Square-shell battery cell
By designing the inner and outer wall structures and buffer spacing of the housing assembly, the performance problems of the prismatic cell in the early and late stages of its lifespan were solved, maintaining the structural stability and performance of the cell.
Patent Information
- Application Number
- CN202422773591.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-13
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-11-13
AI Technical Summary
During charge and discharge cycles, the expansion of the bare cell causes the casing to deform, affecting the performance of the cell in the later stages of its lifespan. In addition, in the early stages of its lifespan, the reduced initial group margin leads to problems such as loosening and wrinkling of the internal layers of the bare cell.
The design employs a housing assembly, including an outer sidewall and an inner sidewall. There is a buffer gap between the top of the inner sidewall and the outer sidewall. The inward-facing surface of the top of the inner sidewall is smaller than that of the outer sidewall. The inner sidewall can deform to provide buffer space when the cell expands, and supports the bare cell through the support and elastic elements, reducing deformation and wrinkles.
In the early stages of a cell's lifespan, reducing the looseness and wrinkles in the inner layers of the bare cell extends its initial performance. In the later stages, buffering deformation reduces casing changes and maintains stable cell performance.
Smart Images
Figure CN223539781U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of lithium-ion battery technology, and in particular relates to a square-shell battery cell. Background Technology
[0002] Prismatic cells typically have a high initial group margin to achieve higher energy density. However, the bare cells in prismatic cells, especially those using high-silicon anode materials, gradually expand during charge-discharge cycles. This leads to significant deformation and large expansion forces in the later stages of the cell's lifespan. The expanding bare cells compress the cell casing, causing casing deformation, which in turn leads to deformation and damage to components such as the cell module's endplate, resulting in a substantial decrease in cell performance later in its lifespan.
[0003] Reducing the initial group margin of prismatic cells can decrease the impact of the expansion force of the bare cell on the casing and cell module in the later stages of the cell's lifespan. However, in the early stages of the cell's lifespan, the reduced initial group margin weakens the constraint of the cell casing on the bare cell. This makes it easier for the layers inside the bare cell to develop wrinkles and loosening during charging and discharging, resulting in a significant reduction in the cell's performance in the early stages of its lifespan. Utility Model Content
[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a square-shell battery cell to solve the problem that the performance of the existing square-shell battery cell is prone to a significant decrease in the early stage of the cell's lifespan.
[0005] To achieve the above and other related objectives, this utility model provides a square-shell battery cell, comprising:
[0006] A housing assembly comprising two housing walls disposed opposite each other in a first direction, the housing walls including an outer side wall and an inner side wall;
[0007] A bare battery cell, wherein the bare battery cell is disposed between the two shell walls, and the bare battery cell has two flat surfaces in the first direction;
[0008] The inner sidewall includes a top and a support portion. The top and the outer sidewall have a buffer gap in the first direction. The inward-facing surface of the top is a first inner wall surface, and the inward-facing surface of the outer sidewall is a second inner wall surface. The support portion extends from the top to the second inner wall surface adjacent to the outer sidewall and is supported on the second inner wall surface. The area of the first inner wall surface is smaller than the area of the second inner wall surface.
[0009] Optionally, there are at least two support portions, which are respectively connected to the edges of opposite sides of the top and extend from the edges of the top toward the second inner wall surface.
[0010] Optionally, the extension direction of the support portion intersects the first direction at an angle.
[0011] Optionally, the angle between the support and the top is an obtuse angle.
[0012] Optionally, the two support portions are located on both sides of the top in the height direction of the square-shell cell, the first inner wall surface has a dimension of h in the height direction of the square-shell cell, and the second inner wall surface has a dimension of H in the height direction of the square-shell cell, where 0.85H≤h≤0.95H.
[0013] Optionally, the thickness of the inner sidewall is less than the thickness of the outer sidewall, wherein the thickness of the inner sidewall is 2mm to 6mm and the thickness of the outer sidewall is 3mm to 10mm.
[0014] Optionally, the first inner wall surface of the inner sidewall abuts against the flat surface of the bare cell opposite to the first inner wall surface.
