Battery cell insulation film, battery cell, and battery pack

Abstract

The utility model relates to battery technology field discloses electric core insulating film, electric core and battery package, wherein the electric core insulating film mainly includes: bottom film and side film, the bottom film one side surface is outward bulging and forms thickening area, the side film is located the opposite two sides or the circumferential side of bottom film, and the junction of bottom film and side film is equipped with the crease, and the side film is suitable for bending through the crease relative bottom film and is equipped with thickening area one side, the thickness of bottom film is T1, the thickness of thickening area is T2, satisfies 0.08mm <= T1 <= 0.15mm, 0.5mm <= T2 <= 2mm. The utility model sets up thickening area on bottom film, utilizes thickening area to support electric core, can omit the support plate of traditional electric core, thereby omits the process that support plate and bare electric core insulating piece hot melt fixed, when assembling, only need to utilize the crease and fold the side film and cover in the outer periphery of pole group, has simplified the assembly process of electric core, has improved the production efficiency of electric core, can also improve the assembly yield and reduce the use cost.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to cell insulating film, cell, and battery pack. Background Technology

[0002] New energy batteries are widely used in various fields such as transportation power supply, power storage power supply, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high working voltage, strong charge retention capacity and long cycle life.

[0003] A battery cell is the smallest unit of a battery pack. Existing battery cells generally consist of electrode arrays, electrolyte, bare cell insulating sheets, support plates, cover plates (usually integrating terminals, filling holes, explosion-proof valves, etc.), and a casing. The casing and cover plates are welded together to form a closed space housing the electrode arrays. The bare cell insulating sheets and support plates wrap around the electrode arrays, providing electrical insulation and supporting and protecting them.

[0004] For blade cells, such as Figure 1 and Figure 2 As shown, the support plate is first heat-fused to the narrow side of the electrode group 5' along its length; this support plate is also known as the side plate 200'. Because the blade cell is relatively long, placing the side plate 200' on the narrow side of the bottom of the electrode group 5' provides some support, facilitating its insertion into the casing. The blade cell assembly process is as follows: the first cover plate 400' is welded to the electrode group 5'; the side plate 200' is heat-fused to the bare cell insulating sheet 100'; the bare cell insulating sheet 100' wraps around the electrode group 5'; simultaneously, both ends of the bare cell insulating sheet 100' are heat-fused to the first cover plate 400 and the second cover plate 500' respectively; the electrode group 5' is inserted into the casing; the first cover plate 400' is welded to the casing 300'; the second cover plate 500' is welded to the electrode group 5'; and the second cover plate 500' is welded to the casing 300'.

[0005] For square-shell battery cells, such as Figure 3 As shown, the support plate is located at the bottom of the cell. The support plate, also known as the bottom support plate 600', mainly serves to support and protect the electrode group 5', and also prevents the electrode group 5' from interfering with and being cut by the inner corner of the bottom of the casing 300'. The existing bare cell insulation sheet 100' needs to be heat-fused to the bottom support plate 600' first, then wrapped around the electrode group 5', and then inserted into the casing together with the electrode group 5'.

[0006] In the existing cell structures mentioned above, whether it is the side plate of the blade cell or the bottom plate of the prismatic cell, they all need to be heat-fused and fixed to the bare cell insulation sheet before the electrode assembly is wrapped. The assembly process is complicated and the production efficiency is low. Utility Model Content

[0007] In view of this, the present invention provides a cell insulation film, a cell, and a battery pack to solve the problem that in the past, before covering the bare cell insulation sheet with the cell, it was necessary to heat-melt and fix the support plate to the bare cell insulation sheet, which resulted in a complicated assembly process and low production efficiency.

[0008] In a first aspect, this utility model provides a battery cell insulating film, comprising: The base film has a thickened area formed by an outward bulge on one side of its surface. Side film, located on opposite sides or around the bottom film, with creases at the connection between the bottom film and the side film, the side film being adapted to be bent relative to the side of the bottom film where the thickened area is located through the creases; The thickness of the base film is T1, and the thickness of the thickened area is T2, satisfying 0.08 mm ≤ T1 ≤ 0.15 mm and 0.5 mm ≤ T2 ≤ 2 mm.

