Battery

Abstract

Disclosed in the present application is a battery, comprising: a battery cell, comprising a main body and an adhesive layer, wherein the adhesive layer is connected to the main body, and the adhesive layer protrudes relative to the main body; and a housing, comprising 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, a cavity wall of the storage cavity comprises first walls, second walls and third walls, two ends of each second wall are respectively connected to two third walls, 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 that of the second wall and that of the third wall, the two first walls are respectively arranged on two sides of the battery cell in the direction of the thickness of the battery cell, at least one of the first walls is provided with a first thinned region and an un-thinned region, the area of the un-thinned region is greater than that of the first thinned region, and a projection of the adhesive layer on the first wall is located within the first thinned region. The battery of the present application can have a high energy density.

Description

Battery

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202422527805.3, filed on October 18, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a battery. Background Technology

[0004] 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.

[0005] The battery cell has adhesive tape attached to it, which increases its thickness. When the cell is placed inside the aluminum-plastic film, this results in a thicker battery and a lower energy density. Summary of the Invention

[0006] This application aims to solve at least one of the technical problems existing in the related art. To this end, this application proposes a battery capable of having a high energy density.

[0007] The battery according to an embodiment of this application includes:

[0008] A battery cell includes a body and an adhesive layer, the adhesive layer being attached to the body and protruding relative to the body;

[0009] 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 larger than the area of ​​the first thinned area. The projection of the adhesive layer on the first wall is located within the first thinned area.

[0010] The battery according to the embodiments of this application has at least the following beneficial effects: the adhesive layer is connected to the main body and protrudes relative to the main body; therefore, the thickness of the battery cell can be the sum of the thickness of the adhesive layer and the thickness of the main body. The cavity wall of the storage chamber includes a first wall, on which a first thinning area is provided. In related technologies, the thickness of the first wall is the same as the thickness of the sealing portion. After the battery cell is placed inside the casing, the thickness of the battery is the thickness of the casing plus the thickness of the battery cell. However, in this application, after the first thinning area is provided on the first wall, the thickness of the first wall corresponding to the first thinning area is less than the thickness of the sealing portion. Overall, the storage chamber can accommodate more capacity battery cells, thereby improving the energy density of the battery. Specifically, the battery can have a higher energy density.

[0011] According to some embodiments of the battery in this application, both first walls are provided with the first thinned area and the unthinned area.

[0012] 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.

[0013] 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 0 < H2 ≤ H1.

[0014] 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.

[0015] 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.

[0016] According to some embodiments of the battery in this application, the sum of the thicknesses of the first thinned region and the second thinned region is not less than the thickness of the adhesive layer.

[0017] According to some embodiments of the battery in this application, the first wall is provided with a first groove, the size of the cell is E along the width direction of the battery, the size of the first groove is A, the size of the adhesive layer is W, and E≥A≥W.

[0018] According to some embodiments of the battery in this application, the first wall is provided with a first groove, and the coefficient of friction of the groove wall of the first groove is Y, 0.3 < Y < 2.5.

[0019] According to some embodiments of the present application, the battery has a first groove in the first wall, an un-thinned area in the first wall, and an arc portion in the first wall, the two ends of which surround the groove wall connecting the un-thinned area and the first groove.

[0020] According to some embodiments of the battery in this application, the first wall is provided with a first groove, the adhesive layer is disposed in the first groove, along the length direction of the battery, the size of the cell is M, the size of the first groove is B, the size of the adhesive layer is C, and M≥B≥C.

[0021] According to some embodiments of the present application, the battery cell further includes a tab, the main body includes a first part and a second part connected to each other, the tab is connected to the first part, the first wall is provided with a first groove and a second groove, the adhesive layer is disposed in the first groove, and the position on the first part corresponding to the tab is disposed in the second groove.

[0022] According to some embodiments of the battery in this application, the depth of the second groove is greater than or equal to the depth of the first groove.

[0023] 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

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

[0025] Figure 1 is a schematic diagram of the explosion of a battery according to some embodiments of this application;

[0026] Figure 2 is a schematic diagram of the battery casing in the first embodiment of this application;

[0027] Figure 3 is a schematic diagram of the battery casing in the second embodiment of this application;

[0028] Figure 4 is a partial schematic diagram of a battery according to some embodiments of this application;

[0029] Figure 5 is a schematic diagram of the casing in the battery according to the third embodiment of this application.

