Battery cell, battery, and electric device

Abstract

The embodiment of the application provides a battery monomer, a battery and an electric equipment, and belongs to the technical field of batteries. The battery monomer comprises a shell, an electrode assembly and an electrode terminal. The shell comprises a wall part, and the wall part is provided with a lead-out hole. The electrode assembly is accommodated in the shell, and the electrode assembly comprises an active material coating part and a tab, and the tab is arranged at one end of the active material coating part facing the wall part. The electrode terminal comprises a terminal body and a limiting part, the terminal body is arranged in the lead-out hole, and the limiting part comprises a first extension segment protruding from the outer circumferential surface of the terminal body in a first direction. The tab comprises a first connecting part and a second connecting part, the second connecting part is located on one side of the first connecting part in the first direction, the first connecting part is connected to the active material coating part, and the second connecting part is connected to the first extension segment. This structure shortens the length of the second connecting part, and further shortens the length of the tab, reduces the possibility of dislocation and pleating of the tab in the production process, and improves the reliability of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery, and an electrical device. Background Technology

[0002] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] To achieve high capacity in typical battery cells, their size can be increased. However, this increase in size may lead to decreased reliability. Therefore, when designing battery cells, reliability must be considered in addition to capacity. Improving battery cell lifespan is thus a pressing issue in battery technology. Summary of the Invention

[0004] This application provides a battery cell, a battery, and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, including a housing, an electrode assembly, and electrode terminals; the housing includes a wall portion with an outlet hole; the electrode assembly is housed within the housing, the electrode assembly including an active material coating portion and a tab, the tab being disposed at one end of the active material coating portion facing the wall portion; the electrode terminal includes a terminal body and a limiting portion, the terminal body passing through the outlet hole, the limiting portion being configured to restrict the terminal body from disengaging from the outlet hole in a direction away from the active material coating portion, the limiting portion including a first extension protruding from the outer peripheral surface of the terminal body in a first direction; the tab includes a first connecting portion and a second connecting portion, the second connecting portion being located on one side of the first connecting portion along the first direction, the first connecting portion being connected to the active material coating portion, and the second connecting portion being connected to the first extension portion.

[0006] In the above technical solution, the second connecting part is located on one side of the first connecting part along the first direction. The second connecting part is connected to the first extension section of the limiting part that protrudes from the outer peripheral surface of the terminal body along the first direction. This shortens the length of the second connecting part, thereby shortening the length of the tab, reducing the possibility of misalignment or creases in the tab during production, and improving the reliability of the battery cell.

[0007] In some embodiments, the limiting portion further includes a second extension protruding from the outer peripheral surface of the terminal body in the opposite direction to the first direction; along the first direction, the distance between the end of the second extension away from the terminal body and the central axis of the terminal body is a first distance, the first extension includes an elongation region, the distance between the elongation region and the central axis is greater than or equal to the first distance, and the second connecting portion is connected to the elongation region. The provision of the elongation region increases the length of the first extension along the second direction, thereby elongating the second extension away from the terminal body. The second connecting portion is connected to the elongation region, making the second connecting portion further away from the terminal body along the first direction. In this way, the second connecting portion can be made shorter, which is beneficial for further shortening the length of the electrode tab.

[0008] In some embodiments, along the first direction, the distance between the end of the second connecting portion near the terminal body and the central axis is a second distance, which is greater than or equal to the first distance. This causes the end of the second connecting portion near the terminal body to be further away from the terminal body along the first direction, further shortening the length of the second connecting portion, and thus further shortening the length of the electrode tab.

[0009] In some embodiments, the first connecting portion and the active material coating portion are positioned opposite each other at the midpoint along the first direction; and / or, the terminal body and the active material coating portion are positioned opposite each other at the midpoint along the first direction. If the first connecting portion and the active material coating portion are positioned opposite each other at the midpoint along the first direction, the tab is centered before bending, which facilitates tab forming and reduces the difficulty of tab forming. If the terminal body and the active material coating portion are positioned opposite each other at the midpoint along the first direction, the terminal body is centered, which facilitates connection between the electrode terminal and external components, making it easier to output or input electrical energy.

[0010] In some embodiments, the tab further includes a third connecting portion and a fourth connecting portion, with the first connecting portion, the third connecting portion, the fourth connecting portion, and the second connecting portion connected sequentially. Along the axial direction of the terminal body, the second connecting portion and the third connecting portion are disposed opposite to each other. This causes the tab to be bent between the active material coating portion and the electrode terminal, reducing the space occupied by the tab within the battery cell and providing more space for the active material coating portion, which is beneficial for improving the energy density of the battery cell.

[0011] In some embodiments, along the axial direction of the terminal body, the second connecting portion is connected to the side of the first extension facing the active material coating portion. This reduces the axial distance between the second connecting portion and the active material coating portion of the terminal body, effectively reducing the length of the tab.

[0012] In some embodiments, the terminal body and the limiting portion are integrally formed. This results in a stronger connection between the terminal body and the limiting portion, making them more robust and reducing the likelihood of the terminal body separating from the limiting portion due to impact during normal use of the battery cell, thus reducing the possibility of battery cell failure during normal use.

[0013] In some embodiments, the battery cell further includes a first insulating member. Along the axial direction of the terminal body, the first insulating member includes a first insulating portion disposed between the first extension and the wall portion. A heat-insulating structure is provided on the side of the first insulating portion facing the first extension and / or on the side of the first extension facing the first insulating portion. The heat-insulating structure serves to insulate against heat, delaying or preventing heat transfer between the first extension and the first insulating portion, reducing the possibility of heat transfer from the first extension to the first insulating portion causing the first insulating portion to melt, and reducing the possibility of insulation failure of the first insulating portion.

[0014] In some embodiments, the thermal insulation structure includes a clearance groove disposed in the first insulating portion and / or the first extension. The thermal insulation structure is simple and easy to form. The clearance groove makes it difficult for the first extension and the first insulating portion to directly contact each other in the area corresponding to the clearance groove, thus providing a good thermal insulation effect.

[0015] In some embodiments, the second connecting portion is welded to the first extension to form a solder area, and the orthographic projections of the solder area and the clearance groove in a plane perpendicular to the axial direction of the terminal body at least partially overlap. When the second connecting portion is welded to the first extension, the first extension will generate a large amount of heat in the solder area, causing its temperature to rise. Since the orthographic projections of the solder area and the clearance groove in a plane perpendicular to the axial direction of the terminal body at least partially overlap, the clearance groove can provide good heat insulation, reducing the impact of the first extension and the second connecting portion on the first insulating portion during the welding process.

[0016] In some embodiments, the area of ​​the orthographic projection of the solder area in the plane is S1, and the area of ​​the overlapping region of the orthographic projections of the solder area and the clearance groove in the plane is S2, satisfying: S2 / S1≥1 / 3. Thus, the area of ​​the overlapping region of the orthographic projections of the solder area and the clearance groove in the plane is a large proportion of the area of ​​the orthographic projection of the solder area in the plane. This allows the clearance groove to block more of the heat generated by the solder area during the welding process, improving the clearance groove's ability to block heat from the solder area.

[0017] In some embodiments, S2 / S1 ≥ 1 / 2. Further increasing the proportion of S2 in S1 further enhances the heat insulation capability of the vented groove for the solder area.

[0018] In some embodiments, the first extension has a fusible link. When the current through the first extension is too large, the fusible link can automatically melt and break, thereby providing overcurrent protection for the battery cell.

[0019] In some embodiments, the first extension section is provided with a through hole, the two ends of which extend to two opposing surfaces of the first extension section along the axial direction of the terminal body, respectively, to form a corresponding fusible portion. Forming the fusible portion by providing a through hole in the first extension section simplifies the forming process. After providing the through hole in the first extension section, the cross-sectional area of ​​the formed fusible portion is smaller than the cross-sectional area of ​​other parts of the first extension section, resulting in a higher resistance in the fusible portion compared to the other parts of the first extension section. When the current through the first extension section is too large, the fusible portion heats up and melts.

[0020] In some embodiments, the first extension section is provided with a plurality of through holes, which are arranged at intervals along a second direction, and the second direction intersects the first direction. Given a fixed flow area of ​​the fusible link, providing a plurality of through holes on the first extension section allows the through holes to be made smaller, reducing the difficulty of forming the through holes.

[0021] In some embodiments, the first extension section is provided with two through holes, which extend to both ends of the first extension section along the second direction, and the fusible portion is located between the two through holes. In this way, only one fusible portion is formed on the first extension section, which makes it easier to control the flow area of ​​the fusible portion, simplifies the electrode terminal structure, and reduces the molding difficulty of the electrode terminal.

