Battery monomer, battery and electric equipment

Abstract

The utility model provides a battery monomer, a battery and electric equipment. The battery cell includes a housing having a wall portion and an electrode assembly. The electrode assembly is contained in the shell, and the electrode assembly and the wall part are arranged in the first direction. The wall part comprises a pressure relief part and a first supporting part, the pressure relief part is provided with a weak part, and the pressure relief part is configured to be capable of cracking along at least one part of the weak part when the battery monomer is subjected to pressure relief. The first supporting part is arranged on the periphery of the pressure relief part in a surrounding mode. In the first direction, the first support portion has a first surface closest to the electrode assembly, the pressure relief portion has a second surface closest to the electrode assembly, and the first surface is closer to the electrode assembly than the second surface. And when the electrode assembly moves, external force is not easily applied to the pressure relief part, so that the risk that the weak part cracks in advance is reduced. And the first supporting part is arranged around the pressure relief part, so that the protection effect on the pressure relief part can be improved, the counter-acting force on the electrode assembly can be reduced, the electrode assembly is not easy to damage, and the reliability of the battery monomer is improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] Batteries are widely used in the field of new energy, such as electric vehicles and new energy vehicles. New energy vehicles and electric vehicles have become a new trend in the development of the automotive industry. The development of battery technology must consider many design factors at the same time, such as battery life, energy density, 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 current batteries is poor. Utility Model Content

[0003] The purpose of the embodiments of the present application is to provide a battery cell, a battery and an electrical device, which are intended to improve the problem of poor reliability of batteries in related technologies.

[0004] In a first aspect, an embodiment of the present application provides a battery cell, comprising an outer shell and an electrode assembly, wherein the outer shell has a wall portion; the electrode assembly is accommodated in the outer shell, and the electrode assembly and the wall portion are arranged along a first direction; wherein the wall portion comprises a pressure relief portion and a first support portion, the pressure relief portion has a weak portion, and the pressure relief portion is configured to be able to split along at least a portion of the weak portion when the battery cell is pressure-relieved, and the first support portion is arranged around the pressure relief portion, and along the first direction, the first support portion has a first surface closest to the electrode assembly, and the pressure relief portion has a second surface closest to the electrode assembly, and the first surface is closer to the electrode assembly than the second surface.

[0005] In the above technical solution, the surface of the first support portion closest to the electrode assembly is closer to the electrode assembly than the surface of the pressure relief portion closest to the electrode assembly. In this way, when the electrode assembly moves, the electrode assembly will abut against the first support portion, and the electrode assembly is not likely to apply external force to the pressure relief portion, and is not likely to tear the weak portion, thereby reducing the risk of premature cracking of the weak portion, so that the weak portion can achieve normal pressure relief function, which is beneficial to improving the reliability of the battery cell. By surrounding the pressure relief portion with the first support portion, not only can the pressure relief portion be protected from all sides, thus improving the protection effect of the pressure relief portion, but also the reaction force on the electrode assembly can be reduced, so that the electrode assembly is not likely to be damaged due to stress concentration, which is beneficial to improving the reliability of the battery cell.

[0006] As an optional technical solution of an embodiment of the present application, the pressure relief portion includes a main body area and a thinning area, the thinning area connects the main body area and the first support portion, the weak portion is formed in the thinning area, the thickness of the thinning area is less than the thickness of the main body area, and the second surface is formed in the main body area.

[0007] In the above technical solution, during manufacturing, the thinning area can be formed by stamping, and the weak part in the thinning area can also be formed by stamping. During the stamping process, the material is squeezed into the main body area, so that the thickness of the main body area is greater than the thickness of the thinning area. Since the thickness of the main body area is greater than the thickness of the thinning area, the main body area is more susceptible to the movement of the electrode assembly than the thinning area. Therefore, the second surface is formed in the main body area, and the surface of the first support part closest to the electrode assembly is closer to the electrode assembly than the surface of the main body area closest to the electrode assembly. In this way, when the electrode assembly moves, the electrode assembly will abut against the first support part, and the electrode assembly is not easy to apply external force to the main body area, and it is not easy to tear the weak part, which reduces the risk of premature cracking of the weak part, so that the weak part can achieve normal pressure relief function, which is conducive to improving the reliability of the battery cell.

[0008] As an optional technical solution of an embodiment of the present application, along the first direction, the main body area includes a third surface arranged opposite to the second surface, the third surface is farther away from the electrode assembly than the thinning area, and the second surface is closer to the electrode assembly than the thinning area.

[0009] In the above technical solution, the second surface is closer to the electrode assembly than the surface of the thinned area closest to the electrode assembly, and the third surface is farther away from the electrode assembly than the surface of the thinned area farthest from the electrode assembly. That is to say, along the first direction, both sides of the thinned area are thinned relative to the main area, so that the thinned area is less likely to interfere with other components, which is conducive to reducing the risk of premature cracking of the weak part set in the thinned area, thereby improving the reliability of the battery cell.

[0010] As an optional technical solution of the embodiment of the present application, along the first direction, the wall portion forms first grooves on both sides of the thinning area.

[0011] In the above technical solution, by forming a first groove on both sides of the thinning area, both sides of the thinning area along the first direction are thinned relative to the main area. The thinning area is less likely to interfere with other components, which is beneficial to reducing the risk of premature cracking of the weak part set in the thinning area, thereby improving the reliability of the battery cell.

[0012] As an optional technical solution of an embodiment of the present application, the thinning area is arranged around the main area.

[0013] In the above technical solution, by setting the thinned area around the main area, when the battery cell is depressurized, the weak part located in the thinned area is cracked, so that the main area can open a larger opening, thereby facilitating rapid depressurization of the battery cell and helping to improve the reliability of the battery cell.

[0014] As an optional technical solution of the embodiment of the present application, the thinning area is provided with a pressure relief groove, and the thinning area forms the weak portion at the position of the pressure relief groove.

[0015] In the above technical solution, the weak part is formed by providing a pressure relief groove on the thinning area, which is simple, convenient and low-cost. In addition, the pressure relief groove can be formed by stamping. During the stamping process, the material is squeezed to the main area, so that the thickness of the main area is greater than the thickness of the thinning area. The surface of the first support portion closest to the electrode assembly is closer to the electrode assembly than the surface of the main area closest to the electrode assembly. In this way, when the electrode assembly moves, the electrode assembly will abut against the first support portion, and it is not easy for the electrode assembly to apply external force to the main area, and it is not easy to tear the weak part, which reduces the risk of premature cracking of the weak part, so that the weak part can achieve normal pressure relief function, which is beneficial to improve the reliability of the battery cell.

[0016] As an optional technical solution of an embodiment of the present application, the pressure relief groove is an annular groove arranged around the main area.

[0017] In the above technical solution, the pressure relief groove is an annular groove, and the pressure relief groove is arranged around the main body area, and the weak part is also an annular structure, and the weak part is arranged around the main body area. When the battery cell releases pressure, the weak part cracks, so that the pressure relief part can open a larger opening, thereby facilitating rapid pressure relief of the battery cell, which is beneficial to improving the reliability of the battery cell.

[0018] As an optional technical solution of the embodiment of the present application, the pressure relief portion and the first support portion are integrally formed.

[0019] In the above technical solution, the pressure relief part and the first support part are integrally formed so that the integrity of the pressure relief part and the first support part is better, and the first support part can better absorb the reaction force of the electrode assembly, thereby improving the protection effect of the pressure relief part.

