Battery monomer, battery and electric equipment

Abstract

The utility model provides a battery monomer, a battery and electric equipment. The battery monomer comprises a shell and a protection piece, the shell comprises a first wall part, the first wall part is provided with a first surface, the first surface is provided with a pressure relief groove, and the first wall part is configured to be capable of cracking along the pressure relief groove when the battery monomer is subjected to pressure relief. The protection piece is arranged on the first surface and shields the pressure relief groove, and the protection piece and a groove opening of the pressure relief groove are arranged in a clearance mode in the thickness direction of the first wall part. The first wall part of the battery monomer is provided with the protection piece, and the protection piece can resist external force interference, protect the pressure relief groove, limit the deformation of the first wall part, and reduce the risk that the first wall part cracks in advance along the pressure relief groove due to the change of the pressure in the battery monomer on the pressure relief groove. According to the battery, the protection piece and the notch gap of the pressure relief groove are arranged, so that the protection piece is not easy to prevent the first wall part from cracking along the pressure relief groove when the battery monomer is subjected to pressure relief, the pressure relief groove can be quickly cracked for pressure relief when the battery monomer is subjected to pressure relief, and the reliability of the battery monomer is favorably 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 the first aspect, an embodiment of the present application provides a battery cell, which includes an outer shell and a protective member, the outer shell includes a first wall portion, the first wall portion has a first surface, the first surface is provided with a pressure relief groove, and the first wall portion is configured to be able to split along the pressure relief groove when the battery cell is pressure released; the protective member is provided on the first surface, the protective member blocks the pressure relief groove, and a gap is provided between the protective member and the notch of the pressure relief groove along the thickness direction of the first wall portion.

[0005] In the above technical solution, the first wall of the battery cell is provided with a protective member, which has a certain strength, can resist external interference, protect the pressure relief groove, and can also limit the deformation of the first wall, reducing the risk of the first wall being prematurely cracked along the pressure relief groove due to the pressure change inside the battery cell. In addition, by setting a gap between the protective member and the notch of the pressure relief groove, the protective member is not easy to prevent the first wall from cracking along the pressure relief groove when the battery cell is depressurized, so that the pressure relief groove can quickly crack and release pressure when the battery cell is depressurized, which is conducive to improving the reliability of the battery cell.

[0006] As an optional technical solution of an embodiment of the present application, a protrusion is provided on the first surface, and the protrusion contacts the protective member so that a gap is set between the protective member and the notch of the pressure relief groove.

[0007] In the above technical solution, by providing a protrusion on the first surface, the protective member can be attached to the first surface and the protrusion, which can not only protect the pressure relief groove, but also limit the deformation of the first wall, and reduce the risk of the first wall being cracked prematurely along the pressure relief groove due to the pressure change inside the battery cell. Since the protrusion protrudes from the first surface, when the protective member is provided on the first surface and the protrusion, the protective member can cross the notch position of the pressure relief groove, so that the protective member and the notch gap of the pressure relief groove are provided.

[0008] As an optional technical solution of the embodiment of the present application, the pressure relief groove defines a predetermined pressure relief area, and the predetermined pressure relief area is configured to split with the pressure relief groove as a boundary when the battery cell releases pressure, and the protrusion is located in the predetermined pressure relief area.

[0009] In the above technical solution, the pressure relief groove defines a predetermined pressure relief area, and the protrusion is arranged in the predetermined pressure relief area. It can also be understood that the pressure relief groove is surrounded by the outside of the protrusion. In this way, when the protective member contacts the protrusion and the first surface, it can better cover the pressure relief groove and be arranged with a gap between the pressure relief groove and the notch of the pressure relief groove.

[0010] As an optional technical solution of an embodiment of the present application, the first surface is a surface of the first wall portion facing away from the interior of the shell.

[0011] In the above technical solution, the first surface is the outer surface of the first wall, which can more conveniently set the protective member. On the other hand, when the gas in the battery cell acts on the first wall, it does not need to bypass the protective member, which is conducive to rapid pressure relief of the battery cell.

[0012] As an optional technical solution of an embodiment of the present application, the protective member includes an insulating layer and a first adhesive layer, the first adhesive layer is arranged on one side of the insulating layer, and the first adhesive layer connects the first wall portion and the insulating layer.

[0013] In the above technical solution, the protective member includes an insulating layer, which can play a role of insulation isolation, reducing the risk of other components contacting the first wall and causing a short circuit. The protective member also includes a first adhesive layer, which is sticky and can quickly bond the protective member to the first wall through the first adhesive layer.

[0014] As an optional technical solution of an embodiment of the present application, the protective member includes a second adhesive layer and a plurality of the insulating layers, the plurality of the insulating layers are stacked, and two adjacent insulating layers are connected via the second adhesive layer.

[0015] In the above technical solution, multiple insulating layers are provided so that the multiple insulating layers are stacked and can provide higher strength and better insulation. Two adjacent insulating layers are connected by a second adhesive layer, so that the protective member has better toughness and is more likely to be attached to the shell to better protect the pressure relief groove, limit the deformation of the first wall, and reduce the risk of the first wall cracking along the pressure relief groove in advance due to the pressure change inside the battery cell.

[0016] As an optional technical solution of the embodiment of the present application, the material of the insulating layer is polyethylene terephthalate or polyimide.

