Battery cell and battery module

Abstract

The utility model relates to the technical field of batteries, in particular to a battery monomer and a battery module, and aims to solve the technical problems of pole piece dislocation and battery internal short circuit caused by insufficient supporting force of an existing cover plate on a roll core and collapse and deformation of the roll core. Therefore, the battery monomer provided by the utility model comprises the components of a cover plate which is provided with a convex part; the supporting plate is provided with mounting holes corresponding to the protruding parts, the protruding parts are fixed to the mounting holes in a pressing rivet mode, and the supporting plate is fixed to the side, facing the electrode assembly, of the cover plate. The supporting plate can provide enough supporting force for the electrode assembly, pole piece dislocation caused by collapse and deformation of the electrode assembly is prevented, and serious consequences such as short circuit and fire are avoided; the protruding parts and the mounting holes are fixed in a pressing riveting mode, in-mold riveting and cleaning can be directly conducted in the punching process, the technology is simple, the number of procedures is small, and the manufacturing cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and specifically provides a battery monomer and a battery module. Background Art

[0002] At present, new energy vehicles usually use power batteries as the driving force source, which provides a broad application space for the application and development of batteries. Large cylindrical batteries are receiving more and more attention. The design adopts a full-ear design, which effectively shortens the current path, reduces the internal resistance of the battery cell itself, and significantly reduces Joule heat loss. The structure mainly includes components such as the shell, cover plate, electrode assembly and collector plate. Among them, the cover plate is located directly below the electrode assembly, and the weight of the electrode assembly falls entirely on the cover plate, which supports the electrode assembly. However, the existing cover plate does not provide sufficient support for the electrode assembly, causing the electrode assembly to sag and deform, resulting in the misalignment of the pole piece, and in severe cases, causing a short circuit inside the battery.

[0003] Therefore, in the development process of battery technology, how to solve the above technical problems has always been a key research direction in the industry. Utility Model Content

[0004] The utility model aims to solve the above technical problems, that is, to solve the technical problems that the existing cover plate has insufficient support force on the winding core, the winding core sags and deforms, resulting in misalignment of the pole pieces and internal short circuit of the battery.

[0005] In a first aspect, the utility model provides a battery cell, comprising: a cover plate, the cover plate is provided with a protrusion; a support plate, the support plate is provided with a mounting hole corresponding to the protrusion, the protrusion is fixed to the mounting hole by riveting, and the support plate is fixed to the side of the cover plate facing the electrode assembly.

[0006] In the above technical solution, a support plate is provided on the side of the cover plate of the battery cell facing the electrode assembly. The support plate can provide sufficient support force for the electrode assembly to prevent the electrode assembly from collapsing and deforming, thereby causing the pole piece to be misaligned, and avoid serious consequences such as short circuit and fire. By providing a raised portion on the cover plate, the support plate is provided with a mounting hole corresponding to the raised portion, and the raised portion is fixed to the mounting hole by riveting. Compared with the welding fixing method, which requires the pre-welded parts to be cleaned and then assembled and welded separately, the riveting fixing can be directly riveted in the mold and then cleaned during the stamping process. The process is simple, the process is less, and the manufacturing cost is low.

[0007] In some embodiments, the diameter of the mounting hole gradually decreases along the direction of the support plate away from the electrode assembly.

[0008] In the above technical solution, when the protrusion is fixed to the mounting hole by riveting, the end of the wall of the mounting hole may pierce the protrusion during the process of the protrusion being stamped and deformed, causing damage to the protrusion and affecting the fixing effect of the support plate and the cover plate; by setting the aperture of the mounting hole to gradually decrease in the direction in which the support plate is away from the electrode assembly, that is, the inclination direction of the hole wall of the mounting hole is basically consistent with the direction in which the protrusion is stamped and deformed, it is possible to avoid the hole wall of the mounting hole piercing the protrusion.

[0009] In some embodiments, the hole wall of the mounting hole includes a vertical portion and an inclined portion. Along the direction of the cover plate away from the electrode assembly, the hole diameter of the mounting hole in the vertical portion is the same, and the hole diameter of the mounting hole in the inclined portion gradually decreases.