[0020] As an optional technical solution of an embodiment of the present application, along the first direction, the distance between the first surface and the second surface is L, satisfying: 0.05mm≤L≤0.8mm.

[0021] In the above technical solution, when L≥0.05mm, the distance between the first surface and the second surface along the first direction is large. When the electrode assembly moves, the electrode assembly is less likely to apply external force to the pressure relief portion, reducing the risk of premature cracking of the weak portion, which is beneficial to improving the reliability of the battery cell. When L≤0.8mm, the distance between the first surface and the second surface along the first direction is not too large, and the first support portion occupies less space inside the shell, which is beneficial to improving the energy density of the battery cell. Therefore, when 0.05mm≤L≤0.8mm, both the energy density and reliability of the battery cell can be taken into account.

[0022] As an optional technical solution of the embodiment of the present application, 0.1mm≤L≤0.5mm.

[0023] In the above technical solution, when L≥0.1mm, the distance between the first surface and the second surface along the first direction is larger. When the electrode assembly moves, the electrode assembly is less likely to apply external force to the pressure relief portion, reducing the risk of premature cracking of the weak portion, which is beneficial to improving the reliability of the battery cell. When L≤0.5mm, the first support portion occupies less space inside the shell, which is beneficial to improving the energy density of the battery cell. Therefore, when 0.05mm≤L≤0.8mm, it is more possible to take into account both the energy density and reliability of the battery cell.

[0024] As an optional technical solution of an embodiment of the present application, the wall portion includes a main body portion, and the first supporting portion is connected to the main body portion and protrudes from the main body portion.

[0025] In the above technical solution, by making the first support part protrude from the main body, when the electrode assembly moves, the electrode assembly will lean against the first support part, the electrode assembly is not easy to apply external force to the main body, and can protect the main body, which is beneficial to improving the reliability of the battery cell.

[0026] As an optional technical solution of an embodiment of the present application, the main body portion has a fourth surface and a fifth surface relative to each other, the first support portion is connected to the fourth surface and protrudes from the fourth surface, and along the first direction, the fifth surface is the surface of the main body portion farthest from the electrode assembly; the fifth surface is provided with a second support portion, and the second support portion is surrounded by the pressure relief portion, and along the first direction, the second support portion has a sixth surface facing away from the fifth surface, and the pressure relief portion has a third surface farthest from the electrode assembly, and the sixth surface is farther away from the electrode assembly than the third surface.

[0027] In the above technical solution, by arranging the second support portion on the fifth surface of the main body portion, the surface of the second support portion farthest from the electrode assembly is farther away from the electrode assembly than the surface of the pressure relief portion farthest from the electrode assembly. In this way, when other components interfere with the wall portion, other components are more likely to act on the second support portion, and it is not easy to apply external force to the pressure relief portion, so it is not easy to tear the weak portion, thereby reducing the risk of premature cracking of the weak portion, so that the weak portion can realize the normal pressure relief function, which is beneficial to improving the reliability of the battery cell.

[0028] As an optional technical solution of the embodiment of the present application, the battery cell further includes a protective member, which is connected to the sixth surface and covers the pressure relief portion.

[0029] In the above technical solution, by providing a protective member to protect the pressure relief part, the risk of interference between other components and the pressure relief part is further reduced, and the risk of premature cracking of the weak part is reduced, so that the weak part can achieve normal pressure relief function, which is beneficial to improving the reliability of the battery cell.

[0030] As an optional technical solution of the embodiment of the present application, the pressure relief portion, the first support portion and the main body portion are integrally formed.

[0031] In the above technical solution, by integrally forming the pressure relief portion, the first support portion and the main body, the wall portion has better integrity, and the pressure relief portion, the first support portion and the main body have higher connection strength, which can more effectively resist external force impact, and is beneficial to improving the reliability of the battery cell.

[0032] As an optional technical solution of an embodiment of the present application, the wall portion includes a main body portion, the main body portion has a fourth surface and a fifth surface relative to each other, the first support portion is protruded from the fourth surface, and along the first direction, the fifth surface is the surface of the main body portion farthest from the electrode assembly; the pressure relief portion has a third surface farthest from the electrode assembly, and the third surface is closer to the electrode assembly than the fifth surface.

[0033] In the above technical solution, the surface of the main body farthest from the electrode assembly is farther away from the electrode assembly than the surface of the pressure relief portion farthest from the electrode assembly. In this way, when other components interfere with the wall, other components are more likely to act on the main body, and it is not easy to apply external force to the pressure relief portion, so it is not easy to tear the weak portion, thereby reducing the risk of premature cracking of the weak portion, so that the weak portion can realize the normal pressure relief function, which is beneficial to improving the reliability of the battery cell.

[0034] As an optional technical solution of the embodiment of the present application, the wall portion is formed with a second groove, the groove bottom wall of the second groove includes the pressure relief portion, and the groove side wall of the second groove includes the first support portion.

[0035] In the above technical solution, by setting the second groove on the wall, the bottom wall of the second groove includes a pressure relief portion, the side wall of the second groove includes a first support portion, and the pressure relief portion is recessed inward compared to the notch position of the second groove, thereby reducing the risk of interference between other components and the pressure relief portion, which is beneficial to improving the reliability of the battery cell. In addition, forming the pressure relief portion and the first support portion by setting the second groove is simple, convenient, and easy to manufacture.

[0036] As an optional technical solution of an embodiment of the present application, the battery cell includes an insulating member, which is arranged between the electrode assembly and the wall portion along the first direction to insulate and isolate the electrode assembly from the wall portion; a third groove is provided on the side of the insulating member facing away from the electrode assembly, and along the first direction, the projections of the pressure relief portion and the first support portion are both located in the third groove.

[0037] In the above technical solution, the insulating member is provided to insulate and isolate the electrode assembly and the wall portion, thereby reducing the risk of short circuit of the battery cell. By providing a third groove on the insulating member and making the projections of the pressure relief portion and the first support portion both located in the third groove, the third groove can play a role of avoiding the pressure relief portion and the first support portion, making it difficult for external force to act on the pressure relief portion, reducing the risk of premature cracking of the weak portion, and helping to improve the reliability of the battery cell.

[0038] As an optional technical solution of the embodiment of the present application, a fourth groove is arranged on the bottom surface of the third groove, and along the first direction, the projection of the outer contour of the opening of the fourth groove is located within the pressure relief portion.

[0039] In the above technical solution, the fourth groove is provided on the bottom surface of the third groove to further avoid the pressure relief part. The area of ​​the pressure relief part is larger than the opening area of ​​the fourth groove. When the electrode assembly moves, the insulating part will first contact the first support part under the action of the electrode assembly. The insulating part is blocked by the first support part and is not easy to apply external force to the pressure relief part, which reduces the risk of premature cracking of the weak part, so that the weak part can achieve normal pressure relief function, which is conducive to improving the reliability of the battery cell.

[0040] As an optional technical solution of an embodiment of the present application, a fourth groove is arranged on the bottom surface of the third groove, and along the first direction, the projection of the pressure relief part is located inside the fourth groove, and the projection of the first support part is located outside the fourth groove.

[0041] In the above technical solution, the area of ​​the pressure relief portion is roughly equal to the area of ​​the fourth groove. When the electrode assembly moves, the insulating part will first contact the first support portion under the action of the electrode assembly. The insulating part is blocked by the first support portion and is not easy to apply external force to the pressure relief portion, thereby reducing the risk of premature cracking of the weak portion, so that the weak portion can realize normal pressure relief function, which is beneficial to improving the reliability of the battery cell.