[0030] Reference numerals: Battery 10, Cell 100, Body 110, Adhesive layer 120, Tab 130, First part 140, Second part 150, Shell 200, Sealing part 210, Storage part 220, Storage cavity 221, First wall 222, Second wall 223, Third wall 224, First groove 225, Second groove 226, Arc part 230, Unthinned area 240, Cover part 250, Outer layer 300, Metal layer 400, Second thinned area 410, Heat-sealing layer 500, First thinned area 510. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The battery will be introduced first.

[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 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.

[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, gel electrolytes include a polymer-based 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 polyether (polyoxyethylene), polysiloxane, polycarbonate, 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 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.

[0079] The battery cell has adhesive tape attached to it, which increases its thickness. When the cell is placed inside the aluminum-plastic film, this results in a thicker battery and lower energy density. Therefore, this application proposes a new battery design.

[0080] Please refer to Figures 1 to 5. Figure 1 shows a schematic diagram of the battery cell 100 before it is encapsulated by the aluminum-plastic film. 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. 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. The casing 200 includes a sealing portion 210, a storage portion 220, and a cover portion 250. The casing 200 can be an aluminum-plastic film. The sealing portion 210 surrounds the edge connected to the storage portion 220. The sealing portion 210 can be heat-sealed to encapsulate the battery cell 100. The storage section 220 and the cover section 250 together define the storage cavity 221. The shape of the storage cavity 221 is not specifically limited and can be square or triangular, etc. The battery cell 100 is disposed in the storage cavity 221. The cavity wall of the storage cavity 221 includes two first walls 222, two second walls 223, and two third walls 224 disposed opposite to each other. The two ends of the second walls 223 are respectively connected to the two third walls 224. The two second walls 223 and the two third walls 224 surround and are connected to the first wall 222. The area of ​​the first wall 222 is larger than the area of ​​the second wall 223 and the area of ​​the third wall 224. The two sides of the battery cell 100 are respectively connected to the two first walls 222. That is, along the thickness direction of the battery cell 100, the two first walls 222 are respectively disposed on the two sides of the battery cell 100. At least one first wall 222 is provided with a first thinned area 510 and an unthinned area 240. The area of ​​the unthinned area 240 is larger than the area of ​​the first thinned area 510. The projection of the adhesive layer 120 on the first wall 222 is located within the first thinned area 510. Specifically, the adhesive layer 120 is attached to the main body 110 and protrudes relative to the main body 110. Therefore, the thickness of the cell 100 can be the sum of the thickness of the adhesive layer 120 and the thickness of the main body 110. The cavity wall of the storage chamber 221 includes a first wall 222, on which a first thinning area 510 is provided. In related technologies, the thickness of the first wall 222 is the same as the thickness of the sealing portion 210. After the cell 100 is placed inside the housing 200, the thickness of the battery 10 is the thickness of the housing 200 plus the thickness of the cell 100. However, in this application, after the first thinning area 510 is provided on the first wall 222, the thickness of the first wall 222 corresponding to the first thinning area 510 is less than the thickness of the sealing portion 210. This allows the storage chamber 221 to hold a larger capacity cell 100, thereby increasing the energy density of the battery 10. Specifically, the battery 10 can have a higher energy density.

[0081] Continuing the explanation below, the first wall 222 is provided with a first thinning area 510. Specifically, the projection of the adhesive layer 120 onto the first wall 222 is located within the first thinning area 510. This can be achieved by providing a first groove 225 on the first wall 222 at a position corresponding to the adhesive layer 120, allowing the adhesive layer 120 to reside within the first groove 225. This indirectly avoids the problem of the adhesive layer 120 protruding from the main body 110, which would increase the thickness of the battery cell 100, thereby improving the energy density of the battery 10. 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 222 is reduced, it can still effectively protect the battery cell 100.

[0082] In some embodiments, both first walls 222 are provided with a first thinned area 510 and an unthinned area 240. After both first walls 222 are provided with the first thinned area 510, the adhesive layers 120 on both sides of the main body 110 can be disposed in the first thinned area 510, which can further improve the energy density of the battery 10.

