Battery

Abstract

The present application discloses a battery, comprising: a battery cell; and a case, which comprises a sealing portion, a storage portion and a cover portion, wherein the sealing portion is connected to the storage portion and the cover portion; the cover portion is connected to the storage portion; the cover portion and the storage portion together define a storage cavity; the battery cell is arranged in the storage cavity; cavity walls of the storage cavity comprise two oppositely arranged first walls, two oppositely arranged second walls and two oppositely arranged third walls; two ends of each second wall are respectively connected to the two third walls; the two second walls and the two third walls are connected to the first walls in a surrounding manner; the area of the first wall is greater than the area of the second wall and the area of the third wall; in the thickness direction of the battery cell, the two first walls are respectively arranged on two sides of the battery cell; at least one first wall is provided with a first thinned region and an unthinned region, and the area of the unthinned region is less than the area of the first thinned region. The battery of the present application can achieve a high energy density.

Description

Battery Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery. Background Technology

[0002] In related technologies, a battery comprises a casing and a battery cell. The casing has a storage cavity in which the battery cell is housed. The casing primarily serves to protect and encapsulate the battery cell. It prevents external physical damage to the battery cell, such as impacts and compression, and also prevents leakage of internal chemicals. Casings are typically of two types: aluminum-plastic film and metal casing.

[0003] In this process, the aluminum-plastic film is stamped to form a storage cavity, and the battery cell can then be placed inside the cavity. In some cases, the battery size is typically fixed, allowing it to be adapted to different electrical devices. Consequently, increasing the battery's energy density within this fixed size becomes a significant challenge. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a battery capable of having a high energy density.

[0005] The battery according to an embodiment of this application includes:

[0006] Battery cell;

[0007] The housing includes a sealing portion, a storage portion, and a cover portion. The sealing portion is connected to the storage portion and the cover portion, and the cover portion is connected to the storage portion. The cover portion and the storage portion together define a storage cavity. The battery cell is disposed in the storage cavity. The cavity wall of the storage cavity includes two opposing first walls, two opposing second walls, and two opposing third walls. The two ends of the second walls are respectively connected to the two third walls. The two second walls and the two third walls surround and are connected to the first walls. The area of ​​the first wall is larger than the area of ​​the second walls and the area of ​​the third walls. Along the thickness direction of the battery cell, the two first walls are respectively disposed on both sides of the battery cell. At least one first wall is provided with a first thinned area and an unthinned area. The area of ​​the unthinned area is smaller than the area of ​​the first thinned area.

[0008] The battery according to the embodiments of this application has at least the following beneficial effects: the battery cell can be disposed in the storage cavity, wherein, by providing a first thinning region on at least one first wall, the thickness of the first wall can be reduced, thereby indirectly reducing the thickness of the casing and increasing the thickness of the battery cell. Thus, within limited size constraints, the capacity of the battery cell can be increased, thereby improving the energy density of the battery. Specifically, the battery can have a high energy density.

[0009] According to some embodiments of the battery in this application, both first walls are provided with the first thinned area and the unthinned area.

[0010] According to some embodiments of the present application, the battery's first wall includes an outer layer, a metal layer, and a heat-sealing layer stacked sequentially, wherein the heat-sealing layer has a first thinning region.

[0011] According to some embodiments of the battery in this application, the thickness of the heat-sealing layer is H1, the thickness of the first thinned region is H2, and 1 / 2H1≤H2≤H1.

[0012] According to some embodiments of the battery in this application, the metal layer is provided with a second thinning region, and the first thinning region and the second thinning region are connected.

[0013] According to some embodiments of the battery in this application, the thickness of the metal layer is H3, the thickness of the second thinned region is H4, and 0 < H4 ≤ 1 / 2H3.

[0014] According to some embodiments of the battery in this application, the first thinning area is configured as a first groove, the thickness of the battery cell is L, the size of the first groove along the width direction of the battery is A, and the size of the battery cell is W, where WL≤A≤W+L.

