Battery cells, battery packs and electrical devices

Abstract

This application provides a battery cell, a battery device, and an electrical device. The battery cell includes a casing, an electrolyte, and multiple electrode assemblies. The casing has a first wall. The electrolyte is contained within the casing. Multiple electrode assemblies are contained within the casing. The first wall supports the multiple electrode assemblies along a first direction. Each electrode assembly includes a tab and a body portion. The multiple body portions are stacked along the first direction. At least one end of each body portion along a second direction is provided with a tab, and the second direction is perpendicular to the first direction. The multiple electrode assemblies include a first electrode assembly and a second electrode assembly. Along the first direction, the body portion of the second electrode assembly is closest to the first wall. The end of the tab of the first electrode assembly furthest from the body portion of the first electrode assembly is designated as a first end, extending into the electrolyte. The minimum distance between the first end and the inner surface of the first wall is less than or equal to half the thickness of the body portion of the second electrode assembly. Such a battery cell can improve its performance.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] Battery devices are widely used in portable electronic devices, electric vehicles, power tools, drones, energy storage devices, and other fields. In the development of battery cell technology, the performance of individual battery cells is a crucial issue. Therefore, improving the performance of individual battery cells is a pressing technical problem that needs to be solved in battery technology. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device that can improve the performance of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, including a casing, an electrolyte, and multiple electrode assemblies; the casing has a first wall; the electrolyte is contained within the casing; multiple electrode assemblies are contained within the casing, the first wall supports the multiple electrode assemblies along a first direction, each electrode assembly includes a tab and a body portion, the body portions of the multiple electrode assemblies are stacked along the first direction, and at least one end of each body portion along a second direction is provided with a tab, the second direction being perpendicular to the first direction; the multiple electrode assemblies include a first electrode assembly and a second electrode assembly, along the first direction, the body portion of the second electrode assembly is the body portion closest to the first wall, the body portion of the first electrode assembly is located on the side of the body portion of the second electrode assembly away from the first wall, the end of the tab of the first electrode assembly away from the body portion of the first electrode assembly is a first end, the first end extends into the electrolyte, and the minimum distance between the first end and the inner surface of the first wall is less than or equal to half the thickness of the body portion of the second electrode assembly.

[0006] In the above technical solution, as the number of cycles of a battery cell increases, the electrolyte in the battery cell decreases, causing the electrolyte level to drop. By extending the first end into the electrolyte, and ensuring that the distance between the first end and the inner surface of the first wall is less than or equal to half the thickness of the main body of the second electrode assembly, the electrolyte can rise through the tabs of the first electrode assembly to the main body of the first electrode assembly, improving the wetting effect of the first electrode assembly. When half of the main body of the second electrode assembly is below the electrolyte level and the first electrode assembly is above the electrolyte level, the first end can be below the electrolyte level. The tabs of the first electrode assembly can guide the electrolyte to the main body of the first electrode assembly, extending the time during which the main body of the first electrode assembly can be wetted by the electrolyte, improving the wetting effect of the main body of the first electrode assembly, thereby improving the electrochemical reaction performance of the first electrode assembly and ultimately improving the performance of the battery cell.

[0007] In some embodiments, along the first direction, the minimum distance between the first end and the inner surface of the first wall is less than or equal to one-quarter of the thickness of the main body of the second electrode assembly. This distance, being less than or equal to one-quarter of the thickness of the main body of the second electrode assembly, lowers the position of the first end. When the electrolyte is at a lower position, the first end is kept below the electrolyte surface, further extending the time during which the main body of the first electrode assembly can be wetted by the electrolyte, improving the wetting effect of the main body of the first electrode assembly, thereby enhancing the electrochemical reaction performance of the first electrode assembly and ultimately improving the performance of the battery cell.

[0008] In some embodiments, the first end does not contact the inner surface of the first wall. This reduces the risk of deformation due to the outer casing being susceptible to deformation, as the first end is less likely to deform upon contact with the first wall, thus improving the structural stability of the battery cell.