[0022] In some embodiments, the battery cell further includes a second insulating member that covers at least a portion of the outer surface of the fused portion. The second insulating member serves as an insulator, reducing the risk that the electrode terminals will conduct electricity to the positive and negative electrode plates after the fused portion melts.

[0023] In some embodiments, the second insulating element includes an insulating coating disposed on the outer surface of the fusible portion, an insulating adhesive layer bonded to the outer surface of the fusible portion, or a hot-melt insulating layer hot-melt-fused to the outer surface of the fusible portion. The insulating coating is a coating disposed on the outer surface of the fusible portion, with a small thickness and small footprint. The insulating adhesive layer can be bonded to the fusible portion, resulting in high assembly efficiency and low production cost. The hot-melt insulating layer is hot-melt-fused to the fusible portion. After the fusible portion melts, the hot-melt insulating layer not only provides insulation but also acts as a limiting element, maintaining the original shape of the electrode terminals and reducing the possibility of the electrode terminals contacting the electrode sheets in the active material coating portion after the fusible portion melts, thus reducing the possibility of a short circuit inside the battery cell.

[0024] In some embodiments, the second insulating member includes a second insulating portion and a third insulating portion, which together define a first space. The fusible portion is accommodated within the first space, and the second insulating portion and the third insulating portion are detachably connected. This allows for convenient installation and removal of the second insulating member. After the fusible portion melts, this structure not only provides insulation but also acts as a limiting mechanism, maintaining the original shape of the electrode terminals and reducing the likelihood of the electrode terminals contacting the electrode sheets in the active material coating after the fusible portion melts, thus reducing the possibility of a short circuit within the battery cell.

[0025] In some embodiments, the second insulating part is provided with a first snap-fit ​​part, and the third insulating part is provided with a second snap-fit ​​part, with the first snap-fit ​​part and the second snap-fit ​​part engaging. When installing the second insulating member, engaging the first snap-fit ​​part with the second snap-fit ​​part connects the second insulating part and the third insulating part together, while disengaging the first snap-fit ​​part from the second snap-fit ​​part separates the second insulating part and the third insulating part, thus facilitating the installation and removal of the second insulating part and the third insulating part.

[0026] In some embodiments, the limiting portion is provided with a weight-reducing structure. The weight-reducing structure can reduce the weight of the electrode terminals, thereby reducing the weight of the battery cell.

[0027] In some embodiments, the weight-reducing structure includes a weight-reducing hole disposed in the limiting portion, with both ends of the weight-reducing hole extending to two opposing surfaces of the limiting portion along the axial direction of the terminal body. Reducing the weight of the electrode terminal by providing a weight-reducing hole in the limiting portion is a simple method.

[0028] In some embodiments, the weight-reduction structure includes a plurality of weight-reduction holes arranged around the terminal body. Providing a plurality of weight-reduction holes on the limiting portion can further reduce the weight of the electrode terminal.

[0029] In some embodiments, weight-reduction holes are provided at each of the four corners of the limiting portion. The weight-reduction holes at the four corners of the limiting portion further reduce the weight of the electrode terminals while minimizing the impact on overcurrent in the electrode terminals.

[0030] In some embodiments, a weight-reducing hole is provided in the first extension section to correspondingly form a fusible portion. By providing a weight-reducing hole in the first extension section, the weight of the electrode terminal is reduced while forming the fusible portion.

[0031] In some embodiments, the housing includes a casing and an end cap, the casing having an opening and the end cap closing the opening; the end cap is a wall portion. When assembling a battery cell, the electrode terminals can be first installed on the end cap, then the tabs can be connected to the electrode terminals, the electrode assembly can be housed within the casing, and finally the end cap can be connected to the casing to close the opening of the casing. This structure allows for more convenient installation of the electrode terminals and connection of the tabs to the electrode terminals.

[0032] Secondly, embodiments of this application provide a battery, including the battery cell provided in any of the embodiments of the first aspect described above.

[0033] Thirdly, embodiments of this application provide an electrical device including a battery cell provided in any of the embodiments of the first aspect above, wherein the battery cell is used to provide electrical energy to the electrical device. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0036] Figure 2 Exploded views of batteries provided for some embodiments of this application;

[0037] Figure 3 Exploded views of a single battery cell provided in some embodiments of this application;

[0038] Figure 4 Partial views of a battery cell provided for some embodiments of this application;

[0039] Figure 5 for Figure 4 A magnified view of a section at point A in the middle;

[0040] Figure 6 for Figure 4 The isometric view of the electrode terminals shown;

[0041] Figure 7 for Figure 6 A top view of the electrode terminals shown;

[0042] Figure 8 Partial views of a battery cell provided for other embodiments of this application;

[0043] Figure 9 for Figure 8 The diagram shows the structure of the electrode terminals;

[0044] Figure 10 for Figure 8 A magnified view of point B in the image;

[0045] Figure 11 for Figure 10 The isometric view of the electrode terminals shown;

[0046] Figure 12 Axonometric views of electrode terminals provided for other embodiments of this application;

[0047] Figure 13 Axonometric views of the electrode terminals and the second insulating member connected according to some embodiments of this application;

[0048] Figure 14 for Figure 13 The cross-sectional view shown is after the electrode terminals and the second insulating component are connected.

[0049] Figure 15 Axonometric view of the electrode terminals and the second insulator connected, provided for other embodiments of this application;

[0050] Figure 16 Axonometric views of the electrode terminals and the second insulating member connected, provided for some embodiments of this application;

[0051] Figure 17 for Figure 16 The diagram shows the structure after the electrode terminals and the second insulating component are connected.

[0052] Figure 18 for Figure 17 The shown is a CC cross-sectional view after the electrode terminals and the second insulating component are connected.

[0053] Figure 19 Axonometric view of electrode terminals provided for some embodiments of this application.

[0054] Icons: 1-Outer shell; 11-Shell; 12-End cap; 13-Wall; 131-Lead-out hole; 2-Electrode assembly; 21-Active material coating; 22-Taper; 221-First connecting part; 222-Second connecting part; 223-Taper root; 224-Third connecting part; 225-Fourth connecting part; 3-Electrode terminal; 31-Terminal body; 311-Outer peripheral surface; 312-Central axis; 32-Limiting part; 321-First extension; 3211-Extension area; 3212-Connection area; 3213-First surface; 3214-Second surface; 3215-Void groove; 3216-Soldering area; 3217-Fuse part; 3218-Through hole; 322-First cross-section; 323-Second extension; 324-Second cross-section; 235-Third cross-section; 326-Weight reduction hole; 4-Third insulating component; 5-Connector; 6-Fourth insulating component; 7-Sealing component; 8-First insulating component; 81-First insulating part; 9-Second insulating component; 91-Second insulating part; 911-First snap-fit ​​part; 92-Third insulating part; 921-Second snap-fit ​​part; 93-First space; 10-Battery cell; 20-Box; 201-First part; 202-Second part; 100-Battery; 200-Controller; 300-Motor; 1000-Vehicle; X-First direction; Y-Second direction; Z-Axis. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0056] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0057] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0058] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0059] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0060] In this application, "multiple" means two or more (including two).

[0061] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0062] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0063] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0064] 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.

[0065] 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.

[0066] 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.).

[0067] 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 may 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 oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 ( ), and at least one of its modified compounds, etc.

[0068] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, 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 may also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0069] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0070] 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 electrodes, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, 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.).

[0071] 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.

[0072] 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.

[0073] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. 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 battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0074] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0075] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0076] 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.

[0077] 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.

[0078] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0079] 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.

[0080] 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.

[0081] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0082] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0083] 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.

[0084] 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.

[0085] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0086] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0087] In some implementations, the electrode assembly is a stacked structure.

[0088] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0089] 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.

[0090] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0091] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0092] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0093] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0094] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0095] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0096] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0097] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0098] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0099] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0100] 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.

[0101] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0102] For a single battery cell, the battery cell may include a casing, an electrode assembly, and electrode terminals. The electrode assembly is housed within the casing, and the electrode terminals are disposed on the wall of the casing. The electrode assembly includes an active material coating portion and a tab disposed at the end of the active material coating portion. The tab is electrically connected to the electrode terminals to input or output electrical energy through the electrode terminals.

[0103] To improve the current carrying capacity of a single battery cell, the tabs of the electrode assembly can be directly connected to the electrode terminals, with the tabs located in the central area of ​​the electrode terminals. To achieve an effective connection between the tabs and the electrode terminals, the tabs need to be bent between the active material coating and the electrode terminals. To meet the high-capacity requirements of single batteries, the size of the battery cell can be increased. As the size of the battery cell increases, the width of the wall portion of the casing where the electrode terminals are located also increases. Taking the electrode terminals being located on the end cap as an example, as the width of the end cap increases, the length of the portion of the tab used to connect to the electrode terminals in the width direction of the end cap also increases, resulting in an overall increase in the length of the tab. Excessively long tabs are prone to misalignment and creases during production, leading to poor reliability of the battery cell.

