Cylindrical battery monomer, battery and electric equipment

Abstract

The utility model provides a cylindrical battery monomer, a battery and electric equipment. The cylindrical battery monomer comprises a shell, an electrode assembly and an elastic insulating part, wherein the electrode assembly is accommodated in the shell. The electrode assembly comprises a first pole piece, a second pole piece and a separator, the polarity of the first pole piece is opposite to that of the second pole piece, and the first pole piece, the separator and the second pole piece are arranged in a winding mode. The housing includes a sidewall disposed around the electrode assembly. The elastic insulating part is arranged between the electrode assembly and the side wall, and the elastic insulating part abuts against the outer surface of the electrode assembly and the inner surface of the side wall. The elastic insulating part can fill the gap between the electrode assembly and the side wall, so that expansion of the electrode assembly is inhibited to a certain extent, the risk of excessive expansion of the electrode assembly is reduced, the slippage of the pole piece is reduced, shear force generated in the slippage process is reduced, the risk of cracking of the pole piece is reduced, and the risk that burrs generated at the cracking position pierce the isolating part is reduced; and the reliability of the cylindrical battery monomer is improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and more particularly, to a cylindrical battery cell, a battery, and an electrical device using the same. Background Art

[0002] Batteries are widely used in the new energy field, such as electric vehicles, new energy vehicles, etc. Electric vehicles and new energy vehicles have become a new trend in the development of the automotive industry. The development of battery technology needs to consider various design factors at the same time. For example, performance parameters such as energy density, cycle life, discharge capacity, charge and discharge rate, etc. In addition, the reliability of the battery also needs to be considered. However, at present, the reliability of cylindrical battery cells using wound electrode assemblies is poor. Summary of the Utility Model

[0003] An object of embodiments of the present application is to provide a cylindrical battery cell, a battery, and an electrical device using the same, which aims to improve the problem of poor reliability of cylindrical battery cells in related technologies.

[0004] In a first aspect, an embodiment of the present application provides a cylindrical battery cell, the cylindrical battery cell includes a housing, an electrode assembly, and an elastic insulating member. The electrode assembly is accommodated in the housing. The electrode assembly includes a first pole piece, a second pole piece, and a separator. The polarities of the first pole piece and the second pole piece are opposite. The first pole piece, the separator, and the second pole piece are wound together. The housing includes a side wall disposed around the electrode assembly. The elastic insulating member is disposed between the electrode assembly and the side wall, and the elastic insulating member is in contact with the outer surface of the electrode assembly and the inner surface of the side wall respectively.

[0005] In the above technical solution, an elastic insulating member is disposed between the electrode assembly and the side wall of the housing. The elastic insulating member is in contact with the outer surface of the electrode assembly and the inner surface of the side wall respectively, filling the gap between the electrode assembly and the side wall, reducing the expansion space of the electrode assembly, inhibiting the expansion of the electrode assembly to a certain extent, reducing the risk of excessive expansion of the electrode assembly, reducing the slip amount of the pole piece, reducing the shear force generated during the slipping process, thereby reducing stress concentration and reducing the risk of pole piece cracking, and improving the reliability of the cylindrical battery cell. In addition, the elastic insulating member has a certain elasticity, which can allow the electrode assembly to expand to a certain extent, so that the pressure on the electrode assembly is not too large, thereby reducing the risk of the electrolyte in the electrode assembly being squeezed out, and being beneficial to maintaining the performance of the electrode assembly.

[0006] As an optional technical solution of an embodiment of the present application, the cylindrical battery cell includes a plurality of the elastic insulating members, and the plurality of elastic insulating members are arranged at intervals along the axial direction of the cylindrical battery cell.

[0007] In the above technical solution, by providing a plurality of elastic insulating members and arranging the plurality of elastic insulating members at intervals along the axial direction of the cylindrical battery cell, the plurality of elastic insulating members suppress the expansion of the electrode assembly at multiple positions along the axial direction of the cylindrical battery cell, having a good suppression effect, capable of reducing the risk of pole piece cracking and enhancing the reliability of the cylindrical battery cell. In addition, along the axial direction of the cylindrical battery cell, there is a certain interval between two adjacent elastic insulating members, which can reduce the material consumption of the elastic insulating members and lower the cost of the cylindrical battery cell.

[0008] As an alternative technical solution of the embodiment of the present application, the cylindrical battery cell includes two of the elastic insulating members. Along the axial direction of the cylindrical battery cell, the separator includes two end regions, and the two elastic insulating members respectively surround the two end regions.

[0009] In the above technical solution, by providing two elastic insulating members, along the axial direction of the cylindrical battery cell, the two elastic insulating members respectively surround the two end regions of the separator, which can not only have a good suppression effect, reduce the risk of pole piece cracking and enhance the reliability of the cylindrical battery cell, but also reduce the material consumption of the elastic insulating members and lower the cost of the cylindrical battery cell.

[0010] As an alternative technical solution of the embodiment of the present application, along the axial direction of the cylindrical battery cell, the length of the elastic insulating member is L1, and the length of the separator is L2, satisfying: 0.1 ≤ L1 / L2 ≤ 0.3.

[0011] In the above technical solution, when L1 / L2 ≥ 0.1, the length of the elastic insulating member along the axial direction of the cylindrical battery cell is relatively large, which can effectively suppress the expansion of the electrode assembly, reduce the slip amount of the pole piece, and lower the shear force generated during the slip process, thereby reducing stress concentration and the risk of pole piece cracking, and enhancing the reliability of the cylindrical battery cell. When L1 / L2 ≤ 0.3, the length of the elastic insulating member along the axial direction of the cylindrical battery cell is not too large, which is beneficial to reducing the cost of the cylindrical battery cell. Therefore, when 0.1 ≤ L1 / L2 ≤ 0.3, the reliability of the cylindrical battery cell and the cost of the cylindrical battery cell can be taken into account.

[0012] As an alternative technical solution of the embodiment of the present application, 0.15 ≤ L1 / L2 ≤ 0.25.

[0013] In the above technical solution, when L1 / L2≥0.15, the length of the elastic insulating member along the axial direction of the cylindrical battery cell is greater, which can more effectively inhibit the expansion of the electrode assembly, further reduce the slip amount of the electrode sheet, reduce the shear force generated during the slipping process, thereby further reducing the stress concentration and further reducing the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell. When L1 / L2≤0.25, the length of the elastic insulating member along the axial direction of the cylindrical battery cell is not too large, which is beneficial to reducing the cost of the cylindrical battery cell. Therefore, when 0.15≤L1 / L2≤0.25, the reliability of the cylindrical battery cell and the cost of the cylindrical battery cell can be better balanced.

[0014] As an alternative technical solution of the embodiment of the present application, there is one elastic insulating member. Along the axial direction of the cylindrical battery cell, the length of the elastic insulating member is L1, and the length of the separator is L2, satisfying: 0.5≤L1 / L2≤1.2.

[0015] In the above technical solution, when there is one elastic insulating member and L1 / L2≥0.5, the length of the elastic insulating member along the axial direction of the cylindrical battery cell is relatively large, which can effectively inhibit the expansion of the electrode assembly, reduce the slip amount of the electrode sheet, reduce the shear force generated during the slipping process, thereby reducing the stress concentration and reducing the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell. When there is one elastic insulating member and L1 / L2≤1.2, the length of the elastic insulating member along the axial direction of the cylindrical battery cell is not too large, which is beneficial to reducing the cost of the cylindrical battery cell. Therefore, when there is one elastic insulating member and 0.5≤L1 / L2≤1.2, the reliability of the cylindrical battery cell and the cost of the cylindrical battery cell can be balanced.

[0016] As an alternative technical solution of the embodiment of the present application, along the axial direction of the cylindrical battery cell, the two ends of the elastic insulating member are respectively flush with the two ends of the separator.

[0017] In the above technical solution, when along the axial direction of the cylindrical battery cell, the two ends of the elastic insulating member are respectively flush with the two ends of the separator, the length of the elastic insulating member is equal to the length of the separator, that is, L1 = L2. At this time, the elastic insulating member just completely wraps the separator along the axial direction of the cylindrical battery cell, which can more effectively inhibit the expansion of the electrode assembly, further reduce the slip amount of the electrode sheet, reduce the shear force generated during the slipping process, thereby further reducing the stress concentration and further reducing the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell.

[0018] As an alternative technical solution of the embodiment of the present application, along the circumferential direction of the cylindrical battery cell, the elastic insulating member is disposed around the electrode assembly. The elastic insulating member has a first end and a second end, and the first end and the second end are spaced apart. A notch region that does not cover the electrode assembly is formed between the first end and the second end.

[0019] In the above technical solution, along the circumferential direction of the cylindrical battery cell, by disposing the elastic insulating member around the electrode assembly, the gap between the electrode assembly and the side wall can be better filled, the expansion space of the electrode assembly can be reduced, the expansion of the electrode assembly can be inhibited, the slip amount of the electrode sheet can be reduced, and the shear force generated during the slip process can be reduced, thereby reducing stress concentration and reducing the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell. In addition, by forming a notch region that does not cover the electrode assembly between the first end and the second end, on the one hand, the material consumption of the elastic insulating member can be reduced, and the cost of the cylindrical battery cell can be reduced. On the other hand, due to the existence of the notch region, the first end and the second end are not easily overlapped to form an overlapping region (the overlapping region has a relatively thick thickness, and the overlapping region will cause stress concentration of the electrode assembly), and stress concentration of the electrode assembly is not easily caused, which is beneficial to improving the reliability of the cylindrical battery cell.

[0020] As an alternative technical solution of the embodiment of the present application, the first electrode sheet has a first end and a second end, a part of the second electrode sheet extends beyond the first end and second end along the winding direction of the electrode assembly, the second electrode sheet includes the electrode sheet located in the outermost circle of the electrode assembly, the second electrode sheet has a second end and a second end, and the second end is located in the notch region.

[0021] In the above technical solution, the second end is located in the notch region, that is, the position of the notch region corresponds to the position of the second end. The diameter of the electrode assembly corresponding to the position where the second end is located is relatively large. By making the position of the notch region correspond to the position of the second end, the elastic insulating member does not have to cover the position where the second end is located, thereby greatly reducing the material consumption of the elastic insulating member and reducing the cost of the cylindrical battery cell.

[0022] As an alternative technical solution of the embodiment of the present application, along the circumferential direction of the cylindrical battery cell, the length of the notch region is L3, and the total length of the elastic insulating member and the notch region is L4, satisfying: L3 / L4 ≤ 0.5.

[0023] In the above technical solution, when L3 / L4 ≤ 0.5, the length of the notch area along the circumferential direction of the cylindrical battery cell is short, and the elastic insulating member can be disposed around the outer side of the electrode assembly to a large extent along the circumferential direction of the cylindrical battery cell, preferably filling the gap between the electrode assembly and the side wall, reducing the expansion space of the electrode assembly, preferably suppressing the expansion of the electrode assembly, reducing the slippage amount of the electrode sheet, reducing the shear force generated during the slippage process, thereby reducing stress concentration and reducing the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell.