[0015] Optionally, the bare cell has a stacked structure, and the bare cell includes a positive electrode, a negative electrode, and a separator, wherein the positive electrode, the negative electrode, and the separator are stacked along the first direction.
[0016] Optionally, the bare cell has a wound structure, and the bare cell includes a positive electrode, a negative electrode, and a separator, wherein the winding axes of the positive electrode, the negative electrode, and the separator are all perpendicular to the first direction.
[0017] Optionally, a gas channel penetrating the inner sidewall is provided on the inner sidewall, and the gas channel is a through hole or a notch.
[0018] Optionally, an elastic member is provided between the inner sidewall and the adjacent outer sidewall, and the elastic member abuts against the inner sidewall and the outer sidewall respectively along the first direction.
[0019] As described above, the square-shell battery cell of this invention has the following beneficial effects: Since the shell wall includes an outer side wall and an inner side wall, and there is a buffer gap between the top of the inner side wall and the outer side wall in a first direction, the bare battery cell has two flat surfaces in the first direction. Therefore, the inner side wall reduces the movable space of the bare battery cell in the shell assembly along the first direction, which helps to reduce the probability of wrinkles and loosening of the internal layers of the bare battery cell during the charging and discharging process in the early stage of the battery cell's lifespan, thus helping to maintain the performance of the battery cell in the early stage of its lifespan. Simultaneously, there is a buffer gap between the top of the outer side wall and the top of the inner side wall, and the inward-facing surface of the top of the inner side wall is smaller than the inward-facing surface of the outer side wall. Therefore, in the later stages of the battery cell's lifespan, the inner side wall can deform along with the bare battery cell after being squeezed by the bare battery cell. The buffer gap between the top of the outer side wall and the top of the inner side wall provides a buffer space for the deformation of the bare battery cell, which helps to prevent the expansion force of the bare battery cell from acting directly on the outer side wall, thereby reducing changes in the shape of the battery cell shell. Furthermore, in the later stages of a battery cell's lifespan, the inner wall, after being squeezed by the bare battery cell, generates a reverse force and presses firmly against the flat surface of the bare battery cell. This helps reduce deformation and wrinkles in the layers of the bare battery cell, thereby helping to maintain the cell's performance in the later stages of its lifespan. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the cross-sectional structure of the square-shell battery cell perpendicular to its length direction in an embodiment of this utility model;
[0021] Figure 2 This is a cross-sectional structural diagram of the housing assembly in an embodiment of the present utility model;
[0022] Figure 3 This is a three-dimensional cross-sectional view of the square-shell battery cell in an embodiment of this utility model;
[0023] Figure 4 This is a three-dimensional sectional view of the housing assembly in an embodiment of the present utility model;
[0024] Figure 5 This is one of the three-dimensional structural diagrams of the inner wall in an embodiment of the present utility model;
[0025] Figure 6 This is a second three-dimensional structural diagram of the inner wall in an embodiment of this utility model;
[0026] Figure 7 This is one of the cross-sectional structural diagrams of the square-shell battery cell perpendicular to the height direction in an embodiment of this utility model;
[0027] Figure 8 This is the second schematic diagram of the cross-sectional structure of the square-shell battery cell perpendicular to the height direction in this embodiment of the present invention.
[0028] Explanation of reference numerals in the attached drawings: 1. Outer side wall; 2. Inner side wall; 3. Bare battery cell; 4. Vent; 5. Top; 6. Support; 7. Buffer gap; 8. First direction X. Detailed Implementation
[0029] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.
[0030] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives of this utility model, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.
[0031] In prismatic battery cells, the bare cell gradually expands during charge-discharge cycles, resulting in significant deformation and substantial expansion force in the later stages of the cell's lifespan. This is especially true for high-nickel, high-silicon cells, which use high-nickel ternary cathode materials and silicon-containing anode materials to increase energy density. In high-nickel, high-silicon cells, the silicon-containing anode material experiences greater rebound during cycling due to silicon deformation, leading to a significant increase in the expansion force of the bare cell.
