Battery cell and battery pack
The four-layer folded edge structure design solves the problem of low strength of the folded edge structure of soft-pack batteries, and improves the safety performance and assembly stability of the cells.
Patent Information
- Application Number
- CN202423053310.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2034-12-10
AI Technical Summary
The existing pouch battery has a low edge strength, which affects the safety performance of the cell.
The design adopts a four-layer folded edge structure, including a first folded edge segment, a second folded edge segment, a third folded edge segment, and a fourth folded edge segment set in sequence. Each folded edge segment is attached to the inner or outer wall surface of the adjacent folded edge segment in sequence, and is transitioned and bent through an arc transition segment to form a folded edge structure with good integrity.
The overall strength and stability of the folded edge structure are improved, the impact resistance of the battery cell is enhanced, the battery cell is prevented from being damaged by collisions during assembly, and the safety performance of the battery cell is guaranteed.
Smart Images
Figure CN223797413U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, specifically to a battery cell and battery pack. Background Technology
[0002] Pouch batteries have advantages such as high energy density, small size, and light weight, resulting in a large market for their application. A pouch battery mainly consists of electrode groups and a sealing film. The sealing film includes a main body and a sealing edge area. The main body wraps around the electrode groups, and then the sealing film is hot-pressed onto the outside of the electrode groups to seal them within the sealing film. The hot-pressed sealing film forms the sealing edge area, which extends outwards roughly parallel to the large surface of the cell. To reduce the space occupied by the sealing edge area in the width direction of the cell, the sealing edge area is folded towards the side of the cell to form a folded edge structure. The folded edge structure in existing technology has relatively low strength, affecting the safety performance of the cell. Utility Model Content
[0003] In view of this, the present invention provides a battery cell and battery pack to solve the problem that the folded edge structure in the prior art has low strength, which affects the safety performance of the battery cell.
[0004] In a first aspect, this utility model provides a battery cell, comprising:
[0005] pole group;
[0006] An encapsulation film includes an encapsulation body and a sealing area. The encapsulation body covers the electrode assembly, and the sealing area is located outside the electrode assembly. The sealing area includes an extension and a folded edge structure. The extension extends outward toward the electrode assembly, and the folded edge structure includes a first folded edge segment, a second folded edge segment, a third folded edge segment, and a fourth folded edge segment arranged sequentially. One end of the first folded edge segment is connected to the end of the extension away from the electrode assembly, and the first folded edge segment is bent toward one side of the electrode assembly in the thickness direction. The second folded edge segment is bent toward the extension and adheres to one side wall of the first folded edge segment. The third folded edge segment is bent away from the extension and adheres to one side wall of the second folded edge segment. The fourth folded edge segment is bent toward the extension and adheres to the other side wall of the first folded edge segment.
[0007] Beneficial effects: The battery cell with this structure has a folded edge structure comprising a first folded edge segment, a second folded edge segment, a third folded edge segment, and a fourth folded edge segment connected and bent sequentially. This folded edge structure forms four layers of folds, with each folded edge segment sequentially attached to the inner or outer wall surface of an adjacent folded edge segment. The folded edge structure has good overall integrity, improving its overall strength and stability. This effectively enhances the impact resistance of the battery cell's sides during assembly, preventing damage from collisions and ensuring the cell's safety. In an optional embodiment, the fourth folded edge segment extends backwards from the extension portion by a length L1, the third folded edge segment extends along the length direction of the fourth folded edge segment by a length L2, and the total length of the extension portion and the folded edge structure is L3, where L2 < L1 < L3.
[0008] Beneficial effects: The length of the second folded edge segment is less than that of the fourth folded edge segment. The end of the fourth folded edge segment facing the extension is set closer to the extension relative to the second folded edge segment. After bending, it can effectively ensure the fit length between the fourth folded edge segment and the first folded edge segment, preventing the fourth folded edge segment from curling outward after bending, thereby improving the compactness of the folded edge structure and reducing the space occupied by the folded edge structure in the width direction of the battery cell.
[0009] In one optional embodiment, the angle between the folded edge structure and the extension is θ, where 60°≤θ≤120°.