[0024] As an alternative technical solution of the embodiment of the present application, 0.1 ≤ L3 / L4 ≤ 0.4.

[0025] In the above technical solution, when L3 / L4 ≤ 0.4, the length of the notch area along the circumferential direction of the cylindrical battery cell is shorter, and the elastic insulating member can be disposed around the outer side of the electrode assembly to a greater extent along the circumferential direction of the cylindrical battery cell, preferably filling the gap between the electrode assembly and the side wall, reducing the expansion space of the electrode assembly, preferably suppressing the expansion of the electrode assembly, reducing the slippage amount of the electrode sheet, reducing the shear force generated during the slippage process, reducing the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell. When L3 / L4 ≥ 0.1, the length of the notch area is not too short, which can reduce the material consumption of the elastic insulating member, reduce the cost of the cylindrical battery cell, and can also reduce the risk of the first end and the tail end overlapping to form an overlapping area. Therefore, when 0.1 ≤ L3 / L4 ≤ 0.4, the reliability and cost of the cylindrical battery cell can be taken into account.

[0026] As an alternative technical solution of the embodiment of the present application, 1 mm ≤ L3 ≤ 5 mm.

[0027] In the above technical solution, when L3 ≤ 5 mm, the length of the notch area along the circumferential direction of the cylindrical battery cell is short, and the elastic insulating member can be disposed around the outer side of the electrode assembly to a large extent along the circumferential direction of the cylindrical battery cell, preferably filling the gap between the electrode assembly and the side wall, reducing the expansion space of the electrode assembly, preferably suppressing the expansion of the electrode assembly, reducing the slippage amount of the electrode sheet, reducing the shear force generated during the slippage process, reducing the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell. When L3 ≥ 1 mm, the length of the notch area is not too short, which can reduce the material consumption of the elastic insulating member, reduce the cost of the cylindrical battery cell, and can also reduce the risk of the first end and the tail end overlapping to form an overlapping area. Therefore, when 1 mm ≤ L3 ≤ 5 mm, the reliability and cost of the cylindrical battery cell can be taken into account.

[0028] As an alternative technical solution of the embodiment of the present application, the first end and the tail end are located in the notch area.

[0029] In the above technical solution, the first end is located within the notch area, that is, the position of the notch area corresponds to the position of the first end. The diameter of the electrode assembly is larger at the position corresponding to the first end. By making the position of the notch area correspond to the position of the first end, the elastic insulating member does not have to cover the position where the first end is located, thereby being able to greatly reduce the material consumption of the elastic insulating member and reduce the cost of the cylindrical battery cell.

[0030] As an alternative technical solution of the embodiment of the present application, along the circumferential direction of the cylindrical battery cell, the elastic insulating member wraps around the electrode assembly for a full circle.

[0031] In the above technical solution, by making the elastic insulating member wrap around the electrode assembly for a full circle along the circumferential direction of the cylindrical battery cell, it is more capable of effectively suppressing the expansion of the electrode assembly, further reducing the slip amount of the electrode sheet, reducing the shear force generated during the slipping process, thereby further reducing the stress concentration and further reducing the risk of electrode sheet cracking, and improving the reliability of the cylindrical battery cell.

[0032] As an alternative technical solution of the embodiment of the present application, the elastic insulating member is an annular structure arranged around the electrode assembly.

[0033] In the above technical solution, the elastic insulating member is an annular structure. On the one hand, it can effectively suppress the expansion of the electrode assembly, reduce the risk of electrode sheet cracking, and improve the reliability of the cylindrical battery cell. On the other hand, when the elastic insulating member is arranged outside the electrode assembly, there is no overlapping area, which is not likely to cause stress concentration of the electrode assembly, and is beneficial to improving the reliability of the cylindrical battery cell.

[0034] As an alternative technical solution of the embodiment of the present application, the material of the elastic insulating member includes oriented polystyrene.

[0035] In the above technical solution, oriented polystyrene can expand greatly when absorbing electrolyte. Before the elastic insulating member absorbs electrolyte, the volume of the elastic insulating member is small, so it is convenient to arrange the elastic insulating member between the electrode assembly and the side wall. Then, the elastic insulating member absorbs the electrolyte in the cylindrical battery cell and expands, filling the gap between the electrode assembly and the side wall, reducing the expansion space of the electrode assembly, suppressing the expansion of the electrode assembly, reducing the slip amount of the electrode sheet, reducing the shear force generated during the slipping process, thereby reducing the stress concentration and reducing the risk of electrode sheet cracking, and improving the reliability of the cylindrical battery cell.

[0036] As an optional technical solution of an embodiment of the present application, the first pole piece includes a first pole lug, and the second pole piece includes a second pole lug; the cylindrical battery cell includes a first electrode lead-out portion and a second electrode lead-out portion, the first electrode lead-out portion is electrically connected to the first pole lug, and the second electrode lead-out portion is electrically connected to the second pole lug; in the axial direction of the cylindrical battery cell, the first electrode lead-out portion and the second electrode lead-out portion are located on the same side of the electrode assembly.

[0037] In the above technical solution, when multiple cylindrical battery cells are assembled into a group, the first electrode lead-out parts and the second electrode lead-out parts of the multiple cylindrical battery cells can be arranged on the same side, which is convenient for connecting the busbar component with the first electrode lead-out parts and the second electrode lead-out parts, simplifying the battery structure.

[0038] As an optional technical solution of an embodiment of the present application, the shell includes a shell and an end cover, the shell includes the side wall and end wall formed integrally, the end wall and the end cover are opposite to each other along the axial direction of the cylindrical battery cell, and the end cover is sealed to the side wall.

[0039] As an optional technical solution of an embodiment of the present application, the first pole piece includes a first pole ear, and the second pole piece includes a second pole ear; the cylindrical battery cell also includes an electrode terminal insulated and arranged on the end wall, the first pole ear is electrically connected to the electrode terminal, and the second pole ear is electrically connected to the end wall.

[0040] In the above technical solution, the electrode terminal and the end wall can serve as two exposed electrodes of the cylindrical battery cell. The electrode terminal and the end wall are located on the same side, which is conducive to assembling multiple cylindrical battery cells into groups and simplifying the battery structure.

[0041] As an optional technical solution of an embodiment of the present application, the cylindrical battery cell further includes a first current collecting member, which is located on a side of the first pole tab facing the end wall and connected to the first pole tab; the electrode terminal is abutted against and connected to a surface of the first current collecting member facing the end wall.

[0042] In the above technical solution, the first current collecting member can play a transition role to achieve electrical connection between the first electrode tab and the electrode terminal.

[0043] As an optional technical solution of an embodiment of the present application, a terminal recess is provided on the side of the electrode terminal facing the first current collecting component, and / or a terminal recess is provided on the side of the electrode terminal away from the first current collecting component; and the bottom wall of the terminal recess is welded to the first current collecting component.

[0044] In the above technical solution, by providing the terminal recess, the thickness of the bottom wall of the terminal recess can be reduced, the power required for welding the external welding electrode terminal and the first current collector member can be lowered, the risk of particles generated by welding falling into the housing can be reduced, and the reliability of the cylindrical battery cell can be improved.

[0045] As an alternative technical solution of the embodiment of the present application, both the first tab and the second tab are located at one end of the electrode assembly facing the end wall.

[0046] In the above technical solution, the first tab and the second tab can share space in the axial direction of the cylindrical battery cell, thereby improving the space utilization rate and the energy density.

[0047] As an alternative technical solution of the embodiment of the present application, the first tab is located at one end of the electrode assembly facing the end wall, and the second tab is located at one end of the electrode assembly facing the end cover; the cylindrical battery cell further includes a second current collector member connected to the second tab; the second current collector member is connected to at least one of the end cover and the side wall.

[0048] As an alternative technical solution of the embodiment of the present application, the height of the housing is 1.3 times to 4 times the outer diameter of the housing.

[0049] In the above technical solution, when the housing meets the above size requirements, the structural stability of the housing can be relatively high, and the use reliability of the cylindrical battery cell can be improved.

[0050] As an alternative technical solution of the embodiment of the present application, the height of the housing is 50 mm to 150 mm; and / or the outer diameter of the housing is 40 mm to 80 mm.

[0051] In the above technical solution, when the height of the housing is 50 - 150 mm and / or the outer diameter of the housing is 40 - 80 mm, the cylindrical battery cell is relatively large, and the electrode assembly is more likely to expand excessively. The effect of the cylindrical battery cell in the embodiment of the present application is better.

[0052] In a second aspect, the embodiment of the present application further provides a battery, and the battery includes the above-mentioned cylindrical battery cell.

[0053] In a third aspect, the embodiment of the present application further provides an electrical device, and the electrical device includes the above-mentioned cylindrical battery cell, and the cylindrical battery cell is used to supply electrical energy to the electrical device. Description of the Drawings

[0054] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0055] Figure 1 Structural schematic diagram of a vehicle provided for some embodiments of the present application;

[0056] Figure 2 Explosion diagram of a battery provided for some embodiments of the present application;

[0057] Figure 3 Structural schematic diagram of a cylindrical battery cell provided for some embodiments of the present application;

[0058] Figure 4 Explosion diagram of a cylindrical battery cell provided for some embodiments of the present application;

[0059] Figure 5 Cross-sectional view of a cylindrical battery cell provided for some embodiments of the present application;

[0060] Figure 6 Simplified schematic diagram of the positional relationship between an elastic insulating member and an electrode assembly provided for some embodiments of the present application;

[0061] Figure 7 Simplified schematic diagram of the positional relationship between an elastic insulating member and an electrode assembly provided for some other embodiments of the present application;

[0062] Figure 8 Simplified schematic diagram of the positional relationship between an elastic insulating member and an electrode assembly provided for some other embodiments of the present application;

[0063] Figure 9 Cross-sectional view of a cylindrical battery cell provided for some other embodiments of the present application; Figure 10 Cross-sectional view of an elastic insulating member provided for some embodiments of the present application;

[0064] Figure 11 Cross-sectional view of an elastic insulating member provided for some other embodiments of the present application.

[0065] Icons: 10 - box body; 11 - first part; 12 - second part; 20 - cylindrical battery cell; 21 - outer shell; 211 - housing; 2111 - side wall; 2112 - end wall; 212 - end cover; 213 - first electrode lead-out part; 214 - second electrode lead-out part; 22 - electrode assembly; 221 - main body part; 2211 - first pole piece; 22111 - first end; 2212 - separator; 2213 - second pole piece; 22131 - second end; 222 - first tab; 223 - second tab; 23 - elastic insulating part; 231 - head end; 232 - tail end; 233 - notch area; 234 - first adhesive layer; 235 - expansion layer; 236 - insulating layer; 237 - second adhesive layer; 24 - electrode terminal; 251 - first current collector member; 252 - second current collector member; 26 - lower plastic; 100 - battery; 200 - controller; 300 - motor; 1000 - vehicle. Detailed implementation manners

[0066] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0067] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above drawings are used to distinguish different objects and are not used to describe a specific order or primary-secondary relationship.

[0068] Referring to "embodiment" in the present application means that the specific features, structures, or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0069] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" 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 of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0070] The term "and / or" in the present application is merely a correlative relationship describing associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the associated objects before and after.