[0104] In view of this, the present application provides a battery cell, wherein the electrode terminal includes a terminal body and a limiting portion, the limiting portion includes a first extension protruding from the outer peripheral surface of the terminal body along a first direction, the electrode tab includes a first connecting portion and a second connecting portion, the second connecting portion is located on one side of the first connecting portion along the first direction, the first connecting portion is connected to the active material coating portion, and the second connecting portion is connected to the first extension portion.

[0105] In such a battery cell, the second connection portion is located on one side of the first connection portion along the first direction. The second connection portion is connected to the first extension portion of the limiting portion that protrudes from the outer peripheral surface of the terminal body along the first direction. This shortens the length of the second connection portion, thereby shortening the length of the tab, reducing the possibility of misalignment or creases in the tab during production, and improving the reliability of the battery cell.

[0106] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0107] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0108] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0109] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery 100 is disposed inside the vehicle 1000, and the battery 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000.

[0110] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0111] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0112] Please refer to Figure 2 , Figure 2This is an exploded view of a battery 100 provided in some embodiments of this application. The battery 100 includes a battery cell 10 and a housing 20, wherein the battery cell 10 is housed within the housing 20.

[0113] The housing 20 is a component that houses the battery cell 10, providing a space for the battery cell 10. The housing 20 can adopt various structures. In some embodiments, the housing 20 may include a first portion 201 and a second portion 202, which overlap each other to define a space for accommodating the battery cell 10. The first portion 201 and the second portion 202 can have various shapes, such as cuboid or cylindrical. The first portion 201 can be a hollow structure open on one side, and the second portion 202 can also be a hollow structure open on one side, with the open side of the second portion 202 overlapping the open side of the first portion 201, thus forming a housing 20 with a accommodating space. Alternatively, the first portion 201 can be a hollow structure open on one side, and the second portion 202 can be a plate-like structure, with the second portion 202 overlapping the open side of the first portion 201, thus forming a housing 20 with a accommodating space.

[0114] In battery 100, there can be one or more battery cells 10. If there are multiple battery cells 10, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 10 are connected in both series and parallel. Alternatively, multiple battery cells 10 can be first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 20. Another option is that all battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 10 is housed within the housing 20.

[0115] In some embodiments, the battery 100 may further include a busbar component, through which multiple battery cells 10 can be electrically connected to each other to achieve series, parallel, or mixed connection of multiple battery cells 10. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0116] Please refer to Figure 3 , Figure 3 This is an exploded view of a battery cell 10 provided in some embodiments of this application. The battery cell 10 may include a housing 1, an electrode assembly 2, and an electrode terminal 3. The electrode assembly 2 is housed within the housing 1, and the electrode terminal 3 is disposed on the housing 1 and electrically connected to the electrode assembly 2.

[0117] The housing 1 is a component for housing the electrode assembly 2 and electrolyte, etc. As an example, the housing 1 may include a housing 11 and an end cap 12.

[0118] The shell 11 can be a hollow structure with an opening at one end, or it can be a hollow structure with openings at both opposite ends. The shell 11 can be in various shapes, such as cylindrical or prismatic. The shell 11 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, or plastic.

[0119] End cap 12 is a component that closes the opening of housing 11 to isolate the internal environment of battery cell 10 from the external environment. End cap 12 and housing 11 together define a receiving space for accommodating electrode assembly 2, electrolyte, and other components. The shape of end cap 12 can be adapted to the shape of housing 1. For example, if housing 11 is a cuboid structure, end cap 12 can be a rectangular plate structure adapted to housing 1; or if housing 11 is a cylindrical structure, end cap 12 can be a circular plate structure adapted to housing 11. End cap 12 can also be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, or plastic. The materials of end cap 12 and housing 11 can be the same or different.

[0120] In an embodiment where the housing 11 has an opening at one end, one end cap 12 may be provided accordingly. In an embodiment where the housing 11 has openings at both opposite ends, two end caps 12 may be provided accordingly. The two end caps 12 respectively close the two openings of the housing 11, and the two end caps 12 and the housing 11 together define the receiving space.

[0121] Electrode terminal 3 is a component in battery cell 10 used for inputting or outputting electrical energy. Electrode terminal 3 is disposed on housing 1 and is used for electrical connection with tab 22 of electrode assembly 2. Electrode terminal 3 can be disposed on housing 11 of housing 1 or end cap 12 of housing 1. Electrode terminal 3 and tab 22 can be directly connected, for example, by direct welding.

[0122] As an example, such as Figure 3 As shown, the housing 11 is a hollow structure with openings at both opposite ends. Both opposite ends of the housing 11 are provided with end caps 12, and both end caps 12 at both ends of the housing 11 are provided with electrode terminals 3. Both opposite ends of the electrode assembly 2 are provided with tabs 22. The tab 22 at one end of the electrode assembly 2 is the positive tab, and the tab 22 at the other end of the electrode assembly 2 is the negative tab. The electrode terminal 3 on one end cap 12 is electrically connected to the positive tab, and the electrode terminal 3 on the other end cap 12 is electrically connected to the negative tab.

[0123] In some embodiments, the battery cell 10 may further include a third insulating member 4 disposed between the electrode assembly 2 and the housing 11, the third insulating member 4 serving to insulate and isolate the electrode assembly 2 and the housing 11. The third insulating member 4 is made of an insulating material, such as plastic, rubber, etc. As an example, the third insulating member 4 is an insulating film covering the electrode assembly 2.

[0124] Please refer to Figure 4 and Figure 5 , Figure 4 This is a partial view of a battery cell 10 provided in some embodiments of this application. Figure 5 for Figure 4 A partial enlarged view at point A. This application provides a battery cell 10, including a housing 1, an electrode assembly 2, and electrode terminals 3. The housing 1 includes a wall portion 13, with a lead-out hole 131. The electrode assembly 2 is housed within the housing 1, and includes an active material coating portion 21 and a tab 22, with the tab 22 disposed at the end of the active material coating portion 21 facing the wall portion 13. The electrode terminal 3 includes a terminal body 31 and a limiting portion 32. The terminal body 31 passes through the lead-out hole 131, and the limiting portion 32 is configured to restrict the terminal body 31 from disengaging from the lead-out hole 131 in a direction away from the active material coating portion 21. The limiting portion 32 includes a first extension 321 protruding along a first direction X from the outer peripheral surface 311 of the terminal body 31. The tab 22 includes a first connecting portion 221 and a second connecting portion 222. The second connecting portion 222 is located on one side of the first connecting portion 221 along the first direction X. The first connecting portion 221 is connected to the active material coating portion 21, and the second connecting portion 222 is connected to the first extension section 321.

[0125] The wall portion 13 can be the end cap 12 in the outer casing 1, and it is understood that the electrode terminal 3 is disposed on the end cap 12; the wall portion 13 can also be a wall of the housing 11 in the outer casing 1, and it is understood that the electrode terminal 3 is disposed on the housing 11. The wall portion 13 can be a circular wall portion, a rectangular wall portion, etc.

[0126] The lead-out hole 131 on the wall portion 13 is used to lead out the terminal body 31 of the electrode terminal 3, so that the terminal body 31 can be connected to the external components of the battery cell 10, such as the terminal body 31 being connected to the busbar component. The lead-out hole 131 penetrates the wall portion 13 along the thickness direction of the wall portion 13, and the lead-out hole 131 can be a rectangular hole, a circular hole, etc.

[0127] Electrode assembly 2 may include a positive electrode, a negative electrode, and a separator. Electrode assembly 2 can be a wound structure formed by winding the positive electrode, separator, and negative electrode, or a stacked structure formed by arranging the positive electrode, separator, and negative electrode in layers. The active material coating portion 21 is the main body of electrode assembly 2. The active material coating portion 21 may be the part of electrode assembly 2 corresponding to the area of ​​the electrode coated with the active material layer. The tab 22 may be the part of the electrode that is not coated with the active material layer.

[0128] The first connecting portion 221 is the part of the tab 22 used to connect with the active material coating portion 21, and the second connecting portion 222 is the part of the tab 22 used to connect with the electrode terminal 3. The first connecting portion 221 can be a flat sheet structure or an arc-shaped sheet structure; the second connecting portion 222 can be a flat sheet structure or an arc-shaped sheet structure. Figure 4 In the illustrated embodiment, both the first connecting portion 221 and the second connecting portion 222 are flat sheet-like structures. As an example, the tab 22 is bent between the electrode terminal 3 and the active material coating portion 21, and the tab 22 is bent to form multiple connected bent segments. The first connecting portion 221 and the second connecting portion 222 are two bent segments at both ends of the tab 22.