[0042] As an optional technical solution of an embodiment of the present application, the shell includes a shell and an end cover, the shell has an opening; the end cover is arranged on the shell and closes the opening; wherein the end cover is the wall portion.

[0043] In the above technical solution, when the end cover is a wall portion, the pressure relief portion and the first support portion are arranged on the end cover, which is simple and convenient to manufacture.

[0044] In a second aspect, an embodiment of the present application further provides a battery, which includes the above-mentioned battery cell.

[0045] In a third aspect, an embodiment of the present application further provides an electrical device, wherein the electrical device comprises the above-mentioned battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0048] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0049] Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0050] Figure 4 An exploded view of a battery cell provided for some embodiments of the present application;

[0051] Figure 5 A schematic top view of a wall portion provided for some embodiments of the present application;

[0052] Figure 6 for Figure 5 Sectional view at the AA position;

[0053] Figure 7 for Figure 6 A magnified view of position B in the middle;

[0054] Figure 8 Cross-sectional views of walls provided for other embodiments of the present application;

[0055] Fig. 9 for Figure 8 Enlarged view of the C position in the middle;

[0056] Fig.10 A cross-sectional view of a wall portion provided for some other embodiments of the present application;

[0057] Fig.11 for Fig.10 Enlarged view of position D in the middle.

[0058] Icons: 10-box; 11-first part; 12-second part; 20-battery cell; 21-housing; 211-end cover; 212-housing; 213-wall; 2131-pressure relief part; 21311-main body; 2131a-second surface; 2131b-third surface; 21312-thinning area; 21313-weak part; 21314-pressure relief groove; 21315-first groove; 2132-first support Support portion; 21321-first surface; 2133-main body; 21331-fourth surface; 21332-fifth surface; 2134-second groove; 22-electrode assembly; 23-second support portion; 231-sixth surface; 24-electrode terminal; 25-protective member; 26-insulating member; 261-third groove; 262-fourth groove; 100-battery; 200-controller; 300-motor; 1000-vehicle. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0060] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0061] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0062] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0063] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0064] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0065] The term "plurality" used in the present application refers to two or more (including two).

[0066] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0067] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0068] A 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 battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0069] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0070] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0071] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (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.).

[0072] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium-containing phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (also referred to as LFP), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO 2 ), lithium nickel oxide (such as LiNiO 2 ), lithium manganese oxide (such as LiMnO 2 、LiMn 2 O4 ), 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 O 2 (Also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O 2 (Also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O 2 (Also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O 2 (Also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O 2 (Also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O 2 ) and at least one of its modified compounds.

[0073] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0074] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0075] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, nickel or titanium, etc. may be used. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper 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.).

[0076] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0077] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0078] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0079] 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.

[0080] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0081] In some embodiments, the separator is a separator membrane. There may be many types of separator membranes, and any known porous separator membrane with good chemical stability and mechanical stability may be selected.

[0082] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0083] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0084] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0085] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0086] In some embodiments, the solvent may 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, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may 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.

[0087] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0088] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0089] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0090] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0091] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0092] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0093] In some embodiments, the electrode assembly is a laminate structure.

[0094] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0095] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0096] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0097] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0098] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0099] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0100] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0101] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0102] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes but is not limited to a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc.

[0103] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0104] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0105] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0106] 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.

[0107] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0108] 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.

[0109] The development of battery technology must consider many design factors at the same time, such as battery life, energy density, 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 current batteries is poor.

[0110] For battery cells, in order to improve the reliability of battery cells, the prior art provides a pressure relief mechanism on the end cap of the battery cell, which is used to open when the internal pressure of the battery cell reaches the detonation pressure to release the pressure inside the battery cell, thereby reducing the risk of battery cell explosion and fire. However, during use, the pressure relief mechanism is often opened prematurely, resulting in failure to achieve the normal pressure relief function.

[0111] During the transportation or use of battery cells, the battery cells are easily vibrated, and the electrode assemblies inside the battery cells are easily moved, thereby acting on the pressure relief mechanism, exerting external force on the pressure relief mechanism, causing the pressure relief mechanism to open prematurely, resulting in the pressure relief mechanism being unable to perform its normal pressure relief function, making the battery reliability poor.

[0112] In view of this, an embodiment of the present application provides a battery cell, the battery cell includes a shell and an electrode assembly, and the shell has a wall portion. The electrode assembly is accommodated in the shell, and the electrode assembly and the wall portion are arranged along a first direction. Among them, the wall portion includes a pressure relief portion and a first support portion, the pressure relief portion has a weak portion, the pressure relief portion is configured to be able to split along at least a portion of the weak portion when the battery cell is depressurized, and the first support portion is arranged around the pressure relief portion. Along the first direction, the first support portion has a first surface closest to the electrode assembly, the pressure relief portion has a second surface closest to the electrode assembly, and the first surface is closer to the electrode assembly than the second surface.

[0113] The surface of the first support portion closest to the electrode assembly is closer to the electrode assembly than the surface of the pressure relief portion closest to the electrode assembly. In this way, when the electrode assembly moves, the electrode assembly will lean against the first support portion, and the electrode assembly is not likely to apply external force to the pressure relief portion, and is not likely to tear the weak portion, reducing the risk of premature cracking of the weak portion, so that the weak portion can achieve normal pressure relief function, which is beneficial to improving the reliability of the battery cell. By surrounding the pressure relief portion with the first support portion, not only can the pressure relief portion be protected from all sides, improving the protection effect of the pressure relief portion, but also the reaction force on the electrode assembly can be reduced, so that the electrode assembly is not easily damaged due to stress concentration, which is beneficial to improving the reliability of the battery cell.

[0114] The battery cells disclosed in the embodiments of the present application can be used, but not limited to, in electrical equipment such as vehicles, ships or aircraft. The power supply system of the electrical equipment can be composed of the battery cells and batteries disclosed in the present application.

[0115] Electrical equipment may be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools, etc. Spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc.

[0116] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle 1000 as an example.

[0117] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for 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 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0118] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for 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 An exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, and the battery cell 20 is accommodated in the housing 10. The housing 10 is used to provide a housing cavity for the battery cell 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first part 11 and a second part 12, and the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a housing cavity for accommodating the battery cell 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, and 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 a housing cavity; the first part 11 and the second part 12 can also 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 housing 10 formed by the first part 11 and the second part 12 can be in a variety of shapes, such as a cylinder, a cuboid, etc.

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

[0121] Each battery cell 20 may be a secondary battery cell or a primary battery cell, or a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0122] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 , Figure 3 This is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of the present application. Figure 4 An exploded view of a battery cell 20 provided in some embodiments of the present application. Figure 5 A schematic top view of the wall portion 213 provided in some embodiments of the present application. Figure 6 for Figure 5 Cross-sectional view at the AA position. Figure 7 for Figure 6 An enlarged view of position B in the figure. The embodiment of the present application provides a battery cell 20, which includes a shell 21 and an electrode assembly 22, and the shell 21 has a wall portion 213. The electrode assembly 22 is accommodated in the shell 21, and the electrode assembly 22 and the wall portion 213 are arranged along a first direction. Among them, the wall portion 213 includes a pressure relief portion 2131 and a first support portion 2132, the pressure relief portion 2131 has a weak portion 21313, and the pressure relief portion 2131 is configured to be able to split along at least a portion of the weak portion 21313 when the battery cell 20 is depressurized, and the first support portion 2132 is arranged around the pressure relief portion 2131. Along the first direction, the first support portion 2132 has a first surface 21321 closest to the electrode assembly 22, and the pressure relief portion 2131 has a second surface 2131a closest to the electrode assembly 22, and the first surface 21321 is closer to the electrode assembly 22 than the second surface 2131a.

