Battery cell and battery thereof
By setting a support area and a liquid storage gap in the bending area of the battery cell, the problem of electrolyte being squeezed out is solved, the electrolyte holding space and lithium ion diffusion effect are improved, and lithium plating on the negative electrode is avoided.
Patent Information
- Application Number
- CN202423175039.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2034-12-23
AI Technical Summary
In existing technologies, the electrolyte in wound-structured cells is easily squeezed out at the bends, resulting in poor lithium-ion diffusion and consequently lithium plating in the negative electrode area.
A support area is set in the bending area to create a liquid storage gap between the positive electrode and the separator, thereby increasing the electrolyte capacity, preventing the electrolyte from being squeezed out, and improving the support strength.
By setting a support area and a liquid storage gap, lithium plating on the negative electrode is avoided, and the liquid retention capacity of the electrolyte and the lithium ion diffusion effect are improved.
Smart Images
Figure CN223797373U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of batteries, and in particular to a battery cell and its battery. Background Technology
[0002] Currently, wound battery cells have a bending area. In the bending area, the positive electrode, separator, and negative electrode are tightly attached. After repeated cycles of expansion, the electrolyte in the bending area is easily squeezed out, resulting in poor lithium ion diffusion in the bending area, which in turn leads to black spots of lithium plating in the negative electrode area of the bending area. Utility Model Content
[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. It provides a battery cell and battery thereof, in which a support area is provided in the bending region, creating a liquid storage gap between the conventional region and the separator. This liquid storage gap provides space for the electrolyte, preventing lithium plating from occurring on the negative electrode in the bending region.
[0004] To achieve the above objectives, this utility model provides a battery cell, comprising intersecting first and second directions, including a winding structure formed by sequentially stacked positive electrode sheets, separators, and negative electrode sheets. The winding structure has a bending region, and the positive electrode sheet located in the bending region has a conventional region and a support region. In the first direction, the thickness of the support region is greater than the thickness of the conventional region, so that one side of the support region is in contact with the separator. The conventional region and the separator have a liquid storage gap between them in the first direction.
[0005] As a preferred embodiment, multiple support areas are provided, and the multiple support areas are spaced apart along the second direction, with the regular area located between adjacent support areas.
[0006] As a preferred embodiment, the positive electrode includes a first conductive layer and a positive active layer, the positive active layer being connected to one side of the first conductive layer facing the separator, and the support region and the conventional region being disposed on the positive active layer.
[0007] As a preferred embodiment, the positive electrode sheet is provided with a dividing groove, the dividing groove penetrates the opposite surface of the positive electrode active layer in the first direction, and the dividing groove is arranged around the edge of the support area.
[0008] As a preferred embodiment, the width of the dividing groove is D mm, where D > 0.1 mm.
[0009] As a preferred embodiment, the winding structure has a straight region, the bending region is connected to one end of the straight region in a first direction, and the two ends of the support region extend to the straight region respectively.
[0010] As a preferred embodiment, the bending area is arc-shaped, the radius of the bending area is R, and the length of the support area is Lmm, wherein L-π×R≥4mm.
[0011] As a preferred embodiment, the height of the support area in the second direction is H mm, where H ≥ 3 mm.
[0012] As a preferred embodiment, in the first direction, the thickness of the support region is at least 3 μm greater than the thickness of the conventional region.
[0013] A battery comprising the aforementioned battery cell.
[0014] Compared with the prior art, the beneficial effects of this utility model embodiment of a battery cell and its battery are as follows: the battery cell, which consists of a positive electrode sheet, a separator, and a negative electrode sheet wound together to form a wound structure, wherein the wound structure has a bending region, and the positive electrode sheet located in the bending region has a conventional region and a support region. In the first direction, the thickness of the support region is greater than the thickness of the conventional region, so that the support region is in contact with the separator on both sides of the positive electrode sheet in the first direction, thereby achieving support of the positive electrode sheet for the separator and improving the support strength of the positive electrode sheet for the separator. At the same time, there is a liquid storage gap between the separator on both sides of the positive electrode sheet in the first direction and the conventional region. The liquid storage gap provides more electrolyte storage space for the bending region and provides expansion space for the positive electrode sheet, preventing the electrolyte from being squeezed out after the positive electrode sheet expands, increasing the electrolyte retention in the bending region, and avoiding lithium plating on the negative electrode sheet in the bending region. Attached Figure Description
[0015] Figure 1 This is a cross-sectional schematic diagram of the overall structure of an embodiment of this utility model.
[0016] Figure 2 This is a schematic diagram of the unfolded structure of the positive electrode sheet in the bending region of this utility model embodiment.
[0017] Figure 3 This is an embodiment of the present utility model. Figure 1 A cross-sectional view of point AA in the diagram.
