Battery cell, battery and electric equipment

Abstract

The utility model discloses a battery cell, battery and electric equipment, the battery cell comprises a first pole piece and a second pole piece, the battery cell is formed by winding after the first pole piece and the second pole piece are laminated, the first pole piece comprises a plurality of first straight sections and a plurality of first bent sections, and the first straight sections and the first bent sections are arranged along the winding direction of the battery cell. The first straight sections and the first bent sections are alternately arranged, each first straight section comprises a first end and a second end, each first end is provided with a first connecting part, and each second end is provided with a second connecting part; the distance between two adjacent first connecting parts in the winding direction of the battery cell is greater than the distance between two adjacent second connecting parts in the winding direction of the battery cell, the plurality of first connecting parts are laminated and connected with each other to form a first connecting body, and the plurality of second connecting parts are laminated and connected with each other to form a second connecting body; and the first connector is electrically connected to the first tab. The battery cell provided by the utility model can have longer service life.

Description

Technical Field

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

[0002] In related technologies, batteries need to be recharged after their charge is depleted. During charging, current flows into the battery. A uniform distribution of current density after it enters the battery reduces localized overheating and stress concentration, thereby lowering the risk of battery aging and damage, and extending battery life. Specifically, in existing technologies, the current density distribution after it enters the battery is not uniform, which leads to a shorter battery life. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a battery cell that has a long service life.

[0004] This utility model also proposes a battery.

[0005] This utility model also proposes an electrical device.

[0006] According to a first aspect of the present invention, a battery cell includes a first electrode and a second electrode. The battery cell is formed by stacking and winding the first electrode and the second electrode. The first electrode includes a plurality of first straight sections and a plurality of first curved sections. Along the winding direction of the battery cell, the first straight sections and the first curved sections are alternately arranged. The first straight section includes a first end and a second end. The first end has a first connecting portion, and the second end has a second connecting portion. The distance between two adjacent first connecting portions in the winding direction of the battery cell is greater than the distance between two adjacent second connecting portions in the winding direction of the battery cell. The plurality of first connecting portions are stacked and connected to each other to form a first connecting body, and the plurality of second connecting portions are stacked and connected to each other to form a second connecting body. The first connecting body is electrically connected to a first tab.

[0007] The battery cell according to the embodiments of this utility model has at least the following beneficial effects: The battery cell includes a first electrode sheet, the first electrode sheet includes multiple first straight sections, each first straight section includes a first end and a second end, the first end has a first connecting portion, the second end has a second connecting portion, the multiple first connecting portions are stacked and interconnected, and the multiple second connecting portions are stacked and interconnected. The first connecting portions are connected to a first tab, allowing external current to enter the first connecting portion through the first tab. The current can then flow from the first end to the second end, and also to the periphery of the first end. After flowing to the second end, the current can continue to flow through the second connecting portions to various corners of the first electrode sheet. That is, by interconnecting the multiple first connecting portions and the multiple second connecting portions, and setting the distance between two adjacent first connecting portions in the battery cell winding direction to be greater than the distance between two adjacent second connecting portions in the battery cell winding direction, a uniform current density distribution can be achieved in the first electrode sheet, which can effectively improve the battery cell's service life. Specifically, the battery cell can have a longer service life.

[0008] According to some embodiments of the present invention, the second end of the battery cell further has a third connecting portion, and a plurality of the third connecting portions are stacked and interconnected to form a third connecting body.

[0009] According to some embodiments of the present invention, the distance between two adjacent first connecting portions in the winding direction of the battery cell is A, and the size of the first electrode is B along the length direction of the battery cell, where A ≥ 2B.

[0010] According to some embodiments of the present invention, in a battery cell, along the thickness direction of the battery cell, a plurality of first straight segments form an abutment surface, and a second connector is attached to the abutment surface.

[0011] According to some embodiments of the present invention, the battery cell further includes a first insulating member located between the second connector and the abutment surface.