[0009] Beneficial Effects: The battery cell insulating film of this invention features a thickened area on the bottom film. After the insulating film covers the electrode assembly of the battery cell, the thickened area supports the electrode assembly, eliminating the need for a support plate in traditional battery cells. This also eliminates the need for the process of heat-melting the support plate to the bare battery cell insulating sheet. During assembly of the insulating film and electrode assembly, only the side film needs to be folded using creases and the insulating film wrapped around the outer periphery of the electrode assembly. This simplifies the battery cell assembly process, significantly improves production efficiency, increases assembly yield, and reduces operating costs. By controlling the thickness of the bottom film and the thickened area within appropriate ranges, it ensures that the thickened area has sufficient support strength to support the battery cell's electrode assembly, while preventing the thickened area from becoming too thick, thus reducing the battery cell's internal volume and affecting its energy density.

[0010] Secondly, this utility model also provides a battery cell, comprising: The housing has an internal mounting cavity; The electrode assembly is located within the mounting cavity; The aforementioned cell insulating film is wrapped around the outside of the electrode assembly; a pair of side films are attached to the large surfaces of a pair of sidewalls of the electrode assembly, and the thickened area on the bottom film is attached to the bottom surface of the electrode assembly.

[0011] Beneficial Effects: The battery cell insulating film of this invention features a thickened area on the bottom film. After the insulating film covers the electrode assembly of the battery cell, the thickened area supports the electrode assembly, eliminating the need for a support plate in traditional battery cells. This also eliminates the need for the process of heat-sealing the support plate to the bare battery cell insulating sheet. During assembly of the insulating film and electrode assembly, only the side film needs to be folded using creases and the insulating film wrapped around the outer periphery of the electrode assembly. This simplifies the battery cell assembly process, significantly improves production efficiency, increases assembly yield, and reduces operating costs. By controlling the thickness of the bottom film and the thickened area within appropriate ranges, it is ensured that the thickened area has sufficient support strength to support the battery cell's electrode assembly, while avoiding excessive thickness that would occupy internal battery cell volume and affect energy density.

[0012] In one optional embodiment, the battery cell is a blade battery cell, the thickness of the electrode group is T3, and the width of the bottom film along the Y direction is W1, satisfying T3=W1.

[0013] Beneficial effects: For blade cells, the weld seam of the thickened area facing the shell can eliminate the need for the side plate of traditional blade cells, avoid the weld seam from scratching the cell insulation film, and control the width of the bottom film to be equal to the width of the electrode group, so that the cell insulation film can compactly cover the electrode group, reduce the space occupied by the cell insulation film, and improve the energy density of the cell.

[0014] In one alternative implementation, 12.5 mm ≤ T3 ≤ 23 mm.

[0015] Beneficial effects: By controlling the thickness of the electrode assembly, i.e. the width of the bottom film, within a suitable range, the thin-film design of the blade cell can be achieved, thereby allowing the blade cells to be tightly arranged in the battery pack housing. It also helps to quickly dissipate the heat of the cell and reduce the risk of thermal runaway.

[0016] In one optional implementation, the width of the thickened area along the Y direction is W2, satisfying 9 mm ≤ W2 ≤ 17 mm and 3.5 mm ≤ W1 - W2 ≤ 6.5 mm.

[0017] Beneficial effects: The width of the thickened area is less than the thickness of the base film, and the thickened area is spaced a certain distance from the edge of the base film on both sides along the Y direction. This avoids the thickened area directly pressing against the creases, causing stress concentration and damage to the cell insulation film. Moreover, controlling the width of the thickened area within a suitable range ensures that it has sufficient support area to stably support the electrode assembly.

