Battery cell cover plate assembly, battery cell, and battery pack

Abstract

This utility model relates to the field of battery technology and discloses a cell cover assembly, a cell, and a battery pack. The cell cover assembly includes: a cover body with a first through hole; a riveting block disposed on a first side of the cover body and having a second through hole coaxially arranged and connected to the first through hole; a terminal post including a terminal post body and a terminal post base disposed at one end of the terminal post body, the terminal post body passing through the first and second through holes, the terminal post base being located on a second side of the cover body, the first side and the second side being opposite to each other; and a support member passing through the first through hole and sleeved on the terminal post body, one end of the support member abutting against the riveting block, and the other end abutting against the terminal post base. By sleeved on the terminal post body and having both ends of the support member abutting against the riveting block and the terminal post base respectively, not only can the deformation or collapse of the terminal post body due to its soft material be avoided; it can also keep the riveting block stable during the riveting process, preventing it from changing due to deformation of the terminal post body.

Description

Technical Field

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

[0002] In current cell cover assembly designs, after the riveting block in the cell cover assembly is riveted to the electrode post, the stepped surface on the electrode post becomes the supporting surface of the bottom of the riveting block along the thickness direction of the cell cover assembly. However, since the electrode post is usually made of copper, aluminum, or copper-aluminum composite materials, although these materials have good conductivity, their structural strength is relatively poor. Therefore, when the riveting part of the electrode post undergoes plastic deformation under external force, the electrode post itself is relatively soft and cannot withstand high pressure. As a result, the stepped surface of the electrode post is prone to deformation or collapse, which in turn leads to the collapse of the riveting block connected to the electrode post. Utility Model Content

[0003] In view of this, the present invention provides a cell cover plate assembly, a cell, and a battery pack to solve the problem in the prior art where the riveting block also collapses due to the collapse of the pole during the riveting process.

[0004] In a first aspect, this utility model provides a battery cell cover assembly, comprising:

[0005] The cover body has a first through hole;

[0006] A riveting block is provided on the first side of the cover body, and a second through hole is provided that is coaxially arranged and connected to the first through hole;

[0007] The pole includes a pole body and a pole base disposed at one end of the pole body. The pole body passes through the first through hole and the second through hole, and the pole base is located on the second side of the cover body. The first side and the second side are disposed opposite to each other.

[0008] A support member is inserted into the first through hole and sleeved on the pole body. The first end of the support member abuts against the rivet block, and the second end abuts against the pole base. The first end and the second end are arranged opposite to each other.

[0009] Beneficial effects: This utility model, by installing a support member on the outer casing of the electrode post body, with both ends of the support member abutting against the riveting block and the electrode post base respectively, allows the support member to share the riveting pressure on the electrode post body during riveting. This not only avoids deformation or collapse of the electrode post body due to its soft material, but also keeps the position of the riveting block stable during the riveting process, preventing it from changing due to deformation of the electrode post body. This improves the overall structural strength and stability of the cell cover assembly, ensures a reliable connection between the electrode post and the riveting block, reduces contact resistance, optimizes electrical performance, effectively reduces safety hazards caused by poor riveting, and improves the service life and practicality of the cell cover assembly.

[0010] In one optional embodiment, the inner wall of the support member is fitted with the outer wall of the pole body, and the outer wall of the support member is fitted with the inner wall of the first through hole; or an insulating seal is provided between the outer wall of the support member and the inner wall of the first through hole, and the outer wall of the support member is fitted with the inner wall of the first through hole through the insulating seal.

[0011] Beneficial Effects: This invention, by fitting the inner wall of the support member to the outer wall of the electrode body, not only reduces the gap between them, making the overall structure of the cell cover assembly more compact, but also provides lateral support for the electrode body, preventing it from shifting or shaking due to uneven force during riveting, thus enhancing the accuracy of electrode body positioning. Similarly, fitting the outer wall of the support member to the inner wall of the first through hole further improves the structural stability of the cell cover assembly and increases the lateral support force on the electrode body, reducing the possibility of deformation of the electrode body during riveting. Furthermore, the fitting of the inner wall of the support member to the outer wall of the electrode body, and the fitting of the outer wall of the support member to the inner wall of the first through hole, seals the gap between the first through hole and the electrode body. This not only prevents impurities from the external environment from entering the cell through the gap, but also prevents the electrolyte inside the cell from leaking into the external environment through the gap.