[0032] The expansion of the bare battery cell compresses the cell casing, easily causing the casing to deform. This, in turn, leads to deformation and damage to components such as the cell module end plate, resulting in a significant performance reduction in the later stages of the cell's lifespan. The cell's group margin refers to the proportion of the bare cell's thickness to the total thickness of the prismatic cell. While reducing the initial group margin of the prismatic cell can decrease the impact of the bare cell's expansion force on the casing and cell module in the later stages of the cell's lifespan, in the early stages, the reduced initial group margin weakens the casing's constraint on the bare cell. This makes the internal layers of the bare cell prone to wrinkling and loosening during charging and discharging, leading to a significant performance reduction in the early stages of the cell's lifespan.
[0033] In view of this, please refer to Figures 1 to 8This embodiment provides a square-shell battery cell, including a housing assembly and a bare battery cell 3. The housing assembly includes two opposing housing walls, and the bare battery cell 3 is disposed between the two housing walls. The housing walls include an outer side wall 1 and an inner side wall 2. The two housing walls of the housing assembly are opposite to each other in a first direction X, and the bare battery cell 3 has two flat surfaces in the first direction X.
[0034] The inner wall 2 includes a top 5 and a support 6. The top 5 of the inner wall 2 and the outer wall 1 have a buffer gap 7 in the first direction X. The inward-facing surface of the top 5 of the inner wall 2 is the first inner wall surface, and the inward-facing surface of the outer wall 1 is the second inner wall surface. The support 6 extends from the top 5 to the second inner wall surface of the adjacent outer wall 1 and is supported on the second inner wall surface. The area of the first inner wall surface is smaller than the area of the second inner wall surface.
[0035] Since the shell wall includes an outer side wall 1 and an inner side wall 2, and there is a buffer gap 7 between the top 5 of the inner side wall 2 and the outer side wall 1 in the first direction X, the bare cell 3 has two flat surfaces in the first direction X. Therefore, the inner side wall 2 reduces the movable space of the bare cell 3 in the shell assembly in the first direction X, which helps to avoid problems such as wrinkling and loosening of the internal layers of the bare cell 3 during the charging and discharging process in the early stage of the cell's life, and thus helps to maintain the performance of the cell in the early stage of its life.
[0036] Meanwhile, since there is a buffer gap 7 between the second inner wall surface of the outer side wall 1 and the top 5 of the inner side wall 2, the inner side wall 2 can deform along with the bare cell 3 after being squeezed by the bare cell 3 in the later stages of the cell's life. The buffer gap 7 between the outer side wall 1 and the top 5 of the inner side wall 2 provides a buffer space for the deformation of the bare cell 3, which helps to prevent the expansion force of the bare cell 3 from acting directly on the outer side wall 1, thereby reducing the change in the shape of the cell casing. The inward-facing surface of the top 5 of the inner side wall 2 is smaller than the inward-facing surface of the outer side wall 1, so that there is space around the top 5 of the inner side wall 2 that can be extended. When the inner side wall 2 is squeezed by the bare cell 3 and deformed along the first direction X, the inner side wall 2 can extend outward.
[0037] Furthermore, in the later stages of the battery cell's lifespan, after the inner wall 2 is squeezed by the bare battery cell 3, the inner wall 2 will generate a reverse force. This force presses against the flat surface of the bare battery cell 3, which helps to reduce the deformation and wrinkles of each layer of the bare battery cell 3, and thus helps to maintain the performance of the battery cell in the later stages of its lifespan.
[0038] like Figure 1 As shown, in this embodiment, the first inner wall surface of the inner sidewall 2 abuts against the flat surface of the bare cell 3 opposite to the first inner wall surface. That is, the inner sidewall 2 is directly pressed against the flat surface of the bare cell 3. When the bare cell 3 expands, the pressing force of the inner sidewall 2 increases accordingly, which helps to reduce the deformation and wrinkles of each layer of the bare cell 3 during the charging and discharging process.