[0010] In one alternative implementation, the folded edge structure is perpendicular to the extension.
[0011] In one alternative implementation,
[0012] Beneficial effects: This design controls the length of the third folded edge within a suitable range, facilitating upward bending of the double-layer encapsulation area while ensuring that the third folded edge has sufficient area to adhere to the inner wall of the first folded edge after bending. It also prevents the third folded edge from being too long, thus preventing interference between the ends of the third and second folded edges and the extension after bending, and preventing the ends of the third and second folded edges from abutting against the extension, thus preventing deformation and warping of the third and second folded edges, and also preventing wear on the encapsulation film after contact between the segments.
[0013] In one alternative implementation,
[0014] Beneficial effects: This design ensures that the fourth folded edge has sufficient length, guaranteeing the fit between the fourth and first folded edge segments after bending. It prevents deformation and warping due to the fourth folded edge being too short, ensuring the fourth folded edge effectively adheres to the first folded edge. Simultaneously... This can prevent the fourth folded edge section from being too long and extending beyond the bottom surface of the extension, and can reduce the space occupied by the folded edge structure in the direction of cell thickness.
[0015] In one optional embodiment, the distance between the fourth folded edge segment and the extension is D1, where D1 ≥ 1 mm.
[0016] In one optional embodiment, the distance between the third folded edge segment and the extension is D2, where D2 ≥ 1 mm.
[0017] In one optional embodiment, an arc transition section is provided between the first folded edge segment and the second folded edge segment, between the second folded edge segment and the third folded edge segment, and between the third folded edge segment and the fourth folded edge segment.
[0018] Beneficial effects: The rounded transition sections between each segment effectively ensure the strength of the joints after bending, preventing damage to the encapsulation film due to excessive bending.
[0019] Secondly, this utility model also provides a battery pack, including the battery cell described in any of the above descriptions. The battery pack includes the battery cell and has the same technical effects as the battery cell, which will not be repeated here. Attached Figure Description
[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0021] Figure 1 This is a three-dimensional structural diagram of a battery cell in related technologies;
[0022] Figure 2 This is a three-dimensional structural diagram of another type of battery cell in the related technology;
[0023] Figure 3 This is a side view of a battery cell in the related art;
[0024] Figure 4 This is a side view of another type of battery cell in the related technology;
[0025] Figure 5 This is a side view of a battery cell according to an embodiment of the present utility model;
[0026] Figure 6 for Figure 5 Enlarged view of part A in the middle;
[0027] Figure 7 for Figure 5 Enlarged view of part A in the middle;
[0028] Figure 8 This is a side view of another type of battery cell according to an embodiment of the present utility model.
[0029] Explanation of reference numerals in the attached figures:
[0030] 1', Encapsulation film; 11', Encapsulation body; 12', Sealing area;
[0031] 1. Encapsulation film; 11. Encapsulation body; 12. Sealing area; 121. Extension; 122. Folded edge structure; 1221. First folded edge section; 1222. Second folded edge section; 1223. Third folded edge section; 1224. Fourth folded edge section; 1225. Arc transition section. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0033] like Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, the x-axis is called the length direction of the battery cell, the y-axis is called the width direction of the battery cell, and the z-axis is called the thickness direction of the battery cell. The upper part of the z-axis is called the upper part of the battery cell, and the lower part of the z-axis is called the lower part of the battery cell. The large surface of the battery cell facing upward is its top surface, and the large surface of the battery cell facing downward is its bottom surface.
[0034] like Figures 1 to 4 As shown, the battery cell in the related technology includes an electrode assembly and a sealing film 1'. The sealing film 1' includes a sealing body 11' and a sealing edge area 12'. The sealing body 11' has a groove, the electrode assembly is located in the groove, and the sealing edge area 12' is located outside the electrode assembly. The sealing edge area is folded into a folded edge structure. The folded edge structure has a low overall bending ratio and low overall strength. Furthermore, the folded edge structure is prone to deformation and reset, which will affect the safety performance of the battery cell.