[0015] According to some embodiments of the battery in this application, the battery cell is a wound cell, WL≤A≤W; and / or, the battery cell is a laminated cell, W≤A≤W+L.

[0016] According to some embodiments of the battery in this application, the first thinning area is configured as a first groove, and the coefficient of friction of the bottom wall of the first groove is Y, 0.3 < Y < 2.5.

[0017] According to some embodiments of the present application, the first thinning area of ​​the battery is configured as a first groove, the battery cell includes a body and an adhesive layer, the adhesive layer is connected to the body and protrudes relative to the body, and the adhesive layer is disposed in the first groove.

[0018] According to some embodiments of the battery in this application, along the length direction of the battery, the size of the first groove is B, the size of the cell is C, and the size of the adhesive layer protruding from the body is D, where BCD≥0.

[0019] According to some embodiments of the battery in this application, the BCD is ≥ 0.5 mm.

[0020] According to some embodiments of the battery in this application, the first thinned area is configured as a first groove, and the first wall further includes an arc portion, the two ends of which respectively surround the groove wall connecting the unthinned area and the first groove.

[0021] Additional aspects and advantages of this application 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 this application. Attached Figure Description

[0022] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0023] Figure 1 is a schematic diagram of a battery according to some embodiments of this application;

[0024] Figure 2 is a schematic diagram of the battery casing in the first embodiment of this application;

[0025] Figure 3 is a schematic diagram of the battery casing in the second embodiment of this application;

[0026] Figure 4 is a schematic diagram of the casing in the battery according to the third embodiment of this application;

[0027] Figure 5 is a partial schematic diagram of the battery according to the first embodiment of this application;

[0028] Figure 6 is a partial schematic diagram of the battery according to the second embodiment of this application;

[0029] Figure 7 is a schematic diagram of the battery casing in the fourth embodiment of this application.

[0030] Figure label:

[0031] Battery 10, cell 100, body 110, adhesive layer 120, tab 130, shell 200, sealing part 210, storage part 220, cover part 230, storage cavity 240, first wall 241, second wall 242, third wall 243, first groove 250, outer layer 300, metal layer 400, second thinning area 410, heat sealing layer 500, first thinning area 510, unthinned area 520, arc part 530. Detailed Implementation

[0032] The embodiments of this application 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 application, and should not be construed as limiting this application.

[0033] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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 application.

[0034] In the description of this application, "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 application, unless otherwise expressly defined, terms such as "setup," "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 application in conjunction with the specific content of the technical solution.

[0036] In the description of this application, 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 application. 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 will be introduced first.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.).

[0043] 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 positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium 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 manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides may include, but are not limited to, at least one of lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also abbreviated as NCM333), LiNi0.5Co0.2Mn0.3O2 (also abbreviated as NCM523), LiNi0.5Co0.25Mn0.25O2 (also abbreviated as NCM211), LiNi0.6Co0.2Mn0.2O2 (also abbreviated as NCM622), LiNi0.8Co0.1Mn0.1O2 (also abbreviated as NCM811), lithium nickel cobalt aluminum oxides (such as LiNi0.85Co0.15Al0.05O2) and their modified compounds.

[0044] 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.

[0045] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0046] 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.).

[0047] 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.

[0048] 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.

[0049] 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.

[0050] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0051] In some implementations, the battery cell also includes an isolation element disposed between the positive and negative terminals.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0059] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0060] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0061] 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.

[0062] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0063] In some implementations, the battery cell has a wound structure. The positive and negative electrode plates are wound into a wound structure.

[0064] In some implementations, the battery cell has a laminated structure.

[0065] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0066] 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.