[0009] In some embodiments, the minimum distance between the first end and the inner surface of the first wall is 1mm-8mm. When the distance between the first end and the inner surface of the first wall is greater than or equal to 1mm, on the one hand, the distance between the first end and the inner surface of the first wall is not too small, reducing the risk of interference between the first end and the first wall; on the other hand, it can save the material used for the tabs of the first electrode assembly, reducing the manufacturing cost of the battery cell. When the distance between the first end and the inner surface of the first wall is less than or equal to 8mm, the distance between the first end and the inner surface of the first wall is not too large, extending the time the first end is immersed in the electrolyte, thus extending the service life of the battery cell. Therefore, when the minimum distance between the first end and the inner surface of the first wall is 1mm-8mm, the reliability, manufacturing cost, and service life of the battery cell can be balanced.

[0010] In some embodiments, the battery cell further includes electrode terminals and current collectors. The electrode terminals are disposed on the housing, and the current collectors correspond one-to-one with the electrode terminals. The current collectors are connected to the electrode terminals, and the tabs of the first electrode assembly and the second electrode assembly are both connected to the current collectors. In this way, the tabs of the first electrode assembly and the second electrode assembly are connected to the electrode terminals through the current collectors, which reduces the difficulty of electrically connecting the tabs of the first electrode assembly and the second electrode assembly to the electrode terminals, and reduces the manufacturing difficulty of the battery cell.

[0011] In some embodiments, the tab of the first electrode assembly is a first tab, which is welded to a current collector to form a first solder mark. Along a first direction, the main body of the second electrode assembly has a first surface facing away from the first wall, and the first solder mark is closer to the first wall than the first surface. Thus, the first solder mark is located below the first surface. When the electrolyte level is higher than the first surface along the first direction, the first solder mark is immersed in the electrolyte. The first tab can reduce the influence of the first solder mark on the electrolyte climbing up the first tab by wetting the portion above the first solder mark with the electrolyte.

[0012] In some embodiments, the second electrode assembly has a mid-section perpendicular to a first direction, and along the first direction, a first solder mark is located between the mid-section and the inner surface of the first wall. Thus, when the electrolyte level is higher than the mid-section of the second electrode assembly, the first solder mark can be located below the electrolyte level, allowing the electrolyte to rise to the main body of the first electrode assembly through the portion of the first tab above the first solder mark, reducing the influence of the first solder mark on the electrolyte's rise on the first tab.

[0013] In some embodiments, each first tab is welded to a current collector to form a plurality of first solder marks, which are spaced apart. By spaced apart, the electrolyte can pass through the area where the first tabs are welded between two adjacent first solder marks to rise into the body of the first electrode assembly, reducing the risk of poor wetting of the body of the first electrode assembly and improving the performance of the battery cell.

[0014] In some embodiments, a plurality of first solder marks are arranged in multiple rows and columns, with each row of first solder marks spaced apart along a third direction and each column of first solder marks spaced apart along a second direction, the first direction, the second direction, and the third direction being perpendicular to each other. This increases the solder area between the plurality of first tabs, thereby improving the connection stability between them; furthermore, the arrangement of the plurality of first solder marks in multiple rows and columns allows for the formation of channels for electrolyte conduction between adjacent first solder marks, facilitating electrolyte upwelling.

[0015] In some embodiments, along a third direction, the ratio of the sum of the dimensions of each row of first solder marks to the dimensions of the first tab is 1 / 3 to 2 / 3. A ratio greater than or equal to 1 / 3 increases the dimensions of the solder marks on the multiple first tabs along the third direction, thereby improving the connection strength between the multiple first tabs. A ratio less than or equal to 2 / 3 allows for the provision of electrolyte upwelling channels at the un-soldered positions on the multiple first tabs, improving the wetting effect of the electrolyte into the main body of the first electrode assembly. Therefore, a ratio of 1 / 3 to 2 / 3 balances the connection strength between the multiple first tabs and the improved wetting effect of the electrolyte into the main body of the first electrode assembly.

[0016] In some embodiments, the tab of the first electrode assembly is a first tab, the main body of the first electrode assembly is a first main body, the first tab includes a plurality of first sub-tabs, the plurality of first sub-tabs are stacked, the first sub-tabs have a connecting end and a free end, the connecting end is connected to the first main body, and the free end closest to the first wall is the first end. In this way, the electrolyte can wet the plurality of first sub-tabs through the free end closest to the first wall, and the stacked first sub-tabs form a channel to facilitate the rise of the electrolyte, reduce the difficulty of wetting the first main body, and improve the wetting effect of the electrolyte into the first main body.