[0017] In the above technical solution, polyethylene terephthalate or polyimide is used as the material to make the insulation layer, which not only has good insulation performance but also has low cost.

[0018] As an optional technical solution of the embodiment of the present application, the protective member is configured to be destroyed when the battery cell is depressurized.

[0019] In the above technical solution, when the battery cell releases pressure, the protective member can be destroyed, thereby allowing the first wall portion to split along the pressure relief groove, opening a larger opening for pressure relief, which is beneficial to improving the timeliness of the battery cell pressure relief, thereby improving the reliability of the battery cell.

[0020] As an optional technical solution of the embodiment of the present application, the protective member is an insulating film.

[0021] In the above technical solution, when the protective member is an insulating film, the first wall portion can be insulated from other components, reducing the risk of short circuit caused by contact between the first wall portion and other components. In addition, the insulating film is relatively thin and is easily damaged when the battery cell is depressurized, thereby facilitating the first wall portion to open a larger opening to release pressure.

[0022] As an optional technical solution of the embodiment of the present application, the thickness of the protective member is H, satisfying: 0.02mm≤H≤0.14mm.

[0023] In the above technical solution, when H≥0.02mm, the thickness of the protective member is relatively large, the protective member has relatively high strength, and has a better protective effect on the pressure relief groove. When H≤0.14mm, the thickness of the protective member is not too large, and the strength is not too high. When the battery cell releases pressure, the protective member can be destroyed, thereby facilitating the first wall portion to open a larger opening for pressure relief.

[0024] As an optional technical solution of the embodiment of the present application, 0.055mm≤H≤0.11mm.

[0025] In the above technical solution, when H≥0.055mm, the thickness of the protective member is greater, the protective member has a higher strength, and has a better protective effect on the pressure relief groove. When H≤0.11mm, the thickness of the protective member is not too large, and the strength is not too high. When the battery cell releases pressure, the protective member can be destroyed, which makes it easier for the first wall to open a larger opening for pressure relief, so as to facilitate rapid pressure relief of the battery cell.

[0026] As an optional technical solution of an embodiment of the present application, the pressure relief groove extends along a non-closed trajectory.

[0027] In the above technical solution, the pressure relief groove is arranged to extend along a non-closed trajectory. When the battery cell releases pressure, the predetermined pressure relief area will open outward in a flipped form. After opening, the predetermined pressure relief area is still partially connected to other parts of the first wall except the predetermined pressure relief area. The predetermined pressure relief area will not detach and fly out due to the rapid discharge of emissions.

[0028] As an optional technical solution of an embodiment of the present application, the pressure relief groove includes a first groove section, a second groove section and a third groove section, the first groove section is arranged opposite to the third groove section, and the second groove section connects the first groove section and the third groove section.

[0029] In the above technical solution, the pressure relief groove includes a first groove section, a second groove section and a third groove section, and the second groove section connects the first groove section and the third groove section, so that the first wall portion can be split along the first groove section, the second groove section and the third groove section when the battery cell is depressurized, so as to open the predetermined pressure relief area to release the internal pressure of the battery cell, and the connection position between the first groove section and the second groove section and the connection position between the first groove section and the third groove section are weaker, easier to split and open the predetermined pressure relief area for pressure relief, and can further increase the pressure relief area and pressure relief rate of the battery cell.

[0030] As an optional technical solution of an embodiment of the present application, the pressure relief groove extends along a closed trajectory.

[0031] In the above technical solution, by extending the pressure relief groove along the closed track, when the battery cell releases pressure, the predetermined pressure relief area will be completely separated from other parts of the first wall except the predetermined pressure relief area, thus having a larger pressure relief area.

[0032] As an optional technical solution of an embodiment of the present application, the outer 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 at least one wall portion in the shell is the first wall portion.

[0033] In the above technical solution, when the shell includes a first wall portion, the pressure relief groove is arranged on a wall portion of the shell, and the ejected fluid medium is not easy to act on other electrical connection structures on the end cover, which is beneficial to reduce the risk of short circuit of the battery cell.

[0034] As an optional technical solution of an embodiment of the present application, the shell is a cylindrical structure, and the wall portion of the shell arranged around the center line thereof is the first wall portion.

[0035] In the above technical solution, the peripheral wall of the cylindrical structure is the first wall portion, and the peripheral wall has a large area, which is convenient for setting the pressure relief groove. In addition, the protective member can be coated on the outer side of the peripheral wall to provide a better protection effect for the pressure relief groove.

[0036] In a second aspect, an embodiment of the present application further provides a battery, which includes the above-mentioned battery cell.

[0037] 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

[0038] 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.

[0039] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0040] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0041] Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0042] Figure 4 An exploded view of a battery cell provided for some embodiments of the present application;

[0043] Figure 5 A schematic top view of a battery cell provided in some embodiments of the present application;

[0044] Figure 6 for Figure 5 Sectional view at the AA position;

[0045] Figure 7 for Figure 6 A magnified view of position B in the middle;

[0046] Figure 8 A cross-sectional view of a protective member provided in accordance with some embodiments of the present application.

[0047] Icons: 1000-vehicle; 100-battery; 10-casing; 11-first casing body; 12-second casing body; 20-battery cell; 21-casing; 211-housing; 212-end cover; 213-first wall; 2131-first surface; 2132-pressure relief groove; 2132a-first groove section; 2132b-second groove section; 2132c-third groove section; 2133-predetermined pressure relief area; 22-protective member; 221-insulating layer; 222-first adhesive layer; 223-second adhesive layer; 23-electrode assembly; 24-electrode terminal; 25-protrusion; 200-controller; 300-motor. DETAILED DESCRIPTION

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] The term "plurality" used in the present application refers to two or more (including two).

