Battery and electric equipment

Abstract

The utility model discloses a battery and electric equipment. The battery comprises a battery cell and a battery cover, the shell is provided with a storage cavity, the cavity wall of the storage cavity comprises a first wall, the first wall is located on at least one side of the battery cell in the thickness direction, a groove is formed in the first wall, and the battery cell is arranged in the groove; the protective layer covers the surface of the bottom wall of the groove, the protective layer is located between the bottom wall of the groove and the battery cell, and the protective layer is formed by oxide, fluoride or phosphorylate of any one of tungsten, aluminum, zirconium, titanium, magnesium, molybdenum, cerium, strontium or boron; wherein the thickness of the protective layer is smaller than the depth of the groove. According to the battery disclosed by the utility model, the effective volume of the battery core is maximized while the packaging reliability is ensured, and the battery has relatively high energy density.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery and electrical equipment. Background Technology

[0002] In related technologies, a battery includes a casing and battery cells. The casing has a storage cavity; the larger the volume of the storage cavity, the more battery cells it can accommodate, and the higher the energy density of the battery. Furthermore, the higher the energy density of the battery, the more electrical energy it can store.

[0003] The casing can typically be an aluminum-plastic film or a steel casing. Traditional aluminum-plastic film structures usually consist of an outer nylon layer, a middle aluminum layer, and an inner polypropylene (PP) layer. The PP layer is thermally bonded to the tabs and tab adhesive during cell encapsulation. However, the PP layer is typically 20-50 μm thick, which occupies space in the cell placement cavity, limiting the effective volume of the cell and making it difficult to further increase the amount of active material, thus restricting the battery's energy density.

[0004] To increase the volume of the battery's storage cavity, the aluminum-plastic film can be thinned. In other words, reducing the thickness of the aluminum-plastic film increases the volume of the storage cavity. However, thinning the aluminum-plastic film sacrifices its original barrier properties or mechanical strength, thus affecting battery performance. Utility Model Content

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a battery that maximizes the effective volume of the cell while ensuring packaging reliability, resulting in a high energy density.

[0006] This utility model also proposes an electrical device.

[0007] The battery according to a first aspect embodiment of the present invention includes:

[0008] Battery cell;

[0009] The housing has a storage cavity, the cavity wall of which includes a first wall located on at least one side in the thickness direction of the battery cell, the first wall being provided with a groove, and the battery cell being disposed in the groove;

[0010] A protective layer is provided, covering the bottom wall surface of the groove, between the bottom wall of the groove and the battery cell, and the protective layer is formed of an oxide, fluoride or phosphate of any one of the elements selected from tungsten, aluminum, zirconium, titanium, magnesium, molybdenum, cerium, strontium or boron.

[0011] The thickness of the protective layer is less than the depth of the groove.

[0012] The battery according to the embodiments of this utility model has at least the following beneficial effects: the casing has a storage cavity for placing the battery cell. The cavity wall includes a first wall with a groove, in which the battery cell is located. This improves the battery's energy density. Furthermore, after a protective layer is attached to the groove wall, the protective layer prevents external moisture from entering the storage cavity, thereby improving the casing's barrier performance and protecting the battery. Specifically, the battery maximizes the effective volume of the battery cell while ensuring packaging reliability, resulting in a high energy density.

[0013] According to some embodiments of the present invention, the protective layer of the battery is formed by a chemical vapor deposition process or a physical vapor deposition process.

[0014] According to some embodiments of the present invention, the protective layer of the battery is one of ZrO2 film, Al2O3 film, MgO film, WO3 film or TiO2 film.

[0015] According to some embodiments of the present invention, the battery of the storage cavity further includes a second wall surrounding a circumferential edge connected to the first wall.

[0016] According to some embodiments of the present invention, the bottom wall of the groove of the first wall includes a first heat-sealing layer, a first metal layer and a first outer layer stacked together, and the second wall includes a second heat-sealing layer, a second metal layer and a second outer layer stacked together.

[0017] According to some embodiments of the present invention, the thickness of the first heat-sealing layer is B, the thickness of the second heat-sealing layer is A, and B ≤ 0.1A.

[0018] According to some embodiments of the present invention, the bottom wall of the groove of the first wall includes a first metal layer and a first outer layer stacked together, and the second wall includes a second heat-sealing layer, a second metal layer and a second outer layer stacked together. The depth of the groove is greater than or equal to the thickness of the second heat-sealing layer, the thickness of the first metal layer is less than or equal to the thickness of the second metal layer, and the thickness of the first outer layer is equal to the thickness of the second outer layer.