[0129] The first connecting portion 221 and the active material coating portion 21 can be directly connected or indirectly connected. As an example, the first connecting portion 221 is connected to the active material coating portion 21 through the tab root portion 223.

[0130] The first direction X is the direction in which the first extension segment 321 protrudes from the outer peripheral surface 311 of the terminal body 31. The first direction X is unidirectional and can be perpendicular to the axial direction Z of the terminal body 31. Taking the wall portion 13 as a cuboid wall portion as an example, the first direction X can be parallel to the length direction of the wall portion 13, or the first direction X can be parallel to the width direction of the wall portion 13.

[0131] The second connection portion 222 is located on one side of the first connection portion 221 along the first direction X. Taking the first direction X as an example of pointing from the left side of the electrode terminal 3 to the right side, the second connection portion 222 is located on the right side of the first connection portion 221.

[0132] Electrode terminal 3 is a metallic conductor. Electrode terminal 3 can be made entirely of the same conductive material, such as copper, iron, aluminum, steel, or aluminum alloy; electrode terminal 3 can also be formed by combining multiple parts of different conductive materials, for example, the terminal body 31 can be formed by combining copper and aluminum parts.

[0133] The terminal body 31 is the portion that passes through the lead-out hole 131. The terminal body 31 is cylindrical, prismatic, or similar. The limiting portion 32 is the portion of the electrode terminal 3 used to prevent the terminal body 31 from disengaging from the lead-out hole 131 in the direction away from the active material coating portion 21. The limiting portion 32 can be a plate-like component, such as a rectangular plate or a circular plate. The limiting portion 32 can be connected to the end of the terminal body 31 facing the electrode assembly 2. As an example, the limiting portion 32 is located inside the wall portion 13, that is, the limiting portion 32 is located on the side of the wall portion 13 facing the active material coating portion 21. The orthographic projections of the limiting portion 32 and the wall portion 13 in a plane perpendicular to the axial direction Z of the terminal body 31 at least partially overlap, so that the limiting portion 32 can effectively prevent the terminal body 31 from disengaging from the lead-out hole 131 in the direction away from the active material coating portion 21.

[0134] The battery cell 10 may further include a connector 5 located on the side of the wall 13 opposite to the active material coating portion 21, and connected to the terminal body 31. The connector 5 is configured to restrict the movement of the terminal body 31 in a direction close to the electrode assembly 2, so as to fix the electrode terminal 3 to the wall 13 together with the limiting portion 32. As an example, the connector 5 is riveted to the terminal body 31. The connector 5 can be used to connect to external components to increase the current-carrying area of ​​the electrode terminal 3. To achieve insulation between the connector 5 and the wall 13, a fourth insulating member 6 may be provided between the connector 5 and the wall 13. To improve the sealing between the terminal body 31 and the wall 13, a sealing member 7 may be provided between the terminal body 31 and the wall 13, and the sealing member 7 is at least partially located within the lead-out hole 131.

[0135] The first extension 321 is the portion of the limiting part 32 that protrudes along the first direction X from the outer peripheral surface 311 of the terminal body 31. The outer peripheral surface 311 of the terminal body 31 is arranged around the axis of the terminal body 31. Please refer to... Figure 6 and Figure 7 , Figure 6 for Figure 4 The isometric view of electrode terminal 3 shown; Figure 7 for Figure 6 The diagram shows a top view of the electrode terminal 3. Taking the outer peripheral surface 311 of the terminal body 31 as a cylindrical surface as an example, the first cross-section 322, where the limiting part 32 is tangent to the outer peripheral surface 311, is the starting position of the first extension segment 321. The first cross-section 322 is perpendicular to the first direction X, and the first extension segment 321 extends from this starting position along the first direction X. The first extension segment 321 and the second connecting part 222 can be connected in various ways, such as welding or bonding, to achieve an electrical connection between the electrode terminal 3 and the tab 22.

[0136] In related technologies, the tab 22 is generally connected to the central region of the electrode terminal 3, which is also the central region of the terminal body 31. This makes the tab 22 too long, and it is prone to misalignment and creases during the production process, resulting in poor reliability of the battery cell 10. However, in this embodiment, the second connecting portion 222 is located on the side of the first connecting portion 221 along the first direction X. The second connecting portion 222 is connected to the first extension 321 of the limiting portion 32 that protrudes from the outer peripheral surface 311 of the terminal body 31 along the first direction X. This shortens the length of the second connecting portion 222, thereby shortening the length of the tab 22, reducing the possibility of misalignment and creases in the tab 22 during the production process, and improving the reliability of the battery cell 10.

[0137] In some embodiments, please refer to Figure 8 and Figure 9 , Figure 8 A partial view of a battery cell 10 provided for other embodiments of this application; Figure 9 for Figure 8 The diagram shows the structure of the electrode terminal 3. The limiting part 32 also includes a second extension 323 that protrudes from the outer peripheral surface 311 of the terminal body 31 in the opposite direction of the first direction X. Along the first direction X, the distance between the end of the second extension 323 away from the terminal body 31 and the central axis 312 of the terminal body 31 is a first distance L1. The first extension 321 includes an elongation region 3211, and the distance between the elongation region 3211 and the central axis 312 is greater than or equal to the first distance L1. The second connecting part 222 is connected to the elongation region 3211.

[0138] The second extension segment 323 is the portion of the limiting portion 32 that protrudes from the outer peripheral surface 311 of the terminal body 31 in the opposite direction to the first direction X. The extension direction of the second extension segment 323 is opposite to that of the first extension. Taking the first direction X as an example of extending from the left side of the electrode terminal 3 to the right side, the first extension segment 321 extends from the outer peripheral surface 311 of the terminal body 31 from left to right, and the second extension segment 323 extends from the outer peripheral surface 311 of the terminal body 31 from right to left. Taking the outer peripheral surface 311 of the terminal body 31 as a cylindrical surface, the second cross-section 324, which is tangent to the outer peripheral surface 311 of the limiting portion 32, is the starting position of the second extension segment 323. The second cross-section 324 is perpendicular to the first direction X. The second cross-section 324 and the first cross-section 322 are located on both sides of the terminal body 31 along the first direction X, and the second extension segment 323 extends from this starting position in the opposite direction to the first direction X.

[0139] The extended region 3211 can be the area in the first extension segment 321 beyond the first distance L1 from the central axis 312. The first extension segment 321 also includes a connecting region 3212, which is located between the terminal body 31 and the extended region 3211 along the first direction X, connecting the terminal body 31 and the extended region 3211. As an example, along the first direction X, the length of the connecting region 3212 is equal to the length of the second extension segment 323. Along the first direction X, the length of the first extension segment 321 is greater than the length of the second extension segment 323, and the difference between the lengths of the first extension segment 321 and the second extension segment 323 is equal to the length of the extended region 3211.

[0140] The limiting portion 32 has a third cross section 235 perpendicular to the first direction X. Along the first direction X, the distance between the third cross section 235 and the central axis 312 of the terminal body 31 is a first distance L1. The third cross section 235 can serve as the starting position of the extension region 3211, which extends along the first direction X from this starting position.

[0141] The first distance L1 can be measured using vernier calipers. Specifically, firstly, the position of the central axis 312 of the terminal body 31 is determined on the end face of one end of the terminal body 31 along the Z-axis, and a mark is made; then, in an environment of 25±2℃, the distance from the end of the second extension segment 323 away from the terminal body 31 to the mark along the first direction X is measured using vernier calipers. This distance is the first distance L1.

[0142] In this embodiment, the extension region 3211 increases the length of the first extension segment 321 along the second direction Y, thereby extending the second extension segment 323 away from the terminal body 31. The second connecting portion 222 is connected to the extension region 3211, so that the second connecting portion 222 is further away from the terminal body 31 along the first direction X. In this way, the second connecting portion 222 can be made shorter, which is beneficial to further shorten the length of the tab 22.

[0143] In some embodiments, please continue to refer to Figure 9 Along the first direction X, the distance between the end of the second connecting part 222 near the terminal body 31 and the central axis 312 of the terminal body 31 is the second distance L2, which is greater than or equal to the first distance L1.

[0144] The difference between L2 and L1 can be either L2 > L1 or L2 = L1, such that the orthographic projections of the second connecting portion 222 and the connecting area 3212 in the plane perpendicular to the Z-axis of the terminal body 31 do not overlap. It can be understood that the greater the difference between L2 and L1, the farther the second connecting portion 222 is from the central axis 312 of the terminal body 31.

[0145] The second distance L2 can also be measured using vernier calipers. Specifically, firstly, the position of the central axis 312 of the terminal body 31 is determined on the end face of one end of the terminal body 31 along the Z-axis, and a mark is made; then, in an environment of 25±2℃, the distance from the end of the second extension segment 323 away from the terminal body 31 to the mark along the first direction X is measured using vernier calipers. This distance is the first distance L1.