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.).

[0061] 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 can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium 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 LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0062] 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.

[0063] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0064] 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.).

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0077] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0078] 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.

[0079] 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.

[0080] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0081] 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.

[0082] In some embodiments, the electrode assembly is a laminate structure.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0097] 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.

[0098] For battery cells, in order to improve the reliability of battery cells, the prior art is to weld a pressure relief mechanism on the battery cells, and a weak portion is provided on the pressure relief mechanism, which defines a pressure relief portion. When the internal pressure of the battery cell reaches the detonation pressure, the weak portion cracks and the pressure relief portion opens to release the pressure inside the battery cell, thereby reducing the risk of explosion or fire of the battery cell.

[0099] However, during the use of the battery cell, the weak part is easily opened prematurely by external force, or the pressure relief mechanism is repeatedly deformed by the internal air pressure of the battery cell, causing the weak part to fatigue and fail, opening prematurely, resulting in failure to achieve normal pressure relief function.

[0100] In view of this, an embodiment of the present application provides a battery cell, the battery cell includes a shell and a protective member. The shell includes a first wall portion, the first wall portion has a first surface, the first surface is provided with a pressure relief groove, and the first wall portion is configured to be able to split along the pressure relief groove when the battery cell is depressurized. The protective member is provided on the first surface, and the protective member blocks the pressure relief groove. Along the thickness direction of the first wall portion, a gap is provided between the protective member and the notch of the pressure relief groove.

[0101] The first wall of the battery cell is provided with a protective member, which has a certain strength, can resist external interference, protect the pressure relief groove, and can also limit the deformation of the first wall, reducing the risk of the first wall being prematurely cracked along the pressure relief groove due to the pressure change inside the battery cell. In addition, by setting a gap between the protective member and the notch of the pressure relief groove, the protective member is not easy to prevent the first wall from cracking along the pressure relief groove when the battery cell is depressurized, so that the pressure relief groove can quickly crack and release pressure when the battery cell is depressurized, which is conducive to improving the reliability of the battery cell.

[0102] The battery cells disclosed in the embodiments of the present application can be used in, but not limited to, electrical devices such as vehicles, ships or aircraft. A power supply system comprising the battery cells and batteries disclosed in the present application can be used to form the electrical device, which is beneficial to improving the reliability of the battery cells.

[0103] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0104] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0105] Please refer to Figure 1 , Figure 1A 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 of the vehicle 1000, or at the head of the vehicle 1000, or at the 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 or a power source for the vehicle 1000, etc. 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 the starting, navigation and working power requirements of the vehicle 1000 during driving.

[0106] In some embodiments of the present application, the battery 100 can not only serve as an operating power source or a use 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.

[0107] Please refer to Figure 2 , Figure 2 This is 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 . The battery cell 20 is used to be accommodated in the housing 10 .

[0108] The box body 10 is used to provide an assembly space for the battery cell 20, and the box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include a first box body 11 and a second box body 12, the first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cell 20. The second box body 12 may be a hollow structure with one end open, and the first box body 11 may be a plate-like structure, and the first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define an assembly space; the first box body 11 and the second box body 12 may also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0109] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid or a cube. Figure 2 In the embodiment, the box body 10 is in the shape of a rectangular parallelepiped.

[0110] In the battery 100, the battery cell 20 disposed in the box 10 may be one or more. When there are more than one battery cell 20 disposed in the box 10, the multiple battery cells 20 may be connected in series, in parallel, or in mixed connection. 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 mixed connection, and then the whole formed by the multiple battery cells 20 may be 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 mixed connection, and then the multiple battery modules may be connected in series, in parallel, or in mixed connection to form a whole, and then the whole may be accommodated in the box 10.

[0111] In some embodiments, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which is used to connect the plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0112] Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be in a rectangular parallelepiped, a cylinder, a prism or other shapes. For example, Figure 2 In the figure, the battery cell 20 is a cylindrical structure.

[0113] 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 a battery cell 20 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 a protective member 22. The shell 21 includes a first wall portion 213, the first wall portion 213 has a first surface 2131, and the first surface 2131 is provided with a pressure relief groove 2132, and the first wall portion 213 is configured to be able to split along the pressure relief groove 2132 when the battery cell 20 is depressurized. The protective member 22 is provided on the first surface 2131, and the protective member 22 blocks the pressure relief groove 2132. Along the thickness direction of the first wall portion 213, the notch gap between the protective member 22 and the pressure relief groove 2132 is provided.

[0114] The battery cell 20 refers to the smallest unit constituting the battery 100 .

[0115] The housing 21 includes an end cover 212 and a shell 211 . The shell 211 has an opening. The end cover 212 is connected to the shell 211 and closes the opening.

[0116] The end cap 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the shell 211 to match the shell 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as an aluminum alloy), so that the end cap 212 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. The material of the end cap 212 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this. Functional components such as electrode terminals 24 can be provided on the end cap 212. The electrode terminal 24 can be used to electrically connect to the electrode assembly 23 for outputting or inputting electrical energy of the battery cell 20. In some embodiments, the battery cell 20 further includes an insulating member, which is disposed inside the end cap 212 and can be used to isolate the electrical connection components in the housing 211 from the end cap 212 to reduce the risk of short circuit. For example, the insulating member can be plastic, rubber, etc.