[0019] According to some embodiments of the present invention, the depth of the groove is C, the thickness of the second heat-sealing layer is D, the thickness of the second metal layer is E, and 0 < C ≤ D + 0.5E.

[0020] According to some embodiments of the present invention, the thickness of the protective layer in the battery is L, where 400nm≤L≤1000nm.

[0021] The electrical device according to the second aspect of the present invention includes the battery described in any one of the first aspect embodiments.

[0022] The electrical device according to the embodiments of this utility model has at least the following beneficial effects: the housing has a storage cavity for placing a battery cell. The cavity wall includes a first wall with a groove, in which the battery cell is located. This improves the battery's energy density. Furthermore, after a protective layer is attached to the groove wall, the protective layer prevents external moisture from entering the storage cavity, thereby improving the housing's barrier performance and protecting the battery. Specifically, the battery maximizes the effective volume of the battery cell while ensuring packaging reliability, resulting in a high energy density. Furthermore, the electrical device with this battery has a longer lifespan.

[0023] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0025] Figure 1 This is a schematic diagram of the battery casing in the first embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the battery casing in the second embodiment of the present invention;

[0027] Figure 3 This is a partial schematic diagram of the battery casing in the first embodiment of the present invention;

[0028] Figure 4 This is a partial schematic diagram of the battery casing in the second embodiment of the present invention;

[0029] Figure 5 This is a partial schematic diagram of the battery casing in the third embodiment of the present invention.

[0030] Figure label:

[0031] Battery 10, casing 100, storage cavity 200, first wall 210, groove 211, second wall 220, protective layer 300, first heat-sealing layer 400, first metal layer 500, first outer layer 600, second heat-sealing layer 700, second metal layer 800, second outer layer 900. Detailed Implementation

[0032] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0033] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0034] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0035] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0036] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0037] The battery can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0038] A battery typically consists of a cell. The cell includes a positive electrode, a negative electrode, and a separator. During charging and discharging, active ions (such as lithium ions) move back and forth between the positive and negative electrodes, inserting and releasing. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0039] In some embodiments, the positive electrode may be a positive electrode sheet, which 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.

[0040] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0041] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be 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. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can 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.).

[0042] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides 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, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM523), LiNi 0.5 Co 0.25Mn 0.25 O2 (also known as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0043] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0044] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0045] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can 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.).

[0046] 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.

[0047] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0048] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in batteries. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional 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.

[0049] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0050] In some implementations, the battery cell also includes an isolation element disposed between the positive and negative terminals.

[0051] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0052] As an example, the material of the separator may include at least one of glass fiber, nonwoven 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 it may be attached to the surfaces of the positive and negative electrodes.

[0053] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0054] In some embodiments, the battery also includes an electrolyte that acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0055] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0056] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0057] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0058] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0059] As an example, polymer solid electrolytes can be polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0060] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0061] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0062] In some implementations, the battery cell has a wound structure. The positive and negative electrode plates are wound into a wound structure.

[0063] In some implementations, the battery cell has a laminated structure.

[0064] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0065] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0066] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0067] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0068] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0069] In some implementations, the battery cell can be cylindrical, flat, or polygonal, etc.

[0070] In some implementations, the battery cell is provided with tabs that allow current to be drawn out of the cell. The tabs include a positive tab and a negative tab.

[0071] In some embodiments, the battery may include a casing. The casing is used to encapsulate components such as the battery cell and electrolyte. The casing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0072] As an example, the battery can be a cylindrical battery, a prismatic battery, a pouch battery, or a battery of other shapes. Prismatic batteries include, but are not limited to, square-shell batteries, blade-shaped batteries, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0073] The battery mentioned in the embodiments of this application refers to a single physical module that includes one or more batteries to provide higher voltage and capacity.

[0074] In some embodiments, the battery can be a battery module, and when there are multiple batteries, the multiple batteries are arranged and fixed to form a battery module.

[0075] In some embodiments, the battery may be a battery pack, which includes a housing and a battery, with the battery or battery module housed within the housing.