[0146] In this embodiment, L2≥L1, which makes the end of the second connection portion 222 closer to the terminal body 31 further away from the terminal body 31 along the first direction X, further shortening the length of the second connection portion 222, and thus further shortening the length of the tab 22.

[0147] In some embodiments, please continue to refer to Figure 8 The first connecting portion 221 and the active material coating portion 21 are opposite each other at the middle position along the first direction X; and / or, the terminal body 31 and the active material coating portion 21 are opposite each other at the middle position along the first direction X.

[0148] The first connecting portion 221 is opposite to the active material coating portion 21 at the middle position along the first direction X, that is, the distance from the first connecting portion 221 to the two ends of the active material coating portion 21 along the first direction X is basically equal.

[0149] The terminal body 31 and the active material coating part 21 are opposite each other at the middle position along the first direction X, that is, the distance from the central axis 312 of the terminal body 31 to the two ends of the active material coating part 21 along the first direction X is basically equal.

[0150] If the first connecting portion 221 and the active material coating portion 21 are positioned opposite each other along the first direction X, so that the tab 22 is centered along the first direction X at the bending front edge, it is beneficial to form the tab 22 and reduces the forming difficulty of the tab 22. If the terminal body 31 and the active material coating portion 21 are positioned opposite each other along the first direction X, so that the terminal body 31 is centered along the first direction X, it is beneficial to connect the electrode terminal 3 to external components (such as busbar components) and facilitate the output or input of electrical energy.

[0151] In some embodiments, please continue to refer to Figure 8 The electrode tab 22 also includes a third connecting part 224 and a fourth connecting part 225. The first connecting part 221, the third connecting part 224, the fourth connecting part 225 and the second connecting part 222 are connected in sequence. Along the axial direction Z of the terminal body 31, the second connecting part 222 and the third connecting part 224 are arranged opposite to each other.

[0152] The third connecting portion 224 can be a flat sheet structure or an arc-shaped sheet structure; the fourth connecting portion 225 can be a flat sheet structure or an arc-shaped sheet structure. The third connecting portion 224 is bent relative to the first connecting portion 221, the fourth connecting portion 225 is bent relative to the third connecting portion 224, and the second connecting portion 222 is bent relative to the fourth connecting portion 225. The third connecting portion 224 and the first connecting portion 221 can be set at an acute angle, an obtuse angle, or a right angle; the fourth connecting portion 225 and the third connecting portion 224 can be set at an acute angle, an obtuse angle, or a right angle; the second connecting portion 222 and the fourth connecting portion 225 can be set at an acute angle, an obtuse angle, or a right angle. Figure 8 In the illustrated embodiment, the first connecting portion 221, the second connecting portion 222, the third connecting portion 224, and the fourth connecting portion 225 are all flat sheet-like structures. The third connecting portion 224 is set at a right angle to the first connecting portion 221, the fourth connecting portion 225 is set at a right angle to the third connecting portion 224, and the second connecting portion 222 is set at a right angle to the fourth connecting portion 225.

[0153] The second connecting portion 222 and the third connecting portion 224 are arranged opposite each other along the axial direction Z of the terminal body 31, that is, the orthogonal projections of the second connecting portion 222 and the third connecting portion 224 in a plane perpendicular to the axial direction Z of the terminal body 31 at least partially overlap.

[0154] In this embodiment, the tab 22 is bent between the active material coating portion 21 and the electrode terminal 3, which reduces the space occupied by the tab 22 in the internal space of the battery cell 10, so as to provide more space for the active material coating portion 21 and improve the energy density of the battery cell 10.

[0155] In some embodiments, please continue to refer to Figure 9 Along the axial direction Z of the terminal body 31, the second connecting portion 222 is connected to the side of the first extension 321 facing the active material coating portion 21.

[0156] As an example, along the axial direction Z of the terminal body 31, the first extension 321 has a first surface 3213 and a second surface 3214 facing each other, the first surface 3213 facing the active material coating portion 21, the second surface 3214 facing away from the active material coating portion 21, and the second connecting portion 222 connected to the first surface 3213.

[0157] In this embodiment, the second connecting portion 222 is connected to the side of the first extension 321 facing the active material coating portion 21, which reduces the distance between the second connecting portion 222 and the active material coating portion 21 in the axial Z direction of the terminal body 31, and can effectively reduce the length of the tab 22.

[0158] In other embodiments, the second connection portion 222 may also be connected to other locations of the first extension portion 321, for example, along the axial direction Z of the terminal body 31, the second connection portion 222 is connected to the side of the first extension portion 321 away from the active material coating portion 21.

[0159] In some embodiments, please continue to refer to Figure 9 The terminal body 31 and the limiting part 32 are integrally formed. The connection strength between the terminal body 31 and the limiting part 32 is higher, and the terminal body 31 and the limiting part 32 are more secure, which reduces the possibility that the terminal body 31 will separate from the limiting part 32 due to impact during normal use of the battery cell 10, and reduces the possibility of failure of the battery cell 10 during normal use.

[0160] In other embodiments, the terminal body 31 and the limiting part 32 may also be separately provided and connected. For example, the terminal body 31 and the limiting part 32 may be made of different materials, one of which may be made of copper and the other of aluminum, and the terminal body 31 and the limiting part 32 may be combined together.

[0161] In some embodiments, please refer to Figure 10 , Figure 10 for Figure 8 The enlarged view at point B in the figure. The battery cell 10 also includes a first insulating member 8 along the axial direction Z of the terminal body 31. The first insulating member 8 includes a first insulating portion 81 disposed between the first extension 321 and the wall portion 13. The side of the first insulating portion 81 facing the first extension 321 and / or the side of the first extension 321 facing the first insulating portion 81 is provided with a heat insulation structure.

[0162] The first insulating member 8 is disposed on the side of the wall portion 13 facing the active material coating portion 21. The first insulating member 8 separates the limiting portion 32 and the wall portion 13 to achieve insulation isolation between the wall portion 13 and the limiting portion 32. The first insulating member 8 is made of an insulating material, such as plastic or rubber. The first insulating portion 81 is the part of the first insulating member 8 located between the first extension 321 and the wall portion 13.

[0163] The heat insulation structure may be provided only on the side of the first insulating portion 81 facing the first extension section 321, or only on the side of the first extension section 321 facing the first insulating portion 81, or both the side of the first insulating portion 81 facing the first extension section 321 and the side of the first extension section 321 facing the first insulating portion 81 may have heat insulation structures. The heat insulation structure can be of various types, such as a groove or a heat insulation component.

[0164] The heat insulation structure plays a heat insulation role, delaying or preventing heat transfer between the first extension section 321 and the first insulating part 81, reducing the possibility that heat on the first extension section 321 will be transferred to the first insulating part 81 and cause the first insulating part 81 to melt, and reducing the possibility that the first insulating part 81 will fail to maintain its insulation.

[0165] In some embodiments, please continue to refer to Figure 10 and Figure 11 , Figure 11 for Figure 10 The diagram shows an isometric view of electrode terminal 3. The thermal insulation structure includes a recessed groove 3215 disposed in the first insulating portion 81 and / or the first extension 321.

[0166] It is understandable that the clearance groove 3215 may be provided only on the first insulating part 81, or only on the first extension section 321, or both the first insulating part 81 and the first extension section 321 may be provided with clearance grooves 3215.

[0167] Taking the first extension segment 321 with a clearance groove 3215 as an example, along the axial direction Z of the terminal body 31, the surface of the first extension segment 321 facing the first insulating part 81 is the second surface 3214, and the clearance groove 3215 is disposed on the second surface 3214 of the first extension segment 321. In embodiments where the first extension segment 321 has an extended region 3211, the clearance groove 3215 can be disposed on the extended region 3211.

[0168] In this embodiment, the heat insulation structure is simple and easy to form. The arrangement of the clearance groove 3215 makes it difficult for the first extension section 321 and the first insulating part 81 to directly contact each other in the area corresponding to the clearance groove 3215, thus achieving a good heat insulation effect.

[0169] In other embodiments, a heat insulation member may be provided on the first insulating portion 81 and / or the first extension 321, based on the provision of a clearance groove 3215 on the first insulating portion 81 and / or the first extension 321.

[0170] In some embodiments, please continue to refer to Figure 10 The second connecting part 222 is welded to the first extension 321 to form a solder area 3216. The orthogonal projections of the solder area 3216 and the clearance groove 3215 in the plane perpendicular to the axial direction Z of the terminal body 31 at least partially overlap.

[0171] The second connecting portion 222 is welded to the first extension 321, and the solder area 3216 is the solder mark formed by welding the second connecting portion 222 and the first extension 321. It can be understood that the projection of the solder area 3216 along the axial direction Z of the terminal body 31 is at least partially located within the clearance groove 3215.