[0018] In one optional embodiment, the length of the thickened area along the X direction is L2, and the length of the bottom surface of the pole group is L1, satisfying 395 mm≤L1≤580 mm, 380 mm≤L2≤560 mm, and 15 mm≤L1-L2≤20 mm.

[0019] Beneficial effects: The length of the thickened area is less than the length of the electrode assembly, and the length of the electrode assembly is less than the length of the base film. This provides space for the thermal expansion of the electrode assembly during normal use, preventing friction between the electrode assembly and the thickened area due to thermal expansion, and reducing stress concentration. Moreover, controlling the length of the thickened area within a suitable range ensures that it has sufficient support area to stably support the electrode assembly.

[0020] In one optional embodiment, the battery cell is a prismatic cell, the thickness of the electrode assembly is T3, and the width of the bottom film along the Y direction is W1, satisfying 24.5 mm ≤ T3 ≤ 52 mm and 3 mm ≤ W1 - T3 ≤ 5 mm.

[0021] Beneficial effects: For square-shell cells, the thickened area can eliminate the need for the bottom support plate of traditional square-shell cells, and control the width of the bottom film to be slightly larger than the width of the electrode assembly, so as to leave room for folding the cell insulation film to cover the bottom and sides of the electrode assembly, which facilitates assembly.

[0022] In one optional implementation, the width of the thickened area along the Y direction is W2, satisfying 23.5 mm ≤ W2 ≤ 50 mm and 1 mm ≤ T3 - W2 ≤ 2 mm.

[0023] Beneficial effects: The width of the thickened area is less than the thickness of the base film, and the thickened area is spaced a certain distance from the edge of the base film on both sides along the Y direction. This avoids the thickened area directly pressing against the creases, causing stress concentration and damage to the cell insulation film. Moreover, controlling the width of the thickened area within a suitable range ensures that it has sufficient support area to stably support the electrode assembly.

[0024] In one optional embodiment, the length of the thickened area along the X direction is L2, and the length of the bottom surface of the pole group is L1, satisfying 145 mm≤L1≤280 mm, 143 mm≤L2≤277 mm, and 2 mm≤L1-L2≤3 mm.

[0025] Beneficial effects: The length of the thickened area is less than the length of the electrode assembly, providing space for thermal expansion during normal use and preventing friction between the electrode assembly and the thickened area due to thermal expansion. This also reduces stress concentration. Furthermore, controlling the length of the thickened area within a suitable range ensures sufficient support area for stable support of the electrode assembly.

[0026] Thirdly, the present invention also provides a battery pack, comprising: at least one of the above-mentioned battery cells.

[0027] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells, which will not be repeated here. Attached Figure Description

[0028] 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.

[0029] Figure 1 An exploded view of an existing blade battery cell; Figure 2 This is a schematic diagram of the bare cell insulation sheet and side plate of an existing blade battery cell; Figure 3 A schematic diagram of the bare cell insulation sheet and base plate of an existing square-shell battery cell; Figure 4 This is a schematic diagram of the structure of a battery cell insulating film according to an embodiment of the present invention; Figure 5 for Figure 4 Top view; Figure 6 This is a partial cross-sectional view of the battery cell insulating film according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the electrode assembly and cover plate of a blade battery cell according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of another battery cell insulating film according to an embodiment of the present invention; Figure 9 for Figure 8 Top view; Figure 10 This is a side view of the electrode assembly and cover plate of a square-shell battery cell according to an embodiment of the present invention. Figure 11 This is a front view of the electrode assembly and cover plate of a square-shell battery cell according to an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached figures: Existing technology: 100', bare cell insulating sheet; 200', side plate; 300', housing; 400', first cover plate; 500', second cover plate; 600', bottom support plate; 5', pole group; This application includes: 1. bottom film; 2. thickened area; 3. side film; 4. crease; 5. electrode assembly; 6. cover plate. Detailed Implementation

[0031] 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.

[0032] The following is combined Figures 4 to 11 The following describes embodiments of the present invention.