[0017] In some embodiments, the dimension by which the first sub-tab extends from the connecting end to the free end is the extension length of the first sub-tab. The connecting ends of the plurality of first sub-tabs are arranged along a first direction. In two adjacent first sub-tabs, the extension length of the first sub-tab whose connecting end is farther from the first wall is greater than the extension length of the first sub-tab whose connecting end is closer to the first wall. In this way, the free end of the first sub-tab farther from the first wall can be brought closer to the first wall, so that two adjacent first sub-tabs have more overlapping areas. This is beneficial for the electrolyte to climb to the first main body through the overlapping areas, thereby improving the wetting effect of the electrolyte in wetting the first main body.

[0018] In some embodiments, the free ends of the plurality of first sub-tabs are flush along the first direction. This reduces the processing difficulty and cost of the first sub-tabs. Furthermore, since the free ends of the plurality of first sub-tabs are first ends, all free ends of the plurality of first sub-tabs can be immersed in the electrolyte, which facilitates the electrolyte to rise through the plurality of first sub-tabs to the first main body, thereby improving the wetting effect of the electrolyte in the first main body.

[0019] In some embodiments, the first electrode tab is provided with a through hole that extends through multiple first sub-electrodes. Electrolyte can enter the through hole and wet between two adjacent first sub-electrodes, which facilitates the electrolyte to rise to the first main body and thus improves the wetting effect of the electrolyte in the first main body.

[0020] In some embodiments, along a first direction, the main body of the second electrode assembly has a first surface facing away from the first wall, and along the first direction, the through hole is closer to the first wall than the first surface. This lower position of the through hole, and its closer proximity to the first wall, facilitates the entry of electrolyte into the through hole and allows the electrolyte to climb through the multiple first tabs to the first main body, thus improving the wetting effect of the electrolyte in the first main body.

[0021] In some embodiments, the aperture of the through-hole is 0.5mm-1.5mm. An aperture greater than or equal to 0.5mm increases the capacity of the through-hole, allowing it to hold more electrolyte, which facilitates electrolyte uptake and improves the wetting effect of the electrolyte into the first body portion. An aperture less than or equal to 1.5mm increases the strength of the first tab and reduces the risk of damage to the first tab. Therefore, an aperture of 0.5mm-1.5mm balances increasing the capacity of the through-hole with the strength of the first tab, improving the wetting effect of the electrolyte into the first body portion, and reducing the risk of damage to the first tab.

[0022] In some embodiments, a liquid-conducting layer is provided on at least one surface of the first tab in its thickness direction, the liquid-conducting layer being used to guide the electrolyte to the first body portion. In this way, the liquid-conducting layer can enhance the climbing ability of the electrolyte on the first tab and improve the wetting effect of the electrolyte into the first body portion.

[0023] In some embodiments, the liquid-conducting layer has a porous structure. The electrolyte rises to the first body portion through the porous structure of the liquid-conducting layer, which helps to improve the electrolyte's ability to rise on the first tab.

[0024] In some embodiments, the liquid-conducting layer is an inorganic particle coating, a sponge layer, or a porous organic polymer layer. By using any of the above materials to manufacture the liquid-conducting layer, it is beneficial to improve the guiding ability of the liquid-conducting layer to guide the electrolyte to the first body portion, and to improve the wetting effect of the electrolyte in wetting the first body portion.

[0025] In some embodiments, the first body portion includes a first electrode segment, a second electrode segment, and an isolation segment. Along a first direction, the first electrode segment and the second electrode segment are stacked, and the isolation segment is disposed between the first electrode segment and the second electrode segment. The first electrode segment and the second electrode segment have opposite polarities. Each first electrode segment has a first sub-electrode tab, and multiple first sub-electrode tabs on the first electrode segments are stacked to form a first electrode tab. Alternatively, each second electrode segment has a first sub-electrode tab, and multiple first sub-electrode tabs on the second electrode segments are stacked to form a first electrode tab. At least one portion of the isolation segment extends between two adjacent first sub-electrode tabs in the first electrode tab to form a liquid-conducting layer. Thus, the isolation segment between two adjacent first sub-electrode tabs can guide the electrolyte to the portion of the isolation segment located between the first electrode segment and the second electrode segment. This reduces the processing difficulty of the liquid-conducting layer and improves the wetting effect of the electrolyte into the first body portion.