[0012] In one optional embodiment, the wall thickness of the support member is a along the thickness direction perpendicular to the cover body, and the value of a ranges from 0.3mm ≤ a ≤ 3mm.

[0013] Beneficial Effects: If the wall thickness 'a' of the support member is less than 0.3mm, it means that the structural strength of the support member is poor, and the maximum force that the support member can withstand will be less than the force shared by the support member for the electrode body during the riveting process. Therefore, during the riveting process, the force transmitted to the support member will cause deformation, thus failing to effectively solve the problem of deformation or collapse of the electrode body during riveting. If the wall thickness 'a' of the support member is greater than 0.3mm, although it means that the support member has better structural strength, the excessive wall thickness will increase the installation space requirement of the support member. Therefore, this utility model limits the value range of the support member wall thickness 'a' to 0.3mm≤a≤3mm, which can ensure that the support member has good structural strength while having a relatively reasonable volume, conforming to the design trend of lightweight and miniaturized battery cell cover assemblies.

[0014] In one optional embodiment, the second through hole includes a first sub-hole and a second sub-hole that are coaxially arranged and connected, the diameter of the first sub-hole is larger than the diameter of the second sub-hole, and a stepped surface is formed at the connection between the first sub-hole and the second sub-hole; the end of the pole body located in the first sub-hole forms an annular flange, and the annular flange abuts against the stepped surface.

[0015] Beneficial effects: This utility model designs the second through hole as two interconnected sub-holes with different diameters, forming a stepped surface at the connection. Simultaneously, the annular flange at one end of the pole body abuts against the stepped surface, effectively limiting the axial movement of the pole within the riveting block and preventing excessive sinking of the pole body. Furthermore, the abutment between the annular flange and the stepped surface increases the contact area, evenly distributing the riveting pressure and reducing the possibility of deformation or collapse of the pole body due to concentrated stress, thereby improving the stability of the connection between the pole body and the riveting block.

[0016] In one optional embodiment, the outer wall of the annular flange is fitted with the inner wall of the first sub-hole. Along the thickness direction perpendicular to the cover body, the width of the portion of the annular flange that abuts against the stepped surface is b, and the value of b is in the range of 0.2mm≤b≤0.8mm.

[0017] Beneficial effects: By tightly fitting the outer wall of the annular flange to the inner wall of the first sub-hole, this utility model enables the annular flange and the first sub-hole to achieve a riveted fit. This not only enhances the stability of the connection between the two but also improves the sealing performance at the connection point, preventing electrolyte leakage. Furthermore, limiting the width b of the portion of the annular flange that abuts against the stepped surface to between 0.2mm and 0.8mm avoids both insufficient support due to excessive width and increased difficulty in expanding the electrode body due to excessive width.

[0018] In one optional embodiment, the distance between the stepped surface and the support member along the thickness direction of the cover body is c, and the value of c ranges from 0.6mm ≤ c ≤ 2.5mm.

[0019] Beneficial effects: If the value of c is less than 0.6mm, it means that the thickness of the part of the riveting block below the step surface is relatively thin. Therefore, this part is prone to deformation during the riveting process, and the electrode post body will sink under this influence. If the value of c is greater than 2.5mm, it will increase the overall thickness of the cell cover assembly, which is not conducive to the miniaturization and lightweight design of the product. It can be seen that this utility model controls the value of c within the above-mentioned reasonable range, which can ensure that the support component can fully play its role in distributing pressure and preventing deformation of the electrode post body, while also ensuring that the cell cover assembly has a compact structure, improving space utilization and assembly reliability.

[0020] In one alternative embodiment, the outer wall of the annular flange is welded to the inner wall of the first sub-hole at the contact point.

[0021] Beneficial effects: This utility model welds the outer wall of the annular flange to the inner wall of the first sub-hole, which on the one hand can improve the connection strength between the two and reduce the possibility of the rivet block falling off the pole during subsequent use; on the other hand, the welding connection can also reduce the contact resistance, optimize the electrical connection performance, ensure stable current conduction, and improve the safety and service life of the battery cell.

[0022] In one optional embodiment, the material hardness of the support member is greater than that of the pole body; and / or, the material of the support member is stainless steel or ceramic.

[0023] Beneficial effects: The support component is made of a material with a hardness greater than that of the pole body, which means that the support component can effectively withstand and distribute the riveting pressure, preventing the softer pole body from deforming and collapsing due to excessive force.

