole, 3 Battery module, 31 Power transmission side, 32 Cell, 321 Sealing edge portion, 322 Tab, 3221 Third connection portion, 3222 Fourth connection portion, 323 Main body portion, 33 First connection member, 331 First connection portion, 332 Second connection portion, 333 Bending portion, 34 Second connection member, 35 Support member, 36 First cushioning member.

Claims

1. The battery pack includes a plurality of unit cells (32) having end faces on which tabs (322) are provided, and a plurality of first connection members (33) and a plurality of second connection members (34), each of which is a flexible member; The first connecting member (33) has a first connecting portion (331) and a second connecting portion (332), both of which are strip-shaped, and a bent portion (333) whose both ends are connected to the first connecting portion (331) and the second connecting portion (332), respectively; The plurality of unit cells (32) are stacked one on top of the other, the first connection portion (331) connects the tabs (322) of two adjacent unit cells (32), the second connection member (34) is strip-shaped and connects the second connection portions (332) of two adjacent first connection members (33), and the second connection member (34), the first connection portion (331), and the second connection portion (332) are stacked on end faces of the unit cells (32). Battery module.

2. The battery further includes a support member (35), wherein the cell (32) has a main body portion (323) and a seal edge portion (321), the thickness of the main body portion (323) is greater than the thickness of the seal edge portion (321), the support member (35) is provided between the seal edge portions (321) of two adjacent cells (32), and a side surface of the support member (35) abuts against at least one of the first connecting member (33) and the second connecting member (34). The battery module according to claim 1 .

3. The support member (35) is a flexible support block. The battery module according to claim 2 .

4. A strip-shaped first buffer member (36) is provided between two adjacent cells (32). The battery module according to claim 1 .

5. The tab (322) comprises a third connection portion (3221), both of which are strip-shaped, and a fourth connection portion (3222) that is connected to a battery core in the single battery (32) by the third connection portion (3221), is connected perpendicular to the third connection portion (3221), is parallel to an end face of the single battery (32), and is connected to the first connection portion (331). The battery module according to claim 1 .

6. A battery module (3) according to any one of claims 1 to 5, comprising: a case (1); and the battery module (3) provided in the case (1), the side surface of the battery module (3) being abutted against an inner wall of the case (1). Battery pack.

7. The battery pack further includes a lead wire (210) and a second buffer member (2), the case (1) is provided with a current output stand (13), the battery module (3) has a power transmission side (31), a second connection member (34) of the battery module (3) is provided on the power transmission side (31), both ends of the lead wire (210) are connected to the current output stand (13) and the second connection member (34), respectively, and the second buffer member (2) is provided between the power transmission side (31) and an inner wall of the case (1). The battery pack according to claim 6.

8. A wiring groove (21) in which the lead wire (210) is provided is provided in the second buffer member (2). The battery pack according to claim 7.

9. The second buffer member (2) is provided with a lightening hole (22). The battery pack according to claim 7.

10. There are a plurality of the battery modules (3), and a plurality of partition plates (12) are further provided inside the case (1), the partition plates (12) are fixed to the inner wall of the case (1), and the partition plates (12) are provided between two adjacent battery modules (3) so as to abut against the side surfaces of the battery modules (3). The battery pack according to claim 6.

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