[0035] Furthermore, the outer edge of the encapsulation area is a cutting edge. After the encapsulation area is folded, the cutting edge faces the side of the encapsulation body 11. Since the folded structure is easy to reset and lift after bending, the folded structure will lift towards the side of the encapsulation body 11. The cutting edge is located at the end of the folded structure. After the cutting edge lifts, it is easy to scratch the side of the encapsulation body 11, thereby affecting the overall sealing performance of the encapsulation film 1' and the safety performance of the battery cell.
[0036] The following is combined with Figures 5 to 8 The following describes embodiments of the present invention.
[0037] According to an embodiment of the present invention, in one aspect, a battery cell is provided, including an electrode assembly and an encapsulation film 1, wherein the encapsulation film 1 includes an encapsulation body 11 and a sealing region 12, the encapsulation body 11 covering the electrode assembly, the sealing region 12 being located outside the electrode assembly, the sealing region 12 including an extension 121 and a folded edge structure 122, the extension 121 extending outward toward the electrode assembly, the folded edge structure 122 including a first folded edge segment 1221, a second folded edge segment 1222, a third folded edge segment 1223 and a fourth folded edge segment 1224 arranged sequentially, wherein the first folded edge segment 1221... One end is connected to the end of the extension 121 away from the electrode assembly. The first folded edge segment 1221 is bent toward the side of the electrode assembly thickness direction. The second folded edge segment 1222 is bent toward the extension 121 and is attached to one side wall of the first folded edge segment 1221. The third folded edge segment 1223 is bent away from the extension 121 and is attached to one side wall of the second folded edge segment 1222. The fourth folded edge segment 1224 is bent toward the extension 121 and is attached to the other side wall of the first folded edge segment 1221.
[0038] The battery cell with this structure has a folded edge structure 122, which includes a first folded edge segment 1221, a second folded edge segment 1222, a third folded edge segment 1223, and a fourth folded edge segment 1224 that are connected and bent in sequence. The folded edge structure 122 forms four folded edges, and each folded edge segment is sequentially attached to the inner or outer wall surface of the adjacent folded edge segment. The folded edge structure 122 has good integrity, which can improve the overall strength and stability of the folded edge structure 122. This can effectively improve the impact resistance of the battery cell side during assembly, avoid damage to the battery cell due to collisions during assembly, and thus effectively ensure the safety performance of the battery cell.
[0039] Optionally, in some embodiments, the second folded edge segment 1222 is attached to the inner wall surface of the first folded edge segment 1221, the third folded edge segment 1223 is attached to the inner wall surface of the second folded edge segment 1222, and the fourth folded edge segment 1224 is attached to the outer wall surface of the first folded edge segment 1221. The edge of the folded edge structure 122 is located at the fourth folded edge segment 1224, the cut edge is located at the end of the first folded edge segment 1221, and the fourth folded edge segment 1224 is located outside the first folded edge segment 1221. This arrangement ensures that the fourth folded edge segment 1224 and the cut edge are away from the side of the encapsulation body 11 facing the folded edge structure 122, effectively preventing the cut edge from damaging the side of the encapsulation body 11 when the fourth folded edge segment 1224 deforms and warps, thereby ensuring the integrity of the encapsulation film 1 and guaranteeing the sealing and protective effect of the encapsulation film 1.
[0040] In some embodiments, such as Figure 6 and Figure 7 As shown, the fourth folded edge segment 1224 extends away from the extension portion 121 by a length of L1, and the third folded edge segment 1223 extends along the length direction of the fourth folded edge segment 1224 by a length of L2. The total length of the extension portion 121 and the folded edge structure 122 is L3, where L2 < L1 < L3. The length of the second folded edge segment 1222 is less than the length of the fourth folded edge segment 1224. The end of the fourth folded edge segment 1224 facing the extension portion 121 is positioned relatively close to the extension portion 121 relative to the second folded edge segment 1222. After bending, this effectively ensures the fit length between the fourth folded edge segment 1224 and the first folded edge segment 1221, preventing the fourth folded edge segment 1224 from warping outwards after bending. This improves the compactness of the folded edge structure 122 and reduces the space occupied by the folded edge structure 122 in the cell width direction.