[0010] In the above technical solution, the hole wall of the mounting hole is configured to include a vertical portion with the same hole diameter and an inclined portion with a gradually decreasing hole diameter. On the one hand, the inclined portion can prevent the hole wall of the mounting hole from piercing the protrusion. On the other hand, the vertical portion is tightly connected to the un-stamped portion of the protrusion, which not only ensures the reliability of the protrusion but also ensures the fixing effect of the protrusion and the mounting hole.

[0011] In some embodiments, the inclination angle of the inclined portion is greater than or equal to 30° and less than or equal to 85°.

[0012] In the above technical solution, the inclination angle of the inclined portion is set too small, which makes processing difficult; the inclination angle is set too large, which does not meet the applicable scenarios of press riveting.

[0013] In some embodiments, the support plate includes a support portion and a fixing portion connected to the support portion, the mounting hole is provided in the fixing portion, and the distance from the support portion to the electrode assembly is smaller than the distance from the fixing portion to the electrode assembly.

[0014] In the above technical solution, the fixing portion is closer to the electrode assembly than the supporting portion. On the one hand, it can enhance the overall strength of the support plate. On the other hand, after the support plate is installed on the cover plate, the support plate as a whole remains flush with the welding plane of the cover plate, thereby avoiding stress concentration and adverse effects when supporting the electrode assembly.

[0015] In some embodiments, the supporting portion includes a plurality of supporting members, one ends of the plurality of supporting members jointly form a first avoidance hole, and two adjacent supporting members and the fixing portion jointly form a second avoidance hole.

[0016] In some embodiments, the cover plate includes a plurality of welding portions, the support plate is fixed to the cover plate, and the welding portions pass through the second avoidance hole to be electrically connected to the electrode assembly.

[0017] In the above technical solution, multiple support members can increase the supporting area of ​​the support plate for the electrode assembly; one end of the multiple support members is combined to form a first avoidance hole to prevent interference between the support plate and the injection channel of the cover plate; two adjacent support members and the fixing part are combined to form a second avoidance hole to prevent interference between the support plate and the welding of the cover plate and the electrode assembly.

[0018] In some embodiments, the cover plate includes a weakened portion, and the weakened portion is located outside the welding portion.

[0019] In some embodiments, the weak portion is a closed notch on the surface of the cover plate, and the welding portion is located on the inner side of the weak portion.

[0020] In the above technical solution, compared with the solution in which the weak portion is arranged on the inside of the welding portion, the solution in which the weak portion is arranged on the outside of the welding portion allows the pole ear on the inside of the weak portion on the electrode assembly to be welded to the welding portion, thereby shortening the transmission path of electrons on the pole piece, reducing the internal resistance of the battery cell, and enhancing the current carrying capacity of the battery cell.

[0021] In some embodiments, the protrusion is located outside the weakened portion.

[0022] In the above technical solution, the protrusion is arranged on the outside of the weak part to prevent the weak part from bursting when the valve opening pressure is reached when the battery cell has thermal runaway, thereby adversely affecting the fixation of the support plate and the cover plate.

[0023] In some embodiments, the protrusion includes a first recess and a second recess, the first recess and the second recess are formed by riveting, and the opening directions of the first recess are opposite to those of the second recess.

[0024] In some embodiments, a distance from a bottom surface of the first recess to the electrode assembly is smaller than a distance from a bottom surface of the second recess to the electrode assembly.

[0025] In some embodiments, a diameter of a bottom surface of the first recess is greater than a diameter of a bottom surface of the second recess.

[0026] In some embodiments, the maximum diameter of the first recess is greater than or equal to 1 mm and less than or equal to 3 mm; and / or the maximum diameter of the second recess is greater than or equal to 1 mm and less than or equal to 2.5 mm.

[0027] In some embodiments, the diameter of the mounting hole is greater than or equal to 1.3 mm and less than or equal to 3.5 mm.

[0028] In the above technical solution, if the diameter of the mounting hole is set too small, the difficulty of the riveting process will be increased; if the diameter of the mounting hole is set too large, the corresponding raised portion will occupy a larger area on the cover plate, affecting the welding area and the valve opening area.

[0029] In some embodiments, the cover plate is provided with a liquid injection hole and a flange portion connected to the cover plate along an edge of the liquid injection hole, and the free end of the flange portion has a first rounded corner.