[0012] According to some embodiments of the present invention, the battery cell further includes a second insulating member, which is wrapped around the second connector.

[0013] According to some embodiments of the present invention, the second electrode includes a plurality of second straight sections and a plurality of second curved sections. Along the winding direction of the battery cell, the second straight sections and the second curved sections are alternately arranged. The second straight section includes a third end and a fourth end. The third end has a fourth connecting portion. The plurality of fourth connecting portions are stacked and interconnected to form a fourth connecting body.

[0014] According to some embodiments of the present invention, the fourth end of the battery cell has a fifth connecting portion, a plurality of the fifth connecting portions are stacked and connected to each other, the distance between two adjacent fourth connecting portions in the winding direction of the battery cell is greater than the distance between two adjacent fifth connecting portions in the winding direction of the battery cell, and the fourth connecting body is electrically connected to the second tab.

[0015] According to some embodiments of the present invention, the fourth end of the battery cell further has a sixth connecting portion, and a plurality of the sixth connecting portions are stacked and interconnected.

[0016] The battery according to the second aspect embodiment of the present invention includes the battery cell described in any one of the first aspect embodiments.

[0017] The battery according to the embodiments of this utility model has at least the following beneficial effects: The battery cell includes a first electrode sheet, the first electrode sheet includes multiple first straight sections, each first straight section includes a first end and a second end, the first end has a first connecting portion, the second end has a second connecting portion, the multiple first connecting portions are stacked and interconnected, and the multiple second connecting portions are stacked and interconnected. The first connecting portions are connected to a first tab, allowing external current to enter the first connecting portion through the first tab. The current can then flow from the first end to the second end, and also to the periphery of the first end. After flowing to the second end, the current can continue to flow through the second connecting portions to various corners of the first electrode sheet. That is, by interconnecting the multiple first connecting portions and the multiple second connecting portions, and setting the distance between two adjacent first connecting portions in the cell winding direction to be greater than the distance between two adjacent second connecting portions in the cell winding direction, a uniform current density distribution can be achieved in the first electrode sheet, which can effectively improve the battery cell's lifespan. Specifically, the battery cell can have a longer lifespan. Furthermore, the battery with this battery cell has a longer lifespan.

[0018] The electrical device according to a third aspect embodiment of the present invention includes the battery described in the second aspect embodiment.

[0019] The electrical device according to the embodiments of this utility model has at least the following beneficial effects: The battery cell includes a first electrode sheet, the first electrode sheet includes multiple first straight sections, each first straight section includes a first end and a second end, the first end has a first connecting portion, the second end has a second connecting portion, the multiple first connecting portions are stacked and interconnected, and the multiple second connecting portions are stacked and interconnected. The first connecting portions are connected to a first tab, allowing external current to enter the first connecting portion through the first tab. The current can then flow from the first end to the second end, and also to the periphery of the first end. After flowing to the second end, the current can continue to flow through the second connecting portions to various corners of the first electrode sheet. That is, by interconnecting the multiple first connecting portions and the multiple second connecting portions, and setting the distance between two adjacent first connecting portions in the battery cell winding direction to be greater than the distance between two adjacent second connecting portions in the battery cell winding direction, a uniform current density distribution can be achieved in the first electrode sheet, which can effectively improve the battery cell's lifespan. Specifically, the battery cell can have a longer lifespan. Furthermore, the battery with this battery cell has a longer lifespan. Furthermore, electrical devices equipped with this battery also have a longer lifespan.

[0020] 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

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 This is a schematic diagram of the battery cell according to the first embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the battery cell according to the second embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the first electrode sheet being flattened in a battery cell according to some embodiments of the present invention;

[0025] Figure 4 This is a schematic diagram of the second electrode sheet being flattened in a battery cell according to some embodiments of the present invention;

[0026] Figure 5 This is a schematic diagram of the battery cell according to the third embodiment of this utility model.