[0039] Specifically, in this embodiment, the bare cell 3 has a multi-layer structure. For example... Figure 7 As shown, in an optional embodiment of this example, the bare cell 3 has a stacked structure, comprising a positive electrode, a negative electrode, and a separator, which are stacked along a first direction X. The side of the bare cell 3 along the first direction X is a flat surface, which is also the normal direction of the flat surface. When the bare cell 3 expands and compresses the inner sidewall 2, the inner sidewall 2 provides a reaction force, which acts on the bare cell 3 along the first direction X, i.e., the normal direction of the flat surface. The reaction force provided by the inner sidewall 2 can compact the layers of the bare cell 3, which helps to reduce the gaps and wrinkles between the layers of the bare cell 3, thereby helping to maintain the stability of the bare cell 3 structure.
[0040] like Figure 8 As shown, in another optional embodiment of this example, the bare cell 3 has a wound structure, comprising a positive electrode sheet, a negative electrode sheet, and a separator. The winding axes of the positive electrode sheet, negative electrode sheet, and separator are all perpendicular to the first direction X. That is, the positive electrode sheet, negative electrode sheet, and separator are processed into the bare cell 3 using a winding process. For a bare cell 3 adapted to a prismatic cell and using a winding process, its flat surfaces are typically the two largest and opposite sides among all sides of the bare cell 3, while the sides between the two flat surfaces are typically curved. When the bare cell 3 expands and compresses the inner sidewall 2, the inner sidewall 2 provides a reaction force, which acts on the bare cell 3 along the normal direction of the flat surface (i.e., the first direction X). After the bare cell 3 is subjected to the force of the inner sidewall 2, it helps to reduce wrinkles in each layer of the bare cell 3 and maintain the stability of the bare cell 3 structure.
[0041] In some embodiments, the bare cell 3 has the smallest thickness in the normal direction of the flat surface. Therefore, when the bare cell 3 is subjected to a force along the normal direction of the flat surface (i.e., the first direction X), the layers of the bare cell 3 have good stability and are not prone to problems such as misalignment or separation.
[0042] Specifically, such as Figure 5 , Figure 6 As shown, in this embodiment, there are at least two support portions 6 on the inner wall 2. The two support portions 6 are respectively connected to the edges on opposite sides of the top 5 and extend from the edges of the top 5 toward the second inner wall surface. The extension direction of the support portion 6 intersects the first direction X at an inclination.
[0043] The support portion 6 is connected to the opposite edges of the top 5 and extends from the edges of the top 5 towards the second inner wall surface. This facilitates the connection of the support portion 6 to the edges of the top 5. The connection between the support portion 6 and the top 5 requires no additional structure, resulting in a simple and reliable structure that simplifies the structure of the inner wall 2 and reduces its weight. Furthermore, the support portion 6 serves as a flange connected to the edges of the top 5, allowing the inner wall 2 to be manufactured by bending sheet metal, simplifying processing and making it suitable for large-scale industrial applications.
[0044] Two support parts 6 enhance the overall support effect of the top 5. When the inner wall 2 is compressed by the bare cell 3, they provide sufficient reaction force to compress the bare cell 3, reducing deformation and wrinkles in each layer of the bare cell 3, thus helping to maintain the performance of the cell in the later stages of its life. The two support parts 6 are respectively connected to opposite sides of the top 5, providing uniform support to the top 5 and reducing the risk of excessive or insufficient local deformation of the inner wall 2 after being compressed.
[0045] like Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, in this embodiment, the extension direction of the support part 6 is inclined to intersect with the first direction X, that is, the extension direction of the support part 6 does not coincide with the first direction X. When the support part 6 is subjected to pressure from the bare cell 3 along the first direction X, it will generate a component force perpendicular to the first direction X. The component force pushes the support part 6 to deflect outward or inward, which is beneficial to guide the inner wall 2 to deform after being pressed.
[0046] Specifically, in this embodiment, the angle between the support portion 6 and the top 5 is an obtuse angle, meaning that the extension direction of the support portion 6 is obliquely outward. When the support portion 6 is subjected to pressure from the bare cell 3 along the first direction X, the support portion 6 will further obliquely outward. After the inner wall 2 is deformed by pressure, the support portion 6 is located in the space around the top 5, avoiding the support portion 6 being stacked between the top 5 and the outer wall 1. This helps to reduce the final thickness of the inner wall 2 after deformation and increases the buffer space for the expansion of the bare cell 3.