[0030] In the above technical solution, a first rounded corner is provided at the free end of the flange portion. Compared with a flange portion with a right-angled free end, during the process of assembling the cover plate to the battery cell, the flange portion can be prevented from interfering with the winding core hole in the electrode assembly, thereby scratching the diaphragm of the electrode assembly, causing short circuit or leakage of the positive and negative electrodes, and causing safety accidents such as battery overheating, fire, and explosion; at the same time, damage to the diaphragm will also cause mixing and reaction of materials inside the battery, resulting in reduced capacitance, reduced carrying capacity, and reduced performance.

[0031] In some embodiments, the connection between the flange portion and the cover plate has a second rounded corner.

[0032] In the above technical solution, a second fillet is provided at the connection between the flange portion and the cover plate. When the seal is installed at the injection hole, the second fillet can play a guiding role, facilitating the assembly of the seal.

[0033] In a second aspect, the utility model further provides a battery module, the battery module comprising a plurality of the above-mentioned battery cells.

[0034] The advantages of the battery module and the above-mentioned battery cell over the prior art are the same, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 It is a schematic diagram of the structure of a battery cell provided by an embodiment of the utility model;

[0037] Figure 2 yes Figure 1 A partial enlarged view of the middle AA;

[0038] Figure 3 It is a structural schematic diagram of a cover plate and a support plate provided in an embodiment of the utility model;

[0039] Figure 4 yes Figure 3 A partial enlarged view of the middle BB;

[0040] Figure 5 It is a structural schematic diagram of a support plate provided in an embodiment of the utility model;

[0041] Figure 6 It is a structural schematic diagram of a cover plate provided by an embodiment of the utility model;

[0042] List of reference numerals:

[0043] 1. Battery cell; 2. Cover plate; 21. Raised portion; 211. First recessed portion; 212. Second recessed portion; 22. Welded portion; 23. Weak portion; 24. Injection hole; 25. Flanged portion; 251. First fillet; 252. Second fillet; 3. Support plate; 31. Mounting hole; 311. Vertical portion; 312. Inclined portion; 32. Support portion; 321. Support member; 33. Fixed portion; 34. First avoidance hole; 35. Second avoidance hole; 4. Electrode assembly; 5. Shell; 51. Side wall; 52. Top wall; 6. Electrode terminal; 7. Sealing member. DETAILED DESCRIPTION

[0044] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0045] It should be noted that in the description of the present invention, the terms "inside", "outside", "top", "bottom" and other terms indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0046] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0048] In the present application, the battery cell 1 may be cylindrical, flat, rectangular or in other shapes, etc., and the present application embodiment does not limit this. The following is an example of a cylindrical battery cell 1:

[0049] like Figure 1 As shown, the cylindrical battery cell 1 of the embodiment of the present application includes: a shell 5, one end of which has an opening. The shell 5 is a hollow structure with an opening on one side, which is used to accommodate the electrode assembly 4 and the electrolyte cavity, and the electrode assembly 4 is arranged in the accommodating cavity of the shell 5. The cover plate 2 is arranged at the opening of the shell 5, and the cover plate 2 assembly is electrically connected to the shell 5 and the electrode assembly 4 respectively. The shell 5 includes a side wall 51 and a top wall 52, and the top wall 52 is arranged opposite to the opening and connected to the side wall 51. The side wall 51 and the top wall 52 can be an integrally formed structure, that is, the shell 5 is an integrally formed component. In addition, the side wall 51 and the top wall 52 can also be two components arranged separately, and then connected together by welding or the like, which is not limited here. The side wall 51 is a cylindrical structure, and the top wall 52 is a plate-like structure, and its shape corresponds to the shape of the side wall 51. In some embodiments, the top wall 52 has an electrode lead-out hole, and the electrode terminal 6 is insulated and arranged on the top wall 52. The electrode terminal 6 can be fixed as a whole on the outside of the top wall 52, or can be extended into the interior of the housing 5 through the electrode lead-out hole. In some embodiments, the electrode assembly 4 has a positive electrode tab and a negative electrode tab, the positive electrode tab is connected to the electrode terminal 6, and the negative electrode tab is connected to the cover plate 2 assembly; alternatively, the positive electrode tab is connected to the cover plate 2 assembly, and the negative electrode tab is connected to the electrode terminal 6.