[0071] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components shown in the drawings in the embodiments of the present application, as well as the overall thickness, length, width, etc. of the integrated device, are only illustrative and should not constitute any limitation to the present application.

[0072] The term "a plurality of" appearing in the present application refers to two or more (including two).

[0073] In the embodiments of the present application, the cylindrical battery cell can be a secondary battery, which refers to a cylindrical battery cell that can be activated by charging after discharging so that the active material can be reused.

[0074] The cylindrical battery cell includes but is not limited to lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium-metal batteries, sodium-metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0075] The cylindrical battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the cylindrical battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can reduce the risk of short circuit between the positive and negative electrodes and at the same time allow active ions to pass through.

[0076] In some embodiments, the positive electrode can be a positive electrode tab, and the positive electrode tab can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0077] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode active material is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0078] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0079] As an example, the positive electrode active material can include at least one of the following materials: lithium-containing phosphate, lithium transition metal oxide, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as the positive electrode active material of the battery can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of the lithium-containing phosphate can include but are not limited to lithium iron phosphate (such as LiFePO4 (which can also be abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and at least one of a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be abbreviated as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be abbreviated as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be abbreviated as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be abbreviated as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (which can also be abbreviated as NCM 811 )、lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and their modified compounds, etc. and at least one of them.

[0080] In some embodiments, the positive electrode may employ a porous metal. The porous metal may be porous nickel, porous copper, porous aluminum, a porous alloy, etc. When the porous metal serves as the positive electrode, the positive electrode active material may not be provided on the surface of the porous metal. Of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited in the porous metal. The lithium source material is lithium metal and / or a lithium-rich material.

[0081] In some embodiments, the negative electrode may be a negative electrode tab, and the negative electrode tab may include a negative electrode current collector.

[0082] As an example, the negative electrode current collector may employ a metal foil, a porous metal, or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. may be used. The porous metal may be porous nickel, porous copper, porous aluminum, a porous alloy, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as copper, a copper alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0083] As an example, the negative electrode tab may include a negative electrode current collector and a negative electrode active material provided on at least one surface of the negative electrode current collector.

[0084] As an example, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material is provided on any one or both of the two opposite surfaces of the negative electrode current collector.

[0085] As an example, the negative electrode active material may employ a negative electrode active material well-known in the art for a cylindrical battery cell. 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, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material may be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as the battery negative electrode active material may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0086] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0087] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical stability and mechanical stability.

[0088] As an example, the material of the separator membrane can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator membrane can be a single-layer film or a multi-layer composite film. When the separator membrane is a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a single component located between the positive and negative electrodes, or attached to the surfaces of the positive and negative electrodes.

[0089] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions to transport ions and isolate the positive and negative electrodes.

[0090] In some embodiments, the cylindrical battery cell further includes an electrolyte, which functions to conduct ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0091] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluoro(bis(oxalato))phosphate, and lithium tetrafluoro(oxalato)phosphate.

[0092] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, and crown ether.

[0093] Among them, the gel-like electrolyte includes a polymer as the backbone network of the electrolyte, combined with an ionic liquid-lithium salt.

[0094] Among them, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0095] As an example, the polymer solid electrolyte can be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single-ion polymer, polyionic liquid-lithium salt, cellulose, etc.

[0096] As an example, the inorganic solid electrolyte can include oxide solid electrolytes (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON film), sulfide solid electrolytes (crystalline lithium superionic conductor (lithium germanium phosphorus sulfur, argyrodite), amorphous sulfide), and one or more of halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0097] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to the polymer solid electrolyte.

[0098] In some embodiments, the electrode assembly is in a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0099] As an example, multiple separators can be provided and are respectively provided between any adjacent positive electrode sheets or negative electrode sheets.

[0100] As an example, the separators can be provided continuously and are provided between any adjacent positive electrode sheets or negative electrode sheets by a winding method.

[0101] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or multi-prismatic, etc.

[0102] In some embodiments, the electrode assembly is provided with tabs, and the tabs can conduct current out of the electrode assembly. The tabs include a positive electrode tab and a negative electrode tab.

[0103] In some embodiments, the cylindrical battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0104] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more cylindrical battery cells to provide higher voltage and capacity.

[0105] In some embodiments, the battery can be a battery module. When there are multiple cylindrical battery cells, the multiple cylindrical battery cells are arranged and fixed to form a battery module.

[0106] In some embodiments, the battery can be a battery pack. The battery pack includes a box body and cylindrical battery cells, and the cylindrical battery cells or battery modules are accommodated in the box body.

[0107] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0108] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0109] At present, from the perspective of market development, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of battery application areas, its market demand is also constantly expanding.

[0110] The development of battery technology must consider multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the reliability of the battery must also be considered. However, the reliability of cylindrical battery cells using wound electrode assemblies is currently poor.

[0111] For cylindrical battery cells that use wound electrode assemblies, there is a large gap between the electrode assembly and the shell. During the cycle of the cylindrical battery cell, the electrode assembly is prone to over-expansion, and the inner electrode sheet has a large slippage relative to the outer electrode sheet. The shear force generated on the outer electrode sheet is large, which can easily cause stress concentration on the outer electrode sheet and cause the outer electrode sheet to break. When the electrode sheet breaks, there will be burrs at the fracture and even metal debris. These burrs and debris may pierce the separator, causing the positive and negative electrode sheets to overlap, causing the cylindrical battery cell to short-circuit, causing the cylindrical battery cell to catch fire or even explode, resulting in poor reliability of the cylindrical battery cell.

[0112] In view of this, an embodiment of the present application provides a cylindrical battery cell, the cylindrical battery cell includes a shell, an electrode assembly and an elastic insulating member, and the electrode assembly is accommodated in the shell. The electrode assembly includes a first pole piece, a second pole piece and a separator, the polarities of the first pole piece and the second pole piece are opposite, and the first pole piece, the separator and the second pole piece are wound. The shell includes a side wall arranged around the electrode assembly. The elastic insulating member is arranged between the electrode assembly and the side wall, and the elastic insulating member abuts against the outer surface of the electrode assembly and the inner surface of the side wall respectively.

[0113] An elastic insulating member is provided between the side wall of the electrode assembly and the outer casing of the cylindrical battery cell. The elastic insulating member abuts against the outer surface of the electrode assembly and the inner surface of the side wall respectively, fills the gap between the electrode assembly and the side wall, reduces the expansion space of the electrode assembly, suppresses the expansion of the electrode assembly to a certain extent, reduces the risk of excessive expansion of the electrode assembly, reduces the slip amount of the electrode sheet, reduces the shear force generated during the slipping process, thereby reducing stress concentration and reducing the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell. In addition, the elastic insulating member has a certain elasticity and can allow the electrode assembly to expand to a certain extent, so that the pressure on the electrode assembly is not too large, thereby reducing the risk of the electrolyte in the electrode assembly being extruded, which is beneficial to maintaining the performance of the electrode assembly.

[0114] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical equipment using the batteries.

[0115] The electrical equipment may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator, an electric planer, etc. The embodiments of the present application do not impose special restrictions on the above electrical equipment.

[0116] For the convenience of description, the following embodiments will take the electrical equipment as a vehicle as an example for description.

[0117] Please refer to Figure 1 , Figure 1 FIG. 1000 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as an operating power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300. For example, it is used for the power consumption requirements during the start, navigation and driving of the vehicle 1000.

[0118] In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle 1000, but also as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0119] Please refer to Figure 2 , Figure 2 is an exploded view of the battery 100 provided in some embodiments of the present application. The battery 100 includes a box body 10 and cylindrical battery cells 20, and the cylindrical battery cells 20 are accommodated in the box body 10. Among them, the box body 10 is used to provide an accommodation space for the cylindrical battery cells 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 can include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define an accommodation space for accommodating the cylindrical battery cells 20. The second part 12 can be a hollow structure with one end open, and the first part 11 can be a plate-like structure. The first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define an accommodation space; the first part 11 and the second part 12 can also both be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0120] In the battery 100, there can be multiple cylindrical battery cells 20, and the multiple cylindrical battery cells 20 can be connected in series, parallel, or in a hybrid connection. A hybrid connection means that there are both series and parallel connections among the multiple cylindrical battery cells 20. The multiple cylindrical battery cells 20 can be directly connected in series, parallel, or in a hybrid connection together, and then the whole formed by the multiple cylindrical battery cells 20 is accommodated in the box body 10; of course, the battery 100 can also be that multiple cylindrical battery cells 20 are first connected in series, parallel, or in a hybrid connection to form a battery module form, and then multiple battery modules are connected in series, parallel, or in a hybrid connection to form a whole and are accommodated in the box body 10. The battery 100 can also include other structures. For example, the battery 100 can also include a busbar component for realizing the electrical connection among the multiple cylindrical battery cells 20.

[0121] Among them, each cylindrical battery cell 20 can be a secondary cylindrical battery cell or a primary cylindrical battery cell; it can also be a lithium-sulfur cylindrical battery cell, a sodium-ion cylindrical battery cell, or a magnesium-ion cylindrical battery cell, but is not limited thereto.

[0122] Please refer to Figure 3 , Figure 4 and Figure 5 , Figure 3 is a schematic structural view of the cylindrical battery cell 20 provided in some embodiments of the present application. Figure 4Explosion diagram of the cylindrical battery cell 20 provided by some embodiments of the present application. Figure 5 Cross-sectional view of the cylindrical battery cell 20 provided by some embodiments of the present application. Some embodiments of the present application provide a cylindrical battery cell 20, which includes a housing 21, an electrode assembly 22, and an elastic insulating member 23. The electrode assembly 22 is accommodated in the housing 21. The electrode assembly 22 includes a first electrode tab 2211, a second electrode tab 2213, and a separator 2212. The polarities of the first electrode tab 2211 and the second electrode tab 2213 are opposite, and the first electrode tab 2211, the separator 2212, and the second electrode tab 2213 are wound together. The housing 21 includes a side wall 2111 disposed around the electrode assembly 22. The elastic insulating member 23 is disposed between the electrode assembly 22 and the side wall 2111, and the elastic insulating member 23 abuts against the outer surface of the electrode assembly 22 and the inner surface of the side wall 2111 respectively.

[0123] The cylindrical battery cell 20 refers to the smallest unit that makes up the battery 100.

[0124] The housing 21 includes an end cap 212 and a housing body 211. The housing body 211 has a receiving space with one end open, and the receiving space is used to accommodate the electrode assembly 22. The end cap 212 is connected to the housing body 211 and closes the opening.

[0125] The end cap 212 refers to a component that covers the opening of the housing body 211 to isolate the internal environment of the cylindrical battery cell 20 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the housing body 211 to cooperate with the housing body 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 212 is not easily deformed when subjected to extrusion and collision, enabling the cylindrical battery cell 20 to have higher structural strength and improved safety performance. The material of the end cap 212 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The embodiments of the present application do not make special restrictions on this. The cylindrical battery cell 20 further includes an insulating member, which is disposed inside the end cap 212 and can be used to isolate the electrical connection components in the housing body 211 from the end cap 212 to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc. Optionally, an electrode terminal 24 can also be provided on the end cap 212. The electrode terminal 24 is used to electrically connect to the tab of the electrode assembly 22 to input or output the electrical energy of the cylindrical battery cell 20. The electrode terminal 24 and the tab can be directly connected. For example, the electrode terminal 24 is directly welded to the tab. The electrode terminal 24 and the tab can also be indirectly connected. For example, the electrode terminal 24 and the tab are indirectly connected through a current collecting member.