[0026] In some embodiments, the tabs of the first electrode assembly and the second electrode assembly are arranged along a third direction, with the first direction, the second direction, and the third direction being perpendicular to each other. This allows the tabs of the first electrode assembly and the second electrode assembly to be located on the same side of the first electrode assembly along the second direction, which helps to reduce the size of the battery cell along the second direction occupied by the tabs of the first and second electrode assemblies, thereby improving the space utilization rate of the battery cell and increasing its volumetric energy density.

[0027] Secondly, embodiments of this application provide a battery device, including a battery cell as provided in any embodiment of the first aspect.

[0028] Thirdly, embodiments of this application provide an electrical device, including a single battery cell as provided in any embodiment of the first aspect or a battery device as provided in any embodiment of the second aspect. Attached Figure Description

[0029] 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.

[0030] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments; Figure 2 Exploded views of battery devices provided in some embodiments of this application; Figure 3 Exploded views of a single battery cell provided in some embodiments of this application; Figure 4 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application; Figure 5 A partial structural schematic diagram of a battery cell provided in some embodiments of this application; Figure 6 for Figure 5 A magnified view of a portion of region A in the middle; Figure 7 Exploded views of a battery cell provided in some embodiments of this application; Figure 8 A partial structural schematic diagram of a battery cell provided for some embodiments of this application; Figure 9 This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application; Figure 10 This application provides schematic diagrams of the structure of electrode assemblies in some of its embodiments. Figure 11 This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application; Figure 12 This is a schematic diagram of the structure of a first electrode assembly provided in some embodiments of this application.

[0031] Icons: 1-Outer shell; 11-Shell; 12-End cap; 13-First wall; 2-Electrode assembly; 21-Electrode tab; 211-First end; 22-Main body; 2a-First electrode assembly; 21a-First electrode tab; 211a-First daughter electrode tab; 2111a-Connecting end; 2112a-Free end; 212a-Through hole; 213a-Liquid guiding layer; 22a-First main body; 221a-First electrode segment; 222a-Second electrode segment; 223a-Isolation segment; 2b - Second electrode assembly; 21b - Second tab; 221b - First surface; 222b - Second surface; 223b - Mid-section; 3-Electrode terminal; 4-Current collector; 5-First solder mark; 6-Second solder mark; 10 - Battery cell; 20 - Housing; 201 - First housing; 202 - Second housing; 100 - Battery unit; 200 - Controller; 300 - Motor; 1000 - Vehicle; Z - First direction; X - Second direction; Y - Third direction. Detailed Implementation

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] 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.

[0037] 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.

[0038] In this application, "multiple" means two or more (including two).

[0039] 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.

[0040] 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.

[0041] 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, reduces the risk of short circuits while allowing active ions to pass through.

[0042] 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.

[0043] 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.

[0044] As an example, the positive electrode current collector can be a foil or a composite current collector. For example, as a 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, 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.).

[0045] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as 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 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0046] 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.

[0047] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0048] As an example, the negative electrode current collector can be a foil, a foamed metal, or a composite current collector. For example, as a foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, 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 alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0060] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0061] As an example, polymer solid electrolytes can be polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0062] 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.

[0063] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0064] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0065] In some implementations, the electrode assembly is a stacked structure.

[0066] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0067] 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.

[0068] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0069] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0070] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0071] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0072] 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.

[0073] 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.

[0074] As an example, a 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0080] In a single battery cell, the casing typically contains an electrolyte. This electrolyte wets the electrode assembly within the casing, enhancing ion transport capabilities and thus improving the electrochemical reaction performance of the electrode assembly, ultimately improving the overall performance of the battery cell. When the battery cell is used upright (with the longest side of the electrode assembly vertical), a portion of the electrode assembly may be above the electrolyte level. The electrolyte needs to rise to the portion of the electrode assembly above the electrolyte level to ensure effective wetting. As the number of battery cell cycles increases, the amount of electrolyte within the casing decreases, making it easier for more of the electrode assembly to remain above the electrolyte level. This increases the difficulty of electrolyte rising and negatively impacts the effectiveness of electrolyte wetting of the electrode assembly.