[0050] like Figures 2 to 6As shown, the cylindrical battery cell 1 of the embodiment of the present application also includes a support plate 3. Before the cover plate 2 is assembled to the opening of the shell 5, the support plate 3 is pre-installed on the cover plate 2 and is located on the side of the cover plate 2 facing the electrode assembly 4. The support plate 3 can prevent the occurrence of safety problems such as battery short circuit and fire caused by the collapse and dislocation of the electrode assembly 4. In this embodiment, the support plate 3 and the cover plate 2 are fixed by riveting. Specifically, a protrusion 21 is provided on the cover plate 2, and a mounting hole 31 is provided at a position corresponding to the protrusion 21 of the support plate 3. In the actual production process, the cover plate 2 with the protrusion 21 is first placed in the riveting die of the riveting machine to align it with the support plate 3. Then, the riveting machine is started to apply pressure to the cover plate 2. Through the pressing action, the protrusion 21 passes through the mounting hole 31 and is compressed and deformed, and is firmly fixed to the support plate 3 to complete the assembly. Compared with the welding fixing method, which requires the support plate 3 and the cover plate 2 to be cleaned separately and then assembled and welded, the riveting fixing method has a simpler process, fewer processes, and lower manufacturing costs. Furthermore, the applicant discovered that during the riveting process, when the protrusion 21 is deformed by the external force applied by the pressure riveting machine, the hole wall of the mounting hole 31 will pierce the protrusion 21, causing damage to the protrusion 21 and affecting the effect of riveting fixation. In order to solve the aforementioned problem, the present application sets the aperture of the mounting hole 31 to gradually decrease along the direction in which the support plate 3 deviates from the electrode assembly 4, that is, the direction in which the protrusion 21 is subjected to external force, so that the inclination direction of the hole wall of the mounting hole 31 is basically consistent with the direction in which the protrusion 21 is deformed by stamping, which can prevent the hole wall of the mounting hole 31 from piercing the protrusion 21. In some embodiments, the hole wall of the mounting hole 31 includes a vertical portion 311 and an inclined portion 312. Along the direction in which the cover plate 2 deviates from the electrode assembly 4, the aperture of the mounting hole 31 in the vertical portion 311 is the same, and the aperture of the mounting hole 31 in the inclined portion 312 gradually decreases. Thus, the vertical portion 311 can tightly connect the unpunched portion of the protrusion 21, and the inclined portion 312 ensures the fixing effect of the protrusion 21 and the mounting hole 31. Furthermore, the inclination angle of the inclined portion 312 is greater than or equal to 30° and less than or equal to 85°. The applicant found that if the inclination angle of the inclined portion 312 is set to less than 30°, the processing difficulty of the mounting hole 31 is very large; and if the inclination angle of the inclined portion 312 is set to greater than 85°, it is no longer suitable for the application scenario of the pressure riveting fixing method. Optionally, the inclination angle of the inclined portion 312 can be set to 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80° or 85°. Preferably, the inclination angle of the inclined portion 312 is 60°. In some embodiments, the support plate 3 includes a support portion 32 and a fixing portion 33 connected to the support portion 32 , the mounting hole 31 is provided in the fixing portion 33 , and the distance from the support portion 32 to the electrode assembly 4 is smaller than the distance from the fixing portion 33 to the electrode assembly 4 .That is to say, the plane where the support portion 32 is located is not on the same plane as the plane where the fixing portion 33 is located. In the actual manufacturing process, the support portion 32 can be stamped from the support plate 3 as a whole. In this way, the support portion 32 can enhance the overall strength of the support plate 3 while playing the role of supporting the electrode assembly 4. In addition, the height difference between the support portion 32 and the fixing portion 33, after the support plate 3 is installed on the cover plate 2, keeps the support plate 3 as a whole flush with the welding plane of the cover plate 2, avoiding stress concentration when supporting the electrode assembly 4, causing adverse effects. Further, the support portion 32 includes a plurality of support members 321, one end of the plurality of support members 321 encloses to form a first avoidance hole 34, and two adjacent support members 321 and the fixing portion 33 enclose to form a second avoidance hole 35. The plurality of support members 321 can increase the support area of ​​the support plate 3 for the electrode assembly 4, the first avoidance hole 34 prevents interference between the injection channel of the support plate 3 and the cover plate 2, and the second avoidance hole 35 prevents interference between the welding of the support plate 3 and the cover plate 2 and the electrode assembly 4. In this embodiment, the support portion 32 has four support members 321, the angle between two adjacent support members 321 is 90°, and the four support members 321 are symmetrically distributed. Correspondingly, the fixing portion 33 is provided with four mounting holes 31 corresponding to the support members 321 respectively. In some embodiments, the cover plate 2 includes a plurality of welding portions 22, the support portion 32 is fixed to the cover plate 2, and the welding portion 22 is electrically connected to the electrode assembly 4 through the second avoidance hole 35. Compared with the existing cylindrical battery, the cylindrical battery cell 1 provided in this embodiment cancels the negative electrode collector plate, and the cover plate 2 is directly welded to the electrode assembly 4. In this embodiment, the number of welding portions 22 is adapted to the number of support members 321, and the number of welding portions 22 and support members 321 is 4, and the four welding portions 22 are symmetrically distributed. Further, the cover plate 2 also includes a weak portion 23, and the weak portion 23 is located on the outside of the welding portion 22. In some embodiments, the weak portion 23 is a closed indentation on the surface of the cover plate 2, and the welding portion 22 is located on the inside of the weak portion 23. The applicant found that the welding portion 22 of the existing cover plate 2 is generally arranged on the inner side of the weak portion 23, so that the pole piece located in the inner circle of the electrode assembly 4 is not welded to the cover plate 2, resulting in a longer transmission path of electrons on the pole piece. In this embodiment, the weak portion 23 is arranged on the outer side of the welding portion 22, and the pole pieces of the inner circle of the electrode assembly 4 can be welded to the cover plate 2, which reduces the internal resistance of the battery cell 1 and enhances the current capacity of the battery cell 1. Furthermore, the protrusion 21 is located on the outer side of the weak portion 23, and the number of the protrusions 21 is adapted to the number of the mounting holes 31. In this embodiment, the number of the protrusions 21 and the number of the mounting holes 31 are both 4. When the battery cell 1 has thermal runaway, the weak portion 23 reaches the valve opening pressure and explodes. The protrusion 21 is arranged on the outer side of the weak portion 23, which can avoid being affected by the explosion of the weak portion 23 and detaching from the cover plate 2, thereby affecting the fixation of the support plate 3 and the cover plate 2.In some embodiments, the support plate 3 is fixed to the cover plate 2, and the protrusion 21 is riveted to form a first recess 211 and a second recess 212, and the opening directions of the first recess 211 and the second recess 212 are opposite. In this embodiment, the distance from the bottom surface of the first recess 211 to the electrode assembly 4 is less than the distance from the bottom surface of the second recess 212 to the electrode assembly 4. That is, the opening of the second recess 212 is away from the direction of the electrode assembly 4, and the opening of the first recess 211 is toward the electrode assembly 4. In some embodiments, the diameter of the bottom surface of the first recess 211 is greater than the diameter of the bottom surface of the second recess 212. Further, the maximum diameter of the first recess 211 is greater than or equal to 1 mm and less than or equal to 3 mm. Optionally, the maximum diameter of the first recess 211 can be 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm. Preferably, the maximum diameter of the first recess 211 is 2.3 mm. Furthermore, the maximum diameter of the second recess 212 is greater than or equal to 1 mm and less than or equal to 2.5 mm. Optionally, the maximum diameter of the second recess 212 may be 1 mm, 1.5 mm, 2 mm or 2.5 mm. Preferably, the maximum diameter of the second recess 212 is 2.2 mm. In some embodiments, the diameter of the mounting hole 31 is greater than or equal to 1.3 mm and less than or equal to 3.5 mm. Optionally, the diameter of the mounting hole 31 may be 1.3 mm, 1.4 mm, 1.5 mm ... 3.4 mm or 3.5 mm. Preferably, the diameter of the mounting hole 31 is 2.5 mm.