[0033] According to embodiments of the present invention, on the one hand, such as Figure 4 and Figure 5 As shown, a battery cell insulating film is provided, mainly comprising: a bottom film 1 and a side film 3. One side surface of the bottom film 1 protrudes outward to form a thickened area 2. The side film 3 is located on opposite sides or around the bottom film 1, and a crease 4 is provided at the connection between the bottom film 1 and the side film 3. The side film 3 is adapted to be bent relative to the side of the bottom film 1 with the thickened area 2 through the crease 4.

[0034] Furthermore, such as Figure 6 As shown, the thickness of the base film 1 is T1, and the thickness of the thickened area 2 is T2, satisfying 0.08 mm ≤ T1 ≤ 0.15 mm and 0.5 mm ≤ T2 ≤ 2 mm.

[0035] The battery cell insulating film provided in this embodiment of the invention has a thickened area 2 on the bottom film 1. After the battery cell insulating film covers the electrode group 5 of the battery cell, the thickened area 2 supports the electrode group 5, which eliminates the need for the support plate of the traditional battery cell, thus eliminating the process of heat-melting the support plate to the bare battery cell insulating sheet. When assembling the battery cell insulating film and the electrode group 5, it is only necessary to fold the side film 3 using the crease 4 and cover the outer periphery of the electrode group 5 with the battery cell insulating film, which simplifies the battery cell assembly process, significantly improves the battery cell production efficiency, and can also improve the assembly yield and reduce the use cost. By controlling the thickness of the bottom film 1 and the thickness of the thickened area 2 within a suitable range, it can be ensured that the thickened area 2 has sufficient support strength to support the electrode group 5 of the battery cell, while avoiding the thickened area 2 being too thick, occupying the internal volume of the battery cell, and affecting the energy density of the battery cell.

[0036] If T1 is too small, the overall structural strength of the cell insulation film will be weak, and the bottom film 1 will be easily punctured, leading to a short circuit in the cell. If T1 is too large, the bottom film 1 will occupy a large space in the cell, resulting in a lower energy density. If T2 is too small, the structural strength of the thickened region 2 will be weak, making it difficult to effectively support the cell. If T2 is too large, the thickened region 2 will occupy a large space in the cell, resulting in a lower energy density.

[0037] Specifically, the base film 1 is thickened by injection molding, hot pressing, hot extrusion and other methods to obtain an integrally formed thickened area 2.

[0038] Furthermore, the side membrane 3 and the bottom membrane 1 are integrally formed, and the thickness of the side membrane 3 is equal to the thickness of the bottom membrane 1.

[0039] For example, in this embodiment of the present invention, the value of T1 can be 0.08 mm, 0.1 mm, 0.12 mm, 0.15 mm, etc., and the value of T2 can be 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, etc.

[0040] According to an embodiment of this utility model, another aspect provides a battery cell, mainly comprising: a housing, an electrode assembly 5, and a battery cell insulating film. The housing has an internal mounting cavity. The electrode assembly 5 is disposed within the mounting cavity. The battery cell insulating film wraps around the outer side of the electrode assembly 5. A pair of side films 3 are attached to the large surfaces of a pair of sidewalls of the electrode assembly 5, and the thickened area 2 on the bottom film 1 is attached to the bottom surface of the electrode assembly 5.

[0041] The battery cell provided in this embodiment features a thickened region 2 on the bottom film 1. After the battery cell insulating film covers the electrode assembly 5, the thickened region 2 supports the electrode assembly 5. This eliminates the need for a support plate, a traditional battery cell, and the process of heat-sealing the support plate to the bare battery cell insulating sheet. When assembling the battery cell insulating film and the electrode assembly 5, only the side film 3 needs to be folded using the crease 4 to cover the outer periphery of the electrode assembly 5. This simplifies the battery cell assembly process, significantly improves battery cell production efficiency, increases assembly yield, and reduces usage costs. By controlling the thickness of the bottom film 1 and the thickness of the thickened region 2 within a suitable range, it is ensured that the thickened region 2 has sufficient support strength to support the electrode assembly 5 of the battery cell, while avoiding excessive thickness of the thickened region 2, which would occupy the internal volume of the battery cell and affect its energy density.