[0081] Battery cells can be placed sideways, with the longest side of the electrode assembly placed horizontally, to reduce the height of the electrode assembly and thus improve the wetting effect of the electrolyte on the electrode assembly. However, for battery cells containing multiple electrode assemblies within the casing, these assemblies are stacked along the height direction. As the number of battery cell cycles increases, the amount of electrolyte in the casing decreases. The upper electrode assemblies cannot come into contact with the electrolyte, preventing the electrolyte from wetting them through capillary action. This results in poor wetting of the electrode assemblies, reducing the ion transport capacity within the upper electrode assemblies and affecting the performance of the battery cell.

[0082] In view of this, in order to improve the wetting effect of the electrolyte on the electrode components, this application provides a battery cell including a casing, an electrolyte, and multiple electrode components. The casing has a first wall. The electrolyte is contained within the casing. Multiple electrode components are contained within the casing, and the first wall supports the multiple electrode components along a first direction. Each electrode component includes a tab and a body portion. The body portions of the multiple electrode components are stacked along the first direction, and at least one end of each body portion along a second direction is provided with a tab, the second direction being perpendicular to the first direction. The multiple electrode components include a first electrode component and a second electrode component. Along the first direction, the body portion of the second electrode component is the body portion closest to the first wall, and the body portion of the first electrode component is located on the side of the body portion of the second electrode component away from the first wall. The end of the tab of the first electrode component away from the body portion of the first electrode component is a first end, the first end extending into the electrolyte, and the minimum distance between the first end and the inner surface of the first wall is less than or equal to half the thickness of the body portion of the second electrode component.

[0083] In such a battery cell, as the number of battery cell cycles increases, the electrolyte level decreases, causing the electrolyte level to drop. By extending the first end into the electrolyte, and ensuring that the distance between the first end and the inner surface of the first wall is less than or equal to half the thickness of the main body of the second electrode assembly, the electrolyte can rise through the tabs of the first electrode assembly to the main body of the first electrode assembly. This improves the wetting effect of the first electrode assembly by the electrolyte. When half of the main body of the second electrode assembly is below the electrolyte level and the first electrode assembly is above the electrolyte level, the first end can remain below the electrolyte level. The tabs of the first electrode assembly can guide the electrolyte to the main body of the first electrode assembly, extending the time the main body of the first electrode assembly can be wetted by the electrolyte, improving the wetting effect of the main body of the first electrode assembly, thereby improving the electrochemical reaction performance of the first electrode assembly and ultimately improving the performance of the battery cell.

[0084] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0085] 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.

[0086] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0087] 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 device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0088] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0089] In some embodiments of this application, the battery device 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.

[0090] Please refer to Figure 2 , Figure 2 The following is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 20 and a battery cell 10, wherein the housing 20 is used to house the battery cell 10.

[0091] The housing 20 has an enclosed space inside for accommodating the battery cell 10. The housing 20 can have various structures. In some embodiments, the housing 20 may include a first housing 201 and a second housing 202, which are interlocked. The first housing 201 and the second housing 202 can have various shapes, such as cuboids or cylinders. The first housing 201 can be a hollow structure open on one side, and the second housing 202 can also be a hollow structure open on one side. The open side of the second housing 202 interlocks with the open side of the first housing 201, thus forming a housing 20 with an enclosed space. Alternatively, the first housing 201 can be a hollow structure open on one side, and the second housing 202 can be a plate-like structure, with the second housing 202 interlocked with the open side of the first housing 201, thus forming a housing 20 with a receiving cavity.

[0092] In the battery device 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.

[0093] In some embodiments, the battery device 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.

[0094] 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 and an electrode assembly 2, the electrode assembly 2 being housed within the housing 1.

[0095] In some embodiments, the housing 1 may include a housing 11 and an end cap 12, the housing 11 having an opening, and the end cap 12 closing the opening of the housing 11. Here, "closed" means covered or shut, and can be either sealed or unsealed.

[0096] The housing 11 is a component used to house the electrode assembly 2. The housing 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 housing 11 can have various shapes, such as cylindrical or cuboid. The housing 11 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The electrode assembly 2 can be partially or completely housed within the housing 11.