[0027] Figure label:

[0028] Battery cell 10, first electrode 100, first straight section 110, first end 120, first connecting part 130, second end 140, second connecting part 150, third connecting part 160, first bent section 170, second electrode 200, second straight section 210, third end 220, fourth connecting part 230, fourth end 240, fifth connecting part 250, sixth connecting part 260, second bent section 270, first insulating member 300, first tab 400, second tab 500, contact surface 600. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.).

[0039] 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 Mn1 / 3 O2 (also known as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM523), LiNi 0.5 Co 0.25 Mn 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.

[0040] 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.

[0041] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0042] 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.).

[0043] 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.

[0044] 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.

[0045] 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.

[0046] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0047] In some implementations, the battery cell also includes an isolation element disposed between the positive and negative terminals.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0055] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0056] 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.

[0057] 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.

[0058] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0059] In some implementations, the battery cell has a wound structure. The positive and negative electrode plates are wound into a wound structure.

[0060] In some implementations, the battery cell has a laminated structure.

[0061] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0062] 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.

[0063] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0064] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0065] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0066] In some implementations, the battery cell can be cylindrical, flat, or polygonal, etc.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] In related technologies, batteries need to be recharged after their charge is depleted. During charging, current flows into the battery. A uniform current density distribution within the battery reduces localized overheating and stress concentration, thereby lowering the risk of battery aging and damage, and extending battery life. Specifically, in existing technologies, the current density distribution within the battery is not uniform, leading to a shorter battery life. Therefore, this application proposes a new battery cell.

[0076] Please refer to Figures 1 to 5 In some embodiments, the battery cell 10 includes a first tab 400, a first electrode 100, and a second electrode 200. The battery cell 10 is formed by stacking and winding the first electrode 100 and the second electrode 200. Specifically, a separator is provided between the first electrode 100 and the second electrode 200. After the first electrode 100, the separator, and the second electrode 200 are stacked, they are wound together to form the battery cell 10. The first electrode 100 can be a positive electrode, and the second electrode 200 can be a negative electrode. The first electrode 100 includes a plurality of first straight sections 110 and a plurality of first bent sections 170. Along the winding direction of the battery cell 10, the first straight sections 110 and the first bent sections 170 are alternately arranged. Understandably, the first electrode 100 is sheet-like before winding, and after winding, it forms a first straight section 110 and a first curved section 170. See [reference needed] for details. Figure 3The first straight section 110 includes a first end 120 and a second end 140 disposed opposite to each other. The first end 120 has a first connecting portion 130, and the second end 140 has a second connecting portion 150. The first end 120 having a first connecting portion 130 means that the first end 120 has a foil tab. The second end 140 having a second connecting portion 150 means that the second end 140 has a foil tab. That is, the first straight section 110 includes a foil and an active material layer, wherein the active material layer covers most of the foil, and the portion of the foil not covered by the active material layer is used to conduct current. Multiple first connecting portions 130 are stacked and interconnected, and multiple second connecting portions 150 are stacked and interconnected. The distance between two adjacent first connecting portions 130 in the winding direction of the cell 10 is greater than the distance between two adjacent second connecting portions 150 in the winding direction of the cell 10. The first connecting portion 130 is electrically connected to the first tab 400. Specifically, the battery cell 10 includes a first electrode 100, which includes multiple first straight sections 110. Each first straight section 110 includes a first end 120 and a second end 140. The first end 120 has a first connecting portion 130, and the second end 140 has a second connecting portion 150. The multiple first connecting portions 130 are stacked and interconnected to form a first connecting body, and the multiple second connecting portions 150 are stacked and interconnected to form a second connecting body. The first connecting body is connected to a first tab 400. Current from outside the battery cell 10 can enter the first connecting portion 130 through the first tab 400, and then the current can flow from the first end 120 to the first connecting portion 140. The current flows from the first end 120 to the second end 140, and can also flow to the periphery of the first end 120. After flowing to the second end 140, the current can continue to flow through the second connection 150 to various corners of the first electrode 100. That is, by connecting multiple first connection parts 130 to each other and multiple second connection parts 150 to each other, and setting the distance between two adjacent first connection parts 130 in the winding direction of the cell 10 to be greater than the distance between two adjacent second connection parts 150 in the winding direction of the cell 10, the current density can be uniformly distributed in the first electrode 100, which can effectively improve the service life of the cell 10. In the prior art, the current can only flow from the first end 120 of the first electrode 100 to the periphery, which results in a larger current density at the first end 120 and a smaller current density at the second end 140. Specifically, the cell 10 can have a longer service life.