[0067] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0068] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0069] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0070] In some implementations, the battery cell can be cylindrical, flat, or polygonal, etc.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] In related technologies, a battery comprises a casing and a battery cell. The casing has a storage cavity in which the battery cell is housed. The casing primarily serves to protect and encapsulate the battery cell. It prevents external physical damage to the battery cell, such as impacts and compression, and also prevents leakage of internal chemicals. Casings are typically of two types: aluminum-plastic film and metal casing.

[0080] In this process, after the aluminum-plastic film is stamped to form a storage cavity, the battery cell can be placed inside the storage cavity. In some cases, the battery size is usually a fixed value, which allows the battery to be adapted to electrical devices. Accordingly, how to improve the energy density of the battery within a fixed size becomes a challenge. To address this, this application proposes a battery.

[0081] Please refer to Figures 1 to 7. Figures 1 and 2 illustrate schematic diagrams of the battery cell 100 before the aluminum-plastic film is encapsulated. In some embodiments, the battery 10 includes a battery cell 100 and a casing 200. The battery cell 100 includes a body 110 and an adhesive layer 120. The adhesive layer 120 is connected to the body 110 and protrudes relative to the body 110. The body 110 can be formed by stacking and winding positive and negative electrode sheets, wherein after the positive and negative electrode sheets are wound, the adhesive layer 120 can fix the positive electrode sheet located on the outer layer 300. In addition, a separator is provided between the positive and negative electrode sheets, and the adhesive layer 120 can also roll up the separator. A tab 130 is connected to the body 110. The casing 200 includes a sealing portion 210, a storage portion 220, and a cover portion 230. The casing 200 can be an aluminum-plastic film. The sealing portion 210 surrounds the edge connected to the storage portion 220. The sealing section 210 can be heat-sealed to encapsulate the battery cell 100. The storage section 220 and the cover section 230 together define the storage cavity 240. The shape of the storage cavity 240 is not specifically limited and can be square or triangular, etc. The battery cell 100 is disposed in the storage cavity 240. The cavity wall of the storage cavity 240 includes two first walls 241, two second walls 242, and two third walls 243 disposed opposite to each other. The two ends of the second walls 242 are respectively connected to the two third walls 243. The two second walls 242 and the two third walls 243 surround and are connected to the first wall 241. The area of ​​the first wall 241 is larger than the area of ​​the second wall 242 and the area of ​​the third wall 243. The two sides of the battery cell 100 are respectively connected to the two first walls 241. That is, along the thickness direction of the battery cell 100, the two first walls 241 are respectively disposed on the two sides of the battery cell 100. At least one first wall 241 is provided with a first thinned area 510 and an unthinned area 520. The area of ​​the unthinned area 520 is smaller than the area of ​​the first thinned area 510. Specifically, the battery cell 100 can be disposed in the storage cavity 240. By providing a first thinning region 510 on at least one first wall 241, the thickness of the first wall 241 can be reduced, thereby indirectly reducing the thickness of the casing 200 and increasing the thickness of the battery cell 100. Thus, within limited size constraints, the capacity of the battery cell 100 can be increased, thereby improving the energy density of the battery 10. Specifically, the battery 10 is capable of having a higher energy density. In the prior art, the casing 200 does not have a first thinning region 510, therefore its energy density is relatively lower compared to the battery 10 of this application.

[0082] Continuing the explanation below, at least one first wall 241 may have a first thinning region 510, specifically, one first wall 241 may have a first thinning region 510, or two first walls 241 may have a first thinning region 510. The area of ​​the first thinning region 510 is larger than the area of ​​the unthinned region 520, allowing the flat portion of the cell 100 to contact the first wall 241. It should be noted that the battery 10 of this application not only has a high energy density but also high safety; although the thickness of the first wall 241 is reduced, it can still effectively protect the cell 100. Furthermore, in some embodiments, both first walls 241 have a first thinning region 510 and an unthinned region 520. Having a first thinning region 510 on both first walls 241 can further improve the energy density of the battery 10.