[0123] The battery cell 20 refers to the smallest unit constituting the battery 100 .

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

[0125] The end cap 211 refers to a component that covers the opening of the shell 212 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 211 can be adapted to the shape of the shell 212 to match the shell 212. Optionally, the end cap 211 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 211 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals 24 can be provided on the end cap 211. The electrode terminal 24 can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy of the battery cell 20. The material of the end cap 211 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0126] The shell 212 is a component used to cooperate with the end cap 211 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 22, the electrolyte and other components. The shell 212 and the end cap 211 can be independent components, and an opening can be set on the shell 212, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 211 at the opening. Without limitation, the end cap 211 and the shell 212 can also be integrated. Specifically, the end cap 211 and the shell 212 can form a common joint surface before other components are put into the shell, and when it is necessary to encapsulate the interior of the shell 212, the end cap 211 covers the shell 212. The shell 212 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 212 can be determined according to the specific shape and size of the electrode assembly 22. The material of the shell 212 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0127] The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be contained in the housing 21. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 22, and the parts of the positive and negative electrode sheets without active materials each constitute a pole ear. The positive pole ear and the negative pole ear may be located together at one end of the main body or at both ends of the main body 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] The wall portion 213 may be an end cover 211 of the housing 21, or may be a wall of the shell 212 of the housing 21. In some implementations, such as Figure 3 and Figure 4 As shown, the wall portion 213 is the end cap 211. In other embodiments, the wall portion 213 may be a bottom wall of the housing 212 opposite to the end cap 211. In still other embodiments, the wall portion 213 may also be a side wall of the housing 212 adjacent to and connected to the end cap 211.

[0129] The electrode assembly 22 and the wall portion 213 are arranged along the first direction. Figure 4 , the first direction is the X direction shown in the figure.

[0130] The pressure relief portion 2131 is a part of the wall portion 213. The pressure relief portion 2131 has a weak portion 21313. The weak portion 21313 serves to relieve pressure. The weak portion 21313 is used to enable the pressure relief portion 2131 to be split along the weak portion 21313 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, so as to release the pressure inside the battery cell 20. In some embodiments, the strength of the pressure relief portion 2131 at the weak portion 21313 may be lower than the strength of other positions of the pressure relief portion 2131. In this way, when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, the weak portion 21313 may be split under the action of the internal pressure to release the pressure inside the battery cell 20. In other embodiments, the melting point of the pressure relief portion 2131 at the weak portion 21313 may be lower than the melting point of other positions of the pressure relief portion 2131. In this way, when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, the weak portion 21313 can be ruptured under the action of high temperature to release the pressure inside the battery cell 20 .

[0131] The first support portion 2132 is a support structure disposed around the pressure relief portion 2131. “The first support portion 2132 is disposed around the pressure relief portion 2131” can mean that the first support portion 2132 is disposed halfway around the pressure relief portion 2131, or the first support portion 2132 is disposed completely around the pressure relief portion 2131. When the first support portion 2132 is disposed completely around the pressure relief portion 2131, the first support portion 2132 is disposed around the pressure relief portion 2131.

[0132] The first surface 21321 is the surface of the first support portion 2132 closest to the electrode assembly 22 along the first direction. The second surface 2131a is the surface of the pressure relief portion 2131 closest to the electrode assembly 22 along the first direction. The first surface 21321 is closer to the electrode assembly 22 than the second surface 2131a, and the second surface 2131a is farther away from the electrode assembly 22 than the first surface 21321.

[0133] The surface of the first support portion 2132 closest to the electrode assembly 22 is closer to the electrode assembly 22 than the surface of the pressure relief portion 2131 closest to the electrode assembly 22. Thus, when the electrode assembly 22 moves, the electrode assembly 22 will abut against the first support portion 2132, and the electrode assembly 22 is not likely to apply external force to the pressure relief portion 2131, and is not likely to tear the weak portion 21313, thereby reducing the risk of premature cracking of the weak portion 21313, so that the weak portion 21313 can achieve a normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20. By surrounding the pressure relief portion 2131 with the first support portion 2132, not only can the pressure relief portion 2131 be protected from all sides of the pressure relief portion 2131, thereby improving the protective effect of the pressure relief portion 2131, but also the reaction force on the electrode assembly 22 can be reduced, so that the electrode assembly 22 is not likely to be damaged due to stress concentration, which is beneficial to improving the reliability of the battery cell 20.

[0134] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the pressure relief portion 2131 includes a main body area 21311 and a thinned area 21312, wherein the thinned area 21312 connects the main body area 21311 and the first support portion 2132. The weak portion 21313 is formed in the thinned area 21312, and the thickness of the thinned area 21312 is less than that of the main body area 21311. The second surface 2131a is formed in the main body area 21311.

[0135] The thinning zone 21312 is a region with a smaller thickness in the pressure relief portion 2131 , and the main body zone 21311 is a region with a larger thickness in the pressure relief portion 2131 . The thickness of the main body zone 21311 is greater than that of the thinning zone 21312 , and the thinning zone 21312 connects the main body zone 21311 and the first support portion 2132 .

[0136] The weak portion 21313 is disposed in the skived area 21312 , and the weak portion 21313 is used to enable the skived area 21312 to rupture along the weak portion 21313 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, so as to release the pressure inside the battery cell 20 .

[0137] The second surface 2131a is formed in the main body region 21311 , and the surface of the main body region 21311 closest to the electrode assembly 22 along the first direction is the surface of the pressure relief portion 2131 closest to the electrode assembly 22 along the first direction.

[0138] During manufacturing, the thinning zone 21312 can be formed by stamping, and the weak portion 21313 within the thinning zone 21312 can also be formed by stamping. During the stamping process, the material is squeezed into the main body zone 21311, so that the thickness of the main body zone 21311 is greater than the thickness of the thinning zone 21312. Since the thickness of the main area 21311 is greater than the thickness of the thinned area 21312, the main area 21311 is more susceptible to the movement of the electrode assembly 22 than the thinned area 21312. Therefore, the second surface 2131a is formed in the main area 21311, and the surface of the first support portion 2132 closest to the electrode assembly 22 is closer to the electrode assembly 22 than the surface of the main area 21311 closest to the electrode assembly 22. In this way, when the electrode assembly 22 moves, the electrode assembly 22 will abut against the first support portion 2132, and it is not easy for the electrode assembly 22 to apply external force to the main area 21311, and it is not easy to tear the weak portion 21313, thereby reducing the risk of the weak portion 21313 cracking prematurely, so that the weak portion 21313 can achieve a normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20.

[0139] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, along the first direction, the main body region 21311 includes a third surface 2131b disposed opposite to the second surface 2131a. The third surface 2131b is farther away from the electrode assembly 22 than the skived region 21312, and the second surface 2131a is closer to the electrode assembly 22 than the skived region 21312.

[0140] The third surface 2131 b is arranged opposite to the second surface 2131 a along the first direction, and the third surface 2131 b is the surface of the main body region 21311 farthest from the electrode assembly 22 along the first direction.

[0141] “The third surface 2131 b is farther away from the electrode assembly 22 than the thinned area 21312 ” means that the third surface 2131 b is farther away from the electrode assembly 22 than the surface of the thinned area 21312 which is farthest from the electrode assembly 22 along the first direction.