[0077] Please refer to Figure 3 The aforementioned statement that the distance between two adjacent first connecting portions 130 in the winding direction of the cell 10 is greater than the distance between two adjacent second connecting portions 150 in the winding direction of the cell 10 specifically means that when the first electrode 100 is flattened, the distance between two adjacent first connecting portions 130 in the length direction of the first electrode 100 is greater than the distance between two adjacent second connecting portions 150 in the length direction of the first electrode 100.

[0078] Furthermore, when current enters the cell 10, it passes through the first tab 400. Specifically, the current enters the first end 120 of the first electrode 100 through the first tab 400, and then flows to various positions on the first electrode 100. The second end 140 is farther from the first end 120, so the current flow path is longer and the current density is lower. To minimize the difference in current density between the region far from the first end 120 and the region at the first end 120, a third connection portion 160 can be provided, thereby making the overall current density of the cell 10 uniform. For details, please refer to... Figure 1 and Figure 3 In some embodiments, the second end 140 further has a third connecting portion 160, and multiple third connecting portions 160 are stacked and interconnected to form a third connecting body. The stacking and interconnection of multiple first connecting portions 130 can be achieved by welding. The stacking and interconnection of multiple second connecting portions 150 can be achieved by welding. The stacking and interconnection of multiple third connecting portions 160 can be achieved by welding.

[0079] Further, please refer to Figure 3 In some embodiments, the distance between two adjacent first connection portions 130 in the winding direction of the cell 10 is A, and the size of the first electrode 100 along the length direction of the cell 10 is B, where A ≥ 2B. Specifically, both the first end 120 and the second end 140 of the first electrode 100 are provided with foil tabs, and the number of first connection portions 130 is less than the sum of the number of second connection portions 150 and third connection portions 160. The cell 10 has a low internal resistance and good fast charging performance. When current flows in from the first tab 400, the current flows to the second end 140 and both sides of the length direction of the first electrode 100. When A ≥ 2B, the current will first reach the second connection portion 150 and the third connection portion 160, and then be diverted from the second connection portion 150 and the third connection portion 160 to other positions of the first electrode 100. Thus, the current density flowing into the first electrode 100 will be determined by the impedance of each shunt path within the first electrode 100. Simultaneously, as the cycle progresses, the impedance of the active material increases due to the high current density. The path with the high current density initially suppresses the current density of this path due to the increased impedance, while the current density of other paths increases. This achieves dynamic adjustment of the current within the system, making the current density distribution uniform throughout the first electrode 100 and extending throughout the entire life cycle, thereby improving the interface and enhancing the battery cycle life.

[0080] Furthermore, A≥2B can specifically mean A>2B or A=2B. For details, please refer to Table 1 below.

[0081] Table 1

[0082]

[0083] Comparative Examples 1 and 2 represent the existing battery cell 10. Comparison with these examples shows that when A ≥ 2B, the anode structure allows for better dynamic adjustment of the current within the system, resulting in a more uniform current density distribution. This significantly improves lithium plating in battery cell 10 and also greatly enhances its cycle life. Furthermore, as A gradually increases, the internal resistance of battery cell 10 increases, leading to a corresponding increase in the temperature rise during charge-discharge cycles, which in turn inhibits cycle life. It should be noted that G represents the lithium plating level; higher levels indicate more severe lithium plating. G0 indicates no lithium plating, G1 indicates pointillist lithium plating, G2 indicates continuous lithium plating, G3 indicates moderate lithium plating, G4 indicates severe lithium plating, and G5 indicates extremely severe lithium plating. G2.5 indicates lithium plating between levels 2 and 3.