[0117] The shell 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, the electrolyte and other components. The shell 211 and the end cap 212 can be independent components, and an opening can be set on the shell 211, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 212 at the opening. Without limitation, the end cap 212 and the shell 211 can also be integrated. Specifically, the end cap 212 and the shell 211 can form a common joint surface before other components are put into the shell, and when the interior of the shell 211 needs to be encapsulated, the end cap 212 covers the shell 211. The shell 211 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 211 can be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 211 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0118] The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 23 may be included in the housing 21. The electrode assembly 23 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 23, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 100, the positive active material and the negative active material react with the electrolyte.

[0119] The first wall portion 213 may be an end cover 212 of the housing 21, or may be a wall portion of the shell 211 of the housing 21. Figure 3 and Figure 4 In the embodiment, the shell 211 is a cylindrical structure with two ends opened. The outer shell 21 includes two end covers 212. The two end covers 212 are respectively covered with the two openings of the shell 211. The first wall portion 213 is the shell 211.

[0120] The pressure relief groove 2132 serves to release pressure, and is used to enable the first wall portion 213 to rupture along the pressure relief groove 2132 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. The setting position of the pressure relief groove 2132 can be used to determine which wall portion of the housing 21 is the first wall portion 213. For example, when the pressure relief groove 2132 is set on the end cover 212, the end cover 212 is the first wall portion 213. When the pressure relief groove 2132 is set on the bottom wall of the housing 211, the bottom wall is the first wall portion 213. When the pressure relief groove 2132 is set on the side wall of the housing 211, the side wall is the first wall portion 213.

[0121] The protective member 22 has a protective function. The protective member 22 is arranged on the first wall portion 213 and blocks the pressure relief groove 2132 to protect the pressure relief groove 2132 and reduce the risk of the pressure relief groove 2132 being damaged by external forces. The protective member 22 and the pressure relief groove 2132 are arranged on the same surface of the first wall portion 213. For example, the protective member 22 and the pressure relief groove 2132 can both be arranged on the surface of the first wall portion 213 away from the inside of the housing 21. For another example, the protective member 22 and the pressure relief groove 2132 can both be arranged on the surface of the first wall portion 213 facing the inside of the housing 21.

[0122] “The protective member 22 blocks the pressure relief groove 2132” means that the projection of the protective member 22 can cover the notch of the pressure relief groove 2132 along the thickness direction of the first wall portion 213. Figure 7 , the thickness direction of the first wall portion 213 may be the C direction shown in the figure.

[0123] “A gap is set between the protection member 22 and the notch of the pressure relief groove 2132 along the thickness direction of the first wall portion 213 ” means that there is a distance between the protection member 22 and the notch of the pressure relief groove 2132 along the thickness direction of the first wall portion 213 .

[0124] The first wall portion 213 of the battery cell 20 is provided with a protective member 22. The protective member 22 has a certain strength, can resist external interference, protect the pressure relief groove 2132, and can also limit the deformation of the first wall portion 213, reducing the risk of the first wall portion 213 being prematurely cracked along the pressure relief groove 2132 due to the pressure change inside the battery cell 20. In addition, by setting a gap between the protective member 22 and the notch of the pressure relief groove 2132, the protective member 22 is not easy to prevent the first wall portion 213 from cracking along the pressure relief groove 2132 when the battery cell 20 is depressurized, so that the pressure relief groove 2132 can quickly crack and release pressure when the battery cell 20 is depressurized, which is conducive to improving the reliability of the battery cell 20.

[0125] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the first surface 2131 is provided with a protrusion 25 , and the protrusion 25 contacts the protection member 22 so that a gap is set between the protection member 22 and the notch of the pressure relief groove 2132 .

[0126] The protrusion 25 protrudes from the first surface 2131 , and the protrusion 25 contacts the protection member 22 to partially lift up the protection member 22 , so that a gap is set between the protection member 22 and the notch of the pressure relief groove 2132 .

[0127] Optionally, along the thickness direction of the first wall portion 213 , the protrusion 25 has a second surface farthest from the first surface 2131 , and the protection member 22 is disposed on the second surface.

[0128] By providing the protrusion 25 on the first surface 2131, the protection member 22 can be attached to the first surface 2131 and the protrusion 25, which can not only protect the pressure relief groove 2132, but also limit the deformation of the first wall portion 213, thereby reducing the risk of the first wall portion 213 being prematurely cracked along the pressure relief groove 2132 due to the pressure change inside the battery cell 20. Since the protrusion 25 protrudes from the first surface 2131, when the protection member 22 is provided on the first surface 2131 and the protrusion 25, the protection member 22 can cross the opening position of the pressure relief groove 2132, so that the protection member 22 and the opening gap of the pressure relief groove 2132 are provided.

[0129] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7In some embodiments, the pressure relief groove 2132 defines a predetermined pressure relief area 2133 , and the predetermined pressure relief area 2133 is configured to be split with the pressure relief groove 2132 as a boundary when the battery cell 20 releases pressure. The protrusion 25 is located in the predetermined pressure relief area 2133 .