[0076] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0077] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0078] In related technologies, a battery includes a casing and battery cells. The casing has a storage cavity; the larger the volume of the storage cavity, the more battery cells it can accommodate, and the higher the energy density of the battery. Furthermore, the higher the energy density of the battery, the more electrical energy it can store.

[0079] The casing can typically be an aluminum-plastic film or a steel casing. Traditional aluminum-plastic film structures usually consist of an outer nylon layer, a middle aluminum layer, and an inner polypropylene (PP) layer. The PP layer is thermally bonded to the tabs and tab adhesive during cell encapsulation. However, the PP layer is typically 20-50 μm thick, which occupies space in the cell placement cavity, limiting the effective volume of the cell and making it difficult to further increase the amount of active material, thus restricting the battery's energy density.

[0080] To increase the volume of the storage cavity in the casing, the aluminum-plastic film can be thinned. That is, the volume of the storage cavity is increased by reducing the thickness of the aluminum-plastic film. However, when the aluminum-plastic film is thinned, its original barrier properties or mechanical strength are sacrificed, thus affecting the battery's performance. Therefore, this application proposes a battery.

[0081] Please refer to Figures 1 to 4In some embodiments, the battery 10 includes a housing 100, a battery cell (not shown), and a protective layer 300. The housing 100 has a storage cavity 200, the cavity wall of which includes a first wall 210 and a second wall 220. The second wall 220 surrounds a circumferential edge connected to the first wall 210, and the first wall 210 is located on at least one side in the thickness direction of the battery cell. Specifically, the second wall 220 has a sleeve structure, that is, the second wall 220 can form a cube or cuboid with two openings. There can be two first walls 210, and the two first walls 210 respectively close the two openings of the second wall 220. Wherein, after the first wall 210 is thinned, the first wall 210 can increase the volume of the storage cavity 200 in the thickness direction of the battery cell. The first wall 210 is provided with a groove 211, in which the battery cell is located, which can improve the energy density of the battery 10. The shape of the storage cavity 200 can be a cube, a cuboid, or a cylinder. The shape of the storage cavity 200 is not specifically limited; it can be a regular polygon or an irregular polygon. A protective layer 300 covers the bottom wall surface of the groove 211, and is located between the bottom wall of the groove 211 and the battery cell. The protective layer 300 effectively isolates moisture. The protective layer 300 is formed of an oxide, fluoride, or phosphate of any one of the elements selected from tungsten, aluminum, zirconium, titanium, magnesium, molybdenum, cerium, strontium, or boron. For example, the protective layer 300 can be made of aluminum oxide or magnesium oxide. The thickness of the protective layer 300 is less than the depth of the groove 211; that is, even after the protective layer 300 is attached to the groove wall of the groove 211, the volume of the storage cavity 200 can still be effectively ensured to be greater than the volume of the casing 100 in the prior art, thereby effectively improving the energy density of the battery 10. Specifically, the housing 100 has a storage cavity 200, which can be used to place the battery cell. The cavity wall of the storage cavity 200 includes a first wall 210 and a second wall 220. The first wall 210 is provided with a groove 211, in which the battery cell is located. This can improve the energy density of the battery 10. Furthermore, after the protective layer 300 is connected to the groove wall of the groove 211, the protective layer 300 can prevent external moisture from entering the storage cavity 200, thereby improving the barrier performance of the housing 100 and protecting the battery 10. In essence, the battery 10 maximizes the effective volume of the battery cell while ensuring packaging reliability, and has a high energy density.

[0082] Furthermore, in some embodiments, the protective layer 300 is formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD). PVD can be magnetron sputtering, a highly efficient and controllable PVD technology widely used to prepare high-performance thin films of metals, alloys, oxides, and nitrides. Specifically, the manufacturing process of the housing 100 can involve punching a groove in the storage cavity 200 into the aluminum-plastic film, then machining a groove 211 on the first wall 210 using a laser, and finally machining the protective layer 300 on the groove wall of the groove 211 using magnetron sputtering. The protective layer 300 is relatively thin, which can improve the energy density of the battery 10 while effectively blocking moisture. It should be noted that when the groove 211 is processed into the first wall 210 by laser, if the PP layer is only partially thinned, the processing difficulty will be increased. Therefore, the PP layer can be completely removed to expose the aluminum layer, and then a protective layer 300 can be processed on the aluminum layer by magnetron sputtering.