[0083] Furthermore, the first thinning area 510 can be formed by providing a first groove 250 on the first wall 241. Referring to Figure 3, in some embodiments, the first wall 241 includes an outer layer 300, a metal layer 400, and a heat-sealing layer 500 stacked sequentially, with the heat-sealing layer 500 having the first thinning area 510. Specifically, the outer layer 300 can be made of nylon, the metal layer 400 can be aluminum foil, and the heat-sealing layer 500 can be a PP layer or a PE layer. The first thinning area 510 on the heat-sealing layer 500 specifically refers to thinning the thickness of the heat-sealing layer 500. For example, if the thickness of the heat-sealing layer 500 is 50 μm, then the first thinning area 510 can be a first groove 250 provided on the heat-sealing layer 500, with a depth of 25 μm. In this case, the minimum thickness of the first wall 241 is less than the thickness of the heat-sealing layer 500 in the prior art, which is 25 μm. Furthermore, the first thinning zone 510 may involve thinning the entire heat-sealing layer 500. This thinning can be achieved by using a laser to thin the heat-sealing layer 500. It should be noted that the sealing portion 210 also includes an outer layer 300, a metal layer 400, and a heat-sealing layer 500 stacked sequentially, but the outer layer 300, metal layer 400, and heat-sealing layer 500 on the sealing portion 210 are not thinned. The cover portion 230 also includes an outer layer 300, metal layer 400, and heat-sealing layer 500 stacked sequentially, and the heat-sealing layer 500 on the cover portion 230 is thinned.

[0084] Further, referring to Figure 3, in some embodiments, the thickness of the heat-sealing layer 500 is H1, and the thickness of the first thinning region 510 is H2, where 1 / 2H1≤H2≤H1. Specifically, the thickness of the first thinning region 510 refers to the degree of thinning on the heat-sealing layer 500. The thickness of the first thinning region 510 can be one-half, two-thirds, three-quarters, or all of the heat-sealing layer 500. When the thickness of the first thinning region 510 is less than half of the heat-sealing layer 500, the thickness of the first thinning region 510 is too small, which will result in limited improvement in the energy density of the battery 10.

[0085] Further, referring to Figure 4, in some embodiments, the metal layer 400 is provided with a second thinning area 410, and the first thinning area 510 and the second thinning area 410 are connected. Specifically, in addition to providing the first thinning area 510 on the heat-sealing layer 500, a second thinning area 410 can also be provided on the metal layer 400, thereby further reducing the thickness of the first wall 241. Wherein, after the first thinning area 510 and the second thinning area 410 are connected, a first groove 250 can be formed on the first wall 241. It should be noted that, in another embodiment, the first wall 241 includes a metal layer 400 and an outer layer 300 stacked together, but does not include the heat-sealing layer 500. In this case, the heat-sealing layer 500 is completely thinned, and only the sealing portion 210 has the outer layer 300, the metal layer 400, and the heat-sealing layer 500 stacked together in sequence. In another embodiment, the first wall 241 includes a stacked metal layer 400 and an outer layer 300, but does not include a heat-sealing layer 500. The thickness of the metal layer 400 is half the thickness of the metal layer 400 in the prior art.

[0086] Further, referring to Figure 4, in some embodiments, the thickness of the metal layer 400 is H3, and the thickness of the second thinned region 410 is H4, where 0 < H4 ≤ 1 / 2 H3. Specifically, the thickness of the second thinned region 410 refers to the degree of thinning on the metal layer 400, where the thickness of the second thinned region 410 can be one-quarter, one-third, or one-half of the metal layer 400. When the thickness of the second thinned region 410 is greater than half of the metal layer 400, the thickness of the second thinned region 410 is too large, which may lead to lower safety of the battery 10 due to the metal layer 400 being too thin. In other words, limiting the size of the second thinned region 410 can not only improve the energy density of the battery 10, but also allow the casing 200 to protect the battery 10, thereby improving the safety of the battery 10.