[0042] Specifically, electrode assembly 5 includes a positive electrode sheet and a negative electrode sheet. The portions of the positive and negative electrode sheets containing active materials constitute the main body of electrode assembly 5, while the portions of the positive and negative electrode sheets without active materials each constitute electrode tabs. Electrode tabs include positive electrode tabs and negative electrode tabs, which can be located together at one end of the main body or at opposite ends of the main body.

[0043] In embodiments of this utility model, "cell" refers to a single battery cell capable of independent charging and discharging. For example... Figure 7 As shown, the battery cell also includes electrolyte and cover plate 6, etc.

[0044] Specifically, at least one end of the housing has an opening communicating with the mounting cavity, and a cover plate 6 is placed over the opening and connected to the housing to form a sealed receiving cavity for accommodating the electrode assembly 5. The electrode tabs of the electrode assembly 5 are electrically connected to the electrode post of the cover plate 6 through an electrical connecting piece, and the end of the side diaphragm 3 near the cover plate 6 is also heat-fused and fixedly connected to the cover plate 6.

[0045] It should be noted that the present invention does not impose any particular restrictions on the type or shape of the battery cell; it can be a blade battery cell or a prismatic battery cell, etc. The battery cell in the present invention can be a lithium-ion battery cell, a potassium-ion battery cell, a sodium-ion battery cell, a lithium-sulfur battery cell, etc., with lithium-ion battery cells being particularly preferred.

[0046] In one embodiment, such as Figures 4 to 9 As shown, the battery cell is a blade battery cell, the thickness of the electrode group 5 is T3, and the width of the bottom film 1 along the Y direction is W1, satisfying T3=W1.

[0047] For blade cells, the thickened area 2 is opposite the weld seam of the shell, which can eliminate the side plate of traditional blade cells, avoid the weld seam from scratching the cell insulation film, and control the width of the bottom film 1 to be equal to the width of the electrode group 5 so that the cell insulation film can compactly cover the electrode group 5, reduce the space occupied by the cell insulation film, and improve the energy density of the cell.

[0048] Specifically, the Y direction is the width direction of the bottom film 1 and the side film 3 before folding along the crease 4, such as... Figure 4 and Figure 5 As indicated by the arrow Y in the diagram.

[0049] Furthermore, in one embodiment, 12.5 mm ≤ T3 ≤ 23 mm. By controlling the thickness of the electrode group 5, i.e. the width of the bottom film 1, within a suitable range, a thin-film design for the blade cell can be achieved, thereby allowing the blade cells to be tightly arranged within the battery pack housing. This also facilitates the rapid dissipation of heat from the cells, reducing the risk of thermal runaway.

[0050] For example, in this embodiment of the invention, the value of T3 can be 12.5 mm, 15 mm, 17.5 mm, 20 mm, 23 mm, etc.

[0051] Furthermore, in one embodiment, such as Figure 5 As shown, the width of the thickened region 2 along the Y direction is W2, satisfying 9 mm ≤ W2 ≤ 17 mm and 3.5 mm ≤ W1 - W2 ≤ 6.5 mm. The width of the thickened region 2 is less than the thickness of the bottom film 1, and the thickened region 2 is spaced a certain distance from the edge of the bottom film 1 on both sides along the Y direction. This avoids the thickened region 2 directly pressing on the crease 4, causing stress concentration and damage to the cell insulation film. Moreover, controlling the width of the thickened region 2 within a suitable range ensures that the thickened region 2 has sufficient support area to stably support the electrode assembly 5.