[0041] In some embodiments, such as Figure 6 As shown, the included angle between the folded edge structure 122 and the extension 121 is θ, 60°≤θ≤120°, that is, the folded edge structure 122 is inclined on the extension 121. Along the width direction of the battery cell, the folded edge structure 122 can be inclined towards the inside or outside of the battery cell. The folded edge structure 122 can also be vertically arranged on the extension 121. By controlling the inclination angle of the folded edge structure 122, the angle of inclination of the folded edge structure 122 inward or outward is avoided from being too large, and the folded edge structure 122 is avoided from occupying too much space in the width direction of the battery cell, which can improve the compactness of the overall structure of the battery cell.
[0042] For example, in some embodiments, such as Figure 6 and Figure 7 As shown, the folded edge structure 122 is perpendicular to the extension 121. This arrangement allows the folded edge structure 122 to be parallel to the side of the encapsulation body 11, further reducing the space occupied by the folded edge structure 122 in the cell width direction.
[0043] When the edge structure 122 is bent, the sealing area 12 extends roughly horizontally with the large surface of the battery cell. First, the sealing area 12 is bent downward to form two layers of double-layer encapsulation area that fit together. Then, the middle area of the double-layer encapsulation area is bent upward to form a four-layer structure. Finally, the single-layer sealing area 12 on the inner side of the four-layer structure is bent vertically upward to form the four-layer edge structure 122. If the length of the third folded edge segment 1223 is too short, it will be inconvenient to bend the double-layer encapsulation area upwards, and the bent structure will easily warp and deform, thus preventing the folded edge segment from effectively fitting onto its adjacent folded edge segment. Conversely, if the length of the third folded edge segment 1223 is too long, after folding, the ends of the second folded edge segment 1222 and the third folded edge segment 1223 facing the extension portion 121 will easily abut against the extension portion 121. The extension portion 121 will exert a reverse force on the second folded edge segment 1222 and the third folded edge segment 1223, easily causing deformation of the second folded edge segment 1222 and the third folded edge segment 1223. Furthermore, the contact between the segments will easily wear down the encapsulation film 1, thus affecting the sealing performance of the encapsulation film 1. To avoid these problems, in some embodiments, such as... Figure 6 As shown, the length L2 of the third folded edge segment 1223 extending along the length direction of the fourth folded edge segment 1224 and the total length L3 of the extension 121 and the folded edge structure 122 satisfy the following condition: This design keeps the length of the third folded section 1223 within a suitable range, facilitating upward bending of the double-layer encapsulation area while ensuring that the area of the third folded section 1223 has sufficient space to adhere to the inner wall surface of the first folded section 1221 after bending. It also prevents the third folded section from becoming too long, thus preventing interference between the ends of the third folded section 1223 and the second folded section 1222 and the extension 121 after bending, preventing the ends of the third folded section 1223 and the second folded section 1222 from abutting against the extension 121, preventing deformation and warping of the third folded section 1223 and the second folded section 1222, and preventing wear on the encapsulation film 1 after contact between the sections.
[0044] In some embodiments, such as Figure 6 As shown, This design ensures that the fourth folded edge segment 1224 has sufficient length, guaranteeing the appropriate fit between the fourth folded edge segment 1224 and the first folded edge segment 1221 after bending. This prevents deformation and warping due to the fourth folded edge segment 1224 being too short, ensuring that the fourth folded edge segment 1224 effectively fits onto the first folded edge segment 1221. Simultaneously... This can prevent the fourth folded edge segment 1224 from being too long and extending beyond the bottom surface of the extension 121, and can reduce the space occupied by the folded edge structure 122 in the direction of cell thickness.
[0045] In some embodiments, such as Figure 6As shown, the distance between the fourth folded edge segment 1224 and the extension 121 is D1, where D1 ≥ 1mm. That is, the fourth folded edge segment 1224 and the extension 121 are set at a certain distance apart. This setting can prevent the fourth folded edge segment 1224 from extending out of the bottom surface of the extension 121 when it is deformed by force due to too small a distance between them. It can ensure that the fourth folded edge segment 1224 is located inside the extension 121 in the thickness direction, thus ensuring the compactness of the cell in its thickness direction.