[0087] Further, the first thinning area 510 may be formed by providing a first groove 250 on the first wall 241. Referring to FIG. 5, in some embodiments, the first wall 241 is provided with a first groove 250. The thickness of the battery cell 100 is L. Along the width direction of the battery 10, the size of the first groove 250 is A, and the size of the battery cell 100 is W, where W - L ≤ A ≤ W + L. Specifically, the first wall 241 is thinned at the middle position to form the first groove 250. The first groove 250 can be used to place the adhesive layer 120, or the first groove 250 can be used to place the battery cell 100 (including the main body 110 and the adhesive layer 120). When A is greater than W + L, when the aluminum-plastic film is punched to form the storage cavity 240, the mechanical properties of the aluminum-plastic film in contact with the corner position of the punch are weak, and the impact resistance is weak. The punching pressure of the punch directly acts on the aluminum layer, easily breaking through the aluminum layer. If A < W - L, then the size of the first groove 250 cannot accommodate the main body 110 of the battery cell 100, and the purpose of improving the energy density of the battery 10 cannot be achieved.

[0088] Further, referring to FIGS. 5 and 6, in some embodiments, the battery cell 100 is a wound battery cell, and W - L ≤ A ≤ W. Among them, the main body 110 is formed by winding the positive electrode sheet and the negative electrode sheet. Therefore, the main body 110 is not a strict cuboid and has corners on both sides in the width direction of the main body 110, and the corners are semi-cylindrical. Specifically, the width of the first groove 250 cannot exceed the width of the battery cell 100, otherwise the punch may break through the aluminum layer and damage the battery cell 100. And / or, the battery cell 100 is a stacked battery cell, and W ≤ A ≤ W + L. Among them, the main body 110 is formed by stacking the positive electrode sheet and the negative electrode sheet, and the main body 110 can be a cuboid. If the width of the first groove 250 exceeds W + L, this will cause the width of the first groove 250 to be too large, and the punch may also break through the aluminum layer and damage the battery cell 100.

[0089] Further, in some embodiments, the first thinning area 510 is set as the first groove 250, and the friction coefficient of the bottom wall of the first groove 250 is Y, where 0.3 < Y < 2.5. Y can specifically be 0.4, 1, 2, 2.2 or 2.4. When the friction coefficient of the groove wall of the first groove 250 is small, the battery cell 100 may move in the first groove 250 and be damaged. When the friction coefficient of the groove wall of the first groove 250 is large, although this can effectively prevent the battery cell 100 from sliding in the first groove 250, on the premise of protecting the battery cell 100, an excessive friction coefficient will lead to an increase in manufacturing cost.

[0090] Further, referring to Figure 5, in some embodiments, the first wall 241 is provided with a first groove 250, and the first wall 241 is also provided with an unthinned area 520. The first wall 241 also includes an arcuate portion 530, with both ends of the arcuate portion 530 surrounding the groove wall connecting the unthinned area 520 and the first groove 250, respectively. Specifically, the first groove 250 can be provided on the heat-sealing layer 500 or on the metal layer 400. After the first groove 250 is provided, the groove opening of the first groove 250 can be rounded, that is, the arcuate portion 530 is provided. This can effectively protect the battery cell 100 and prevent the battery cell 100 from being punctured by the sharp groove opening.

[0091] Furthermore, in some embodiments, the first thinning area 510 is configured as a first groove 250, and the adhesive layer 120 is disposed in the first groove 250. Along the length direction of the battery 10, the size of the first groove 250 is B, the size of the cell 100 is C, and the size of the adhesive layer 120 protruding from the main body 110 is D, where BCD≥0. Specifically, BCD can be 0, 0.1mm, 0.3mm, or 0.5mm, which can effectively ensure that the first groove 250 can fully accommodate the cell 100, thereby improving the energy density of the battery 100.