[0172] When the second connection 222 is welded to the first extension 321, the first extension 321 will generate a lot of heat in the solder area 3216, causing the temperature of the first extension 321 to rise. Since the orthographic projections of the solder area 3216 and the clearance groove 3215 in the plane perpendicular to the axial direction Z of the terminal body 31 overlap at least partially, the clearance groove 3215 can play a good heat insulation role, reducing the impact of the first extension 321 and the second connection 222 on the first insulation part 81 during the welding process.

[0173] In some embodiments, the area of ​​the orthographic projection of the solder area 3216 in the plane perpendicular to the axial direction Z of the terminal body 31 is S1, and the area of ​​the overlapping region of the orthographic projections of the solder area 3216 and the clearance groove 3215 in the plane perpendicular to the axial direction Z of the terminal body 31 is S2, satisfying: S2 / S1≥1 / 3.

[0174] S2 / S1 can be a point value of any one of 1 / 3, 1 / 2, 2 / 3, or 1, or a range of values ​​between any two.

[0175] Taking the solder area 3216 and the clearance groove 3215 as being formed on two opposite surfaces of the first extension 321 respectively, the specific methods for measuring S2 and S1 are as follows: The electrode terminal 3 is clamped by a fixture so that the solder area 3216 faces upward; the area defined by the outline of the solder area 3216 is measured by a CCD camera located directly above the electrode terminal 3, and this area is S1; the electrode terminal 3 is flipped by a flipping mechanism in the fixture so that the electrode terminal 3 rotates 180 degrees around the axis extending along the first direction X, at which time the clearance groove 3215 faces upward; the area of ​​the overlapping area between the area defined by the outline of the clearance groove 3215 and the area defined by the outline of the solder area 3216 is measured by a CCD camera, and this overlapping area is S2.

[0176] In this embodiment, S2 / S1≥1 / 3, the area of ​​the overlapping region of the solder area 3216 and the relief groove 3215 in the plane is relatively large, and the heat generated by the solder area 3216 during the welding process can be blocked more by the relief groove 3215, thereby improving the heat blocking ability of the relief groove 3215 on the solder area 3216.

[0177] In some embodiments, S2 / S1 ≥ 1 / 2.

[0178] exist Figure 10 In the illustrated embodiment, S2 / S1 = 1, such that the projection of the solder area 3216 along the axial direction Z of the terminal body 31 is completely located within the clearance groove 3215.

[0179] In this embodiment, S2 / S1≥1 / 2, further increasing the proportion of S2 in S1, and further improving the heat isolation capability of the venting groove 3215 to the soldering area 3216.

[0180] In some embodiments, please refer to Figure 12 , Figure 12 This is an isometric view of the electrode terminal 3 provided in some other embodiments of this application. The first extension 321 has a fusible portion 3217.

[0181] The fusible link 3217 is the portion of the first extension 321 that can be melted during overcurrent. The resistance of the fusible link 3217 is greater than the resistance of other portions of the first extension 321. There can be one or more fusible links 3217 on the first extension 321. The fusible link 3217 can be formed by providing holes or slots in the first extension 321. In embodiments where the first extension 321 includes a connecting region 3212 and an extension region 3211, the fusible link 3217 can be located in the connecting region 3212, the fusible link 3217 can be located in the extension region 3211, or a portion of the fusible link 3217 can be located in the connecting region 3212 and another portion in the extension region 3211.

[0182] In this embodiment, the first extension 321 is provided with a fuse 3217. When the current through the first extension 321 is too large, the fuse 3217 can melt itself to achieve overcurrent protection for the battery cell 10.

[0183] In some embodiments, please continue to refer to Figure 12 The first extension section 321 is provided with a through hole 3218. The two ends of the through hole 3218 extend to two surfaces of the first extension section 321 that are opposite to each other along the axial direction Z of the terminal body 31, so as to form a fusible part 3217.

[0184] There can be one or more through holes 3218 on the first extension segment 321. The through hole 3218 can be a circular hole, a rectangular hole, etc. The through hole 3218 can be a complete hole or an incomplete hole. If the through hole 3218 does not extend to the edge of the first extension segment 321 along the axial direction perpendicular to the terminal body 31 (Z direction), the through hole 3218 is a complete hole; if the through hole 3218 extends to the edge of the first extension segment 321 along the axial direction perpendicular to the terminal body 31 (Z direction), the through hole 3218 is an incomplete hole.

[0185] As an example, the two surfaces of the first extension 321 that are disposed opposite each other along the axial direction Z of the terminal body 31 are the first surface 3213 ( Figure 12 (not shown) and second surface 3214 ( Figure 12 (Not shown), the first surface 3213 faces the active material coating portion 21 ( Figure 12(Not shown), the second surface 3214 is away from the active material coating part 21, the first surface 3213 is used to connect with the second connecting part 222, and the clearance groove 3215 is provided on the second surface 3214.

[0186] In this embodiment, the fuse portion 3217 is formed by providing a through hole 3218 on the first extension 321, which simplifies the forming process. After providing the through hole 3218 on the first extension 321, the cross-sectional area of ​​the formed fuse portion 3217 is smaller than the cross-sectional area of ​​other parts of the first extension 321, resulting in a higher resistance in the fuse portion 3217 than in other parts of the first extension 321. When the current through the first extension 321 is too large, the fuse portion 3217 heats up and melts.

[0187] In some embodiments, the first extension 321 is provided with a plurality of through holes 3218, which are arranged at intervals along the second direction Y, and the second direction Y intersects the first direction X.

[0188] The through holes 3218 on the first extension 321 can be two, three, four, five, etc. Along the second direction Y, a fusible portion 3217 is formed between every two adjacent through holes 3218. As an example, the second direction Y, the first direction X, and the axial direction Z of the terminal body 31 are perpendicular to each other.

[0189] With a fixed flow area in the fuse section 3217, multiple through holes 3218 can be provided on the first extension section 321, which can make the through holes 3218 smaller and reduce the molding difficulty of the through holes 3218.

[0190] In some embodiments, please continue to refer to Figure 12 The first extension section 321 is provided with two through holes 3218. Along the second direction Y, the two through holes 3218 extend to both ends of the first extension section 321 respectively, and the fusible part 3217 is located between the two through holes 3218.

[0191] Since the two through holes 3218 extend to both ends of the first extension section 321 along the second direction Y, the through holes 3218 are incomplete holes. The two through holes 3218 can be regarded as two notches respectively set at both ends of the first extension section 321 in the second direction Y.

[0192] In this embodiment, only one fuse portion 3217 is formed on the first extension 321, which makes it easier to control the flow area of ​​the fuse portion 3217, simplify the structure of the electrode terminal 3, and reduce the molding difficulty of the electrode terminal 3.

[0193] In some embodiments, please refer to Figures 13-15 , Figure 13Axonometric view of the electrode terminal 3 and the second insulating member 9 after connection, provided in some embodiments of this application; Figure 14 for Figure 13 The cross-sectional view shown is after the electrode terminal 3 and the second insulating member 9 are connected. Figure 15 This is an isometric view of the electrode terminal 3 and the second insulating member 9 connected, as provided in some other embodiments of this application. The battery cell 10 also includes the second insulating member 9, which covers at least a portion of the outer surface of the fuse portion 3217.

[0194] The second insulating element 9 is made of an insulating material, such as plastic or rubber. The second insulating element 9 may cover a portion of the outer surface of the fusible portion 3217 or cover the entire outer surface of the fusible portion 3217.

[0195] exist Figure 13 and Figure 14 In the illustrated embodiment, the second insulating member 9 surrounds the fusible portion 3217, thereby covering the entire outer surface of the fusible portion 3217. Figure 15 In the illustrated embodiment, the second insulating member 9 surrounds the first extension 321, such that both the fused portion 3217 and the through hole 3218 are located within and shielded by the second insulating member 9. The second insulating member 9 may partially fill the through hole 3218.

[0196] In this embodiment, the second insulating member 9 serves as an insulating element, reducing the risk that the positive and negative electrode plates will be connected after the electrode terminal 3 melts at the fuse part 3217.

[0197] In some embodiments, the second insulating member 9 includes an insulating coating disposed on the outer surface of the fusible portion 3217, an insulating adhesive layer bonded to the outer surface of the fusible portion 3217, or a hot-melt insulating layer hot-melt bonded to the outer surface of the fusible portion 3217.

[0198] In an embodiment where the second insulating member 9 is an insulating coating provided on the outer surface of the fusible portion 3217, the insulating coating may also be provided on the wall surface of the through hole 3218 if the insulating coating is provided on the surface of the fusible portion 3217. The insulating coating has a small thickness and occupies little space.