[0142] “The second surface 2131 a is closer to the electrode assembly 22 than the thinned area 21312 ” means that the second surface 2131 a is closer to the electrode assembly 22 than the surface of the thinned area 21312 that is closest to the electrode assembly 22 along the first direction.

[0143] The second surface 2131a is closer to the electrode assembly 22 than the surface of the thinned area 21312 closest to the electrode assembly 22, and the third surface 2131b is farther away from the electrode assembly 22 than the surface of the thinned area 21312 farthest from the electrode assembly 22. That is, along the first direction, both sides of the thinned area 21312 are thinned relative to the main area 21311, so that the thinned area 21312 is less likely to interfere with other components, which is conducive to reducing the risk of premature cracking of the weak portion 21313 set in the thinned area 21312, thereby improving the reliability of the battery cell 20.

[0144] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, along the first direction, the wall portion 213 is formed with first grooves 21315 on both sides of the thinned area 21312 .

[0145] First grooves 21315 are formed on both sides of the thinning zone 21312 along the first direction, so that the thickness of the thinning zone 21312 is smaller than the thickness of the main zone 21311, and the third surface 2131b is farther away from the electrode assembly 22 than the surface of the thinning zone 21312 farthest from the electrode assembly 22 along the first direction, and the second surface 2131a is closer to the electrode assembly 22 than the surface of the thinning zone 21312 closest to the electrode assembly 22 along the first direction.

[0146] By forming a first groove 21315 on both sides of the thinning area 21312, the thinning area 21312 is thinned on both sides along the first direction relative to the main area 21311. The thinning area 21312 is less likely to interfere with other components, which is beneficial to reducing the risk of premature cracking of the weak portion 21313 set in the thinning area 21312, thereby improving the reliability of the battery cell 20.

[0147] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the thinning region 21312 is disposed around the main region 21311 .

[0148] The thinning area 21312 is an annular area on the pressure relief portion 2131 , and the main body area 21311 is located on the inner side of the thinning area 21312 and is completely surrounded by the thinning area 21312 .

[0149] By setting the thinned area 21312 around the main area 21311, when the battery cell 20 is depressurized, the weak portion 21313 located in the thinned area 21312 is cracked, so that the main area 21311 can open a larger opening, thereby facilitating rapid depressurization of the battery cell 20 and helping to improve the reliability of the battery cell 20.

[0150] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the thinning zone 21312 is provided with a pressure relief groove 21314 , and the thinning zone 21312 forms a weak portion 21313 at the position of the pressure relief groove 21314 .

[0151] The pressure relief groove 21314 can be formed in various ways, such as stamping, milling, etc. The pressure relief groove 21314 can be disposed on the surface of the thinning area 21312 facing the electrode assembly 22 , or on the surface of the thinning area 21312 away from the electrode assembly 22 .

[0152] The pressure relief groove 21314 may be a groove sunken along the first direction from the surface of the thinned area 21312 facing away from the electrode assembly 22, and the weak portion 21313 is the portion between the surface of the thinned area 21312 facing the electrode assembly 22 and the bottom surface of the pressure relief groove 21314. The pressure relief groove 21314 may also be a groove sunken along the first direction from the surface of the thinned area 21312 facing the electrode assembly 22, and the weak portion 21313 is the portion between the surface of the thinned area 21312 facing away from the electrode assembly 22 and the bottom surface of the pressure relief groove 21314.

[0153] The pressure relief groove 21314 is described as a groove sunken in the thickness direction from the surface of the thinned area 21312 away from the inside of the housing 21. The pressure relief groove 21314 can be a linear groove extending along a linear track or an annular groove extending along a closed track.

[0154] The weak portion 21313 is formed by providing a pressure relief groove 21314 on the thinning area 21312, which is simple, convenient and low in cost. In addition, the pressure relief groove 21314 can be formed by stamping. During the stamping process, the material is squeezed to the main area 21311, so that the thickness of the main area 21311 is greater than the thickness of the thinning area 21312. The surface of the first support portion 2132 closest to the electrode assembly 22 is closer to the electrode assembly 22 than the surface of the main area 21311 closest to the electrode assembly 22. In this way, when the electrode assembly 22 moves, the electrode assembly 22 will abut against the first support portion 2132, and the electrode assembly 22 is not easy to apply external force to the main area 21311, and it is not easy to tear the weak portion 21313, which reduces the risk of premature cracking of the weak portion 21313, so that the weak portion 21313 can achieve normal pressure relief function, which is conducive to improving the reliability of the battery cell 20.

[0155] In some embodiments, the pressure relief groove 21314 is an annular groove arranged around the main body area 21311.

[0156] The pressure relief groove 21314 is a closed groove extending along a closed track. The pressure relief groove 21314 completely surrounds the main body area 21311. The pressure relief groove 21314 can be a circular groove, an elliptical groove, or a runway shape.

[0157] The pressure relief groove 21314 is an annular groove, and the pressure relief groove 21314 is arranged around the main body area 21311. The weak portion 21313 is also an annular structure, and the weak portion 21313 is arranged around the main body area 21311. When the battery cell 20 releases pressure, the weak portion 21313 is cracked, so that the pressure relief portion 2131 can open a larger opening, thereby facilitating the rapid pressure relief of the battery cell 20, which is beneficial to improving the reliability of the battery cell 20.

[0158] In some embodiments, the pressure relief portion 2131 and the first support portion 2132 are integrally formed.

[0159] Integrally formed means that the pressure relief portion 2131 and the first support portion 2132 are an integral structure when provided. For example, the pressure relief portion 2131 and the first support portion 2132 can be integrally formed by stamping.

[0160] By integrally forming the pressure relief portion 2131 and the first support portion 2132 , the integrity of the pressure relief portion 2131 and the first support portion 2132 is improved, and the first support portion 2132 can better absorb the reaction force of the electrode assembly 22 , thereby improving the protection effect of the pressure relief portion 2131 .

[0161] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, along the first direction, the distance between the first surface 21321 and the second surface 2131a is L, satisfying: 0.05mm≤L≤0.8mm.

[0162] L represents the distance between the first surface 21321 and the second surface 2131a along the first direction. The distance between the first surface 21321 and the second surface 2131a along the first direction can be: L=0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, etc.

[0163] When L≥0.05mm, the distance between the first surface 21321 and the second surface 2131a along the first direction is large. When the electrode assembly 22 moves, the electrode assembly 22 is less likely to apply external force to the pressure relief portion 2131, reducing the risk of premature cracking of the weak portion 21313, which is beneficial to improving the reliability of the battery cell 20. When L≤0.8mm, the distance between the first surface 21321 and the second surface 2131a along the first direction is not too large, and the first support portion 2132 occupies less space inside the housing 21, which is beneficial to improving the energy density of the battery cell 20. Therefore, when 0.05mm≤L≤0.8mm, the energy density and reliability of the battery cell 20 can be taken into account.

[0164] Optionally, 0.1mm≤L≤0.5mm.

[0165] The distance between the first surface 21321 and the second surface 2131a along the first direction can be: L=0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.32mm, 0.35mm, 0.38mm, 0.4mm, 0.42mm, 0.45mm, 0.48mm, 0.5mm, etc.