[0130] The predetermined pressure relief area 2133 is the area surrounded by the pressure relief groove 2132, and the pressure relief groove 2132 is arranged along the edge of the predetermined pressure relief area 2133. For example, when the pressure relief groove 2132 is an annular groove, the predetermined pressure relief area 2133 is the area inside the annular groove. For another example, when the pressure relief groove 2132 is a U-shaped groove, the predetermined pressure relief area 2133 is the area surrounded by the line connecting the two ends of the U-shaped groove and the U-shaped groove.

[0131] When the battery cell 20 releases pressure, the predetermined pressure relief area 2133 is split with the pressure relief groove 2132 as a boundary, and the predetermined pressure relief area 2133 can be opened to form an opening on the first wall portion 213 for discharging gas inside the battery cell 20 .

[0132] The protrusion 25 is located in the predetermined pressure relief area 2133. In some embodiments, the protrusion 25 partially protrudes from the predetermined pressure relief area 2133. In other embodiments, the predetermined pressure relief area 2133 protrudes from the first surface 2131 as a whole to form the protrusion 25.

[0133] The pressure relief groove 2132 defines a predetermined pressure relief area 2133, and the protrusion 25 is arranged in the predetermined pressure relief area 2133. It can also be understood that the pressure relief groove 2132 is surrounded by the outside of the protrusion 25. In this way, when the protective member 22 contacts the protrusion 25 and the first surface 2131, it can better cover the pressure relief groove 2132 and be arranged with an opening gap with the pressure relief groove 2132.

[0134] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the first surface 2131 is the surface of the first wall portion 213 facing away from the interior of the housing 21 .

[0135] “The first surface 2131 is the surface of the first wall 213 facing away from the interior of the housing 21 ” means that the first surface 2131 is the outer surface of the first wall 213 . The pressure relief groove 2132 is recessed from the first surface 2131 toward the surface of the first wall 213 facing the interior of the housing 21 .

[0136] The first surface 2131 is the outer surface of the first wall 213, which can more conveniently arrange the protective member 22. On the other hand, when the gas in the battery cell 20 acts on the first wall 213, it does not need to bypass the protective member 22, which is conducive to rapid pressure relief of the battery cell 20.

[0137] Please refer to Figure 8 , Figure 8 A cross-sectional view of a protective member 22 provided in some embodiments of the present application. In some embodiments, the protective member 22 includes an insulating layer 221 and a first adhesive layer 222, and the first adhesive layer 222 is disposed on one side of the insulating layer 221. The first adhesive layer 222 connects the first wall portion 213 and the insulating layer 221.

[0138] The insulating layer 221 is made of insulating material, has an insulating function, and can achieve insulation isolation between the two components. The insulating layer 221 can be made of plastic, rubber, etc.

[0139] The first adhesive layer 222 is disposed on one side of the insulating layer 221 . The first adhesive layer 222 has adhesiveness, and the first adhesive layer 222 can adhere the insulating layer 221 to the first wall portion 213 .

[0140] The protective member 22 includes an insulating layer 221, which can play an insulating isolation role to reduce the risk of short circuit caused by contact between other components and the first wall portion 213. The protective member 22 also includes a first adhesive layer 222, which is sticky and can quickly bond the protective member 22 to the first wall portion 213 through the first adhesive layer 222.

[0141] Please refer to Figure 8 In some embodiments, the protection member 22 includes a second adhesive layer 223 and a plurality of insulating layers 221 . The plurality of insulating layers 221 are stacked, and two adjacent insulating layers 221 are connected by the second adhesive layer 223 .

[0142] The protective member 22 may include two insulating layers 221, three insulating layers 221, four insulating layers 221, or more than four insulating layers 221, wherein the plurality of insulating layers 221 are stacked. Figure 8 ,exist Figure 8 In the illustrated embodiment, the protection member 22 includes two insulating layers 221 .

[0143] The second adhesive layer 223 has adhesiveness and is used to adhere two adjacent insulating layers 221 .

[0144] By providing multiple insulating layers 221, multiple insulating layers 221 are stacked, and multiple insulating layers 221 can provide higher strength and better insulation. Two adjacent insulating layers 221 are connected by the second adhesive layer 223, so that the protective member 22 has better toughness, and the protective member 22 is more likely to be attached to the shell 211, so as to better protect the pressure relief groove 2132, limit the deformation of the first wall 213, and reduce the risk of the pressure relief groove 2132 being subjected to the pressure change inside the battery cell 20, causing the first wall 213 to crack along the pressure relief groove 2132 in advance.

[0145] In some embodiments, the material of the insulating layer 221 is polyethylene terephthalate or polyimide.

[0146] Polyethylene terephthalate, also known as PET (polyethylene glycolterephthalate), has good insulation properties.

[0147] Polyimide, also referred to as PI (Polyimide), has good insulation properties.

[0148] The insulating layer 221 is made of polyethylene terephthalate or polyimide, which not only has good insulation performance but also has low cost.

[0149] In some embodiments, the protection member 22 is configured to be destroyed when the battery cell 20 is depressurized.

[0150] In some embodiments, the protective member 22 may be a thin film structure. When the battery cell 20 is depressurized, the predetermined depressurization area 2133 is opened, and the protective member 22 is torn under the action of the predetermined depressurization area 2133, thereby opening a larger opening for the gas in the battery cell 20 to flow out.