[0126] The housing 211 is a component for cooperating with the end cap 212 to form the internal environment of the cylindrical battery cell 20. Among them, the formed internal environment can be used to accommodate the electrode assembly 22, the electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 is covered at the opening to form the internal environment of the cylindrical battery cell 20. Without limitation, the end cap 212 and the housing 211 can also be integrated. Specifically, the end cap 212 and the housing 211 can form a common joint surface before other components are put into the housing. When it is necessary to encapsulate the inside of the housing 211, the end cap 212 is then covered on the housing 211. The material of the housing 211 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The embodiments of the present application do not make special restrictions on this. The cylindrical battery cell 20 further includes a lower plastic 26, and the lower plastic 26 is arranged inside the end cap 212. The lower plastic 26 can be used to isolate the electrical connection components in the housing 211 from the end cap 212 to reduce the risk of short circuit. Exemplarily, the lower plastic 26 can be plastic, rubber, etc.

[0127] The electrode assembly 22 is a component in the cylindrical battery cell 20 where an electrochemical reaction occurs. The outer shell 21 can contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding a positive electrode sheet and a negative electrode sheet, and generally an isolator 2212 is provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body 221 of the electrode assembly 22, and the parts of the positive electrode sheet and the negative electrode sheet without active materials respectively constitute the electrode tabs. The positive electrode tab and the negative electrode tab can be located at one end of the main body 221 together or at both ends of the main body 221 respectively. During the charge and discharge process of the battery 100, the positive electrode active material and the negative electrode active material react with the electrolyte.

[0128] One of the first electrode sheet 2211 and the second electrode sheet 2213 is the positive electrode sheet, and the other is the negative electrode sheet. For example, when the first electrode sheet 2211 is the positive electrode sheet, the second electrode sheet 2213 is the negative electrode sheet. Another example is that when the first electrode sheet 2211 is the positive electrode sheet, the second electrode sheet 2213 is the negative electrode sheet.

[0129] The isolator 2212 is an insulating structure provided between the first electrode sheet 2211 and the second electrode sheet 2213. The isolator 2212 is used to insulate and isolate the first electrode sheet 2211 and the second electrode sheet 2213 to reduce the risk of short circuit caused by the contact between the first electrode sheet 2211 and the second electrode sheet 2213.

[0130] The first electrode sheet 2211, the isolator 2212, and the second electrode sheet 2213 are wound to form the electrode assembly 22, that is, the electrode assembly 22 is a wound electrode assembly.

[0131] The housing 21 includes a side wall 2111 which surrounds the electrode assembly 22 around the winding axis of the electrode assembly 22. The side wall 2111 has a cylindrical structure.

[0132] The elastic insulating member 23 is disposed between the electrode assembly 22 and the side wall 2111. The elastic insulating member 23 abuts against the outer surface of the electrode assembly 22 and the inner surface of the side wall 2111 respectively. Since the separator 2212 is located on the outermost layer of the electrode assembly 22, the elastic insulating member 23 actually abuts against the separator 2212 and the side wall 2111.

[0133] The elastic insulating member 23 has an insulating function and can insulate and isolate the electrode assembly 22 and the housing 21. In addition, the elastic insulating member 23 also has a certain elasticity, so as to allow the electrode assembly 22 to expand to a certain extent, so that the pressure on the electrode assembly 22 is not too large, thereby reducing the risk of the electrolyte in the electrode assembly 22 being extruded, which is beneficial to maintaining the performance of the electrode assembly 22. The elastic insulating member 23 can be rubber, plastic, etc.

[0134] The elastic insulating member 23 can be a component that can absorb the expansion of the electrolyte. Before the elastic insulating member 23 absorbs the electrolyte, the volume of the elastic insulating member 23 is small, so that it is convenient to dispose the elastic insulating member 23 between the electrode assembly 22 and the side wall 2111. The elastic insulating member 23 absorbs the electrolyte and expands to fill the gap between the electrode assembly 22 and the side wall 2111, reducing the expansion space of the electrode assembly 22 and suppressing the expansion of the electrode assembly 22. Of course, the elastic insulating member 23 can also be directly disposed between the electrode assembly 22 and the side wall 2111 and abut against the outer surface of the electrode assembly 22 and the inner surface of the side wall 2111 without absorbing the electrolyte and expanding.

[0135] An elastic insulating member 23 is disposed between the electrode assembly 22 and the side wall 2111 of the cylindrical battery cell 20. The elastic insulating member 23 abuts against the outer surface of the electrode assembly 22 and the inner surface of the side wall 2111 respectively, fills the gap between the electrode assembly 22 and the side wall 2111, reduces the expansion space of the electrode assembly 22, suppresses the expansion of the electrode assembly 22 to a certain extent, reduces the risk of excessive expansion of the electrode assembly 22, reduces the slip amount of the electrode sheet, reduces the shear force generated during the slip process, thereby reducing the stress concentration and reducing the risk of the electrode sheet cracking, improving the reliability of the cylindrical battery cell 20. In addition, the elastic insulating member 23 has a certain elasticity and can allow the electrode assembly 22 to expand to a certain extent, so that the pressure on the electrode assembly 22 is not too large, thereby reducing the risk of the electrolyte in the electrode assembly 22 being extruded, which is beneficial to maintaining the performance of the electrode assembly 22.

[0136] Please refer to Figure 3 、 Figure 4 、Figure 5 and Figure 6 , Figure 6 is a simplified schematic diagram of the positional relationship between the elastic insulating member 23 and the electrode assembly 22 provided in some embodiments of the present application. In some embodiments, the cylindrical battery cell 20 includes a plurality of elastic insulating members 23, and the plurality of elastic insulating members 23 are arranged at intervals along the axial direction of the cylindrical battery cell 20.

[0137] The cylindrical battery cell 20 may include two elastic insulating members 23, three elastic insulating members 23, four elastic insulating members 23, or more than four elastic insulating members 23. The plurality of elastic insulating members 23 are arranged along the axial direction of the cylindrical battery cell 20, and there is an interval between two adjacent elastic insulating members 23. Each elastic insulating member 23 surrounds the outside of the electrode assembly 22. Along the circumferential direction of the cylindrical battery cell 20, the elastic insulating member 23 may entirely cover the outside of the electrode assembly 22 or partially cover the outside of the electrode assembly 22.

[0138] The axial direction of the cylindrical battery cell 20 refers to the extending direction of the axis of the cylindrical battery cell 20. The circumferential direction of the cylindrical battery cell 20 refers to the circumferential direction of the cylindrical battery cell 20. Please refer to Figure 5 and Figure 6 ; the axial direction of the cylindrical battery cell 20 is the X direction shown in the figure, the circumferential direction of the cylindrical battery cell 20 is the Y direction shown in the figure, and the axial direction of the cylindrical battery cell 20 is perpendicular to the circumferential direction of the cylindrical battery cell 20.

[0139] By providing a plurality of elastic insulating members 23 and arranging the plurality of elastic insulating members 23 at intervals along the axial direction of the cylindrical battery cell 20, the plurality of elastic insulating members 23 inhibit the expansion of the electrode assembly 22 at multiple positions in the axial direction of the cylindrical battery cell 20, having a good inhibition effect, capable of reducing the risk of pole piece cracking, and improving the reliability of the cylindrical battery cell 20. In addition, along the axial direction of the cylindrical battery cell 20, there is a certain interval between two adjacent elastic insulating members 23, which can reduce the material consumption of the elastic insulating members 23 and lower the cost of the cylindrical battery cell 20.

[0140] Please refer to Figure 3 、 Figure 4 、 Figure 5 and Figure 6 ; in some embodiments, the cylindrical battery cell 20 includes two elastic insulating members 23, along the axial direction of the cylindrical battery cell 20, the separator 2212 includes two end regions, and the two elastic insulating members 23 respectively surround the two end regions.

[0141] Along the axial direction of the cylindrical battery cell 20, the separator 2212 includes two end faces disposed opposite to each other. The end region refers to: along the axial direction of the cylindrical battery cell 20, the region within the separator 2212 where the distance from the end face of the separator 2212 is within 1 / 6 of the length of the separator 2212.

[0142] The cylindrical battery cell 20 includes two elastic insulating members 23, and the elastic insulating members 23 are arranged in one-to-one correspondence with the end regions. Each elastic insulating member 23 surrounds the periphery of one end region. It should be noted that the dimension of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 may extend beyond the end region or may not extend beyond the end region.

[0143] By providing two elastic insulating members 23, along the axial direction of the cylindrical battery cell 20, the two elastic insulating members 23 respectively surround the two end regions of the separator 2212, which can not only have a good suppression effect, reduce the risk of pole piece cracking, and improve the reliability of the cylindrical battery cell 20, but also reduce the material consumption of the elastic insulating members 23 and lower the cost of the cylindrical battery cell 20.

[0144] Please refer to Figure 3 、 Figure 4 、 Figure 5 and Figure 6 , in some embodiments, along the axial direction of the cylindrical battery cell 20, the length of the elastic insulating member 23 is L1, and the length of the separator 2212 is L2, satisfying: 0.1 ≤ L1 / L2 ≤ 0.3.

[0145] L1 represents the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20. When measuring, the lengths at different positions of the elastic insulating member 23 can be measured and the average value can be taken as L1.

[0146] L2 represents the length of the separator 2212 along the axial direction of the cylindrical battery cell 20. When measuring, the lengths at different positions of the separator 2212 can be measured and the average value can be taken as L2.

[0147] L1 / L2 represents the ratio of the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 to the length of the separator 2212 along the axial direction of the cylindrical battery cell 20.

[0148] When there are multiple elastic insulating members 23, the ratio of the length of the elastic insulating members 23 along the axial direction of the cylindrical battery cell 20 to the length of the separator 2212 along the axial direction of the cylindrical battery cell 20 can be: L1 / L2 = 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, etc.

[0149] When L1 / L2 ≥ 0.1, the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 is relatively large, which can effectively inhibit the expansion of the electrode assembly 22, reduce the slip amount of the electrode sheet, and reduce the shear force generated during the slipping process, thereby reducing stress concentration and the risk of electrode sheet cracking, and improving the reliability of the cylindrical battery cell 20. When L1 / L2 ≤ 0.3, the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 is not too large, which is beneficial to reducing the cost of the cylindrical battery cell 20. Therefore, when 0.1 ≤ L1 / L2 ≤ 0.3, the reliability and cost of the cylindrical battery cell 20 can be taken into account.

[0150] Optionally, 0.15 ≤ L1 / L2 ≤ 0.25.

[0151] The ratio of the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 to the length of the separator 2212 along the axial direction of the cylindrical battery cell 20 can be: L1 / L2 = 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, etc.