[0084] Further, please refer to Figure 2 In some embodiments, multiple first straight segments 110 form abutment surfaces 600 along the thickness direction of the cell 10, and the second connector is attached to the abutment surface 600. Specifically, after the second connector 150 is attached to the abutment surface 600, the energy density of the cell 10 is effectively improved. This is because, for a fixed size, if the second connector 150 is not attached to the abutment surface 600, the size of the cell 10 will be larger. Although the size of the cell 10 is larger, the content of the active material layer is smaller, so the energy density of the cell 10 is lower.

[0085] Further, please refer to Figure 2 In some embodiments, the battery cell 10 further includes a first insulating member 300, which is located between the second connector and the contact surface 600. The first insulating member 300 can be an insulating pad or an insulating sheet. The material of the first insulating member 300 can be silicone or rubber, etc. The first insulating member 300 is located between the second connector 150 and the contact surface 600, which can effectively prevent the second connector and the second electrode 200 from contacting each other, thereby improving the safety of the battery cell 10.

[0086] Furthermore, the insulation between the second connecting portion 150 and the contact surface 600 can also be achieved in other ways. Specifically, in some embodiments, the battery cell 10 further includes a second insulating member, which is wrapped around the second connecting body. Specifically, the second insulating member can be insulating tape, which wraps around the second connecting portion 150 to achieve insulation between the second connecting portion 150 and the contact surface 600. In some embodiments, the second connecting portion 150 can be wrapped with the second insulating member first, and then a first insulating member 300 can be placed between the second connecting portion 150 and the contact surface 600, which can effectively improve the safety of the battery cell 10.

[0087] Furthermore, the aforementioned method of improving the lifespan of the battery cell 10 by uniformizing the current density in the first electrode 100 can also be used to further improve the lifespan of the battery cell 10 by uniformizing the current density in the second electrode 200. For details, please refer to... Figures 1 to 5 In some embodiments, the battery cell 10 further includes a second tab 500. The second electrode 200 includes a plurality of second straight sections 210 and a plurality of second curved sections 270. It is understood that the second electrode 200 is sheet-like before winding, and after winding, the second electrode 200 forms second straight sections 210 and second curved sections 270. Along the winding direction of the battery cell 10, the second straight sections 210 and second curved sections 270 are alternately arranged. The second straight section 210 includes a third end 220 and a fourth end 240. The third end 220 has a fourth connecting portion 230, and the fourth end 240 has a fifth connecting portion 250. The third end 220 having a fourth connecting portion 230 means that the third end 220 has a foil tab. The fourth end 240 having a fifth connecting portion 250 means that the fourth end 240 has a foil tab. That is, the second straight section 210 includes a foil and an active material layer, wherein the active material layer covers most of the foil, and the portion of the foil not covered by the active material layer is used to conduct current. Multiple fourth connecting portions 230 are stacked and interconnected to form a fourth connecting body, and multiple fifth connecting portions 250 are stacked and interconnected. The distance between two adjacent fourth connecting portions 230 in the winding direction of the cell 10 is greater than the distance between two adjacent fifth connecting portions 250 in the winding direction of the cell 10, and the fourth connecting portions 230 are electrically connected to the second tab 500. Specifically, the battery cell 10 includes a second electrode 200, which includes multiple second straight sections 210. Each second straight section 210 includes a third end 220 and a fourth end 240. The third end 220 has a fourth connecting portion 230, and the fourth end 240 has a fifth connecting portion 250. The multiple fourth connecting portions 230 are stacked and interconnected, and the multiple fifth connecting portions 250 are stacked and interconnected. The fourth connecting portion 230 is connected to a second electrode tab 500. Current from outside the battery cell 10 can enter the fourth connecting portion 230 through the second electrode tab 500, and then the current can flow from the third end 220 to... The fourth terminal 240 allows current to flow to the periphery of the third terminal 220. After the current flows to the fourth terminal 240, it can continue to flow through the fifth connection 250 to various corners of the second electrode 200. That is, by connecting multiple fourth connection 230s to each other and multiple fifth connection 250s to each other, and setting the distance between two adjacent fifth connection 250s in the winding direction of the cell 10 to be greater than the distance between two adjacent fourth connection 230s in the winding direction of the cell 10, the current density can be uniformly distributed in the second electrode 200, which can effectively improve the service life of the cell 10.