[0166] When L≥0.1mm, the distance between the first surface 21321 and the second surface 2131a along the first direction is larger. When the electrode assembly 22 moves, the electrode assembly 22 is less likely to apply external force to the pressure relief portion 2131, reducing the risk of premature cracking of the weak portion 21313, which is beneficial to improving the reliability of the battery cell 20. When L≤0.5mm, the first support portion 2132 occupies less space inside the housing 21, which is beneficial to improving the energy density of the battery cell 20. Therefore, when 0.05mm≤L≤0.8mm, the energy density and reliability of the battery cell 20 can be better taken into account.

[0167] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the wall portion 213 includes a main body portion 2133 , and the first support portion 2132 is connected to the main body portion 2133 and protrudes from the main body portion 2133 .

[0168] The body portion 2133 has a fourth surface 21331 facing the electrode assembly 22 . The first support portion 2132 is connected to the fourth surface 21331 . The first support portion 2132 protrudes from the fourth surface 21331 .

[0169] By making the first support portion 2132 protrude from the main body portion 2133 , when the electrode assembly 22 moves, the electrode assembly 22 will abut against the first support portion 2132 , and the electrode assembly 22 is not likely to apply external force to the main body portion 2133 , which can protect the main body portion 2133 and help improve the reliability of the battery cell 20 .

[0170] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the body portion 2133 has a fourth surface 21331 and a fifth surface 21332 opposite to each other, and the first support portion 2132 is connected to the fourth surface 21331 and protrudes from the fourth surface 21331. Along the first direction, the fifth surface 21332 is the surface of the body portion 21333 farthest from the electrode assembly 22. The fifth surface 21332 is provided with a second support portion 23, and the second support portion 23 is surrounded by the pressure relief portion 2131. Along the first direction, the second support portion 23 has a sixth surface 231 away from the fifth surface 21332, and the pressure relief portion 2131 has a third surface 2131b farthest from the electrode assembly 22, and the sixth surface 231 is farther away from the electrode assembly 22 than the third surface 2131b.

[0171] The body portion 2133 is the main part of the wall portion 213. The first support portion 2132 connects the body portion 2133 and the pressure relief portion 2131. Along the first direction, the body portion 2133 has a fourth surface 21331 and a fifth surface 21332 that are arranged opposite to each other, wherein the fourth surface 21331 is the surface of the body portion 2133 facing the electrode assembly 22, and the fifth surface 21332 is the surface of the body portion 2133 that is farthest from the electrode assembly 22. The first support portion 2132 protrudes from the fourth surface 21331 toward the side where the electrode assembly 22 is located.

[0172] The second support portion 23 is a support structure protruding from the fifth surface 21332, and the second support portion 23 is disposed around the pressure relief portion 2131. “The second support portion 23 is disposed around the pressure relief portion 2131” can mean that the second support portion 23 is semi-enclosed in the pressure relief portion 2131, or the second support portion 23 is completely surrounded in the pressure relief portion 2131. When the second support portion 23 is completely surrounded in the pressure relief portion 2131, the second support portion 23 is disposed around the pressure relief portion 2131.

[0173] The sixth surface 231 is a surface of the second support portion 23 that is away from the fifth surface 21332, and the sixth surface 231 is also a surface of the second support portion 23 that is farthest from the electrode assembly 22 along the first direction. The surface of the second support portion 23 that is farthest from the electrode assembly 22 along the first direction is farther away from the electrode assembly 22 than the surface of the main body region 21311 that is farthest from the electrode assembly 22 along the first direction. The surface of the main body region 21311 that is farthest from the electrode assembly 22 along the first direction is closer to the electrode assembly 22 than the surface of the second support portion 23 that is farthest from the electrode assembly 22 along the first direction.

[0174] By setting the second support portion 23 on the fifth surface 21332 of the main body portion 2133, the surface of the second support portion 23 farthest from the electrode assembly 22 is farther away from the electrode assembly 22 than the surface of the pressure relief portion 2131 farthest from the electrode assembly 22. In this way, when other components interfere with the wall portion 213, it is easier for the other components to act on the second support portion 23, and it is not easy to apply external force to the pressure relief portion 2131, and it is also not easy to tear the weak portion 21313, thereby reducing the risk of the weak portion 21313 cracking prematurely, so that the weak portion 21313 can realize the normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20.

[0175] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the battery cell 20 further includes a protective member 25 , which is connected to the sixth surface 231 and covers the pressure relief portion 2131 .

[0176] The protective member 25 is a member used to shield the pressure relief portion 2131 to protect the pressure relief portion 2131. The protective member 25 can be bonded to the sixth surface 231. The protective member 25 can be made of plastic, rubber or other materials.

[0177] By providing a protective member 25 to protect the pressure relief portion 2131 , the risk of interference between other components and the pressure relief portion 2131 is further reduced, and the risk of premature cracking of the weak portion 21313 is reduced, so that the weak portion 21313 can achieve a normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20 .

[0178] In some embodiments, the pressure relief portion 2131 , the first support portion 2132 and the main body portion 2133 are integrally formed.

[0179] The integrated molding means that the pressure relief portion 2131, the first support portion 2132 and the main body 2133 are an integrated structure when provided. For example, the pressure relief portion 2131, the first support portion 2132 and the main body 2133 can be integrated by stamping.

[0180] By integrally forming the pressure relief portion 2131 , the first support portion 2132 and the main body 2133 , the wall portion 213 has better integrity. The pressure relief portion 2131 , the first support portion 2132 and the main body 2133 have higher connection strength, can more effectively resist external force impact, and are beneficial to improving the reliability of the battery cell 20 .

[0181] Please refer to Figure 8 and Fig. 9 , Figure 8 Cross-sectional views of the wall portion 213 provided in some other embodiments of the present application. Fig. 9 for Figure 8 In some other embodiments, the wall portion 213 includes a body portion 2133, the body portion 2133 has a fourth surface 21331 and a fifth surface 21332 opposite to each other, and the first support portion 2132 is protruded from the fourth surface 21331. Along the first direction, the fifth surface 21332 is the surface of the body portion 2133 farthest from the electrode assembly 22, and the pressure relief portion 2131 has a third surface 2131b farthest from the electrode assembly 22, and the third surface 2131b is closer to the electrode assembly 22 than the fifth surface 21332.

[0182] The fifth surface 21332 is the surface of the body portion 2133 along the first direction that is farthest from the electrode assembly 22. The surface of the body portion 2133 along the first direction that is farthest from the electrode assembly 22 is farther away from the electrode assembly 22 than the surface of the main body region 21311 along the first direction that is farthest from the electrode assembly 22. The surface of the main body region 21311 along the first direction that is farthest from the electrode assembly 22 is closer to the electrode assembly 22 than the surface of the body portion 2133 along the first direction that is farthest from the electrode assembly 22.

[0183] The surface of the main body 2133 farthest from the electrode assembly 22 is farther away from the electrode assembly 22 than the surface of the pressure relief portion 2131 farthest from the electrode assembly 22. In this way, when other components interfere with the wall portion 213, it is easier for the other components to act on the main body 2133, and it is not easy to apply external force to the pressure relief portion 2131, so it is not easy to tear the weak portion 21313, thereby reducing the risk of the weak portion 21313 cracking prematurely, so that the weak portion 21313 can realize the normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20.

[0184] Please refer to Figure 8 and Fig. 9 In some embodiments, the wall portion 213 is formed with a second groove 2134 , the bottom wall of the second groove 2134 includes a pressure relief portion 2131 , and the side wall of the second groove 2134 includes a first support portion 2132 .

[0185] During manufacturing, the second groove 2134 can be punched out on the wall portion 213 by stamping. At this time, the second groove 2134 is recessed toward the electrode assembly 22, the side wall of the second groove 2134 forms the first support portion 2132, and the bottom wall of the second groove 2134 forms the pressure relief portion 2131.