[0199] In an embodiment where the second insulating element 9 is an insulating adhesive layer bonded to the outer surface of the fusible portion 3217, the insulating adhesive layer can cover the area around the fusible portion 3217 and the area around the first extension 321, such that both the fusible portion 3217 and the through hole 3218 are located within and shielded by the insulating adhesive layer. The insulating adhesive layer can be bonded to the fusible portion 3217, resulting in high assembly efficiency and low production cost.

[0200] In an embodiment where the second insulating member 9 is a heat-fused insulating layer heat-fused to the outer surface of the fusible portion 3217, the heat-fused insulating layer can cover the area around the fusible portion 3217 and the area around the first extension 321, such that both the fusible portion 3217 and the through hole 3218 are located within and blocked by the heat-fused insulating layer, and the heat-fused insulating layer can partially fill the through hole 3218. The heat-fused insulating layer is heat-fused to the fusible portion 3217. After the fusible portion 3217 is fused, the heat-fused insulating layer not only provides insulation but also provides a limiting function, maintaining the original shape of the electrode terminal 3, reducing the possibility of the electrode terminal 3 contacting the electrode sheet in the active material coating portion 21 after the fusible portion 3217 is fused, and reducing the possibility of a short circuit occurring inside the battery cell 10.

[0201] In some embodiments, please refer to Figures 16-18 , Figure 16 Axonometric view of the electrode terminal 3 and the second insulating member 9 after connection, provided for some embodiments of this application; Figure 17 for Figure 16 The diagram shows the structure after the electrode terminal 3 and the second insulating component 9 are connected. Figure 18 for Figure 17 The diagram shows a CC cross-sectional view of the electrode terminal 3 and the second insulating member 9 after they are connected. The second insulating member 9 includes a second insulating portion 91 and a third insulating portion 92, which together define a first space 93. A fusible portion 3217 is accommodated within the first space 93. The second insulating portion 91 and the third insulating portion 92 are detachably connected.

[0202] The second insulating part 91 and the third insulating part 92 are two separate parts of the second insulating member 9. The second insulating part 91 and the third insulating part 92 can be detachably connected in various ways, such as snap-fit, interference fit, or locking element connection. The locking element can be a screw, bolt, pin, or other component.

[0203] The first space 93 is the space inside the second insulating member 9. The first space 93 is defined by the second insulating part 91 and the third insulating part 92. It is possible that a part of the first space 93 is located inside the second insulating part 91 and another part is located inside the third insulating part 92.

[0204] In this embodiment, the second insulating part 91 and the third insulating part 92 are detachably connected, which facilitates the installation and removal of the second insulating member 9. This structure of the second insulating member 9 not only provides insulation after the fusible part 3217 melts, but also acts as a limiting element, maintaining the original shape of the electrode terminal 3 and reducing the possibility of the electrode terminal 3 contacting the electrode sheet in the active material coating part 21 after the fusible part 3217 melts, thus reducing the possibility of a short circuit inside the battery cell 10.

[0205] In some embodiments, please continue to refer to Figure 18 The second insulating part 91 is provided with a first snap-fit ​​part 911, and the third insulating part 92 is provided with a second snap-fit ​​part 921. The first snap-fit ​​part 911 and the second snap-fit ​​part 921 are snap-fitted together.

[0206] As an example, in Figure 18 In the first locking part 911, a hook protrudes from the surface of the second insulating part 91 facing the third insulating part 92. The second locking part 921 is a slot that mates with the hook, and the slot is provided on the surface of the third insulating part 92 facing the second insulating part 91.

[0207] When installing the second insulating part 9, the first snap-fit ​​part 911 and the second snap-fit ​​part 921 are snapped together to connect the second insulating part 91 and the third insulating part 92 together. The first snap-fit ​​part 911 and the second snap-fit ​​part 921 are disengaged to separate the second insulating part 91 and the third insulating part 92, which can facilitate the installation and removal of the second insulating part 91 and the third insulating part 92.

[0208] In other embodiments, the first latching portion 911 and the second latching portion 921 may also be other structures. For example, the first latching portion 911 may be a protrusion and the second latching portion 921 may be a socket, with the protrusion inserted into the socket to form an over-fitting connection.

[0209] In some embodiments, the limiting part 32 is provided with a weight reduction structure.

[0210] The weight reduction structure can be of various types, such as holes or slots provided in the limiting part 32.

[0211] In this embodiment, the weight-reducing structure can reduce the weight of the electrode terminal 3, thereby reducing the weight of the battery cell 10.

[0212] In some embodiments, please refer to Figure 19 , Figure 19 This is an isometric view of the electrode terminal 3 provided in some embodiments of this application. The weight reduction structure includes a weight reduction hole 326 provided in the limiting part 32, and the two ends of the weight reduction hole 326 extend to two surfaces of the limiting part 32 that are disposed opposite to each other along the axial direction Z of the terminal body 31.

[0213] The weight-reducing hole 326 on the limiting part 32 can be one or more. The weight-reducing hole 326 can be a circular hole, a rectangular hole, etc. The weight-reducing hole 326 can be a complete hole or an incomplete hole. If the through hole 3218 does not extend to the edge of the limiting part 32 in the direction perpendicular to the axial direction Z of the terminal body 31, the through hole 3218 is a complete hole; if the through hole 3218 extends to the edge of the limiting part 32 in the direction perpendicular to the axial direction Z of the terminal body 31, the through hole 3218 is an incomplete hole.

[0214] In this embodiment, the weight of the electrode terminal 3 is reduced by providing a weight-reducing hole 326 on the limiting part 32, which is a simple method.

[0215] In some embodiments, the weight reduction structure includes a plurality of weight reduction holes 326, which are disposed around the terminal body 31.

[0216] The weight reduction holes 326 on the limiting part 32 can be two, three, four, five, etc.

[0217] In this embodiment, a plurality of weight-reducing holes 326 are provided on the limiting part 32, which can further reduce the weight of the electrode terminal 3.

[0218] In some embodiments, please continue to refer to Figure 19 The four corners of the limiting part 32 are provided with weight reduction holes 326.

[0219] As an example, the limiting part 32 is a rectangular plate, and the weight reduction hole 326 is an incomplete hole that extends to one end of the limiting part 32 in the length direction and one end in the width direction.

[0220] In this embodiment, the weight reduction holes 326 are provided at the four corners of the limiting part 32, which further reduces the weight of the electrode terminal 3 while making it less likely to affect the overcurrent of the electrode terminal 3.

[0221] In some embodiments, the weight reduction hole 326 is provided in the first extension 321 to correspondingly form the fusible portion 3217.

[0222] exist Figure 12 In the illustrated embodiment, the through hole 3218 of the first extension 321 can serve as a weight reduction hole 326.

[0223] In this embodiment, a weight-reducing hole 326 is provided on the first extension 321, which reduces the weight of the electrode terminal 3 while forming the fuse portion 3217.

[0224] In some embodiments, the housing 1 includes a housing 11 and an end cap 12, the housing 11 having an opening, the end cap 12 closing the opening, and the end cap 12 being a wall portion 13.

[0225] It is understandable that the electrode terminal 3 is disposed on the end cover 12. The end cover 12 and the housing 11 can be connected in various ways, such as welding, roll sealing, etc.

[0226] As an example, the end cap 12 is a rectangular end cap, and the width direction of the end cap 12 is parallel to the first direction X.

[0227] When assembling the battery cell 10, the electrode terminal 3 can be installed on the end cap 12 first, then the tab 22 can be connected to the electrode terminal 3, the electrode assembly 2 can be housed in the housing 11, and finally the end cap 12 can be connected to the housing 11 to close the opening of the housing 11. This structure can more conveniently realize the installation of the electrode terminal 3 and the connection between the tab 22 and the electrode terminal 3.

[0228] This application provides a battery 100, including the battery cell 10 provided in any of the above embodiments.

[0229] This application provides an electrical device, including a battery cell 10 provided in any of the above embodiments, the battery cell 10 being used to provide electrical energy to the electrical device.