[0152] When L1 / L2 ≥ 0.15, the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 is larger, which can more effectively inhibit the expansion of the electrode assembly 22, further reduce the slip amount of the electrode sheet, and reduce the shear force generated during the slipping process, thereby further reducing stress concentration and the risk of electrode sheet cracking, and improving the reliability of the cylindrical battery cell 20. When L1 / L2 ≤ 0.25, the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 is not too large, which is beneficial to reducing the cost of the cylindrical battery cell 20. Therefore, when 0.15 ≤ L1 / L2 ≤ 0.25, the reliability and cost of the cylindrical battery cell 20 can be better taken into account.

[0153] Please refer to Figure 7 , Figure 7 which is a simplified schematic diagram of the positional relationship between the elastic insulating member 23 and the electrode assembly 22 provided in some other embodiments of the present application. In some other embodiments, there is one elastic insulating member 23. Along the axial direction of the cylindrical battery cell 20, the length of the elastic insulating member 23 is L1, and the length of the separator 2212 is L2, satisfying: 0.5 ≤ L1 / L2 ≤ 1.2.

[0154] When there is one elastic insulating member 23, the ratio of the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 to the length of the separator 2212 along the axial direction of the cylindrical battery cell 20 can be: L1 / L2 ≤ 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, etc.

[0155] When there is one elastic insulating member 23 and L1 / L2≥0.5, the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 is relatively large, which can effectively inhibit the expansion of the electrode assembly 22, reduce the slip amount of the electrode sheet, and reduce the shear force generated during the slipping process, thereby reducing stress concentration and the risk of electrode sheet cracking, and improving the reliability of the cylindrical battery cell 20. When there is one elastic insulating member 23 and L1 / L2≤1.2, the length of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 is not too large, which is beneficial to reducing the cost of the cylindrical battery cell 20. Therefore, when there is one elastic insulating member 23 and 0.5≤L1 / L2≤1.2, the reliability of the cylindrical battery cell 20 and the cost of the cylindrical battery cell 20 can be taken into account.

[0156] Please refer to Figure 8 , Figure 8 which is a simplified schematic diagram of the positional relationship between the elastic insulating member 23 and the electrode assembly 22 provided by some other embodiments of the present application. In some other embodiments, along the axial direction of the cylindrical battery cell 20, the two ends of the elastic insulating member 23 are respectively flush with the two ends of the separator 2212.

[0157] There is one elastic insulating member 23, and the two end faces of the elastic insulating member 23 along the axial direction of the cylindrical battery cell 20 are respectively flush with the two end faces of the separator 2212 along the axial direction of the cylindrical battery cell 20. At this time, L1 = L2.

[0158] When along the axial direction of the cylindrical battery cell 20, the two ends of the elastic insulating member 23 are respectively flush with the two ends of the separator 2212, the length of the elastic insulating member 23 is equal to the length of the separator 2212, that is, L1 = L2. At this time, the elastic insulating member 23 just completely wraps the separator 2212 along the axial direction of the cylindrical battery cell 20, which can more effectively inhibit the expansion of the electrode assembly 22, further reduce the slip amount of the electrode sheet, and reduce the shear force generated during the slipping process, thereby further reducing stress concentration and further reducing the risk of electrode sheet cracking, and improving the reliability of the cylindrical battery cell 20.

[0159] Please refer to again Figure 5 , in some embodiments, along the circumferential direction of the cylindrical battery cell 20, the elastic insulating member 23 is arranged around the electrode assembly 22. The elastic insulating member 23 has a first end 231 and a second end 232, and the first end 231 and the second end 232 are arranged at intervals. A notch area 233 that does not cover the electrode assembly 22 is formed between the first end 231 and the second end 232.

[0160] Along the circumferential direction of the cylindrical battery cell 20, the elastic insulating member 23 partially wraps the outside of the electrode assembly 22.

[0161] Circumferentially along the cylindrical battery cell 20, the elastic insulating member 23 has a first end 231 and a second end 232 arranged at intervals, and a notch area 233 exposing the electrode assembly 22 is formed between the first end 231 and the second end 232.

[0162] Circumferentially along the cylindrical battery cell 20, by arranging the elastic insulating member 23 around the electrode assembly 22, the gap between the electrode assembly 22 and the side wall 2111 can be better filled, the expansion space of the electrode assembly 22 can be reduced, the expansion of the electrode assembly 22 can be inhibited, the sliding amount of the electrode sheet can be reduced, the shear force generated during the sliding process can be reduced, thereby reducing stress concentration and the risk of electrode sheet cracking, and the reliability of the cylindrical battery cell 20 is improved. In addition, by forming a notch area 233 that does not cover the electrode assembly 22 between the first end 231 and the second end 232, on the one hand, the material consumption of the elastic insulating member 23 can be reduced, and the cost of the cylindrical battery cell 20 can be reduced. On the other hand, due to the existence of the notch area 233, the first end 231 and the second end 232 are not easily overlapped to form an overlapping area (the overlapping area has a relatively thick thickness, and the overlapping area will cause stress concentration of the electrode assembly 22), and stress concentration of the electrode assembly 22 is not easily caused, which is beneficial to improving the reliability of the cylindrical battery cell 20.

[0163] Please refer to Figure 5 , in some embodiments, the first electrode sheet 2211 has a first end 22111, and a part of the second electrode sheet 2213 extends beyond the first end 22111 along the winding direction of the electrode assembly 22. The second electrode sheet 2213 includes the electrode sheet located in the outermost circle of the electrode assembly 22. The second electrode sheet 2213 has a second end 22131, and the second end 22131 is located in the notch area 233.

[0164] The first end 22111 is the winding end 232 of the first electrode sheet 2211. Along the winding direction, the first end 22111 is located at the end of the first electrode sheet 2211, and the first end 22111 is usually close to the outer layer of the electrode assembly 22. The first electrode sheet 2211 also has a first starting end, and the first starting end is the start of winding the first electrode sheet 2211 and is usually located inside the electrode assembly 22.

[0165] The second end 22131 is the winding end 232 of the second electrode sheet 2213. Along the winding direction, the second end 22131 is located at the end of the second electrode sheet 2213, and the second end 22131 is usually close to the outer layer of the electrode assembly 22. The second electrode sheet 2213 also has a second starting end, and the second starting end is the start of winding the second electrode sheet 2213 and is usually located inside the electrode assembly 22. In Figure 5 the illustrated embodiment, the first end 22111 is closer to the inside of the electrode assembly 22 than the second end 22131.

[0166] "The second pole piece 2213 includes the pole piece located at the outermost circle of the electrode assembly 22" means that a part of the second pole piece 2213 is the pole piece located at the outermost circle of the electrode assembly 22. The first pole piece 2211 can be the positive pole piece, the second pole piece 2213 can be the negative pole piece, and the second end 22131 extends beyond the first end 22111 along the winding direction, so that the second pole piece 2213 covers the first pole piece 2211, reducing the risk of lithium plating.

[0167] The second end 22131 is located within the notch area 233, that is, the position of the notch area 233 corresponds to the position of the second end 22131.

[0168] The diameter of the electrode assembly 22 is larger at the position corresponding to the second end 22131. By making the position of the notch area 233 correspond to the position of the second end 22131, the elastic insulating member 23 does not have to cover the position where the second end 22131 is located, thereby being able to greatly reduce the material consumption of the elastic insulating member 23 and reduce the cost of the cylindrical battery cell 20.

[0169] Please refer to Figure 5 , in some embodiments, along the circumferential direction of the cylindrical battery cell 20, the length of the notch area 233 is L3, and the total length of the elastic insulating member 23 and the notch area 233 is L4, satisfying: L3 / L4 ≤ 0.5.

[0170] L3 represents the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20, that is, the distance between the head end 231 and the tail end 232 along the circumferential direction of the cylindrical battery cell 20.

[0171] L4 represents the sum of the length of the elastic insulating member 23 along the circumferential direction of the cylindrical battery cell 20 and the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20. Please refer to Figure 5 , the length of the elastic insulating member 23 along the circumferential direction of the cylindrical battery cell 20 is L5, then L4 = L3 + L5.

[0172] L3 / L4 represents the ratio of the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 to the sum of the length of the elastic insulating member 23 along the circumferential direction of the cylindrical battery cell 20 and the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20.

[0173] The ratio of the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 to the sum of the length of the elastic insulating member 23 along the circumferential direction of the cylindrical battery cell 20 and the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 can be: L3 / L4 = 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1, 0.5, etc.

[0174] When L3 / L4 ≤ 0.5, the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 is shorter, and the elastic insulating member 23 can be disposed around the outside of the electrode assembly 22 to a greater extent along the circumferential direction of the cylindrical battery cell 20, better filling the gap between the electrode assembly 22 and the side wall 2111, reducing the expansion space of the electrode assembly 22, better suppressing the expansion of the electrode assembly 22, reducing the slip amount of the electrode sheet, reducing the shear force generated during the slip process, thereby reducing stress concentration, reducing the risk of electrode sheet cracking, and improving the reliability of the cylindrical battery cell 20.

[0175] Optionally, 0.1 ≤ L3 / L4 ≤ 0.4.

[0176] The ratio of the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 to the sum of the length of the elastic insulating member 23 along the circumferential direction of the cylindrical battery cell 20 and the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 can be: L3 / L4 = 0.1, 0.12, 0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.32, 0.35, 0.38, 0.4, etc.

[0177] When L3 / L4 ≤ 0.4, the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 is shorter, and the elastic insulating member 23 can be disposed around the outside of the electrode assembly 22 to a greater extent along the circumferential direction of the cylindrical battery cell 20, better filling the gap between the electrode assembly 22 and the side wall 2111, reducing the expansion space of the electrode assembly 22, better suppressing the expansion of the electrode assembly 22, reducing the slip amount of the electrode sheet, reducing the shear force generated during the slip process, reducing the risk of electrode sheet cracking, and improving the reliability of the cylindrical battery cell 20. When L3 / L4 ≥ 0.1, the length of the notch area 233 is not too short, which can reduce the material consumption of the elastic insulating member 23, reduce the cost of the cylindrical battery cell 20, and also reduce the risk of the overlap area formed by the overlap of the first end 231 and the second end 232. Therefore, when 0.1 ≤ L3 / L4 ≤ 0.4, the reliability and cost of the cylindrical battery cell 20 can be taken into account.

[0178] In some embodiments, 1 mm ≤ L3 ≤ 5 mm.

[0179] The length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 can be: L3 = 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0180] When L3 ≤ 5 mm, the length of the notch area 233 along the circumferential direction of the cylindrical battery cell 20 is short, and the elastic insulating member 23 can be disposed around the outside of the electrode assembly 22 to a large extent along the circumferential direction of the cylindrical battery cell 20, better filling the gap between the electrode assembly 22 and the side wall 2111, reducing the expansion space of the electrode assembly 22, better suppressing the expansion of the electrode assembly 22, reducing the slippage amount of the electrode plate, reducing the shear force generated during the slippage, reducing the risk of electrode plate cracking, and improving the reliability of the cylindrical battery cell 20. When L3 ≥ 1 mm, the length of the notch area 233 is not too short, which can reduce the material consumption of the elastic insulating member 23, reduce the cost of the cylindrical battery cell 20, and also reduce the risk of the first end 231 and the tail end 232 overlapping to form an overlapping area. Therefore, when 1 mm ≤ L3 ≤ 5 mm, the reliability and cost of the cylindrical battery cell 20 can be taken into account.