[0186] By providing the second groove 2134 in the wall portion 213, the bottom wall of the second groove 2134 includes a pressure relief portion 2131, the groove side wall of the second groove 2134 includes a first support portion 2132, and the pressure relief portion 2131 is recessed inwardly compared to the notch position of the second groove 2134, thereby reducing the risk of interference between other components and the pressure relief portion 2131, which is beneficial to improving the reliability of the battery cell 20. In addition, the pressure relief portion 2131 and the first support portion 2132 are formed by providing the second groove 2134, which is simple, convenient, and easy to manufacture.

[0187] Please refer to Figure 8 and Fig. 9 In some embodiments, the battery cell 20 includes an insulating member 26, which is disposed between the electrode assembly 22 and the wall portion 213 along the first direction to insulate and isolate the electrode assembly 22 and the wall portion 213. A third groove 261 is disposed on the side of the insulating member 26 facing away from the electrode assembly 22, and the projections of the pressure relief portion 2131 and the first support portion 2132 are both located in the third groove 261 along the first direction.

[0188] The insulating member 26 is disposed inside the wall portion 213 and between the wall portion 213 and the electrode assembly 22. The insulating member 26 is used to insulate and isolate the electrode assembly 22 from the wall portion 213 to reduce the risk of short circuit. For example, the second insulating member 26 can be plastic, rubber, etc.

[0189] The third groove 261 is disposed on the side of the insulating member 26 away from the electrode assembly 22, and the third groove 261 is used to avoid the pressure relief portion 2131 and the first support portion 2132. Along the first direction, the projections of the pressure relief portion 2131 and the first support portion 2132 are both located in the third groove 261, that is, the area of ​​the third groove 261 is relatively large, and when viewed from the direction of the electrode assembly 22 pointing to the wall portion 213, the third groove 261 can cover the pressure relief portion 2131 and the first support portion 2132.

[0190] The insulating member 26 is provided to insulate and isolate the electrode assembly 22 and the wall portion 213, thereby reducing the risk of short circuit of the battery cell 20. By providing the third groove 261 on the insulating member 26, and making the projections of the pressure relief portion 2131 and the first support portion 2132 both located in the third groove 261, the third groove 261 can play a role in avoiding the pressure relief portion 2131 and the first support portion 2132, so that external force is not easily applied to the pressure relief portion 2131, reducing the risk of premature cracking of the weak portion 21313, and helping to improve the reliability of the battery cell 20.

[0191] Please refer to Fig.10 and Fig.11 , Fig.10 Cross-sectional views of the wall portion 213 are provided for some further embodiments of the present application. Fig.11 for Fig.10 In some other embodiments, a fourth groove 262 is disposed on the bottom surface of the third groove 261 , and a projection of an outer contour of an opening of the fourth groove 262 is located within the pressure relief portion 2131 along the first direction.

[0192] The fourth groove 262 is disposed on the bottom surface of the third groove 261, and the fourth groove 262 is used to avoid at least a portion of the pressure relief portion 2131. “Along the first direction, the projection of the outer contour of the opening of the fourth groove 262 is located inside the pressure relief portion 2131” can also be understood as the area of ​​the pressure relief portion 2131 is larger than the opening area of ​​the fourth groove 262.

[0193] By providing the fourth groove 262 on the bottom surface of the third groove 261, the pressure relief portion 2131 is further avoided. The area of ​​the pressure relief portion 2131 is larger than the opening area of ​​the fourth groove 262. When the electrode assembly 22 moves, the insulating member 26 will first contact the first support portion 2132 under the action of the electrode assembly 22. The insulating member 26 is blocked by the first support portion 2132 and is not easy to apply external force to the pressure relief portion 2131, which reduces the risk of premature cracking of the weak portion 21313, so that the weak portion 21313 can achieve normal pressure relief function, which is conducive to improving the reliability of the battery cell 20.

[0194] In other embodiments, a fourth groove 262 is disposed on the bottom surface of the third groove 261 , and along the first direction, the projection of the pressure relief portion 2131 is located inside the fourth groove 262 , and the projection of the first support portion 2132 is located outside the fourth groove 262 .

[0195] “Along the first direction, the projection of the pressure relief portion 2131 is located inside the fourth groove 262 , and the projection of the first support portion 2132 is located outside the fourth groove 262 ” can also be understood as the area of ​​the pressure relief portion 2131 is substantially equal to the area of ​​the fourth groove 262 .

[0196] The area of ​​the pressure relief portion 2131 is approximately equal to the area of ​​the fourth groove 262. When the electrode assembly 22 moves, the insulating member 26 will first contact the first support portion 2132 under the action of the electrode assembly 22. The insulating member 26 is blocked by the first support portion 2132 and is not easy to apply external force to the pressure relief portion 2131, thereby reducing the risk of the weak portion 21313 cracking prematurely, so that the weak portion 21313 can achieve a normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20.

[0197] In some embodiments, the housing 21 includes a shell 212 and an end cover 211 , wherein the shell 212 has an opening, and the end cover 211 is disposed on the shell 212 and closes the opening. The end cover 211 is a wall portion 213 .

[0198] When the end cover 211 is the wall portion 213 , the pressure relief portion 2131 and the first support portion 2132 are disposed on the end cover 211 , which is simple and convenient to manufacture.

[0199] The embodiment of the present application further provides a battery 100 , and the battery 100 includes the above-mentioned battery cell 20 .

[0200] The embodiment of the present application further provides an electrical device, which includes the above-mentioned battery cell 20.

[0201] According to some embodiments of this application, please refer to Figure 3 to Figure 11 .

[0202] The embodiment of the present application provides a battery cell 20, which includes a housing 21 and an electrode assembly 22. The housing 21 has a wall portion 213, and the electrode assembly 22 is accommodated in the housing 21. The electrode assembly 22 and the wall portion 213 are arranged along a first direction. The wall portion 213 includes a pressure relief portion 2131 and a first support portion 2132. The pressure relief portion 2131 has a weak portion 21313. The pressure relief portion 2131 is configured to be able to split along at least a portion of the weak portion 21313 when the battery cell 20 is depressurized. The first support portion 2132 is arranged around the pressure relief portion 2131. Along the first direction, the first support portion 2132 has a first surface 21321 closest to the electrode assembly 22, and the pressure relief portion 2131 has a second surface 2131a closest to the electrode assembly 22. The first surface 21321 is closer to the electrode assembly 22 than the second surface 2131a. The surface of the first support portion 2132 closest to the electrode assembly 22 is closer to the electrode assembly 22 than the surface of the pressure relief portion 2131 closest to the electrode assembly 22. Thus, when the electrode assembly 22 moves, the electrode assembly 22 will abut against the first support portion 2132, and the electrode assembly 22 is not likely to apply external force to the pressure relief portion 2131, and is not likely to tear the weak portion 21313, thereby reducing the risk of premature cracking of the weak portion 21313, so that the weak portion 21313 can achieve a normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20. By surrounding the pressure relief portion 2131 with the first support portion 2132, not only can the pressure relief portion 2131 be protected from all sides of the pressure relief portion 2131, thereby improving the protective effect of the pressure relief portion 2131, but also the reaction force on the electrode assembly 22 can be reduced, so that the electrode assembly 22 is not likely to be damaged due to stress concentration, which is beneficial to improving the reliability of the battery cell 20.