[0024] Stainless steel possesses excellent mechanical strength and corrosion resistance, effectively distributing pressure during riveting to prevent deformation of the electrode post body. Furthermore, it is resistant to electrolyte corrosion over long-term use, ensuring cell safety. It also exhibits good toughness and plasticity, facilitating the fabrication of suitable support components. Ceramic materials, on the other hand, are characterized by high hardness, high temperature resistance, and strong insulation. Therefore, they not only provide stable support for the electrode post body during riveting, preventing deformation under stress, but also isolate the electrode post body from the cover body, preventing short circuits.

[0025] Secondly, this utility model also provides a battery cell, comprising:

[0026] The housing has a cavity and an opening communicating with the cavity;

[0027] The electrode assembly is disposed within the cavity and has an electrode tab at one end;

[0028] The aforementioned cell cover assembly covers and seals the opening, and the electrode base is welded to the electrode tab on the side away from the cover body.

[0029] Beneficial effects: The battery cell of this utility model includes the battery cell cover assembly as described above, and has all the beneficial technical effects of the battery cell cover assembly, which will not be repeated here.

[0030] Thirdly, this utility model also provides a battery pack, comprising: a plurality of the above-mentioned battery cells.

[0031] Beneficial effects: The battery pack of this utility model includes the battery cell as described above, and has all the beneficial technical effects of the battery cell, which will not be repeated here. Attached Figure Description

[0032] 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.

[0033] Figure 1 This is a schematic diagram of the structure of a battery cell cover assembly according to an embodiment of the present utility model;

[0034] Figure 2 for Figure 1 An exploded view of the battery cell cover assembly shown.

[0035] Figure 3 for Figure 1 A cross-sectional view of the battery cell cover assembly shown;

[0036] Figure 4 for Figure 3 A magnified view of part A in the image;

[0037] Figure 5 for Figure 1 The figure shows a cross-sectional view of the cover body.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Cover body; 101. First through hole; 2. Riveting block; 201. Second through hole; 2011. First sub-hole; 2012. Second sub-hole; 2013. Stepped surface; 3. Pole post; 301. Pole post body; 3011. Annular flange; 302. Pole post base; 4. Support component; 5. Insulating sealing component. Detailed Implementation

[0040] 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.

[0041] In view of the problem that the riveting block also collapses due to the collapse of the pole during the riveting process in the prior art, this utility model provides a cell cover plate assembly, a cell, and a battery pack.

[0042] The following is combined with Figures 1 to 5 The following describes embodiments of the present invention.

[0043] According to embodiments of the present invention, on the one hand, such as Figures 1 to 5 As shown, a battery cell cover assembly is provided, including: a cover body 1, a riveting block 2, an electrode post 3, and a support member 4.

[0044] Specifically, the cover body 1 is provided with a first through hole 101; the rivet block 2 is provided on the first side of the cover body 1 and is provided with a second through hole 201 that is coaxially arranged and connected to the first through hole 101; the pole post 3 includes a pole post body 301 and a pole post base 302 provided at one end of the pole post body 301. The pole post body 301 passes through the first through hole 101 and the second through hole 201, and the pole post base 302 is located on the second side of the cover body 1, with the first side and the second side being arranged opposite to each other; the support member 4 passes through the first through hole 101 and is sleeved on the outside of the pole post body 301. The first end of the support member 4 abuts against the rivet block 2, and the second end abuts against the pole post base 302, with the first end and the second end being arranged opposite to each other.

[0045] This embodiment of the utility model provides a support member 4 over the electrode body 301, with both ends of the support member 4 abutting against the riveting block 2 and the electrode base 302, respectively. During riveting, the support member 4 can share the riveting pressure with the electrode body 301. This not only avoids deformation or collapse of the electrode body 301 due to its soft material, but also keeps the position of the riveting block 2 stable during the riveting process, preventing it from changing due to deformation of the electrode body 301. This improves the overall structural strength and stability of the cell cover assembly, ensures a reliable connection between the electrode 3 and the riveting block 2, reduces contact resistance, optimizes electrical performance, effectively reduces safety hazards caused by poor riveting, and improves the service life and practicality of the cell cover assembly.