[0051] like Figures 1 to 3 As shown, in this embodiment, the cover plate 2 is provided with an injection hole 24, and the injection hole 24 is arranged at the center of the cover plate 2. The cover plate 2 assembly includes a flange portion 25, and the flange portion 25 is connected to the cover plate 2 along the edge of the injection hole 24. In some embodiments, the flange portion 25 can be welded to the cover plate 2 or formed integrally with the cover plate 2. The free end of the flange portion 25 has a first fillet 251, that is, the metal material at the free end of the flange portion 25 is processed into a conical circle with a first fillet 251 using a cutting tool. Compared with the flange portion 25 with a right-angled edge at the free end, during the assembly of the cover plate 2 to the battery cell 1, the flange portion 25 can be prevented from interfering with the winding core hole in the electrode assembly 4, thereby scratching the diaphragm of the electrode assembly 4, causing the positive and negative electrodes to short-circuit or leak electricity, causing safety accidents such as battery overheating, fire, and explosion; at the same time, the damage of the diaphragm will also cause mixing and reaction of materials inside the battery, resulting in reduced capacitance, reduced carrying capacity, and reduced performance. In some embodiments, the connection between the flange portion 25 and the cover plate 2 has a second rounded corner 252 . When the seal 7 is installed at the injection hole 24 , the second rounded corner can serve as a guide to facilitate the assembly of the seal 7 .