[0088] Please refer to Figure 4The aforementioned statement that the distance between two adjacent fourth connection portions 230 in the winding direction of the cell 10 is greater than the distance between two adjacent fifth connection portions 250 in the winding direction of the cell 10 specifically means that when the second electrode 200 is flattened, the distance between two adjacent fourth connection portions 230 in the length direction of the second electrode 200 is greater than the distance between two adjacent fifth connection portions 250 in the length direction of the second electrode 200.

[0089] Furthermore, when current enters the cell 10, it passes through the second tab 500. Specifically, the current enters the cell 10 through the second tab 500 to the third end 220 of the second electrode 200, and then flows to various positions on the second electrode 200. The fourth end 240 is farther from the third end 220, so the current flow path is longer and the current density is lower. To minimize the difference in current density between the area far from the fourth end 240 and the area at the third end 220, a sixth connection part 260 can be provided, thereby making the overall current density of the cell 10 uniform. For details, please refer to... Figure 5 In some embodiments, the fourth end 240 further has a sixth connecting portion 260, and multiple sixth connecting portions 260 are stacked and interconnected. The stacking and interconnection of multiple fourth connecting portions 230 can be achieved by welding. The stacking and interconnection of multiple fifth connecting portions 250 can be achieved by welding. The stacking and interconnection of multiple sixth connecting portions 260 can be achieved by welding. In another embodiment, the structure of the second electrode 200 is consistent with a conventional structure, with the fourth connecting portion 230 provided at the third end 220 of the second straight section 210 and the sixth connecting portion 260 provided at the fourth end 240. Alternatively, only the fourth connecting portion 230 is provided on the second electrode 200. Alternatively, both the fourth connecting portion 230 and the fifth connecting portion 250 are provided on the second electrode 200.

[0090] Furthermore, when the second electrode 200 also adopts the structure of the first electrode 100, please refer to Table 2 below.

[0091] Table 2

[0092]

[0093] In embodiments 6 to 10, the second electrode 200 adopts the structure of the first electrode 100. By comparing embodiments 1 to 5 in Table 1 and embodiments 6 to 10 in Table 2, it can be seen that when the second electrode 200 adopts the design of the first electrode 100, it can effectively alleviate the local pressure of the cell 10 during cyclic discharge and improve the service life of the cell 10.

[0094] In some embodiments, the battery includes a cell 10 as described in any of the above embodiments. Specifically, the cell 10 includes a first electrode 100, which includes a plurality of first straight sections 110. Each first straight section 110 includes a first end 120 and a second end 140. The first end 120 has a first connecting portion 130, and the second end 140 has a second connecting portion 150. The plurality of first connecting portions 130 are stacked and interconnected, and the plurality of second connecting portions 150 are stacked and interconnected. The first connecting portion 130 is connected to a first tab 400. Current from outside the cell 10 can enter the first connecting portion 130 through the first tab 400, and then the current can flow from the first end 120 to the first connecting portion 140. The second end 140 allows current to flow to the periphery of the first end 120. After the current flows to the second end 140, it can continue to flow through the second connection portion 150 to various corners of the first electrode 100. That is, by connecting multiple first connection portions 130 to each other and multiple second connection portions 150 to each other, and by setting the distance between two adjacent first connection portions 130 in the winding direction of the cell 10 to be greater than the distance between two adjacent second connection portions 150 in the winding direction of the cell 10, a uniform current density distribution can be achieved in the first electrode 100, which can effectively improve the service life of the cell 10. Specifically, the cell 10 can have a longer service life. Furthermore, the battery with this cell 10 has a longer service life.