[0083] Furthermore, in some embodiments, the protective layer 300 is one of a ZrO2 film, an Al2O3 film, a MgO film, a WO3 film, or a TiO2 film. Specifically, ZrO2 film, Al2O3 film, MgO film, WO3 film, and TiO2 film all have excellent high-temperature resistance and corrosion resistance, which can effectively isolate external moisture and protect the battery cell.

[0084] Furthermore, the specific structure of the housing 100 is described below; please refer to [the relevant documentation]. Figure 1 and Figure 3 In some embodiments, the bottom wall of the groove 211 of the first wall 210 includes a first heat-sealing layer 400, a first metal layer 500, and a first outer layer 600 stacked together. The first heat-sealing layer 400 may be a PP layer, the first metal layer 500 may be an aluminum layer, and the first outer layer 600 may be a nylon layer. The second wall 220 includes a second heat-sealing layer 700, a second metal layer 800, and a second outer layer 900 stacked together. The second heat-sealing layer 700 may be a PP layer, the second metal layer 800 may be an aluminum layer, and the second outer layer 900 may be a nylon layer. The first heat-sealing layer 400 has a groove 211. After the first heat-sealing layer 400 is thinned, a groove 211 is formed on the first wall 210, and the space of this groove 211 can accommodate more battery cells.

[0085] Furthermore, in some embodiments, the thickness of the first heat-sealing layer 400 is B, and the thickness of the second heat-sealing layer 700 is A, where B ≤ 0.1A. Specifically, the thickness of the first heat-sealing layer 400 can be 10%, 8%, 7%, or 5% of the thickness of the second heat-sealing layer 700. The smaller the thickness of the first heat-sealing layer 400, the larger the volume of the storage cavity 200, and the higher the energy density of the battery 10.

[0086] Further, please refer to Figure 2 , Figure 4 and Figure 5 In some embodiments, the bottom wall of the groove 211 of the first wall 210 includes a first metal layer 500 and a first outer layer 600 stacked together. The first metal layer 500 may be an aluminum layer, and the first outer layer 600 may be a nylon layer. The second wall 220 includes a second heat-sealing layer 700, a second metal layer 800, and a second outer layer 900 stacked together. The second heat-sealing layer 700 may be a PP layer, the second metal layer 800 may be an aluminum layer, and the second outer layer 900 may be a nylon layer. The depth of the groove 211 is greater than or equal to the thickness of the second heat-sealing layer 700, the thickness of the first metal layer 500 is less than or equal to the thickness of the second metal layer 800, and the thickness of the first outer layer 600 is equal to the thickness of the second outer layer 900. The first heat-sealing layer 400 and the first metal layer 500 together form the groove 211, as detailed in the following reference. Figure 4 and Figure 5 That is, after the first heat-sealing layer 400 is removed, the first metal layer 500 and the first outer layer 600 can be the bottom wall of the groove 211, and the first heat-sealing layer 400 can be the side wall of the groove 211. The thickness of the first metal layer 500 is less than or equal to the thickness of the second metal layer 800, and the thickness of the first outer layer 600 is equal to the thickness of the second outer layer 900. Specifically, after the first heat-sealing layer 400 is removed, the protective layer 300 can be attached to the first metal layer 500. On the one hand, removing the first heat-sealing layer 400 can increase the energy density of the battery 10; on the other hand, after the protective layer 300 is attached to the first metal layer 500, it can effectively isolate external moisture. In addition, the provision of the protective layer 300 can also effectively improve the strength of the casing 100.

[0087] Furthermore, in some embodiments, the depth of the groove 211 is C, the thickness of the second heat-sealing layer 700 is D, and the thickness of the second metal layer 800 is E, where 0 < C ≤ D + 0.5E. Specifically, the maximum depth of the groove 211 is C = D + 0.5E, meaning that in addition to completely removing the first heat-sealing layer 400, the thickness of the first metal layer 500 can also be reduced by half, which can further increase the space of the storage cavity 200. Furthermore, if C is greater than D + 0.5E, then due to the smaller thickness of the remaining first metal layer 500, the strength of the casing 100 may be weaker, reducing the safety of the battery 10.

[0088] Furthermore, in some embodiments, the thickness of the protective layer 300 is L, where 400nm ≤ L ≤ 1000nm. The thickness of the protective layer 300 can be 400nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm, 950nm, or 1000nm. When the thickness of the protective layer 300 is less than 400nm, the thickness is too small, which will result in poor moisture isolation effect. When the thickness of the protective layer 300 is greater than 100nm, the thickness is too large, which will result in excessive space occupied by the protective layer 300, thus reducing the energy density of the battery 10.