[0047] The prismatic battery cell has mutually perpendicular height, length, and thickness directions. In this embodiment, the thickness direction of the prismatic battery cell is the first direction X. For example... Figures 1-4 As shown, in this embodiment, the two support parts 6 are located on both sides of the top 5 in the direction of the height of the square battery cell. The dimension of the first inner wall surface in the direction of the height of the square battery cell is h, and the dimension of the second inner wall surface in the direction of the height of the square battery cell is H, where 0.85H≤h≤0.95H.
[0048] like Figure 5 , Figure 6As shown, in this embodiment, the support part 6 is elongated, with its width extending toward the second inner wall surface and its length extending along the length of the square-shell battery cell. The support part 6 can provide support for the top 5 within a large size range (the length of the square-shell battery cell), which is beneficial to increasing the support effect of the support part 6.
[0049] The larger the ratio of the area of the inner surface of the top 5 to the area of the second inner wall, i.e., the larger the area of the first inner wall, the larger the supporting area of the top 5 of the inner wall on the bare cell when it contacts the flat surface of the bare cell. This results in lower pressure per unit area on the second inner wall, which is beneficial for improving the support effect of the inner wall on the bare cell. Conversely, the smaller the ratio of the area of the inner surface of the top 5 to the area of the second inner wall, i.e., the smaller the area of the first inner wall, the larger the space available for extension around the first inner wall. This is beneficial for the inner wall to fully extend and deform when squeezed by the bare cell, and helps to avoid transferring the expansion force of the bare cell to the outer wall of the housing assembly due to the difficulty in compressing and deforming the inner wall. In this embodiment, the dimension h of the first inner wall in the height direction of the square-shell cell is set to 0.85H to 0.95H. This ensures sufficient extendable space around the first inner wall while guaranteeing sufficient supporting area for the bare cell, thus ensuring the effective support of the inner wall.
[0050] In this embodiment, the thickness of the inner wall is less than the thickness of the outer wall, with the inner wall thickness ranging from 2mm to 6mm and the outer wall thickness from 3mm to 10mm. The thinner inner wall results in a weaker inner wall, meaning the inner wall is more susceptible to compressive deformation than the outer wall. When the inner wall undergoes elastic deformation under the pressure of the bare electrode, the outer wall experiences relatively smaller elastic deformation. When the inner wall undergoes plastic deformation under the pressure of the bare electrode, the outer wall remains in the elastic deformation stage, preventing plastic deformation and damage to the outer wall.
[0051] A gas channel, either a through-hole or a notch, is provided on the inner wall. This gas channel allows gas to pass through, which helps to reduce the pressure difference across the inner wall. For example... Figure 5 , Figure 6 As shown, in this embodiment, the gas channel is a vent 4. The gas channel can be located on the support portion 6 of the inner sidewall or on the top 5 of the inner sidewall. The gas channel can reduce the structural strength of the inner sidewall, which helps to prevent excessive expansion force of the bare cell from being transferred to the outer sidewall due to excessive structural strength of the inner sidewall. There can be multiple gas channels, which are arranged sequentially along the length of the prismatic cell. By adjusting the arrangement direction of the gas channels, the collapse direction of the inner sidewall during plastic deformation can be adjusted, which helps to prevent the inner sidewall from interfering with other internal components of the cell due to excessive deformation.
[0052] like Figure 1, Figure 2 , Figure 5 and Figure 6 As shown, due to the buffer gap between the top 5 of the inner wall 2 and the outer wall 1 in the first direction X, there is a space within the shell wall between the top 5 of the inner wall 2 and the outer wall 1 that can accommodate electrolyte. When electrolyte is added to the cell, the added electrolyte can enter through the gas channel and be stored between the top 5 of the inner wall 2 and the outer wall 1. When the bare cell 3 expands and squeezes the inner wall 2, the electrolyte stored between the top 5 of the inner wall 2 and the outer wall 1 can flow out through the gas channel to replenish the free electrolyte in the cell. This helps to prevent the cell from failing due to a lack of free electrolyte in the later stages of use, thus improving the reliability of the cell.