[0095] In some embodiments, the electrical device includes the battery of the above embodiments. Specifically, the battery cell 10 includes a first electrode 100, the first electrode 100 includes a plurality of first straight sections 110, the first straight section 110 includes a first end 120 and a second end 140, the first end 120 has a first connecting portion 130, the second end 140 has a second connecting portion 150, the plurality of first connecting portions 130 are stacked and interconnected, the plurality of second connecting portions 150 are stacked and interconnected, wherein the first connecting portion 130 is connected to a first tab 400, and the current from outside the battery cell 10 can enter the first connecting portion 130 through the first tab 400, and then the current can flow from the first end 120 to the first connecting portion 140. The second end 140 allows current to flow to the periphery of the first end 120. After the current flows to the second end 140, it can continue to flow through the second connection portion 150 to various corners of the first electrode 100. That is, by connecting multiple first connection portions 130 to each other and multiple second connection portions 150 to each other, and by setting the distance between two adjacent first connection portions 130 in the winding direction of the cell 10 to be greater than the distance between two adjacent second connection portions 150 in the winding direction of the cell 10, a uniform current density distribution can be achieved in the first electrode 100, which can effectively improve the service life of the cell 10. Specifically, the cell 10 can have a longer service life. Furthermore, the battery with this cell 10 has a longer service life. Even further, the electrical device with this battery also has a longer service life.

[0096] 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 cell, characterized in that, The battery cell includes a first electrode and a second electrode. The battery cell is formed by stacking and winding the first electrode and the second electrode. The first electrode includes a plurality of first straight sections and a plurality of first curved sections. Along the winding direction of the battery cell, the first straight sections and the first curved sections are alternately arranged. The first straight section includes a first end and a second end. The first end has a first connecting portion, and the second end has a second connecting portion. The distance between two adjacent first connecting portions in the winding direction of the battery cell is greater than the distance between two adjacent second connecting portions in the winding direction of the battery cell. The plurality of first connecting portions are stacked and connected to each other to form a first connecting body. The plurality of second connecting portions are stacked and connected to each other to form a second connecting body. The first connecting body is electrically connected to a first tab.

2. The battery cell according to claim 1, characterized in that, The second end also has a third connecting portion, and multiple third connecting portions are stacked and connected to each other to form a third connecting body.

3. The battery cell according to claim 1, characterized in that, The distance between two adjacent first connection portions in the winding direction of the battery cell is A, and the size of the first electrode is B along the length direction of the battery cell, where A ≥ 2B.

4. The battery cell according to claim 1, characterized in that, Along the thickness direction of the battery cell, a plurality of first straight segments form an abutment surface, and the second connector is attached to the abutment surface.

5. The battery cell according to claim 4, characterized in that, The battery cell also includes a first insulating element, which is located between the second connector and the contact surface.

6. The battery cell according to claim 4, characterized in that, The battery cell also includes a second insulating component, which is wrapped around the second connector.

7. The battery cell according to claim 1, characterized in that, The second electrode includes a plurality of second straight sections and a plurality of second curved sections along the winding direction of the battery cell. The second straight sections and the second curved sections are alternately arranged. The second straight section includes a third end and a fourth end. The third end has a fourth connecting portion. The plurality of fourth connecting portions are stacked and interconnected to form a fourth connecting body.

8. The battery cell according to claim 7, characterized in that, The fourth end has a fifth connection portion, and multiple fifth connection portions are stacked and connected to each other. The distance between two adjacent fourth connection portions in the cell winding direction is greater than the distance between two adjacent fifth connection portions in the cell winding direction. The fourth connection body is electrically connected to the second tab.

9. The battery cell according to claim 7, characterized in that, The fourth end also has a sixth connecting part, and multiple sixth connecting parts are stacked and connected to each other.

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

11. Electrical equipment, characterized in that, Includes the battery as described in claim 10.

Images