[0230] Please refer to Figures 8-11This application also provides a battery cell 10, which includes a housing 1, an electrode assembly 2, and electrode terminals 3. The housing 1 is a cuboid and includes an end cap 12 of the housing 11. The housing 11 has an opening, and the end cap 12 closes the opening of the housing 11. The end cap 12 has a lead-out hole 131. The electrode assembly 2 is housed within the housing 1 and includes an active material coating portion 21 and a tab 22. The tab 22 is disposed at the end of the active material coating portion 21 facing the end cap 12. The electrode terminal 3 includes an integrally formed terminal body 31 and a limiting portion 32. The terminal body 31 passes through the lead-out hole 131, and the limiting portion 32 is configured to restrict the terminal body 31 from disengaging from the lead-out hole 131 in a direction away from the active material coating portion 21. The terminal body 31 and the active material coating portion 21 are opposite each other at a midpoint along a first direction X. The limiting portion 32 includes a first extension 321 protruding from the outer peripheral surface 311 of the terminal body 31 along the first direction X and a second extension 323 protruding from the outer peripheral surface 311 of the terminal body 31 in the opposite direction of the first direction X. Along the first direction X, the distance between the end of the second extension 323 away from the terminal body 31 and the central axis 312 of the terminal body 31 is a first distance. The first extension 321 includes an elongation area 3211, and the distance between the elongation area 3211 and the central axis 312 is greater than or equal to the first distance. The tab 22 is bent between the electrode terminal 3 and the active material coating portion 21. The tab 22 includes a first connecting portion 221, a second connecting portion 222, a third connecting portion 224, and a fourth connecting portion 225. The first connecting portion 221 is connected to the active material coating portion 21 through the tab root 223. The second connecting portion 222 is welded to the side of the extended region 3211 facing the active material coating portion 21, forming a solder area 3216. The first connecting portion 221, the third connecting portion 224, the fourth connecting portion 225, and the second connecting portion 222 are connected sequentially. Along the axial direction Z of the terminal body 31, the second connecting portion 222 and the third connecting portion 224 are arranged opposite each other. The first connecting portion 221 is opposite to the active material coating portion 21 at the middle position along the first direction X. The first direction X is parallel to the width direction of the end cap 12.

[0231] The battery cell 10 also includes a first insulating member 8 along the axial direction Z of the terminal body 31. The first insulating member 8 includes a first insulating portion 81 disposed between the first extension 321 and the wall portion 13. A clearance groove 3215 is provided on the side of the first extension 321 facing the first insulating portion 81. The orthographic projections of the solder area 3216 and the clearance groove 3215 in a plane perpendicular to the axial direction Z of the terminal body 31 at least partially overlap.

[0232] In this battery cell 10, the second connecting portion 222 is located on one side of the first connecting portion 221 along the first direction X. The second connecting portion 222 is connected to the first extension 321 of the limiting portion 32, which protrudes along the first direction X from the outer peripheral surface 311 of the terminal body 31. This shortens the length of the second connecting portion 222, thereby shortening the length of the tab 22, reducing the possibility of misalignment or creases in the tab 22 during production, and improving the reliability of the battery cell 10. Since the first extension 321 has an elongation region 3211, the second connecting portion 222 is connected to the elongation region 3211, which can further shorten the length of the tab 22. Because the first extension section 321 is provided with a clearance groove 3215, it is difficult for the first extension section 321 and the first insulating part 81 to directly contact each other in the area corresponding to the clearance groove 3215. This can delay or prevent heat transfer between the first extension section 321 and the first insulating part 81, reduce the possibility of heat on the first extension section 321 being transferred to the first insulating part 81 and causing the first insulating part 81 to melt, and reduce the possibility of insulation failure of the first insulating part 81.

[0233] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0234] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The outer casing includes a wall portion, wherein the wall portion has an outlet hole; An electrode assembly is housed within the housing. The electrode assembly includes an active material coating portion and a tab, with the tab disposed at one end of the active material coating portion facing the wall portion. An electrode terminal includes a terminal body and a limiting portion. The terminal body is disposed within the lead-out hole, and the limiting portion is configured to restrict the terminal body from disengaging from the lead-out hole in a direction away from the active material coating portion. The limiting portion includes a first extension protruding from the outer peripheral surface of the terminal body in a first direction. The electrode includes a first connecting portion and a second connecting portion, the second connecting portion being located on one side of the first connecting portion along the first direction, the first connecting portion being connected to the active material coating portion, and the second connecting portion being connected to the first extension section.

2. The battery cell as described in claim 1, characterized in that, The limiting portion further includes a second extension section that protrudes from the outer peripheral surface of the terminal body in the opposite direction to the first direction; Along the first direction, the distance between the end of the second extension segment away from the terminal body and the central axis of the terminal body is a first distance; the first extension segment includes an extended area, the distance between the extended area and the central axis is greater than or equal to the first distance, and the second connecting portion is connected to the extended area.

3. The battery cell as described in claim 2, characterized in that, Along the first direction, the distance between the end of the second connecting portion near the terminal body and the central axis is the second distance, which is greater than or equal to the first distance.

4. The battery cell as described in claim 1, characterized in that, The first connecting portion and the active material coating portion are positioned opposite each other at the midpoint along the first direction; and / or, the terminal body and the active material coating portion are positioned opposite each other at the midpoint along the first direction.

5. The battery cell as described in claim 1, characterized in that, The electrode tab further includes a third connecting part and a fourth connecting part. The first connecting part, the third connecting part, the fourth connecting part and the second connecting part are connected in sequence. Along the axial direction of the terminal body, the second connecting part and the third connecting part are arranged opposite to each other.

6. The battery cell as described in claim 1, characterized in that, Along the axial direction of the terminal body, the second connecting portion is connected to the side of the first extension facing the active material coating portion.

7. The battery cell as described in claim 1, characterized in that, The terminal body and the limiting part are integrally formed.

8. The battery cell according to any one of claims 1-7, characterized in that, The battery cell further includes a first insulating member. Along the axial direction of the terminal body, the first insulating member includes a first insulating portion disposed between the first extension and the wall portion. The side of the first insulating portion facing the first extension and / or the side of the first extension facing the first insulating portion is provided with a heat insulation structure.

9. The battery cell as described in claim 8, characterized in that, The heat insulation structure includes a clearance groove disposed in the first insulating part and / or the first extension section.

10. The battery cell as described in claim 9, characterized in that, The second connecting portion is welded to the first extension to form a solder area, and the solder area and the clearance groove at least partially overlap in orthogonal projection in a plane perpendicular to the axial direction of the terminal body.

11. The battery cell as described in claim 10, characterized in that, The area of ​​the orthographic projection of the soldering area in the plane is S1, and the area of ​​the overlapping region of the orthographic projections of the soldering area and the clearance groove in the plane is S2, satisfying: S2 / S1≥1 / 3.

12. The battery cell as described in claim 11, characterized in that, S2 / S1≥1 / 2.

13. The battery cell according to any one of claims 1-7, characterized in that, The first extension has a fusible portion.

14. The battery cell as described in claim 13, characterized in that, The first extension section is provided with a through hole, and the two ends of the through hole extend to two surfaces of the first extension section that are arranged opposite to each other along the axial direction of the terminal body, so as to form the fuse portion.

15. The battery cell as described in claim 14, characterized in that, The first extension section is provided with a plurality of through holes, which are arranged at intervals along a second direction, the second direction intersecting the first direction.

16. The battery cell as described in claim 15, characterized in that, The first extension section is provided with two through holes, and along the second direction, the two through holes extend to both ends of the first extension section respectively, and the fused portion is located between the two through holes.

17. The battery cell as described in claim 13, characterized in that, The battery cell also includes a second insulating member, which covers at least a portion of the outer surface of the fused portion.

18. The battery cell as described in claim 17, characterized in that, The second insulating component includes an insulating coating disposed on the outer surface of the fused portion, an insulating adhesive layer bonded to the outer surface of the fused portion, or a hot-melt insulating layer hot-melt bonded to the outer surface of the fused portion.

19. The battery cell as described in claim 17, characterized in that, The second insulating member includes a second insulating portion and a third insulating portion, the second insulating portion and the third insulating portion together define a first space, the fusible portion is accommodated in the first space, and the second insulating portion and the third insulating portion are detachably connected.

20. The battery cell as described in claim 19, characterized in that, The second insulating part is provided with a first snap-fit ​​part, and the third insulating part is provided with a second snap-fit ​​part, wherein the first snap-fit ​​part and the second snap-fit ​​part are snap-fitted together.

21. The battery cell according to any one of claims 1-7, characterized in that, The limiting part is equipped with a weight reduction structure.

22. The battery cell as described in claim 21, characterized in that, The weight reduction structure includes a weight reduction hole disposed in the limiting part, and the two ends of the weight reduction hole extend to two surfaces of the limiting part that are disposed opposite to each other along the axial direction of the terminal body.

23. The battery cell as described in claim 22, characterized in that, The weight reduction structure includes multiple weight reduction holes, which are arranged around the terminal body.

24. The battery cell as described in claim 22, characterized in that, The weight-reducing holes are provided at all four corners of the limiting part.

25. The battery cell as described in claim 22, characterized in that, The weight-reducing hole is provided in the first extension section to form a corresponding fusion section.

26. The battery cell according to any one of claims 1-7, characterized in that, The outer casing includes: The shell has an opening; An end cap, which closes the opening, is the wall portion.

27. A battery, characterized in that, Includes the battery cell as described in any one of claims 1-26.

28. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-26, the battery cell being used to provide electrical energy to the electrical equipment.

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