[0052] For example, in this embodiment of the present invention, the value of W1 can be 12.5 mm, the value of W2 can be 9 mm, then W1-W2 is 3.5 mm; or, the value of W1 can be 15 mm, the value of W2 can be 10 mm, then W1-W2 is 5 mm; or, the value of W1 can be 23 mm, the value of W2 can be 16.5 mm, then W1-W2 is 6.5 mm.

[0053] Furthermore, in one embodiment, such as Figure 5 and Figure 7 As shown, the length of the thickened region 2 along the X direction is L2, and the length of the bottom surface of the electrode assembly 5 is L1, satisfying 395 mm ≤ L1 ≤ 580 mm, 380 mm ≤ L2 ≤ 560 mm, and 15 mm ≤ L1 - L2 ≤ 20 mm. The length of the thickened region 2 is less than the length of the electrode assembly 5, and the length of the electrode assembly 5 is less than the length of the bottom film 1. This provides space for the thermal expansion of the electrode assembly 5 during normal use, preventing friction between the electrode assembly 5 and the thickened region 2 due to thermal expansion, and reducing stress concentration. Moreover, controlling the length of the thickened region 2 within a suitable range ensures that it has sufficient support area to stably support the electrode assembly 5.

[0054] Specifically, the X direction is the length direction of the bottom film 1 and the side film 3 along the fold 4 before folding, such as... Figure 4 and Figure 5 As shown by the arrow X in the diagram.

[0055] For example, in this embodiment of the present invention, the value of L1 can be 395 mm, the value of L2 can be 380 mm, and then L1-L2 is 15 mm; or, the value of L1 can be 500 mm, the value of L2 can be 483 mm, and then L1-L2 is 17 mm; or, the value of L1 can be 580 mm, the value of L2 can be 560 mm, and then L1-L2 is 20 mm.

[0056] In one embodiment, such as Figures 8 to 11 As shown, the battery cell is a prismatic cell, the thickness of the electrode group 5 is T3, and the width of the bottom film 1 along the Y direction is W1, satisfying 24.5 mm ≤ T3 ≤ 52 mm, and 3 mm ≤ W1 - T3 ≤ 5 mm. For prismatic cells, the thickened area 2 can omit the bottom support plate of traditional prismatic cells, and the width of the bottom film 1 is controlled to be slightly larger than the width of the electrode group 5, so as to leave room for folding the cell insulation film to cover the bottom surface and sides of the electrode group 5, which is convenient for assembly.

[0057] For example, in this embodiment of the present invention, the value of W1 can be 27.5 mm, the value of T3 can be 24.5 mm, then W1 - T3 is 3 mm; or, the value of W1 can be 42 mm, the value of T3 can be 38 mm, then W1 - T3 is 4 mm; or, the value of W1 can be 57 mm, the value of T3 can be 52 mm, then W1 - T3 is 5 mm.

[0058] Furthermore, in one embodiment, such as Figure 9 As shown, the width of the thickened region 2 along the Y direction is W2, satisfying 23.5mm≤W2≤50 mm and 1 mm≤T3-W2≤2 mm. The width of the thickened region 2 is less than the thickness of the bottom film 1, and the thickened region 2 is spaced a certain distance from the edge of the bottom film 1 on both sides along the Y direction. This avoids the thickened region 2 directly pressing on the crease 4, causing stress concentration and damage to the cell insulation film. Moreover, controlling the width of the thickened region 2 within a suitable range ensures that the thickened region 2 has sufficient support area to stably support the electrode assembly 5.

[0059] For example, in this embodiment of the present invention, the value of T3 can be 24.5 mm, the value of W2 can be 23.5 mm, then T3-W2 is 1 mm; or, the value of T3 can be 38 mm, the value of W2 can be 36.5 mm, then T3-W2 is 1.5 mm; or, the value of T3 can be 52 mm, the value of W2 can be 50 mm, then T3-W2 is 2 mm.