[0181] Please refer to Figure 5 , in some embodiments, the first end and tail end 22111 is located in the notch area 233.

[0182] The first end and tail end 22111 is located within the notch area 233, that is, the position of the notch area 233 corresponds to the position of the first end and tail end 22111.

[0183] The diameter of the electrode assembly 22 is larger at the position corresponding to the first end and tail end 22111. By making the position of the notch area 233 correspond to the position of the first end and tail end 22111, the elastic insulating member 23 does not have to cover the position where the first end and tail end 22111 is located, thereby being able to greatly reduce the material consumption of the elastic insulating member 23 and reduce the cost of the cylindrical battery cell 20.

[0184] Please refer to Figure 9 , in some embodiments, along the circumferential direction of the cylindrical battery cell 20, the elastic insulating member 23 wraps around the electrode assembly 22 for a full circle.

[0185] "Along the circumferential direction of the cylindrical battery cell 20, the elastic insulating member 23 wraps around the electrode assembly 22 for a full circle" means that the elastic insulating member 23 completely wraps around the electrode assembly 22 along the circumferential direction of the cylindrical battery cell 20.

[0186] By making the elastic insulating member 23 wrap around the electrode assembly 22 for a full circle along the circumferential direction of the cylindrical battery cell 20, it is more capable of effectively suppressing the expansion of the electrode assembly 22, further reducing the slippage amount of the electrode plate, reducing the shear force generated during the slippage, thereby further reducing the stress concentration, further reducing the risk of electrode plate cracking, and improving the reliability of the cylindrical battery cell 20.

[0187] Please refer to Figure 9 , in some embodiments, the elastic insulating member 23 is an annular structure disposed around the electrode assembly 22.

[0188] In Figure 9 In the illustrated embodiment, the elastic insulating member 23 is in an annular structure (cylindrical structure). The elastic insulating member 23 is disposed around the outside of the electrode assembly 22.

[0189] The elastic insulating member 23 is in an annular structure. On the one hand, it can effectively inhibit the expansion of the electrode assembly 22, reduce the risk of pole piece cracking, and improve the reliability of the cylindrical battery cell 20. On the other hand, when the elastic insulating member 23 is disposed around the outside of the electrode assembly 22, there is no overlapping area, and it is not easy to cause stress concentration of the electrode assembly 22, which is beneficial to improving the reliability of the cylindrical battery cell 20. Please refer to Figure 10 , Figure 10 which is a cross-sectional view of the elastic insulating member 23 provided in some embodiments of the present application. In an embodiment where the elastic insulating member 23 is a component capable of absorbing the expansion of the electrolyte, the elastic insulating member 23 may include an expansion layer 235 and a first adhesive layer 234. The expansion layer 235 and the first adhesive layer 234 are stacked, and the expansion layer 235 is configured to be able to absorb the electrolyte and expand, and the first adhesive layer 234 is adhered to the inner surface of the side wall 2111.

[0190] The first adhesive layer 234 has adhesiveness. The first adhesive layer 234 is adhered to the inner surface of the side wall 2111 to realize the connection between the elastic insulating member 23 and the side wall 2111. In some embodiments, the first adhesive layer 234 is disposed on the side of the expansion layer 235 facing the side wall 2111, and the first adhesive layer 234 connects the expansion layer 235 and the side wall 2111.

[0191] The expansion layer 235 can absorb the electrolyte and expand to fill the gap between the electrode assembly 22 and the side wall 2111, reduce the expansion space of the electrode assembly 22, and inhibit the expansion of the electrode assembly 22. The expansion layer 235 and the first adhesive layer 234 are arranged along the thickness direction of the elastic insulating member 23.

[0192] The first adhesive layer 234 has adhesiveness. By providing the first adhesive layer 234, the elastic insulating member 23 can be adhered to the inner surface of the outer shell 21, and the connection between the elastic insulating member 23 and the outer shell 21 is relatively firm, reducing the risk of the elastic insulating member 23 leaving between the electrode assembly 22 and the side wall 2111. The expansion layer 235 can absorb the electrolyte and expand along its thickness direction, thereby filling the gap between the electrode assembly 22 and the side wall 2111, reducing the expansion space of the electrode assembly 22, inhibiting the expansion of the electrode assembly 22, reducing the slip amount of the pole piece, reducing the shear force generated during the slip process, thereby reducing stress concentration, reducing the risk of pole piece cracking, and improving the reliability of the electrode assembly 22.

[0193] Please refer to Figure 10 , in some embodiments, the expansion layer 235 is made of an insulating material.

[0194] The swelling layer 235 can not only absorb the swelling of the electrolyte but also has an insulating property, capable of insulating and isolating the electrode assembly 22 from the side wall 2111. For example, the material of the swelling layer 235 can be oriented polystyrene.

[0195] The swelling layer 235 is made of an insulating material, enabling it to not only absorb the swelling of the electrolyte but also have an insulating effect. In this way, the swelling layer 235 can insulate and isolate the side wall 2111 from the electrode assembly 22, reducing the risk of short circuit due to the contact between the side wall 2111 and the electrode assembly 22.

[0196] Please refer to Figure 11 , Figure 11 FIG. is a cross-sectional view of the elastic insulating member 23 provided in some other embodiments of the present application. In some other embodiments, the elastic insulating member 23 further includes an insulating layer 236, and the swelling layer 235 and the insulating layer 236 are stacked.

[0197] The insulating layer 236 has an insulating property and can insulate and isolate the side wall 2111 from the electrode assembly 22. The material of the insulating layer 236 can be plastic, rubber, etc.

[0198] The insulating layer 236 and the swelling layer 235 are arranged along the thickness direction of the elastic insulating member 23. It can be that the insulating layer 236 is closer to the side wall 2111 than the swelling layer 235, or the swelling layer 235 is closer to the side wall 2111 than the insulating layer 236. Please refer to Figure 10 ,in Figure 10 the illustrated embodiment, the insulating layer 236 is closer to the side wall 2111 than the swelling layer 235.

[0199] Optionally, the elastic insulating member 23 further includes a second adhesive layer 237, and the second adhesive layer 237 bonds the insulating layer 236 and the swelling layer 235 to make the connection between the insulating layer 236 and the swelling layer 235 closer.

[0200] The elastic insulating member 23 further includes an insulating layer 236, enabling the elastic insulating member 23 to have an insulating effect. The elastic insulating member 23 can insulate and isolate the side wall 2111 from the electrode assembly 22, reducing the risk of short circuit due to the contact between the side wall 2111 and the electrode assembly 22.

[0201] In some embodiments, the material of the elastic insulating member 23 includes oriented polystyrene.

[0202] The oriented polystyrene can expand significantly when absorbing the electrolyte. Before the elastic insulating member 23 absorbs the electrolyte, the volume of the elastic insulating member 23 is small, so that it is convenient to arrange the elastic insulating member 23 between the electrode assembly 22 and the side wall 2111. After that, the elastic insulating member 23 absorbs the electrolyte in the cylindrical battery cell 20 and expands, filling the gap between the electrode assembly 22 and the side wall 2111, reducing the expansion space of the electrode assembly 22, inhibiting the expansion of the electrode assembly 22, reducing the slip amount of the electrode sheet, reducing the shear force generated during the slip process, thereby reducing stress concentration and the risk of cracking of the electrode sheet, and improving the reliability of the cylindrical battery cell 20.

[0203] Please refer to again Figure 3 and Figure 4 In some embodiments, the first electrode sheet 2211 includes a first tab 222, and the second electrode sheet 2213 includes a second tab 223. The cylindrical battery cell 20 includes a first electrode lead-out portion 213 and a second electrode lead-out portion 214. The first electrode lead-out portion 213 is electrically connected to the first tab 222, and the second electrode lead-out portion 214 is electrically connected to the second tab 223. In the axial direction of the cylindrical battery cell 20, the first electrode lead-out portion 213 and the second electrode lead-out portion 214 are located on the same side of the electrode assembly 22.

[0204] The first tab 222 is the positive tab or negative tab as described above, the second tab 223 is the negative tab or positive tab as described above, and the polarities of the first tab 222 and the second tab 223 are opposite. When the first tab 222 is the positive tab, the second tab 223 is the negative tab. When the first tab 222 is the negative tab, the second tab 223 is the positive tab.

[0205] The first electrode lead-out portion 213 and the second electrode lead-out portion 214 are used to connect to an external circuit to achieve charging or discharging of the cylindrical battery cell 20. Exemplarily, when a plurality of cylindrical battery cells 20 are assembled into a group, the first electrode lead-out portion 213 and the second electrode lead-out portion 214 are used to connect to a busbar component.

[0206] The first electrode lead-out portion 213 can be an electrode terminal 24 provided on the housing 21. The electrode terminal 24 is independently formed with the housing 21 and assembled together during the production process of the cylindrical battery cell 20. As an example, the electrode terminal 24 is insulatingly provided on the end cap 212 or the housing 211.

[0207] Alternatively, the first electrode lead-out portion 213 can also be a part of the housing 21. For example, the first electrode lead-out portion 213 can be the end cap 212 of the housing 21, or the first electrode lead-out portion 213 is the end wall 2112 of the housing 211 opposite to the end cap 212.

[0208] The second electrode lead-out portion 214 may be an electrode terminal 24 provided on the housing 21. Alternatively, the second electrode lead-out portion 214 may be a part of the housing 21. For example, the second electrode lead-out portion 214 may be an end cap 212 of the housing 21, or the second electrode lead-out portion 214 may be an end wall 2112 of the housing body 211 opposite to the end cap 212.

[0209] The first electrode lead-out portion 213 is electrically connected to the first tab 222, and the second electrode lead-out portion 214 is electrically connected to the second tab 223. The first electrode lead-out portion 213 and the second electrode lead-out portion 214 are insulated from each other.

[0210] In some embodiments, in the axial direction of the cylindrical battery cell 20, the first electrode lead-out portion 213 and the second electrode lead-out portion 214 are located on the same side of the electrode assembly 22.

[0211] When a plurality of cylindrical battery cells 20 are assembled into a group, the first electrode lead-out portions 213 and the second electrode lead-out portions 214 of the plurality of cylindrical battery cells 20 may be arranged on the same side, which is convenient for realizing the connection of the bus bar component to the first electrode lead-out portion 213 and the second electrode lead-out portion 214, and simplifies the structure of the battery 100.

[0212] Please refer to Figure 3 and Figure 4 , in some embodiments, the housing 21 includes a housing body 211 and an end cap 212. The housing body 211 includes a side wall 2111 and an end wall 2112 formed integrally. The end wall 2112 and the end cap 212 are opposite to each other in the axial direction of the cylindrical battery cell 20, and the end cap 212 is sealingly connected to the side wall 2111.