[0046] According to one embodiment of the present invention, such as Figure 3 and Figure 4As shown, the inner wall of the support member 4 is fitted with the outer wall of the electrode body 301, and the outer wall of the support member 4 is fitted with the inner wall of the first through hole 101. In this embodiment of the invention, fitting the inner wall of the support member 4 with the outer wall of the electrode body 301 not only reduces the gap between them, making the overall structure of the cell cover assembly more compact, but also provides lateral support for the electrode body 301, preventing it from shifting or shaking due to uneven force during riveting, and enhancing the positioning accuracy of the electrode body 301. Similarly, fitting the outer wall of the support member 4 with the inner wall of the first through hole 101 further improves the structural stability of the cell cover assembly and increases the lateral support force on the electrode body 301, reducing the possibility of deformation of the electrode body 301 during riveting. Furthermore, the inner wall of the support member 4 is in contact with the outer wall of the electrode body 301, and the outer wall of the support member 4 is in contact with the inner wall of the first through hole 101, which can seal the gap between the first through hole 101 and the electrode body 301. This not only prevents impurities in the external environment from entering the cell through the gap, but also prevents the electrolyte inside the cell from leaking into the external environment through the gap.

[0047] In one embodiment, such as Figures 2 to 4 As shown, an insulating seal 5 is also provided between the outer wall of the support member 4 and the inner wall of the first through hole 101. The outer wall of the support member 4 is fitted to the inner wall of the first through hole 101 through the insulating seal 5. The insulating seal 5 can prevent short circuit between the pole body 301 and the cover body 1, and can also seal the gap between the outer wall of the support member 4 and the inner wall of the first through hole 101.

[0048] According to one embodiment of the present invention, such as Figure 4 As shown, along the thickness direction perpendicular to the cover body 1, the wall thickness of the support member 4 is 'a', and the value of 'a' ranges from 0.3mm ≤ a ≤ 3mm. It can be understood that if the wall thickness 'a' of the support member 4 is less than 0.3mm, it means that the structural strength of the support member 4 is poor, and the maximum force that the support member 4 can withstand will be less than the force shared by the support member 4 for the electrode body 301 during the riveting process. Therefore, during the riveting process, the force transmitted to the support member 4 will cause deformation of the support member 4, thus failing to effectively solve the deformation or collapse problem of the electrode body 301 during the riveting process. If the wall thickness 'a' of the support member 4 is greater than 0.3mm, although it means that the support member 4 has better structural strength, the excessive wall thickness will increase the installation space requirement of the support member 4. Therefore, this embodiment of the utility model limits the value range of the wall thickness 'a' of the support member 4 to 0.3mm ≤ a ≤ 3mm, which can ensure that the support member 4 has good structural strength while having a relatively reasonable volume, conforming to the design trend of lightweight and miniaturized battery cell cover assemblies.

[0049] It should be noted that, in this embodiment, the wall thickness 'a' of the support member 4 can be, but is not limited to, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, and 3.0mm.

[0050] In one embodiment, the wall thickness at both ends of the support member 4 is greater than the wall thickness in the middle region. This arrangement increases the contact area between the support member 4 and the rivet block 2 and the pole base 302, preventing structural damage due to insufficient contact area.

[0051] According to one embodiment of the present invention, such as Figure 5 As shown, the second through hole 201 includes a first sub-hole 2011 and a second sub-hole 2012 that are coaxially arranged and connected. The diameter of the first sub-hole 2011 is larger than the diameter of the second sub-hole 2012. A stepped surface 2013 is formed at the connection between the first sub-hole 2011 and the second sub-hole 2012. An annular flange 3011 is formed at one end of the pole post body 301 located in the first sub-hole 2011, and the annular flange 3011 abuts against the stepped surface 2013. In this embodiment of the utility model, the second through hole 201 is designed as a first sub-hole 2011 and a second sub-hole 2012 with different diameters that are connected, and a stepped surface 2013 is formed at the connection. At the same time, the annular flange 3011 at one end of the pole post body 301 abuts against the stepped surface 2013, which can effectively limit the axial movement of the pole post 3 in the riveting block 2 and prevent the pole post body 301 from sinking excessively. Furthermore, the annular flange 3011 abuts against the stepped surface 2013, which increases the contact area between them, evenly distributes the riveting pressure, and reduces the possibility of deformation or collapse of the pole body 301 due to concentrated force, thereby improving the stability of the connection between the pole body 301 and the riveting block 2. In addition, this embodiment makes the size of the first sub-hole 2011 larger, which can reserve more riveting operation space for operators and reduce the difficulty of riveting operations.