[0018] In the picture:
[0019] 10. Positive electrode sheet; 11. First conductive layer; 12. Positive active layer; 13. Separating channel;
[0020] 20. Diaphragm;
[0021] 30. Negative electrode sheet; 31. Second conductive layer; 32. Negative electrode active layer;
[0022] 40. Bending area; 41. Regular area; 42. Support area; 43. Liquid retention gap;
[0023] 50. Straight area;
[0024] X, first direction; Y, second direction; Z, third direction. Detailed Implementation
[0025] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0026] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0027] In the description of this utility model, it should be understood that the terms "connected," "linked," and "fixed," etc., used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0028] like Figures 1 to 3 As shown, a preferred embodiment of the present invention provides a battery cell comprising intersecting first direction X and second direction Y, including a winding structure formed by sequentially stacked positive electrode 10, separator 20, and negative electrode 30. The winding structure has a bending region 40. The positive electrode 10 located in the bending region 40 has a conventional region 41 and a support region 42. In the first direction X, the thickness of the support region 42 is greater than the thickness of the conventional region 41, so that one side of the support region 42 is in contact with the separator 20. The conventional region 41 and the separator 20 have a liquid storage gap 43 between them in the first direction X.
[0029] A battery, including battery cells.
[0030] The present invention relates to a battery cell and its battery, wherein a positive electrode 10, a separator 20, and a negative electrode 30 are wound to form a wound structure. The wound structure has a bending region 40. The positive electrode 10 located in the bending region 40 has a conventional region 41 and a support region 42. In the first direction X, the thickness of the support region 42 is greater than the thickness of the conventional region 41, so that the support region 42 is respectively attached to the separator 20 on both sides of the positive electrode 10 in the first direction X, thereby achieving contact between the positive electrode 10 and the separator 20. The positive electrode 10 provides support, enhancing its support strength to the separator 20. Simultaneously, it creates liquid storage gaps 43 between the separator 20 on both sides of the positive electrode 10 in the first direction X and the conventional region 41. These liquid storage gaps 43 provide more electrolyte storage space for the bending region 40 and expansion space for the positive electrode 10, preventing the electrolyte from being squeezed out after the positive electrode 10 expands. This increases the electrolyte retention capacity of the bending region 40 and prevents lithium plating from occurring on the negative electrode 30 in the bending region 40.
[0031] As one embodiment, such as Figure 1 As shown, the bending area 40 is arc-shaped, and the thickness of the support area 42 is the radial length of the bending area 40.
[0032] As one embodiment, such as Figure 1 As shown, the negative electrode 30 includes a second conductive layer 31 and a negative electrode active layer 32. The second conductive layer 31 is a copper foil, and the negative electrode active layer 32 is a negative electrode active material. The negative electrode active material is a material of the prior art and will not be described in detail here.
[0033] Furthermore, such as Figures 2 to 3 As shown, multiple support regions 42 are provided, and the multiple support regions 42 are spaced apart along the second direction Y. The conventional region 41 is located between adjacent support regions 42, so that multiple liquid storage gaps 43 are formed at intervals in the second direction Y, increasing the electrolyte storage space in the second direction Y, and avoiding lithium plating on the negative electrode 30 of the bending region 40 in the second direction Y.
[0034] As one embodiment, such as Figures 2 to 3 As shown, the support regions 42 are evenly spaced along the second direction Y. The more uniform distribution of the support regions 42 in the second direction Y makes the distribution of the liquid storage gaps 43 in the second direction Y more uniform, thus avoiding lithium deposition on the negative electrode 30 of the bending region 40 in the second direction Y.
[0035] Furthermore, such as Figures 1 to 3As shown, the positive electrode 10 includes a first conductive layer 11 and a positive active layer 12. The positive active layer 12 is located between the first conductive layer 11 and the separator 20. A support region 42 and a conventional region 41 are disposed on the positive active layer 12. The positive active layer 12 is connected to the first conductive layer 11 for fixation, and the first conductive layer 11 provides support for the positive active layer 12. The thickness of the support region 42 in the positive active layer 12 is increased to form a liquid storage gap 43 between the conventional region 41 in the positive active layer 12 and the separator 20.
[0036] As one embodiment, such as Figures 1 to 3 As shown, the first conductive layer 11 is aluminum foil, and the positive electrode active layer 12 is a positive electrode active material. The positive electrode active material is a material of existing technology and will not be described in detail here.
[0037] Furthermore, such as Figures 1 to 3 As shown, the positive electrode 10 is provided with a separating channel 13, which penetrates the positive active layer 12 on the opposite side in the first direction X, and the separating channel 13 is arranged around the edge of the support region 42. By providing the separating channel 13, it is possible to provide a space for the electrolyte, thereby increasing the electrolyte capacity in the bending region 40 and preventing lithium plating from occurring on the negative electrode 30 in the bending region 40.
[0038] Furthermore, such as Figure 2 As shown, the width of the separating channel 13 is D mm, where D > 0.1 mm, to ensure that the separating channel 13 has a set capacity for the electrolyte and to prevent it from being squeezed out when the cell expands.