[0052] The utility model also provides a battery module having a plurality of battery cells. The beneficial effects of the battery module are the same as the advantages of the battery cells in this embodiment over the prior art, and will not be described in detail here.

[0053] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A battery cell, characterized in that: include: A cover plate, wherein the cover plate is provided with a raised portion; A support plate is provided with a mounting hole corresponding to the protrusion, the protrusion is fixed to the mounting hole by riveting, and the support plate is fixed to a side of the cover plate facing the electrode assembly.

2. The battery cell according to claim 1, characterized in that: Along the direction of the support plate away from the electrode assembly, the diameter of the mounting hole gradually decreases.

3. The battery cell according to claim 2, characterized in that: The hole wall of the mounting hole includes a vertical portion and an inclined portion. Along the direction in which the cover plate is away from the electrode assembly, the hole diameter of the mounting hole in the vertical portion is the same, and the hole diameter of the mounting hole in the inclined portion gradually decreases.

4. The battery cell according to claim 3, characterized in that: The inclination angle of the inclined portion is greater than or equal to 30° and less than or equal to 85°.

5. The battery cell according to claim 1, characterized in that: The support plate includes a support portion and a fixing portion connected to the support portion, the mounting hole is provided in the fixing portion, and a distance from the support portion to the electrode assembly is smaller than a distance from the fixing portion to the electrode assembly.

6. The battery cell according to claim 5, characterized in that: The support portion includes a plurality of support members, one ends of the plurality of support members jointly form a first avoidance hole, and two adjacent support members and the fixing portion jointly form a second avoidance hole.

7. The battery cell according to claim 6, characterized in that: The cover plate includes a plurality of welding parts, the support plate is fixed to the cover plate, and the welding parts pass through the second avoidance hole and are electrically connected to the electrode assembly.

8. The battery cell according to claim 7, characterized in that: The cover plate includes a weak portion, and the weak portion is located outside the welding portion.

9. The battery cell according to claim 8, characterized in that: The weak portion is a closed notch on the surface of the cover plate, and the welding portion is located on the inner side of the weak portion.

10. The battery cell according to claim 9, characterized in that: The protrusion is located at the outer side of the weak portion.

11. The battery cell according to claim 1, characterized in that: The protrusion includes a first recess and a second recess, the first recess and the second recess are formed by riveting, and the opening directions of the first recess are opposite to those of the second recess.

12. The battery cell according to claim 11, characterized in that: The distance from the bottom surface of the first recess to the electrode assembly is smaller than the distance from the bottom surface of the second recess to the electrode assembly.

13. The battery cell according to claim 12, characterized in that: The diameter of the bottom surface of the first recess is greater than the diameter of the bottom surface of the second recess.

14. The battery cell according to claim 13, characterized in that: The maximum diameter of the first recess is greater than or equal to 1 mm and less than or equal to 3 mm; and / or the maximum diameter of the second recess is greater than or equal to 1 mm and less than or equal to 2.5 mm.

15. The battery cell according to claim 1, characterized in that: The diameter of the mounting hole is greater than or equal to 1.3 mm and less than or equal to 3.5 mm.

16. The battery cell according to claim 1, characterized in that: The cover plate is provided with a liquid injection hole and a flange portion connected to the cover plate along the edge of the liquid injection hole, and the free end of the flange portion has a first rounded corner.

17. The battery cell according to claim 16, characterized in that: A connection between the flange portion and the cover plate has a second rounded corner.

18. A battery module, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 17.

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