[0097] The end cap 12 and the housing 11 together define a receiving space for accommodating the electrode assembly 2 and other components. The end cap 12 can be connected to the housing 11 by welding, rolling, or other methods to close the opening of the housing 11. The shape of the end cap 12 can be adapted to the shape of the housing 11. For example, if the housing 11 is a cuboid structure, the end cap 12 can be a rectangular plate structure adapted to the housing 11; or if the housing 11 is a cylindrical structure, the end cap 12 can be a circular plate structure adapted to the housing 11. The end cap 12 can also be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The end cap 12 and the housing 11 can be made of the same or different materials.

[0098] There can be one electrode assembly 2 or multiple electrode assemblies.

[0099] 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.

[0100] In some embodiments, the battery cell 10 may further include electrode terminals 3, which are disposed on the housing 1 and are used for electrical connection with the tabs 21 of the electrode assembly 2 to input or output electrical energy of the battery cell 10. The electrode terminals 3 may be disposed on the housing 11 of the housing 1 or on the end cap 12 of the housing 1. The electrode terminals 3 and the tabs 21 may be directly connected, for example, by welding. Alternatively, the electrode terminals 3 and the tabs 21 may be indirectly connected, for example, through a current collector 4. The current collector 4 may be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy.

[0101] As an example, such as Figure 3 As shown, one end of the housing 11 forms an opening, and there is one end cap 12 in the housing 1, which closes one opening of the housing 11. Two electrode terminals 3 are provided on the end cap 12, which are a positive electrode terminal and a negative electrode terminal, respectively. The end of the electrode assembly 2 facing the end cap 12 has a positive electrode tab and a negative electrode tab. The positive electrode terminal is electrically connected to the positive electrode tab, and the negative electrode terminal is electrically connected to the negative electrode tab.

[0102] Please refer to Figures 4-6 , Figure 4 This is a schematic diagram of the structure of a battery cell 10 provided in some embodiments of this application; Figure 5 This is a partial structural schematic diagram of a battery cell 10 provided in some embodiments of this application; Figure 6 for Figure 5A partial enlarged view of region A in the image. This application provides a battery cell 10, including a casing 1, an electrolyte (not shown), and multiple electrode assemblies 2. The casing 1 has a first wall 13. The electrolyte is contained within the casing 1. Multiple electrode assemblies 2 are housed within the casing 1. The first wall 13 supports the multiple electrode assemblies 2 along a first direction Z. Each electrode assembly 2 includes a tab 21 and a main body 22. The main bodies 22 of the multiple electrode assemblies 2 are stacked along the first direction Z. At least one end of each main body 22 is provided with a tab 21 along a second direction X, which is perpendicular to the first direction Z. The plurality of electrode assemblies 2 include a first electrode assembly 2a and a second electrode assembly 2b. Along the first direction Z, the main body portion 22 of the second electrode assembly 2b is the main body portion 22 closest to the first wall 13. The main body portion 22 of the first electrode assembly 2a is located on the side of the main body portion 22 of the second electrode assembly 2b away from the first wall 13. The end of the tab 21 of the first electrode assembly 2a away from the main body portion 22 of the first electrode assembly 2a is the first end 211. The first end 211 extends into the electrolyte, and the minimum distance between the first end 211 and the inner surface of the first wall 13 is less than or equal to half the thickness of the main body portion 22 of the second electrode assembly 2b.

[0103] The outer casing 1 may include a housing 11 and an end cap 12. The first wall 13 may be a wall of the housing 11 or the end cap 12.

[0104] For example, the battery cell 10 is a cylindrical battery cell 10, one end of the casing 11 has an opening, the end cap 12 covers the opening, and the first wall 13 can be the end cap 12 or the wall of the casing 11 opposite to the opening.

[0105] For example, the battery cell 10 is a prismatic battery cell 10, with one end of the housing 11 having an opening, and an end cap 12 covering the opening. The end cap 12 can be the first wall 13, or it can be a wall in the housing 11 opposite to the end cap 12, or it can be one of a plurality of side walls of the housing 11, wherein the plurality of side walls are arranged around the opening. Exemplarily, the first wall 13 is one of the walls of the housing 11 extending to the opening, and the first wall 13 is arranged facing the larger surface of the electrode assembly 2.