[0039] In one embodiment, the battery cell has a third direction Z, and the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The winding structure has two bending regions 40 arranged opposite each other along the first direction X and two straight regions 50 arranged opposite each other along the third direction Z. The straight regions 50 are connected to the bending regions 40 at both ends of the first direction X.
[0040] Furthermore, such as Figure 1 As shown, the winding structure has a straight region 50, a bending region 40 connected to one end of the straight region 50 in the first direction X, and two ends of the support region 42 extending to the straight region 50. By extending the support region 42 to the straight region 50 from both ends, the support region 42 extends along the bending region 40 to the straight region 50. The support region 42 covers the entire bending region 40 in the third direction Z of the cell, meaning the electrolyte gap 43 also spans the entire bending region 40, ensuring sufficient electrolyte space in the bending region 40 and preventing lithium plating on the negative electrode 30 of the bending region 40.
[0041] As one embodiment, the flat area 50 has a regular area 41.
[0042] Furthermore, such as Figures 1 to 2As shown, the bending region 40 is arc-shaped with a radius of R, and the length of the support region 42 is L mm, where L-π×R≥4mm, so that the support region 42 extends along the bending region 40 to the straight region 50. The support region 42 covers the entire bending region 40 in the third direction Z of the cell, that is, the electrolyte gap 43 also spans the entire bending region 40, ensuring the electrolyte containment space in the bending region 40 and preventing lithium plating from occurring on the negative electrode 30 of the bending region 40.
[0043] Where L is the length of the support region 42 after the positive electrode 10 is unfolded.
[0044] Furthermore, such as Figures 2 to 3 As shown, the height of the support area 42 in the second direction Y is H mm, where H ≥ 3 mm.
[0045] Furthermore, such as Figure 3 As shown, in the first direction X, the thickness of the support region 42 is at least 3 μm greater than the thickness of the conventional region 41. By setting the thickness difference between the support region 42 and the conventional region 41, the space of the electrolyte storage gap 43 is set within a predetermined range, resulting in a better electrolyte storage effect.
[0046] In summary, this utility model embodiment provides a battery cell and its battery. The battery cell, consisting of a positive electrode 10, a separator 20, and a negative electrode 30, is wound to form a wound structure. The wound structure has a bending region 40. The positive electrode 10 located in the bending region 40 has a conventional region 41 and a support region 42. In the first direction X, the thickness of the support region 42 is greater than the thickness of the conventional region 41, so that the support region 42 is respectively attached to the separator 20 on both sides of the positive electrode 10 in the first direction X, thereby realizing the bonding between the positive electrode 10 and the separator 20. The diaphragm 20 is supported, which increases the support strength of the positive electrode 10 to the diaphragm 20. At the same time, the diaphragm 20 on both sides of the positive electrode 10 in the first direction X has a liquid storage gap 43 between it and the conventional region 41. The liquid storage gap 43 provides more electrolyte storage space for the bending region 40 and provides expansion space for the positive electrode 10. This prevents the positive electrode 10 from squeezing out the electrolyte after expansion, increases the electrolyte retention in the bending region 40, and avoids lithium plating on the negative electrode 30 in the bending region 40.
[0047] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this utility model, and these improvements and substitutions should also be considered within the protection scope of this utility model.
Claims
1. A battery cell comprising intersecting first and second directions, characterized in that: The invention includes a wound structure formed by sequentially stacking a positive electrode, a separator, and a negative electrode. The wound structure has a bending region. The positive electrode located in the bending region has a conventional region and a support region. In the first direction, the thickness of the support region is greater than the thickness of the conventional region, so that one side of the support region is in contact with the separator. The conventional region and the separator have a liquid storage gap between them in the first direction.
2. The battery cell according to claim 1, characterized in that: Multiple support areas are provided, and the multiple support areas are spaced apart along the second direction. The regular area is located between adjacent support areas.
3. The battery cell according to claim 1, characterized in that: The positive electrode includes a first conductive layer and a positive active layer. The positive active layer is connected to one side of the first conductive layer facing the separator. The support region and the conventional region are disposed on the positive active layer.
4. The battery cell according to claim 3, characterized in that: The positive electrode sheet is provided with a dividing groove, which penetrates the opposite surface of the positive electrode active layer in the first direction and is arranged around the edge of the support area.
5. The battery cell according to claim 4, characterized in that: The width of the dividing groove is D mm, where D > 0.1 mm.
6. The battery cell according to claim 1, characterized in that: The winding structure has a straight section, the bending section is connected to one end of the straight section in a first direction, and the two ends of the support section extend to the straight section respectively.
7. The battery cell according to claim 1, characterized in that: The bending area is arc-shaped, the radius of the bending area is R, and the length of the support area is L mm, where L-π×R≥4mm.
8. The battery cell according to claim 1, characterized in that: The height of the support area in the second direction is H mm, where H ≥ 3 mm.
9. The battery cell according to claim 1, characterized in that: In the first direction, the thickness of the support region is at least 3 μm greater than the thickness of the conventional region.
10. A battery, characterized in that: Includes the battery cell described in any one of claims 1-9.