[0083] Further, referring to Figure 2, in some embodiments, the first wall 222 includes an outer layer 300, a metal layer 400, and a heat-sealing layer 500 stacked sequentially, with the heat-sealing layer 500 having a first thinning area 510. Specifically, the outer layer 300 may be made of nylon, the metal layer 400 may be aluminum foil, and the heat-sealing layer 500 may be a PP layer or a PE layer. The first thinning area 510 in 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 may be a first groove 225 formed on the heat-sealing layer 500, with a depth of 25 μm. In this case, the minimum thickness of the first wall 222 is less than the 25 μm thickness of the heat-sealing layer 500 in related technologies. Furthermore, the first thinning area 510 can be a partial thinning of the heat-sealing layer 500, such as by creating a first groove 225; the first thinning area 510 can also be a complete thinning of the heat-sealing layer 500. The thinning can be performed 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.

[0084] Further, referring to Figure 2, 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 0 ≤ H2 ≤ H1. Specifically, the thickness of the first thinning region 510 refers to the degree of thinning on the heat-sealing layer 500, wherein the thickness of the first thinning region 510 can be one-half, two-thirds, three-quarters, or all of the heat-sealing layer 500.

[0085] Further, referring to Figure 3, 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 222. Wherein, after the first thinning area 510 and the second thinning area 410 are connected, a first groove 225 can be formed on the first wall 222. It should be noted that, in another embodiment, the first wall 222 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 222 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 related art.

[0086] Further, referring to Figure 3, 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, wherein 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] Furthermore, in some embodiments, the sum of the thicknesses of the first thinning region 510 and the second thinning region 410 is not less than the thickness of the adhesive layer 120. Specifically, the sum of the thicknesses of the first thinning region 510 and the second thinning region 410 can be greater than the thickness of the adhesive layer 120, and the sum of the thicknesses of the first thinning region 510 and the second thinning region 410 can be equal to the thickness of the adhesive layer 120. In this case, the adhesive layer 120 can be disposed in the first thinning region 510 and the second thinning region 410, thereby effectively avoiding the effect of the adhesive layer 120 on the thickness increase of the cell 100 and improving the energy density of the battery 10.

[0088] Further, please refer to FIG. 4. In some embodiments, the first wall 222 is provided with a first groove 225. Along the width direction of the battery 10, the size of the battery cell 100 is E, the size of the first groove 225 is A, and the size of the adhesive layer 120 is W, where E≥A≥W. The first wall 222 is provided with the first groove 225 specifically by thinning the middle position of the first wall 222, thereby forming the first groove 225. The first groove 225 can be used to place the adhesive layer 120, or the first groove 225 can be used to place the battery cell 100 (including the main body 110 and the adhesive layer 120). Since the main body 110 is formed by winding the positive electrode sheet and the negative electrode sheet, the main body 110 is not a strictly rectangular parallelepiped, and there are corners on both sides in the width direction of the main body 110, and the corners are semi-cylindrical. If A<W, the size of the first groove 225 cannot accommodate the adhesive layer 120, and the purpose of improving the energy density of the battery 10 cannot be achieved. If A>E, this will cause the width of the first groove 225 to be too large, resulting in an increase in processing costs.

[0089] Further, in some embodiments, the first thinning area 510 is set as the first groove 225, and the friction coefficient of the groove wall of the first groove 225 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 225 is small, the battery cell 100 may move in the first groove 225 and thus be damaged. When the friction coefficient of the groove wall of the first groove 225 is large, although this can effectively prevent the battery cell 100 from sliding in the first groove 225, under the premise of protecting the battery cell 100, an overly large friction coefficient will lead to an increase in manufacturing costs.

[0090] Further, please refer to FIG. 2. In some embodiments, the first wall 222 is provided with a first groove 225, the first wall 222 is further provided with an unthinned area 240, and the first wall 222 further includes an arc portion 230. The two ends of the arc portion 230 are respectively connected around the unthinned area 240 and the groove wall of the first groove 225. Specifically, the first groove 225 can be provided on the heat-sealing layer 500 or on the metal layer 400 on the first wall 222. After the first groove 225 is provided, the notch of the first groove 225 can be rounded, that is, the arc portion 230 is provided. This can effectively protect the battery cell 100 and prevent the battery cell 100 from being damaged by the sharp notch.

[0091] Furthermore, in some embodiments, the first wall 222 is provided with a first groove 225, and the adhesive layer 120 is disposed in the first groove 225. Along the length direction of the battery 10, the size of the cell 100 is M, the size of the first groove 225 is B, and the size of the adhesive layer 120 is C, where M≥B≥C. When the size of the first groove 225 is larger than the size of the adhesive layer 120, this can improve the fault tolerance rate of battery 10 manufacturing. That is, even if the manufacturing precision of the adhesive layer 120 does not meet the requirements, the adhesive layer 120 can still be disposed in the first groove 225, thereby effectively avoiding material waste caused by adhesive layer 120 failure. When the length of the first groove 225 is greater than the length of the cell 100, this will increase the manufacturing cost, provided that the first groove 225 can accommodate the adhesive layer 120.