[0092] Furthermore, in some embodiments, the dimension of the first groove 250 along the length of the battery 10 is greater than the dimension of the adhesive layer 120 along the length of the battery 10. Specifically, BCD ≥ 0.5 mm. That is, the dimension of the first groove 250 along the length of the battery 10 is greater than the dimensions of the adhesive layer 120 and the cell 100 along the length of the battery 10 by 0.5 mm, 0.6 mm, or 0.8 mm. When the dimension of the first groove 250 is greater than the dimension of the adhesive layer 120, the fault tolerance rate of the battery 10 can be improved. That is, even if the manufacturing precision of the adhesive layer 120 does not meet the requirements, the adhesive layer 120 can still be set in the first groove 250, thereby effectively avoiding material waste caused by the failure of the adhesive layer 120.

[0093] Furthermore, the manufacturing process of battery 10 is as follows: after cutting, the aluminum-plastic film is punched to thin the first wall 241 of the storage cavity 240; after thinning, the thinning depth and appearance of the aluminum-plastic film are inspected again; and the battery cell 100 is placed into the storage cavity 240 for packaging.

[0094] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application 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 this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. Battery, including: Battery cell; The housing includes a sealing portion, a storage portion, and a cover portion. The sealing portion is connected to the storage portion and the cover portion, and the cover portion is connected to the storage portion. The cover portion and the storage portion together define a storage cavity. The battery cell is disposed in the storage cavity. The cavity wall of the storage cavity includes two opposing first walls, two opposing second walls, and two opposing third walls. The two ends of the second walls are respectively connected to the two third walls. The two second walls and the two third walls surround and are connected to the first walls. The area of ​​the first wall is larger than the area of ​​the second walls and the area of ​​the third walls. Along the thickness direction of the battery cell, the two first walls are respectively disposed on both sides of the battery cell. At least one first wall is provided with a first thinned area and an unthinned area. The area of ​​the unthinned area is smaller than the area of ​​the first thinned area.

2. The battery of claim 1, wherein, Both first walls are provided with the first thinned area and the unthinned area.

3. The battery of claim 1, wherein, The first wall comprises an outer layer, a metal layer, and a heat-sealing layer stacked sequentially, wherein the heat-sealing layer is provided with the first thinning area.

4. The battery of claim 3, wherein, The thickness of the heat-sealing layer is H1, and the thickness of the first thinning zone is H2, where 1 / 2H1≤H2≤H1.

5. The battery of claim 3, wherein, The metal layer is provided with a second thinning area, and the first thinning area and the second thinning area are connected.

6. The battery of claim 5, wherein, The thickness of the metal layer is H3, and the thickness of the second thinning region is H4, where 0 < H4 ≤ 1 / 2H3.

7. The battery of claim 1, wherein, The first thinning area is set as a first groove, the thickness of the battery cell is L, the size of the first groove along the width direction of the battery is A, the size of the battery cell is W, and WL≤A≤W+L.

8. The battery of claim 7, wherein, The battery cell is a wound battery cell, WL≤A≤W; and / or, the battery cell is a laminated battery cell, W≤A≤W+L.

9. The battery of claim 1, wherein, The first thinning area is set as a first groove, and the friction coefficient of the bottom wall of the first groove is Y, 0.3 < Y < 2.

5.

10. The battery of claim 1, wherein, The first thinning area is configured as a first groove. The battery cell includes a body and an adhesive layer. The adhesive layer is connected to the body and protrudes relative to the body. The adhesive layer is disposed in the first groove.

11. The battery of claim 10, wherein, Along the length of the battery, the size of the first groove is B, the size of the battery cell is C, and the size of the adhesive layer protruding from the main body is D, where BCD≥0.

12. The battery of claim 11, wherein, BCD ≥ 0.5 mm.

13. The battery of claim 1, wherein, The first thinned area is configured as a first groove, and the first wall further includes an arc portion, the two ends of which respectively surround the groove wall connecting the unthinned area and the first groove.

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