[0213] The end cap 212 may be insulated from the side wall 2111 or may be electrically connected.

[0214] One end of the housing body 211 away from the end wall 2112 has an opening, and the end cap 212 covers the opening of the housing body 211.

[0215] Please refer to Figure 3 and Figure 4 , in some embodiments, the first electrode tab 2211 includes a first tab 222, and the second electrode tab 2213 includes a second tab 223. The cylindrical battery cell 20 further includes an electrode terminal 24 insulatedly arranged on the end wall 2112. The first tab 222 is electrically connected to the electrode terminal 24, and the second tab 223 is electrically connected to the end wall 2112.

[0216] As an example, the first tab 222 is electrically connected to the electrode terminal 24, and the second tab 223 is electrically connected to the end wall 2112. The second tab 223 may be directly connected to the end wall 2112 or may be indirectly connected to the end wall 2112 through the end cap 212, the side wall 2111 or other components.

[0217] One of the electrode terminal 24 and the end wall 2112 serves as the first electrode lead-out portion 213, and the other serves as the second electrode lead-out portion 214.

[0218] The electrode terminal 24 and the end wall 2112 can serve as two exposed electrodes of the cylindrical battery cell 20. The electrode terminal 24 and the end wall 2112 are located on the same side, which is beneficial to assembling a plurality of cylindrical battery cells 20 into a group and simplifies the structure of the battery 100.

[0219] Please refer to Figure 3 and Figure 4 In some embodiments, the cylindrical battery cell 20 further includes a first current collector member 251. The first current collector member 251 is located on a side of the first tab 222 facing the end wall 2112 and is connected to the first tab 222. The electrode terminal 24 abuts against and is connected to a surface of the first current collector member 251 facing the end wall 2112.

[0220] The first current collector member 251 can play a role in transfer and realize the electrical connection between the first tab 222 and the electrode terminal 24.

[0221] Please refer to Figure 3 and Figure 4 In some embodiments, a terminal recess is provided on a side of the electrode terminal 24 facing the first current collector member 251, and / or a terminal recess is provided on a side of the electrode terminal 24 facing away from the first current collector member 251; the bottom wall of the terminal recess is welded to the first current collector member 251.

[0222] By providing the terminal recess, the thickness of the bottom wall of the terminal recess can be reduced, the power required for welding the electrode terminal 24 and the first current collector member 251 from the outside can be reduced, the risk of particles generated by welding falling into the housing 21 can be reduced, and the reliability of the cylindrical battery cell 20 can be improved.

[0223] By providing the terminal recess on the inner side of the electrode terminal 24, the internal space of the cylindrical battery cell 20 can also be increased.

[0224] In some embodiments, a terminal recess is provided on a side of the electrode terminal 24 facing away from the first current collector member 251.

[0225] In some embodiments, a terminal recess is provided on a side of the electrode terminal 24 facing the first current collector member 251, and another terminal recess is provided on a side of the electrode terminal 24 facing away from the first current collector member 251; corresponding portions of the bottom surfaces of the two terminal recesses are welded to the first current collector member 251.

[0226] In some embodiments, through holes are provided in the bottom wall of the terminal recess, and the through holes can be used for injecting electrolyte.

[0227] In some embodiments, the cylindrical battery cell 20 further includes a cover plate, which is connected to the electrode terminal 24 and is used to separate the through hole from the external space of the cylindrical battery cell 20.

[0228] In some embodiments, at least a part of the cover plate is received in the terminal recess. In some embodiments, the first electrode lead portion 213 includes the cover plate and the electrode terminal 24.

[0229] In some embodiments, the electrode terminal 24 is riveted to the end wall 2112.

[0230] Please refer to Figure 3 and Figure 4 . In some embodiments, both the first tab 222 and the second tab 223 are located at one end of the electrode assembly 22 facing the end wall 2112.

[0231] The first tab 222 and the second tab 223 can share space in the axial direction of the cylindrical battery cell 20, thereby improving space utilization and energy density.

[0232] Please refer to Figure 3 and Figure 4 . In some embodiments, the first tab 222 is located at one end of the electrode assembly 22 facing the end wall 2112, and the second tab 223 is located at one end of the electrode assembly 22 facing the end cap 212. The cylindrical battery cell 20 further includes a second current collector member 252 connected to the second tab 223, and the second current collector member 252 is connected to at least one of the end cap 212 and the side wall 2111.

[0233] In some examples, the second current collector member 252 is connected to the end cap 212, and the end cap 212 is electrically connected to the side wall 2111. The second tab 223 is electrically connected to the end wall 2112 through the second current collector member 252, the end cap 212, and the side wall 2111.

[0234] In other examples, the second current collector member 252 is connected to the side wall 2111. The second tab 223 is electrically connected to the end wall 2112 through the second current collector member 252 and the side wall 2111. Optionally, the end cap 212 and the side wall 2111 are insulated from each other.

[0235] In some embodiments, the height of the housing 21 is 1.3 to 4 times the outer diameter of the housing 21.

[0236] Exemplarily, the height of the housing 21 may be the dimension of the housing 21 along the axial direction of the cylindrical battery cell 20.

[0237] Optionally, the height of the outer casing 21 is 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2.0 times, 2.1 times, 2.2 times, 2.3 times, 2.4 times, 2.5 times, 2.6 times, 2.7 times, 2.8 times, 2.9 times, 3.0 times, 3.1 times, 3.2 times, 3.3 times, 3.4 times, 3.5 times, 3.6 times, 3.7 times, 3.8 times, 3.9 times or 4.0 times the outer diameter of the outer casing 21.

[0238] When the outer casing 21 meets the above size requirements, the structural stability of the outer casing 21 can be relatively high, and the reliability of use of the cylindrical battery cell 20 can be improved.

[0239] In some embodiments, the height of the outer casing 21 is 1.5 times to 2.5 times the outer diameter of the outer casing 21.

[0240] In some embodiments, the height of the outer casing 21 is 50 mm to 150 mm; and / or the outer diameter of the outer casing 21 is 40 mm to 80 mm.

[0241] In some embodiments, the height of the outer casing 21 is 50 mm to 150 mm. For example, the height of the outer casing 21 is 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 125 mm, 130 mm, 135 mm, 140 mm, 145 mm or 150 mm.

[0242] Optionally, the height of the outer casing 21 is 60 - 100 mm.

[0243] In some embodiments, the outer diameter of the outer casing 21 is 40 mm to 80 mm. For example, the diameter of the outer casing 21 is 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm or 80 mm.

[0244] When the height of the outer casing 21 is 50 - 150 mm and / or the outer diameter of the outer casing 21 is 40 - 80 mm, the cylindrical battery cell 20 is relatively large, and the electrode assembly 22 is more likely to expand excessively. The embodiments of the present application have a better effect on such a cylindrical battery cell 20.

[0245] In some embodiments, the cylindrical battery cell 20 includes two electrode terminals 24 disposed on the end wall 2112, and the first tab 222 and the second tab 223 are electrically connected to the two electrode terminals 24 respectively. The two electrode terminals 24 are the first electrode lead-out portion 213 and the second electrode lead-out portion 214 respectively.

[0246] Optionally, the cylindrical battery cell 20 includes a first current collector member 251 and a second current collector member 252. The first current collector member 251 connects the first tab 222 and one electrode terminal 24, and the second current collector member 252 connects the second tab 223 and the other electrode terminal 24.

[0247] In some other embodiments, the cylindrical battery cell 20 includes one electrode terminal 24 disposed on the end wall 2112. The first tab 222 is electrically connected to the electrode terminal 24, and the second tab 223 is electrically connected to the end wall 2112.

[0248] In some embodiments, the projection of the first tab 222 along the axial direction of the cylindrical battery cell 20 is fan-shaped.

[0249] In some embodiments, the projection of the second tab 223 along the axial direction of the cylindrical battery cell 20 is fan-shaped.

[0250] The embodiment of the present application also provides a battery 100, and the battery 100 includes the above-mentioned cylindrical battery cell 20.

[0251] The embodiment of the present application also provides an electrical device, and the electrical device includes the above-mentioned cylindrical battery cell 20. The cylindrical battery cell 20 is used to provide electrical energy for the electrical device.

[0252] According to some embodiments of the present application, please refer to Figures 3 to 9 .

[0253] An embodiment of the present application provides a cylindrical battery cell 20, which includes a housing 21, an electrode assembly 22, and an elastic insulating member 23. The electrode assembly 22 is accommodated in the housing 21. The electrode assembly 22 includes a first electrode tab 2211, a second electrode tab 2213, and a separator 2212. The polarities of the first electrode tab 2211 and the second electrode tab 2213 are opposite, and the first electrode tab 2211, the separator 2212, and the second electrode tab 2213 are wound. The housing 21 includes a side wall 2111 disposed around the electrode assembly 22. The elastic insulating member 23 is disposed between the electrode assembly 22 and the side wall 2111, and the elastic insulating member 23 is in contact with the outer surface of the electrode assembly 22 and the inner surface of the side wall 2111 respectively. An elastic insulating member 23 is provided between the electrode assembly 22 and the side wall 2111 of the housing 21. The elastic insulating member 23 is in contact with the outer surface of the electrode assembly 22 and the inner surface of the side wall 2111 respectively, filling the gap between the electrode assembly 22 and the side wall 2111, reducing the expansion space of the electrode assembly 22, suppressing the expansion of the electrode assembly 22 to a certain extent, reducing the risk of excessive expansion of the electrode assembly 22, reducing the amount of slip of the electrode tab, reducing the shear force generated during the slip process, thereby reducing stress concentration and reducing the risk of electrode tab cracking, and improving the reliability of the cylindrical battery cell 20. In addition, the elastic insulating member 23 has a certain elasticity and can allow the electrode assembly 22 to expand to a certain extent, so that the pressure on the electrode assembly 22 is not too large, thereby reducing the risk of the electrolyte in the electrode assembly 22 being extruded, which is beneficial to maintaining the performance of the electrode assembly 22.

[0254] The cylindrical battery cell 20 includes two elastic insulating members 23. Along the axial direction of the cylindrical battery cell 20, the separator 2212 includes two end regions, and the two elastic insulating members 23 are respectively disposed around the two end regions. By providing two elastic insulating members 23, along the axial direction of the cylindrical battery cell 20, the two elastic insulating members 23 are respectively disposed around the two end regions of the separator 2212, which can not only have a good suppression effect, reduce the risk of electrode tab cracking, and improve the reliability of the cylindrical battery cell 20, but also reduce the material consumption of the elastic insulating member 23 and reduce the cost of the cylindrical battery cell 20.