[0053] In this embodiment, an elastic element, such as a spring, is provided between the inner sidewall and the adjacent outer sidewall. The elastic element abuts against the inner sidewall and the outer sidewall respectively along the first direction. The elastic element can increase the supporting force of the inner sidewall on the bare cell, which helps to avoid insufficient elasticity of the inner sidewall, thereby ensuring that the inner sidewall has sufficient compressive force on the bare cell when it expands.
[0054] In summary, the prismatic battery cell of this embodiment, with its outer and inner walls, allows the inner wall to constrain the bare cell during the early stages of its lifespan. This helps prevent wrinkles and loosening of the internal layers during charging and discharging, thus maintaining the cell's performance in its early stages. A buffer gap exists between the outer and inner walls, and the top inward-facing surface of the inner wall is smaller than the inward-facing surface of the outer wall. Therefore, in the later stages of the cell's lifespan, the inner wall can deform along with the bare cell when compressed. The buffer gap between the outer and inner walls provides a buffer space for the deformation of the bare cell, preventing the expansion force from acting directly on the outer wall and reducing changes in the cell's casing shape. Simultaneously, when compressed by the bare cell, the inner wall generates a counterforce and presses against the flat surface of the bare cell, reducing deformation and wrinkles in the layers and further maintaining the cell's performance in its later stages.
[0055] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A square-shell battery cell, characterized in that, include: A housing assembly comprising two housing walls disposed opposite each other in a first direction, the housing walls including an outer side wall and an inner side wall; A bare battery cell, wherein the bare battery cell is disposed between the two shell walls, and the bare battery cell has two flat surfaces in the first direction; The inner sidewall includes a top and a support portion. The top and the outer sidewall have a buffer gap in the first direction. The inward-facing surface of the top is a first inner wall surface, and the inward-facing surface of the outer sidewall is a second inner wall surface. The support portion extends from the top to the second inner wall surface adjacent to the outer sidewall and is supported on the second inner wall surface. The area of the first inner wall surface is smaller than the area of the second inner wall surface.
2. The prismatic battery cell according to claim 1, characterized in that, There are at least two support portions, which are respectively connected to the opposite edges of the top and extend from the edges of the top toward the second inner wall surface. The extension direction of the support portion intersects the first direction at an inclination.
3. The prismatic battery cell according to claim 2, characterized in that, The angle between the support and the top is an obtuse angle.
4. The prismatic battery cell according to claim 2, characterized in that, The two support portions are located on both sides of the top in the height direction of the square-shell battery cell, the first inner wall surface has a dimension of h in the height direction of the square-shell battery cell, and the second inner wall surface has a dimension of H in the height direction of the square-shell battery cell, where 0.85H≤h≤0.95H.
5. The prismatic battery cell according to claim 1, characterized in that, The thickness of the inner wall is less than the thickness of the outer wall, the thickness of the inner wall is 2mm to 6mm, and the thickness of the outer wall is 3mm to 10mm.
6. The prismatic battery cell according to claim 1, characterized in that, The first inner wall surface of the inner sidewall abuts against the flat surface of the bare battery cell opposite to the first inner wall surface.
7. The prismatic battery cell according to claim 1, characterized in that, The bare cell has a stacked structure, and the bare cell includes a positive electrode, a negative electrode, and a separator, which are stacked along the first direction.
8. The prismatic battery cell according to claim 1, characterized in that, The bare cell has a wound structure, and the bare cell includes a positive electrode, a negative electrode, and a separator. The winding axes of the positive electrode, the negative electrode, and the separator are all perpendicular to the first direction.
9. The prismatic battery cell according to any one of claims 1 to 6, characterized in that, The inner sidewall is provided with a gas channel that penetrates the inner sidewall, and the gas channel is a through hole or a notch.
10. The prismatic battery cell according to any one of claims 1 to 6, characterized in that, An elastic element is provided between the inner sidewall and the adjacent outer sidewall, and the elastic element abuts against the inner sidewall and the outer sidewall respectively along the first direction.