[0151] In other embodiments, a weak portion may be provided on the protective member 22. When the battery cell 20 is depressurized, the predetermined pressure relief area 2133 is opened, and the weak portion is torn by the predetermined pressure relief area 2133, thereby opening a larger opening for gas in the battery cell 20 to flow out.

[0152] When the battery cell 20 releases pressure, the protective member 22 can be destroyed, thereby allowing the first wall portion 213 to split along the pressure relief groove 2132 and open a larger opening for pressure relief, which is beneficial to improving the timeliness of the pressure relief of the battery cell 20 and thus improving the reliability of the battery cell 20.

[0153] In some embodiments, the protection member 22 is an insulating film.

[0154] Optionally, the protective member 22 may be a blue film.

[0155] When the protective member 22 is an insulating film, the first wall portion 213 can be insulated from other components, reducing the risk of short circuit caused by contact between the first wall portion 213 and other components. In addition, the insulating film is relatively thin and is easily damaged when the battery cell 20 releases pressure, thereby facilitating the first wall portion 213 to open a larger opening to release pressure.

[0156] Please refer to Figure 8 In some embodiments, the thickness of the protective member 22 is H, satisfying: 0.02 mm ≤ H ≤ 0.14 mm.

[0157] H represents the thickness of the protective member 22. The minimum thickness of the protective member 22 is not less than 0.02 mm, and the maximum thickness of the protective member 22 is not more than 0.14 mm.

[0158] The thickness of the protective member 22 may be: H=0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.14 mm, etc.

[0159] When H≥0.02mm, the thickness of the protective member 22 is relatively large, the protective member 22 has relatively high strength, and has a relatively good protective effect on the pressure relief groove 2132. When H≤0.14mm, the thickness of the protective member 22 is not too large, and the strength is not too high. When the battery cell 20 releases pressure, the protective member 22 can be destroyed, thereby facilitating the first wall portion 213 to open a relatively large opening for pressure relief.

[0160] Optionally, 0.055mm≤H≤0.11mm.

[0161] The thickness of the protective member 22 may be: H=0.055 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, etc.

[0162] When H≥0.055mm, the thickness of the protective member 22 is greater, the protective member 22 has a higher strength, and has a better protective effect on the pressure relief groove 2132. When H≤0.11mm, the thickness of the protective member 22 is not too large, and the strength is not too high. When the battery cell 20 releases pressure, the protective member 22 can be destroyed, which makes it easier for the first wall portion 213 to open a larger opening for pressure relief, so that the battery cell 20 can be quickly relieved.

[0163] In some embodiments, the pressure relief groove 2132 extends along a non-enclosed trajectory.

[0164] The pressure relief groove 2132 extends along a non-enclosed track, and there is a gap between the two ends of the pressure relief groove 2132. For example, the pressure relief groove 2132 can extend along a C-shaped track. For another example, the pressure relief groove 2132 can extend along a U-shaped track.

[0165] The pressure relief groove 2132 is arranged to extend along a non-closed trajectory. When the battery cell 20 releases pressure, the predetermined pressure relief area 2133 will open outward in a flipped manner. After opening, the predetermined pressure relief area 2133 is still partially connected to other parts of the first wall portion 213 except the predetermined pressure relief area 2133. The predetermined pressure relief area 2133 will not detach and fly out due to the rapid discharge of emissions.

[0166] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the pressure relief groove 2132 includes a first groove section 2132a, a second groove section 2132b and a third groove section 2132c, the first groove section 2132a is arranged opposite to the third groove section 2132c, and the second groove section 2132b connects the first groove section 2132a and the third groove section 2132c.

[0167] The first slot section 2132a and the third slot section 2132c are arranged at intervals and at least partially opposite to each other. Optionally, the first slot section 2132a and the third slot section 2132c are both straight slot sections.

[0168] The second slot segment 2132b connects the first slot segment 2132a and the third slot segment 2132c, that is, the second slot segment 2132b is located between the first slot segment 2132a and the third slot segment 2132c, and the two ends of the second slot segment 2132b are respectively connected to the first slot segment 2132a and the third slot segment 2132c. Of course, in other embodiments, the two ends of the second slot segment 2132b can extend out of the first slot segment 2132a and the third slot segment 2132c, respectively.

[0169] The line connecting the free end of the first slot section 2132a and the free end of the third slot section 2132c is the first line, and the first line is arranged opposite to the second slot section 2132b. The closed area enclosed by the first slot section 2132a, the second slot section 2132b, the third slot section 2132c and the first line is the predetermined pressure relief area 2133. That is, the first slot section 2132a, the second slot section 2132b and the third slot section 2132c are structures arranged along the edge of the predetermined pressure relief area 2133, so that the predetermined pressure relief area 2133 can be opened with the first slot section 2132a, the second slot section 2132b and the third slot section 2132c as the boundary, that is, the predetermined pressure relief area 2133 is formed in the area enclosed by the first slot section 2132a, the second slot section 2132b and the third slot section 2132c.

[0170] Please refer to Figure 3 and Figure 4 The pressure relief groove 2132 formed by the first groove section 2132a, the second groove section 2132b and the third groove section 2132c may be in a "U"-shaped structure, that is, one end of the second groove section 2132b is connected to one end of the first groove section 2132a, and the other end is connected to one end of the third groove section 2132c, so as to form a predetermined pressure relief area 2133 on the first wall portion 213. At this time, the first connecting line closes the open end of the U-shaped structure.