[0255] Circumferentially along the cylindrical battery cell 20, the elastic insulating member 23 is disposed around the electrode assembly 22. The elastic insulating member 23 has a first end 231 and a second end 232, which are spaced apart, and a notch region 233 that does not cover the electrode assembly 22 is formed between the first end 231 and the second end 232. Circumferentially along the cylindrical battery cell 20, by disposing the elastic insulating member 23 around the electrode assembly 22, the gap between the electrode assembly 22 and the side wall 2111 can be better filled, the expansion space of the electrode assembly 22 can be reduced, the expansion of the electrode assembly 22 can be inhibited, the slip amount of the electrode sheet can be reduced, the shear force generated during the slip process can be reduced, thereby reducing stress concentration and reducing the risk of electrode sheet cracking, and the reliability of the cylindrical battery cell 20 is improved. In addition, by forming a notch region 233 that does not cover the electrode assembly 22 between the first end 231 and the second end 232, on the one hand, the material consumption of the elastic insulating member 23 can be reduced, and the cost of the cylindrical battery cell 20 can be reduced. On the other hand, due to the existence of the notch region 233, the first end 231 and the second end 232 are not easily overlapped to form an overlapping region (the thickness of the overlapping region is relatively thick, and the overlapping region will cause stress concentration of the electrode assembly 22), and stress concentration of the electrode assembly 22 is not easily caused, which is beneficial to improving the reliability of the cylindrical battery cell 20.

[0256] The first electrode sheet 2211 has a first end 22111, and a part of the second electrode sheet 2213 extends beyond the first end 22111 along the winding direction of the electrode assembly 22. The second electrode sheet 2213 includes the electrode sheet located in the outermost circle of the electrode assembly 22. The second electrode sheet 2213 has a second end 22131, and the second end 22131 is located in the notch region 233. The second end 22131 is located within the notch region 233, that is, the position of the notch region 233 corresponds to the position of the second end 22131. The diameter of the electrode assembly 22 corresponding to the position where the second end 22131 is located is larger. By making the position of the notch region 233 correspond to the position of the second end 22131, the elastic insulating member 23 does not have to cover the position where the second end 22131 is located, thereby being able to greatly reduce the material consumption of the elastic insulating member 23 and reduce the cost of the cylindrical battery cell 20.

[0257] The first end 22111 is located in the notch region 233. The first end 22111 is located within the notch region 233, that is, the position of the notch region 233 corresponds to the position of the first end 22111. The diameter of the electrode assembly 22 corresponding to the position where the first end 22111 is located is larger. By making the position of the notch region 233 correspond to the position of the first end 22111, the elastic insulating member 23 does not have to cover the position where the first end 22111 is located, thereby being able to greatly reduce the material consumption of the elastic insulating member 23 and reduce the cost of the cylindrical battery cell 20.

[0258] In some embodiments, the material of the elastic insulating member 23 includes oriented polystyrene. Oriented polystyrene can expand significantly when absorbing the electrolyte. Before the elastic insulating member 23 absorbs the electrolyte, the volume of the elastic insulating member 23 is small, so that it is convenient to arrange the elastic insulating member 23 between the electrode assembly 22 and the side wall 2111. After that, the elastic insulating member 23 absorbs the electrolyte in the cylindrical battery cell 20 and expands, filling the gap between the electrode assembly 22 and the side wall 2111, reducing the expansion space of the electrode assembly 22, inhibiting the expansion of the electrode assembly 22, reducing the slip amount of the electrode plate, reducing the shear force generated during the slipping process, thereby reducing stress concentration, reducing the risk of cracking of the electrode plate, and improving the reliability of the cylindrical battery cell 20.

[0259] In some embodiments, the first electrode plate 2211 includes a first tab 222, and the second electrode plate 2213 includes a second tab 223. The cylindrical battery cell 20 includes a first electrode lead-out portion 213 and a second electrode lead-out portion 214. The first electrode lead-out portion 213 is electrically connected to the first tab 222, and the second electrode lead-out portion 214 is electrically connected to the second tab 223. In the axial direction of the cylindrical battery cell 20, the first electrode lead-out portion 213 and the second electrode lead-out portion 214 are located on the same side of the electrode assembly 22. When a plurality of cylindrical battery cells 20 are assembled into a group, the first electrode lead-out portions 213 and the second electrode lead-out portions 214 of the plurality of cylindrical battery cells 20 can be arranged on the same side, which is convenient for realizing the connection of the busbar component to the first electrode lead-out portion 213 and the second electrode lead-out portion 214, and simplifies the structure of the battery 100.

[0260] In some embodiments, the outer shell 21 includes a housing 211 and an end cap 212. The housing 211 includes a side wall 2111 and an end wall 2112 formed integrally. The end wall 2112 and the end cap 212 are opposite to each other along the axial direction of the cylindrical battery cell 20, and the end cap 212 is sealingly connected to the side wall 2111. The first electrode plate 2211 includes a first tab 222, and the second electrode plate 2213 includes a second tab 223. The cylindrical battery cell 20 further includes an electrode terminal 24 insulatingly disposed on the end wall 2112. The first tab 222 is electrically connected to the electrode terminal 24, and the second tab 223 is electrically connected to the end wall 2112. The electrode terminal 24 and the end wall 2112 can serve as two exposed electrodes of the cylindrical battery cell 20. The electrode terminal 24 and the end wall 2112 are located on the same side, which is beneficial to the assembly of a plurality of cylindrical battery cells 20 into a group and simplifies the structure of the battery 100.

[0261] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0262] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A cylindrical battery cell, characterized in that, Comprising: A housing; An electrode assembly, accommodated within the housing, the electrode assembly including a first pole piece, a second pole piece, and a separator, the polarities of the first pole piece and the second pole piece being opposite, the first pole piece, the separator, and the second pole piece being wound together, and the housing including a side wall disposed around the electrode assembly; An elastic insulating member, disposed between the electrode assembly and the side wall, and the elastic insulating member being in contact with the outer surface of the electrode assembly and the inner surface of the side wall respectively.

2. The cylindrical battery cell according to claim 1, wherein, The cylindrical battery cell includes a plurality of the elastic insulating members, and the plurality of elastic insulating members are spaced apart along the axial direction of the cylindrical battery cell.

3. The cylindrical battery cell according to claim 2, wherein The cylindrical battery cell includes two of the elastic insulating members, along the axial direction of the cylindrical battery cell, the separator includes two end regions, and the two elastic insulating members are respectively disposed around the two end regions.

4. The cylindrical battery cell according to claim 2, wherein, Along the axial direction of the cylindrical battery cell, the length of the elastic insulating member is L1, and the length of the separator is L2, satisfying: 0.1 ≤ L1 / L2 ≤ 0.

3.

5. The cylindrical battery cell according to claim 4, wherein 0.15 ≤ L1 / L2 ≤ 0.

25.

6. The cylindrical battery cell according to claim 1, wherein, There is one elastic insulating member, along the axial direction of the cylindrical battery cell, the length of the elastic insulating member is L1, and the length of the separator is L2, satisfying: 0.5 ≤ L1 / L2 ≤ 1.

2.

7. The cylindrical battery cell according to claim 6, wherein Along the axial direction of the cylindrical battery cell, the two ends of the elastic insulating member are flush with the two ends of the separator respectively.

8. The cylindrical battery cell according to any one of claims 1-7, characterized in that, Along the circumferential direction of the cylindrical battery cell, the elastic insulating member is disposed around the electrode assembly, the elastic insulating member has a first end and a second end, the first end and the second end are spaced apart, and a notch area that does not cover the electrode assembly is formed between the first end and the second end.

9. The cylindrical battery cell according to claim 8, wherein The first pole piece has a first end and a tail end, a part of the second pole piece extends beyond the first end and tail end along the winding direction of the electrode assembly, the second pole piece includes a pole piece located in the outermost circle of the electrode assembly, the second pole piece has a second end and a tail end, and the second end and tail end are located in the notch area.

10. The cylindrical battery cell according to claim 9, wherein, Along the circumferential direction of the cylindrical battery cell, the length of the notch area is L3, and the total length of the elastic insulating member and the notch area is L4, satisfying: L3 / L4 ≤ 0.

5.

11. The cylindrical battery cell according to claim 10, wherein, 0.1 ≤ L3 / L4 ≤ 0.

4.

12. The cylindrical battery cell according to claim 10, wherein, 1 mm ≤ L3 ≤ 5 mm.

13. The cylindrical battery cell according to claim 9, characterized in that, The first end and tail end are located in the notch area.

14. The cylindrical battery cell according to any one of claims 1-7, characterized in that, Along the circumferential direction of the cylindrical battery cell, the elastic insulating member wraps around the electrode assembly for a full circle.

15. The cylindrical battery cell according to claim 14, wherein, The elastic insulating member is an annular structure disposed around the electrode assembly.

16. The cylindrical battery cell according to any one of claims 1-7, characterized in that, The material of the elastic insulating member includes oriented polystyrene.

17. The cylindrical battery cell according to any one of claims 1-7, characterized in that, The first pole piece includes a first tab, and the second pole piece includes a second tab; The cylindrical battery cell includes a first electrode lead-out portion and a second electrode lead-out portion, the first electrode lead-out portion is electrically connected to the first tab, and the second electrode lead-out portion is electrically connected to the second tab; In the axial direction of the cylindrical battery cell, the first electrode lead-out portion and the second electrode lead-out portion are located on the same side of the electrode assembly.

18. The cylindrical battery cell according to any one of claims 1-7, characterized in that, The housing includes a housing body and an end cap. The housing body includes the side wall and the end wall integrally formed. The end wall and the end cap are opposite to each other along the axial direction of the cylindrical battery cell, and the end cap is sealingly connected to the side wall.

19. The cylindrical battery cell according to claim 18, wherein, The first electrode tab includes a first pole ear, and the second electrode tab includes a second pole ear. The cylindrical battery cell further includes an electrode terminal insulatingly disposed on the end wall. The first pole ear is electrically connected to the electrode terminal, and the second pole ear is electrically connected to the end wall.

20. The cylindrical battery cell according to claim 19, wherein, The cylindrical battery cell further includes a first current collecting member located on a side of the first pole ear facing the end wall and connected to the first pole ear. The electrode terminal abuts against and is connected to a surface of the first current collecting member facing the end wall.

21. The cylindrical battery cell according to claim 20, wherein, A terminal recess is provided on a side of the electrode terminal facing the first current collecting member, and / or a terminal recess is provided on a side of the electrode terminal facing away from the first current collecting member. The bottom wall of the terminal recess is welded to the first current collecting member.

22. The cylindrical battery cell according to claim 19, wherein, Both the first pole ear and the second pole ear are located at one end of the electrode assembly facing the end wall.

23. The cylindrical battery cell according to claim 19, wherein, The first pole ear is located at one end of the electrode assembly facing the end wall, and the second pole ear is located at one end of the electrode assembly facing the end cap. The cylindrical battery cell further includes a second current collecting member connected to the second pole ear. The second current collecting member is connected to at least one of the end cap and the side wall.

24. The cylindrical battery cell according to any one of claims 1-7, characterized in that, The height of the housing is 1.3 times to 4 times the outer diameter of the housing.

25. The cylindrical battery cell according to any one of claims 1-7, characterized in that, The height of the housing is 50 mm to 150 mm; and / or The outer diameter of the housing is 40 mm to 80 mm.

26. A battery, characterized in that, Comprising the cylindrical battery cell according to any one of claims 1-25.

27. An electrical device, characterized in that, Comprising the cylindrical battery cell according to any one of claims 1-25, the cylindrical battery cell being configured to supply electrical energy to the electrical device.

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