[0203] The pressure relief portion 2131 includes a main body area 21311 and a thinned area 21312, wherein the thinned area 21312 connects the main body area 21311 and the first support portion 2132, and the weak portion 21313 is formed in the thinned area 21312. The thickness of the thinned area 21312 is less than the thickness of the main body area 21311, and the second surface 2131a is formed in the main body area 21311. During manufacturing, the thinned area 21312 can be formed by stamping, and the weak portion 21313 in the thinned area 21312 can also be formed by stamping. During the stamping process, the material is squeezed into the main body area 21311, so that the thickness of the main body area 21311 is greater than the thickness of the thinned area 21312. Since the thickness of the main area 21311 is greater than the thickness of the thinned area 21312, the main area 21311 is more susceptible to the movement of the electrode assembly 22 than the thinned area 21312. Therefore, the second surface 2131a is formed in the main area 21311, and the surface of the first support portion 2132 closest to the electrode assembly 22 is closer to the electrode assembly 22 than the surface of the main area 21311 closest to the electrode assembly 22. In this way, when the electrode assembly 22 moves, the electrode assembly 22 will abut against the first support portion 2132, and it is not easy for the electrode assembly 22 to apply external force to the main area 21311, and it is not easy to tear the weak portion 21313, thereby reducing the risk of the weak portion 21313 cracking prematurely, so that the weak portion 21313 can achieve a normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20.

[0204] The wall portion 213 includes a body portion 2133, the body portion 2133 has a fourth surface 21331 and a fifth surface 21332 opposite to each other, the first support portion 2132 is protruding from the fourth surface 21331, and along the first direction, the fifth surface 21332 is the surface of the body portion 21333 farthest from the electrode assembly 22. The fifth surface 21332 is provided with a second support portion 23, and the second support portion 23 is surrounded by the pressure relief portion 2131. Along the first direction, the second support portion 23 has a sixth surface 231 away from the fifth surface 21332, and the pressure relief portion 2131 has a third surface 2131b farthest from the electrode assembly 22, and the sixth surface 231 is farther away from the electrode assembly 22 than the third surface 2131b. By setting the second support portion 23 on the fifth surface 21332 of the main body portion 2133, the surface of the second support portion 23 farthest from the electrode assembly 22 is farther away from the electrode assembly 22 than the surface of the pressure relief portion 2131 farthest from the electrode assembly 22. In this way, when other components interfere with the wall portion 213, it is easier for the other components to act on the second support portion 23, and it is not easy to apply external force to the pressure relief portion 2131, and it is also not easy to tear the weak portion 21313, thereby reducing the risk of the weak portion 21313 cracking prematurely, so that the weak portion 21313 can realize the normal pressure relief function, which is beneficial to improving the reliability of the battery cell 20.

[0205] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: a housing having a wall portion; An electrode assembly is contained in the housing, wherein the electrode assembly and the wall portion are arranged along a first direction; Wherein, the wall portion includes a pressure relief portion and a first supporting portion, the pressure relief portion has a weak portion, and the pressure relief portion is configured to be able to split along at least a portion of the weak portion when the battery cell releases pressure, and the first supporting portion is arranged around the pressure relief portion, and along the first direction, the first supporting portion has a first surface closest to the electrode assembly, and the pressure relief portion has a second surface closest to the electrode assembly, and the first surface is closer to the electrode assembly than the second surface.

2. The battery cell according to claim 1, characterized in that: The pressure relief portion includes a main body area and a thinned area, the thinned area connects the main body area and the first support portion, the weak portion is formed in the thinned area, the thickness of the thinned area is smaller than the thickness of the main body area, and the second surface is formed in the main body area.

3. The battery cell according to claim 2, characterized in that: Along the first direction, the main body region includes a third surface disposed opposite to the second surface, the third surface is farther from the electrode assembly than the thinned region, and the second surface is closer to the electrode assembly than the thinned region.

4. The battery cell according to claim 3, characterized in that: Along the first direction, the wall portion forms first grooves on both sides of the thinned area.

5. The battery cell according to claim 2, characterized in that: The thinned region is disposed around the main body region.

6. The battery cell according to claim 2, characterized in that: The thinning area is provided with a pressure relief groove, and the thinning area forms the weak portion at the position of the pressure relief groove.

7. The battery cell according to claim 6, characterized in that: The pressure relief groove is an annular groove arranged around the main body area.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The pressure relief portion and the first supporting portion are integrally formed.

9. The battery cell according to any one of claims 1 to 7, characterized in that: Along the first direction, a distance L between the first surface and the second surface satisfies: 0.05 mm ≤ L ≤ 0.8 mm.

10. The battery cell according to claim 9, characterized in that: 0.1mm≤L≤0.5mm.

11. The battery cell according to any one of claims 1 to 7, characterized in that: The wall portion includes a main body portion, and the first supporting portion is connected to the main body portion and protrudes from the main body portion.

12. The battery cell according to claim 11, characterized in that: The main body has a fourth surface and a fifth surface opposite to each other, the first support portion is connected to the fourth surface and protrudes from the fourth surface, and along the first direction, the fifth surface is the surface of the main body farthest from the electrode assembly; The fifth surface is provided with a second supporting portion, and the second supporting portion is arranged around the pressure relief portion. Along the first direction, the second supporting portion has a sixth surface facing away from the fifth surface, and the pressure relief portion has a third surface farthest from the electrode assembly. The sixth surface is farther away from the electrode assembly than the third surface.

13. The battery cell according to claim 12, characterized in that: The battery cell further includes a protection member connected to the sixth surface and covering the pressure relief portion.

14. The battery cell according to claim 11, characterized in that: The pressure relief portion, the first support portion and the main body portion are integrally formed.

15. The battery cell according to any one of claims 1 to 7, characterized in that: The wall portion includes a body portion, the body portion has a fourth surface and a fifth surface opposite to each other, the first support portion is protruding from the fourth surface, and along the first direction, the fifth surface is the surface of the body portion farthest from the electrode assembly; The pressure relief portion has a third surface farthest from the electrode assembly, and the third surface is closer to the electrode assembly than the fifth surface.

16. The battery cell according to any one of claims 1 to 7, characterized in that: The wall portion is formed with a second groove, a groove bottom wall of the second groove includes the pressure relief portion, and a groove side wall of the second groove includes the first supporting portion.

17. The battery cell according to any one of claims 1 to 7, characterized in that: The battery cell includes an insulating member, and along the first direction, the insulating member is disposed between the electrode assembly and the wall portion to insulate and isolate the electrode assembly from the wall portion; A third groove is provided on a side of the insulating member facing away from the electrode assembly, and along the first direction, projections of the pressure relief portion and the first supporting portion are both located in the third groove.

18. The battery cell according to claim 17, characterized in that: A fourth groove is arranged on the groove bottom surface of the third groove, and along the first direction, a projection of an outer contour of an opening of the fourth groove is located within the pressure relief portion.

19. The battery cell according to claim 17, characterized in that: A fourth groove is arranged on the bottom surface of the third groove, and along the first direction, the projection of the pressure relief portion is located inside the fourth groove, and the projection of the first support portion is located outside the fourth groove.

20. The battery cell according to any one of claims 1 to 7, characterized in that: The housing comprises: a housing having an opening; an end cover, disposed on the housing and closing the opening; Wherein, the end cover is the wall portion.

21. A battery, characterized in that: The battery comprises the battery cell according to any one of claims 1-20.

22. An electrical equipment, characterized in that: The electrical equipment comprises a battery cell according to any one of claims 1-20.

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