[0171] In other embodiments, the shape of the pressure relief groove 2132 formed by the first groove segment 2132a, the second groove segment 2132b and the third groove segment 2132c can be similar to an "H"-shaped structure. In this case, one end of the second groove segment 2132b is connected between the two ends of the first groove segment 2132a, and the other end of the second groove segment 2132b is connected between the two ends of the third groove segment 2132c.

[0172] In yet other embodiments, the pressure relief groove 2132 extends along a closed trajectory.

[0173] The pressure relief groove 2132 extends along a closed track, that is, the pressure relief groove 2132 is an annular groove.

[0174] By extending the pressure relief groove 2132 along a closed track, when the battery cell 20 releases pressure, the predetermined pressure relief area 2133 will be completely separated from other parts of the first wall portion 213 except the predetermined pressure relief area 2133 , thereby having a larger pressure relief area.

[0175] In some embodiments, the housing 21 includes a shell 211 and an end cover 212 . The shell 211 has an opening. The end cover 212 is disposed on the shell 211 and closes the opening. At least one wall portion in the shell 211 is a first wall portion 213 .

[0176] In some embodiments, the outer shell 21 may include a shell 211 and two end covers 212. A accommodating cavity is formed inside the shell 211, and the accommodating cavity is used to accommodate the electrode assembly 23. Openings are formed at both ends of the shell 211, and the two openings are connected to the accommodating cavity. The two end covers 212 respectively close the two openings, and the shell 211 is a first wall portion 213.

[0177] In other embodiments, the housing 211 includes an integrally formed side wall and bottom wall, that is, the housing 211 is manufactured by an integral molding process, such as an integral molding process such as stamping, casting or extrusion molding, that is, the side wall and bottom wall of the housing 211 are an integral structure. An opening is formed at one end of the housing 211, and the opening is arranged opposite to the bottom wall. In this case, one of the side wall and the bottom wall is the first wall portion 213.

[0178] When the shell 211 includes the first wall portion 213 , the pressure relief groove 2132 is disposed on a wall portion of the shell 211 , and the ejected fluid medium is not likely to act on other electrical connection structures on the end cover 212 , which is beneficial to reducing the risk of short circuit of the battery cell 20 .

[0179] Please refer to Figure 3 and Figure 4 In some embodiments, the shell 211 is a cylindrical structure, and the wall portion of the shell 211 arranged around the center line thereof is the first wall portion 213 .

[0180] In some embodiments, the housing 21 may include a shell 211 and two end caps 212. The shell 211 has a receiving cavity formed inside, and the receiving cavity is used to receive the electrode assembly 23. Both ends of the shell 211 have openings, and both openings are connected to the receiving cavity. The two end caps 212 respectively close the two openings. The shell 211 is a cylindrical structure, and the shell 211 itself is the first wall portion 213.

[0181] In some other embodiments, the shell 211 includes an integrally formed side wall and a bottom wall, wherein the side wall is a wall portion of the shell 211 arranged around a center line thereof, that is, the side wall is the first wall portion 213 .

[0182] The peripheral wall of the cylindrical structure is the first wall portion 213, and the peripheral wall has a large area, which is convenient for setting the pressure relief groove 2132. In addition, the protective member 22 can be coated on the outer side of the peripheral wall to provide a better protection effect on the pressure relief groove 2132.

[0183] The embodiment of the present application further provides a battery 100 , and the battery 100 includes the above-mentioned battery cell 20 .

[0184] The embodiment of the present application further provides an electrical device, which includes the above-mentioned battery cell 20.

[0185] According to some embodiments of this application, please refer to Figure 3 to Figure 8 .

[0186] The embodiment of the present application provides a battery cell 20, which includes a shell 21 and a protective member 22. The shell 21 includes a first wall portion 213, the first wall portion 213 has an outer surface, and a pressure relief groove 2132 is provided on the outer surface. The first wall portion 213 is configured to be able to crack along the pressure relief groove 2132 when the battery cell 20 is depressurized. The protective member 22 is provided on the outer surface, and the protective member 22 blocks the pressure relief groove 2132. Along the thickness direction of the first wall portion 213, the protective member 22 and the notch gap of the pressure relief groove 2132 are provided. The first wall portion 213 of the battery cell 20 is provided with a protective member 22, and the protective member 22 has a certain strength, can resist external force interference, protect the pressure relief groove 2132, and can also limit the deformation of the first wall portion 213, reducing the risk of the first wall portion 213 cracking along the pressure relief groove 2132 in advance due to the pressure change inside the battery cell 20. In addition, by setting a gap between the protective member 22 and the notch of the pressure relief groove 2132, the protective member 22 is not easy to prevent the first wall portion 213 from cracking along the pressure relief groove 2132 when the battery cell 20 releases pressure, so that the pressure relief groove 2132 can quickly crack and release pressure when the battery cell 20 releases pressure, which is beneficial to improving the reliability of the battery cell 20.

[0187] The outer surface is provided with a protrusion 25, and the protrusion 25 contacts the protective member 22, so that the protective member 22 is set with a gap between the opening of the pressure relief groove 2132. By providing the protrusion 25 on the outer surface, the protective member 22 can fit the outer surface and the protrusion 25, which can not only protect the pressure relief groove 2132, but also limit the deformation of the first wall 213, and reduce the risk of the first wall 213 cracking along the pressure relief groove 2132 in advance due to the pressure change inside the battery cell 20. Since the protrusion 25 protrudes from the outer surface, when the protective member 22 is provided on the outer surface and the protrusion 25, the protective member 22 can cross the opening position of the pressure relief groove 2132, so that the protective member 22 is set with a gap between the opening of the pressure relief groove 2132.