[0092] Furthermore, in some embodiments, the first wall 222 is provided with a first groove 225, and the adhesive layer 120 is disposed in the first groove 225. The depth of the first groove 225 is G, where 10µm ≤ G ≤ 40µm. Specifically, the depth of the first groove 225 can be 10µm, 20µm, 30µm, or 40µm. When the depth of the first groove 225 is less than 10µm, the depth of the first groove 225 is too small, which will result in a small thickness of the adhesive layer 120 accommodated in the first groove 225, thus the energy density of the battery 10 will not be significantly improved. When the depth of the first groove 225 is greater than 50µm, the depth of the first groove 225 is too large, which may result in a small thickness of the metal layer 400, and lower safety of the battery 10.

[0093] Further referring to Figures 1 and 5, in some embodiments, the battery cell 100 further includes a tab 130, and the main body 110 includes a first part 140 and a second part 150 connected to each other. The tab 130 is connected to the first part 140, and the first wall 222 is provided with a first groove 225 and a second groove 226. The adhesive layer 120 is disposed in the first groove 225, and the position on the first part 140 corresponding to the tab 130 is disposed in the second groove 226. Specifically, after the tab 130 is connected to the first part 140, the thickness of the battery cell 100 is increased. By disposing the adhesive layer 120 in the first groove 225 and the first part 140 in the second groove 226, the energy density of the battery 10 is effectively improved.

[0094] Further, referring to Figure 5, in some embodiments, the depth of the second groove 226 is greater than or equal to the depth of the first groove 225. The tab 130 connecting to the first part 140 can specifically be the tab 130 being connected to either the positive or negative electrode. The thickness of the tab 130 can be greater than or equal to the thickness of the positive electrode. Therefore, after the tab 130 is connected to the first part 140, the final thickness of the first part 140 will be greater than the thickness of the second part 150. Specifically, after the depth of the second groove 226 is greater than or equal to the depth of the first groove 225, the first part 140 can be disposed in the second groove 226, and the adhesive layer 120 can be located in the first groove 225. This allows the battery cell 100 to be parallel to the first wall 222, thereby effectively preventing the battery cell 100 from tilting in the storage cavity 221. In other embodiments, the first groove 225 can communicate with the second groove 226, or the first groove 225 and the second groove 226 can be non-communicating.

[0095] Furthermore, the manufacturing process of battery 10 is as follows: after cutting, the aluminum-plastic film is punched to thin the first wall 222 of the storage cavity 221; 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 221 for packaging.

[0096] 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: A battery cell includes a body and an adhesive layer, the adhesive layer being attached to the body and protruding relative to the body; 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 larger than the area of ​​the first thinned area. The projection of the adhesive layer on the first wall is located within 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 a first thinning zone.

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 0 < 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 5, wherein, The sum of the thicknesses of the first thinning zone and the second thinning zone is not less than the thickness of the adhesive layer.

8. The battery of claim 1, wherein, The first wall is provided with a first groove along the width direction of the battery. The size of the battery cell is E, the size of the first groove is A, and the size of the adhesive layer is W, where E≥A≥W.

9. The battery of claim 1, wherein, The first wall is provided with a first groove, and the coefficient of friction of the groove wall is Y, where 0.3 < Y < 2.

5.

10. The battery of claim 1, wherein, The first wall is provided with a first groove, and the first wall is also provided with an unthinned area. The first wall also includes an arc portion, the two ends of which respectively surround the groove wall connecting the unthinned area and the first groove.

11. The battery of claim 1, wherein, The first wall is provided with a first groove, and the adhesive layer is disposed in the first groove. Along the length direction of the battery, the size of the battery cell is M, the size of the first groove is B, and the size of the adhesive layer is C, where M≥B≥C.

12. The battery of claim 1, wherein, The battery cell also includes a tab. The main body includes a first part and a second part that are connected to each other. The tab is connected to the first part. The first wall is provided with a first groove and a second groove. The adhesive layer is disposed in the first groove. The position on the first part corresponding to the tab is disposed in the second groove.

13. The battery of claim 12, wherein, The depth of the second groove is greater than or equal to the depth of the first groove.

Images