[0089] Furthermore, in some embodiments, the thickness of the protective layer 300 is less than the wall thickness of the groove 211. Specifically, if the thickness of the protective layer 300 is greater than the wall thickness of the groove 211, this would result in material waste and an increase in the manufacturing cost of the battery 10, provided that the protective layer 300 can isolate external moisture.

[0090] For details, please refer to the table below.

[0091]

[0092] In the table above, the leakage current after mechanical vibration refers to the leakage current tested after mechanical vibration and storage at less than 50% SOC for 30 days. Leakage current = decayed capacity / time. The 60℃, 95% humidity, 21D expansion rate in the table refers to the expansion rate of battery 10 after 21 days in an environment of 60℃ and 95% humidity. The larger the expansion rate, the worse the barrier performance of the casing 100. Comparative Example 1's battery 10 does not have a groove 211, therefore, the increased energy density is relatively small. Comparative Example 2 has a groove 211, but no protective layer 300, therefore, the barrier performance of the casing 100 is poor, making it prone to leakage and moisture ingress. Examples 1 to 4, while ensuring packaging reliability, maximize the effective cell volume and have higher energy density.

[0093] In some embodiments, the electrical device includes the battery 10 of any of the above embodiments. The housing 100 has a storage cavity 200 for holding the battery cell. The cavity wall of the storage cavity 200 includes a first wall 210 and a second wall 220. The first wall 210 has a groove 211 in which the battery cell is located. This improves the energy density of the battery 10. Furthermore, after the protective layer 300 is attached to the groove wall of the groove 211, the protective layer 300 can prevent external moisture from entering the storage cavity 200, thus protecting the battery 10. Specifically, the battery 10 maximizes the effective volume of the battery cell while ensuring packaging reliability, resulting in a high energy density. Furthermore, the electrical device with this battery 10 has a longer service life.

[0094] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A battery, characterized in that, include: Battery cell; The housing has a storage cavity, the cavity wall of which includes a first wall located on at least one side in the thickness direction of the battery cell, the first wall being provided with a groove, and the battery cell being disposed in the groove; A protective layer is provided, covering the bottom wall surface of the groove, between the bottom wall of the groove and the battery cell, and the protective layer is formed of an oxide, fluoride or phosphate of any one of the elements selected from tungsten, aluminum, zirconium, titanium, magnesium, molybdenum, cerium, strontium or boron. The thickness of the protective layer is less than the depth of the groove.

2. The battery according to claim 1, characterized in that, The protective layer is formed by chemical vapor deposition or physical vapor deposition.

3. The battery according to claim 2, characterized in that, The protective layer is one of ZrO2 film, Al2O3 film, MgO film, WO3 film or TiO2 film.

4. The battery according to claim 1, characterized in that, The cavity wall of the storage cavity also includes a second wall surrounding a circumferential edge connected to the first wall.

5. The battery according to claim 4, characterized in that, The first wall has a groove bottom wall comprising a first heat-sealing layer, a first metal layer and a first outer layer stacked together, and the second wall has a second heat-sealing layer, a second metal layer and a second outer layer stacked together.

6. The battery according to claim 5, characterized in that, The thickness of the first heat-sealing layer is B, and the thickness of the second heat-sealing layer is A, where B ≤ 0.1A.

7. The battery according to claim 4, characterized in that, The bottom wall of the groove of the first wall includes a first metal layer and a first outer layer stacked together, and the second wall includes a second heat-sealing layer, a second metal layer and a second outer layer stacked together. The depth of the groove is greater than or equal to the thickness of the second heat-sealing layer, the thickness of the first metal layer is less than or equal to the thickness of the second metal layer, and the thickness of the first outer layer is equal to the thickness of the second outer layer.

8. The battery according to claim 7, characterized in that, The depth of the groove is C, the thickness of the second heat-sealing layer is D, the thickness of the second metal layer is E, and 0 < C ≤ D + 0.5E.

9. The battery according to claim 1, characterized in that, The thickness of the protective layer is L, where 400nm ≤ L ≤ 1000nm.

10. Electrical equipment, characterized in that, Includes the battery as described in any one of claims 1 to 9.

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