[0188] The pressure relief groove 2132 defines a predetermined pressure relief area 2133, and the predetermined pressure relief area 2133 is configured to split with the pressure relief groove 2132 as a boundary when the battery cell 20 releases pressure, and the protrusion 25 is located in the predetermined pressure relief area 2133. The pressure relief groove 2132 defines the predetermined pressure relief area 2133, and the protrusion 25 is arranged in the predetermined pressure relief area 2133. It can also be understood that the pressure relief groove 2132 is surrounded by the outside of the protrusion 25, so that when the protective member 22 contacts the protrusion 25 and the outer surface, it can better cover the pressure relief groove 2132 and be arranged with an opening gap of the pressure relief groove 2132.

[0189] The protective member 22 includes an insulating layer 221 and a first adhesive layer 222. The first adhesive layer 222 is disposed on one side of the insulating layer 221, and the first adhesive layer 222 connects the first wall portion 213 and the insulating layer 221. The protective member 22 includes the insulating layer 221, and the insulating layer 221 can play the role of insulation isolation, reducing the risk of short circuit caused by contact between other components and the first wall portion 213. The protective member 22 also includes the first adhesive layer 222, which is sticky, and the protective member 22 can be quickly bonded to the first wall portion 213 through the first adhesive layer 222.

[0190] The protective member 22 includes a second adhesive layer 223 and a plurality of insulating layers 221, wherein the plurality of insulating layers 221 are stacked, and two adjacent insulating layers 221 are connected by the second adhesive layer 223. By arranging a plurality of insulating layers 221, the plurality of insulating layers 221 are stacked, and the plurality of insulating layers 221 can provide higher strength and better insulation. The two adjacent insulating layers 221 are connected by the second adhesive layer 223, so that the protective member 22 has better toughness, and the protective member 22 is more likely to be attached to the shell 211, so as to better protect the pressure relief groove 2132, limit the deformation of the first wall portion 213, and reduce the risk of the first wall portion 213 cracking prematurely along the pressure relief groove 2132 due to the pressure change inside the battery cell 20.

[0191] 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: The housing comprises a first wall portion, the first wall portion having a first surface, the first surface being provided with a pressure relief groove, and the first wall portion being configured to be split along the pressure relief groove when the battery cell is depressurized; A protective member is arranged on the first surface, the protective member blocks the pressure relief groove, and a gap is arranged between the protective member and the notch of the pressure relief groove along the thickness direction of the first wall portion.

2. The battery cell according to claim 1, characterized in that: The first surface is provided with a protrusion, and the protrusion contacts the protection member so that a gap is set between the protection member and the notch of the pressure relief groove.

3. The battery cell according to claim 2, characterized in that: The pressure relief groove defines a predetermined pressure relief area, and the predetermined pressure relief area is configured to be split with the pressure relief groove as a boundary when the battery cell is pressure-released, and the protrusion is located in the predetermined pressure relief area.

4. The battery cell according to claim 1, characterized in that: The first surface is a surface of the first wall portion facing away from the interior of the housing.

5. The battery cell according to claim 1, characterized in that: The protection member includes an insulating layer and a first adhesive layer, wherein the first adhesive layer is disposed on one side of the insulating layer, and the first adhesive layer connects the first wall portion and the insulating layer.

6. The battery cell according to claim 5, characterized in that: The protection member includes a second adhesive layer and a plurality of the insulating layers. The plurality of insulating layers are stacked and two adjacent insulating layers are connected via the second adhesive layer.

7. The battery cell according to claim 5, characterized in that: The insulating layer is made of polyethylene terephthalate or polyimide.

8. The battery cell according to claim 1, characterized in that: The protection member is configured to be destroyed when the battery cell is depressurized.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The protective member is an insulating film.

10. The battery cell according to any one of claims 1 to 8, characterized in that: The thickness of the protective member is H, which satisfies: 0.02mm≤H≤0.14mm.

11. The battery cell according to claim 10, characterized in that: 0.055mm≤H≤0.11mm.

12. The battery cell according to any one of claims 1 to 8, characterized in that: The pressure relief groove extends along a non-closed track.

13. The battery cell according to claim 12, characterized in that: The pressure relief groove includes a first groove section, a second groove section and a third groove section. The first groove section is arranged opposite to the third groove section, and the second groove section connects the first groove section and the third groove section.

14. The battery cell according to any one of claims 1 to 8, characterized in that: The pressure relief groove extends along a closed track.

15. The battery cell according to any one of claims 1 to 8, characterized in that: The housing comprises: a housing having an opening; an end cover, disposed on the housing and closing the opening; Wherein, at least one wall portion in the shell is the first wall portion.

16. The battery cell according to claim 15, characterized in that: The shell is a cylindrical structure, and the wall portion of the shell arranged around the center line thereof is the first wall portion.

17. A battery, characterized in that: Comprising the battery cell according to any one of claims 1-16.

18. An electrical equipment, characterized in that: Comprising the battery cell according to any one of claims 1-16.

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