[0060] Furthermore, in one embodiment, such as Figure 9 and Figure 11 As shown, the length of the thickened region 2 along the X direction is L2, and the length of the bottom surface of the electrode assembly 5 is L1, satisfying 145 mm ≤ L1 ≤ 280 mm, 143 mm ≤ L2 ≤ 277 mm, and 2 mm ≤ L1 - L2 ≤ 3 mm. The length of the thickened region 2 is less than the length of the electrode assembly 5, providing space for thermal expansion during normal use and preventing friction between the electrode assembly 5 and the thickened region 2 due to thermal expansion, while also reducing stress concentration. Furthermore, controlling the length of the thickened region 2 within a suitable range ensures that it has sufficient support area to stably support the electrode assembly 5.

[0061] For example, in this embodiment of the present invention, the value of L1 can be 145 mm, the value of L2 can be 143 mm, then L1-L2 is 2 mm; or, the value of L1 can be 212 mm, the value of L2 can be 209.5 mm, then L1-L2 is 2.5 mm; or, the value of L1 can be 280 mm, the value of L2 can be 277 mm, then L1-L2 is 3 mm.

[0062] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, comprising: at least one of the above-described battery cells.

[0063] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.

[0064] In the embodiments of the utility model, the "battery pack" is formed by combining a certain number of battery cells into a battery module and placing them in a housing to protect the battery cells from external impacts, heat, vibration, etc. The battery pack also includes a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (shell, brackets, etc.), and protective components, which are sealed by a cover assembly to form a complete functional unit that can directly output electrical energy.

[0065] 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 insulating film, characterized in that, include: The base film has a thickened area formed by an outward bulge on one side of its surface. Side film, located on opposite sides or around the bottom film, with creases at the connection between the bottom film and the side film, the side film being adapted to be bent relative to the side of the bottom film where the thickened area is located through the creases; The thickness of the base film is T1, and the thickness of the thickened area is T2, satisfying 0.08 mm ≤ T1 ≤ 0.15 mm and 0.5 mm ≤ T2 ≤ 2 mm.

2. A battery cell, characterized in that, include: The housing has an internal mounting cavity; The electrode assembly is located within the mounting cavity; The cell insulating film of claim 1 is wrapped around the outside of the electrode assembly; a pair of side films are attached to the large surfaces of a pair of sidewalls of the electrode assembly, and the thickened area on the bottom film is attached to the bottom surface of the electrode assembly.

3. The battery cell according to claim 2, characterized in that, The battery cell is a blade battery cell, the thickness of the electrode group is T3, and the width of the bottom film along the Y direction is W1, satisfying T3=W1.

4. The battery cell according to claim 3, characterized in that, 12.5 mm ≤ T3 ≤ 23 mm.

5. The battery cell according to claim 3, characterized in that, The width of the thickened area along the Y direction is W2, which satisfies 9 mm ≤ W2 ≤ 17 mm and 3.5 mm ≤ W1 - W2 ≤ 6.5 mm.

6. The battery cell according to claim 3, characterized in that, The length of the thickened area along the X direction is L2, and the length of the bottom surface of the pole group is L1, satisfying 395 mm≤L1≤580 mm, 380 mm≤L2≤560 mm, and 15 mm≤L1-L2≤20 mm.

7. The battery cell according to claim 2, characterized in that, The battery cell is a prismatic cell, the thickness of the electrode assembly is T3, and the width of the bottom film along the Y direction is W1, satisfying 24.5 mm ≤ T3 ≤ 52 mm and 3 mm ≤ W1 - T3 ≤ 5 mm.

8. The battery cell according to claim 7, characterized in that, The width of the thickened area along the Y direction is W2, which satisfies 23.5mm≤W2≤50 mm and 1 mm≤T3-W2≤2 mm.

9. The battery cell according to claim 7, characterized in that, The length of the thickened area along the X direction is L2, and the length of the bottom surface of the pole group is L1, satisfying 145 mm≤L1≤280 mm, 143 mm≤L2≤277 mm, and 2 mm≤L1-L2≤3 mm.

10. A battery pack, characterized in that, include: At least one battery cell according to any one of claims 2 to 9.

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