[0052] According to one embodiment of the present invention, such as Figure 4As shown, the outer wall of the annular flange 3011 is fitted with the inner wall of the first sub-hole 2011. Along the thickness direction perpendicular to the cover body 1, the width of the portion of the annular flange 3011 that abuts against the stepped surface 2013 is b, and the value of b ranges from 0.2mm ≤ b ≤ 0.8mm. This embodiment of the invention achieves a riveted fit between the annular flange 3011 and the first sub-hole 2011 by tightly fitting the outer wall of the annular flange 3011 with the inner wall of the first sub-hole 2011. This not only enhances the stability of the connection but also improves the sealing at the connection point, preventing electrolyte leakage. Limiting the width b of the portion of the annular flange 3011 that abuts against the stepped surface 2013 to between 0.2mm and 0.8mm avoids both insufficient support due to excessive width and increased difficulty in expanding the electrode body 301 due to excessive width.

[0053] It should be noted that, in this embodiment, the width b of the portion of the annular flange 3011 that abuts against the step surface 2013 can be, but is not limited to, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm.

[0054] It should be further explained that, in this embodiment, the expansion of the pole body 301 refers to the deformation of the riveting part of the pole body 301 towards its periphery during the riveting process, in order to fill the gap left between the inner wall of the first sub-hole 2011 and the outer wall of the pole body 301 in the pre-assembly state.

[0055] According to one embodiment of the present invention, such as Figure 4 As shown, along the thickness direction of the cover body 1, the distance between the stepped surface 2013 and the support member 4 is c, and the value of c is in the range of 0.6mm ≤ c ≤ 2.5mm. If the value of c is less than 0.6mm, it means that the thickness of the part of the riveting block 2 below the stepped surface 2013 is relatively thin, so this part is prone to deformation during the riveting process, and the electrode body 301 will sink under this influence. If the value of c is greater than 2.5mm, it will increase the overall thickness of the cell cover assembly, which is not conducive to the miniaturization and lightweight design of the product. It can be seen that the embodiment of this utility model controls the value of c within the above reasonable range, which can ensure that the support member 4 can fully play its role in dispersing pressure and preventing deformation of the electrode body 301, and can also ensure that the cell cover assembly has a compact structure, improve space utilization and assembly reliability.

[0056] It should be noted that, in this embodiment, the width b of the portion of the annular flange 3011 that abuts against the stepped surface 2013 can be, but is not limited to, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, or 2.5mm.

[0057] According to one embodiment of the present invention, the outer wall of the annular flange 3011 is welded to the inner wall of the first sub-hole 2011 at the contact point. This embodiment of the present invention welds the outer wall of the annular flange 3011 to the inner wall of the first sub-hole 2011, which on the one hand improves the connection strength between the two, reducing the possibility of the rivet block 2 falling off the pole post 3 during subsequent use; on the other hand, the welded connection also reduces contact resistance, optimizes electrical connection performance, ensures stable current conduction, and improves the safety and service life of the battery cell.

[0058] According to one embodiment of this utility model, the material hardness of the support member 4 is greater than that of the pole body 301. It can be understood that the material hardness of the support member 4 being greater than that of the pole body 301 means that the support member 4 can effectively withstand and distribute the riveting pressure, preventing the softer pole body 301 from deforming or collapsing due to excessive force.

[0059] According to one embodiment of this utility model, the support member 4 is made of stainless steel or ceramic. Stainless steel has good mechanical strength and corrosion resistance, effectively distributing pressure during riveting to prevent deformation of the electrode post body 301. Furthermore, it is not easily corroded by the electrolyte during long-term use, ensuring the safety of the battery cell. It also has good toughness and plasticity, making it easy to process into a suitable support member 4. Ceramic material has high hardness, high temperature resistance, and strong insulation. Therefore, it not only provides stable support for the electrode post body 301 during riveting, preventing deformation under stress, but also isolates the electrode post body 301 from the cover body 1, preventing short circuits between the two.

[0060] It should be noted that the stainless steel in this embodiment can be either 304 stainless steel or 316 stainless steel.

[0061] According to an embodiment of the present invention, another aspect provides a battery cell, comprising: a housing, an electrode assembly, and the aforementioned battery cell cover assembly.

[0062] Specifically, the housing has a cavity and an opening communicating with the cavity; the electrode assembly is disposed in the cavity and has an electrode tab at one end; the aforementioned cell cover plate assembly covers and seals the opening, and the electrode post base 302 is welded to the electrode tab on the side away from the cover body 1. The cell of this utility model embodiment includes the cell cover plate assembly as described above, and has all the beneficial technical effects of the cell cover plate assembly, which will not be repeated here.