[0046] In some embodiments, the distance between the third folded edge segment 1223 and the extension 121 is D2, where D2 ≥ 1 mm. This arrangement ensures that the ends of the third folded edge segment 1223 and the second folded edge segment 1222 maintain an appropriate gap with the extension 121, preventing the ends of the third folded edge segment 1223 and the second folded edge segment 1222 from contacting the extension 121 and deforming or wearing the encapsulation film 1.
[0047] like Figure 6 and Figure 7 As shown, there are arc transition sections 1225 between the first folded edge segment 1221 and the second folded edge segment 1222, between the second folded edge segment 1222 and the third folded edge segment 1223, and between the third folded edge segment 1223 and the fourth folded edge segment 1224. The segments are bent through the arc transition sections 1225, which can effectively ensure the strength of the joints of the segments after bending and avoid damage to the encapsulation film 1 due to excessive bending.
[0048] In some embodiments, such as Figure 6 As shown, the thickness of the battery cell is H, and L3≤H. This setting can prevent the folded edge structure 122 from extending beyond the large surface of the battery cell, and can ensure the compactness of the battery cell in the thickness direction.
[0049] like Figure 5 As shown, in some embodiments, the sealing area 12 is located on one side in the thickness direction of the electrode group; in other embodiments, such as Figure 8 As shown, the sealing area 12 is located in the middle region along the thickness direction of the electrode group.
[0050] According to an embodiment of the present invention, another aspect provides a battery pack including the aforementioned battery cell.
[0051] In this battery pack structure, the cell's folded edge structure 122 forms four layers of folds, and each folded edge segment is sequentially attached to the inner or outer wall surface of the adjacent folded edge segment. The folded edge structure 122 has good integrity, which can effectively improve the overall strength and stability of the folded edge structure 122. It can effectively improve the impact resistance of the cell's side during assembly, avoid damage to the cell due to collisions during assembly, and thus effectively ensure the safety performance of the cell and battery pack.
[0052] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A battery cell, characterized in that, include: pole group; An encapsulation film includes an encapsulation body and a sealing area. The encapsulation body covers the electrode assembly, and the sealing area is located outside the electrode assembly. The sealing area includes an extension and a folded edge structure. The extension extends outward toward the electrode assembly, and the folded edge structure includes a first folded edge segment, a second folded edge segment, a third folded edge segment, and a fourth folded edge segment arranged sequentially. One end of the first folded edge segment is connected to the end of the extension away from the electrode assembly, and the first folded edge segment is bent toward the thickness direction of the electrode assembly. The second folded edge segment is bent toward the extension and adheres to one side wall of the first folded edge segment. The third folded edge segment is bent away from the extension and adheres to one side wall of the second folded edge segment. The fourth folded edge segment is bent toward the extension and adheres to the other side wall of the first folded edge segment.
2. The battery cell according to claim 1, characterized in that, The length of the fourth folded edge segment extending away from the extension portion is L1, the length of the third folded edge segment extending along the length direction of the fourth folded edge segment is L2, and the total length of the extension portion and the folded edge structure is L3, where L2 < L1 < L3.
3. The battery cell according to claim 1 or 2, characterized in that, The angle between the folded edge structure and the extension is θ, where 60°≤θ≤120°.
4. The battery cell according to claim 3, characterized in that, The folded edge structure is perpendicular to the extension.
5. The battery cell according to claim 2, characterized in that, 6. The battery cell according to claim 2, characterized in that, 7. The battery cell according to claim 1 or 2, characterized in that, The distance between the fourth folded edge segment and the extension is D1, where D1 ≥ 1 mm.
8. The battery cell according to claim 1 or 2, characterized in that, The distance between the third folded edge segment and the extension is D2, where D2 ≥ 1 mm.
9. The battery cell according to claim 1 or 2, characterized in that, An arc transition section is provided between the first folded edge segment and the second folded edge segment, between the second folded edge segment and the third folded edge segment, and between the third folded edge segment and the fourth folded edge segment.
10. A battery pack, characterized in that, The battery cell includes any one of claims 1 to 9.