[0063] In one embodiment, the electrode assembly includes a plurality of alternately arranged positive and negative electrode plates and a separator disposed between the positive and negative electrode plates. Specifically, the positive electrode plate includes a positive current collector and a positive active material disposed on at least one surface of the positive current collector. As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the opposite surfaces of the positive current collector. As an example, the positive current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, silver-surfaced aluminum or stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc., can be used. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector may include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming metallic materials (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). As an example, the positive electrode active material may include at least one of the following: lithium phosphates, lithium transition metal oxides, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphates include, but are not limited to, lithium iron phosphate (such as LiFePO4 (also abbreviated as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites, at least one of these.

[0064] In some embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector. As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the opposite surfaces of the negative electrode current collector. As an example, the negative electrode current collector may be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc., may be used. The composite current collector may include a polymeric material base layer and a metal layer. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymeric material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0065] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected. As an example, the main material of the separator membrane can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0066] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0067] It should be further noted that the electrode tabs in this embodiment include positive electrode tabs and negative electrode tabs. The positive electrode tab is formed by the portion of the positive electrode plate that does not contain active material, and the negative electrode tab is formed by the portion of the negative electrode plate that does not contain active material. The negative electrode tab and the positive electrode tab can be located together at one end of the electrode assembly or separately at both ends of the electrode assembly.

[0068] According to an embodiment of the present invention, another aspect provides a battery pack comprising a plurality of the aforementioned battery cells.

[0069] The battery pack of this utility model includes the battery cell described above, and has all the beneficial technical effects of the battery cell, which will not be repeated here.

[0070] 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 cell cover assembly, characterized in that, include: The cover body has a first through hole; A riveting block is provided on the first side of the cover body, and a second through hole is provided that is coaxially arranged and connected to the first through hole; The pole includes a pole body and a pole base disposed at one end of the pole body. The pole body passes through the first through hole and the second through hole, and the pole base is located on the second side of the cover body. The first side and the second side are disposed opposite to each other. A support member is inserted into the first through hole and sleeved on the pole body. The first end of the support member abuts against the rivet block, and the second end abuts against the pole base. The first end and the second end are arranged opposite to each other.

2. The cell cover assembly according to claim 1, characterized in that, The inner wall of the support member is in contact with the outer wall of the pole body, and the outer wall of the support member is in contact with the inner wall of the first through hole; or an insulating seal is provided between the outer wall of the support member and the inner wall of the first through hole, and the outer wall of the support member is in contact with the inner wall of the first through hole through the insulating seal.

3. The cell cover assembly according to claim 2, characterized in that, Along the thickness direction perpendicular to the cover body, the wall thickness of the support member is a, and the value of a ranges from 0.3mm to a ≤ 3mm.

4. The cell cover assembly according to claim 1, characterized in that, The second through hole includes a first sub-hole and a second sub-hole that are coaxially arranged and connected. The diameter of the first sub-hole is larger than the diameter of the second sub-hole. A stepped surface is formed at the connection between the first sub-hole and the second sub-hole. An annular flange is formed at one end of the pole body located in the first sub-hole. The annular flange abuts against the stepped surface.

5. The cell cover assembly according to claim 4, characterized in that, The outer wall of the annular flange is in contact with the inner wall of the first sub-hole. Along the thickness direction perpendicular to the cover body, the width of the portion of the annular flange that abuts against the step surface is b, and the value of b is in the range of 0.2mm≤b≤0.8mm.

6. The cell cover assembly according to claim 4, characterized in that, Along the thickness direction of the cover body, the distance between the stepped surface and the support is c, and the value of c is in the range of 0.6mm≤c≤2.5mm.

7. The cell cover assembly according to claim 4, characterized in that, The outer wall of the annular flange is welded to the inner wall of the first sub-hole at the contact point.

8. The cell cover assembly according to any one of claims 1 to 7, characterized in that, The support member has a material hardness greater than that of the pole body; and / or, the support member is made of stainless steel or ceramic.

9. A battery cell, characterized in that, include: The housing has a cavity and an opening communicating with the cavity; The electrode assembly is disposed within the cavity and has an electrode tab at one end; The cell cover assembly according to any one of claims 1 to 8, wherein the opening is covered and sealed, and the electrode base is welded to the electrode tab on the side away from the cover body.

10. A battery pack, characterized in that, include: The battery cell as described in several claims 9.

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