[0106] The number of electrode assemblies 2 can be multiple. For example, the number of electrode assemblies 2 can be two, three, four, five, six, seven, eight, etc.

[0107] In an embodiment where there are two electrode assemblies 2, the two electrode assemblies 2 are a first electrode assembly 2a and a second electrode assembly 2b, respectively. Along the first direction Z, the main body 22 of the second electrode assembly 2b is located between the main body 22 of the first electrode assembly 2a and the first wall 13.

[0108] In embodiments where there are three or more electrode assemblies 2, the electrode assembly 2 closest to the first wall 13 in the main body 22 is the second electrode assembly 2b, and at least one of the multiple electrode assemblies 2 in the main body 22 that are further away from the first wall 13 than the second electrode assembly 2b is the first electrode assembly 2a. Among the multiple electrode assemblies 2 in the main body 22 that are further away from the first wall 13 than the second electrode assembly 2b, there may be only one electrode assembly 2 that is the first electrode assembly 2a; there may be multiple electrode assemblies 2 that are the first electrode assembly 2a; or all of the electrode assemblies 2 may be the first electrode assembly 2a.

[0109] The first direction Z can be the height direction of the battery cell 10 during use, and the first wall 13 is located at the bottom of the multiple electrode assemblies 2 to support the multiple electrode assemblies 2.

[0110] The inner surface of the first wall 13 is the surface of the first wall 13 facing the second electrode assembly 2b. In the first direction Z, the minimum distance between the first end 211 and the inner surface of the first wall 13 can be equal to or less than half the thickness of the main body 22 of the second electrode assembly 2b. In embodiments where there are multiple first electrode assemblies 2a, the minimum distance between each first end 211 and the inner surface of the first wall 13 is less than or equal to the thickness of the main body 22 of the second electrode assembly 2b.

[0111] For example, please refer to Figure 6 Along the first direction Z, the minimum distance between the inner surface of the first wall 13 and the first end 211 is L, and the thickness of the second electrode assembly 2b is H, where L is less than 1 / 2H.

[0112] For the second electrode assembly 2b, during the use of the battery cell 10, the main body 22 of the second electrode assembly 2b is disposed close to the first wall 13. When the first wall 13 supports the second electrode assembly 2b along the first direction Z, at least a portion of the main body 22 of the second electrode assembly 2b can be immersed below the surface of the electrolyte, so that the electrolyte can directly wet the main body 22 of the second electrode assembly 2b. It is understood that the tab 21 of the second electrode assembly 2b can also extend into the electrolyte, and the electrolyte can also rise to the main body 22 of the second electrode assembly 2b through the tab 21 of the second electrode assembly 2b, thereby achieving wetting of the main body 22 of the second electrode assembly 2b.

[0113] In this embodiment, as the number of cycles of the battery cell 10 increases, the electrolyte in the battery cell 10 decreases, causing the electrolyte level to drop. By extending the first end 211 into the electrolyte, and ensuring that the distance between the first end 211 and the inner surface of the first wall 13 is less than or equal to half the thickness of the main body 22 of the second electrode assembly 2b, the electrolyte can rise through the tab 21 of the first electrode assembly 2a to the main body 22 of the first electrode assembly 2a, improving the electrolyte wetting effect of the first electrode assembly 2a. When half of the main body 22 of 2b is below the surface of the electrolyte and the first electrode assembly 2a is above the surface of the electrolyte, the first end 211 can be below the surface of the electrolyte. The tab 21 of the first electrode assembly 2a can guide the electrolyte to the main body 22 of the first electrode assembly 2a, prolonging the time that the main body 22 of the first electrode assembly 2a can be wetted by the electrolyte, improving the wetting effect of the main body 22 of the first electrode assembly 2a, thereby improving the electrochemical reaction performance of the first electrode assembly 2a, and further improving the performance of the battery cell 10.

[0114] In some embodiments, please continue to refer to Figures 4-6 Along the first direction Z, the minimum distance between the first end 211 and the inner surface of the first wall 13 is less than or equal to one-quarter of the thickness of the main body 22 of the second electrode assembly 2b.

[0115] The minimum distance between the first end 211 and the inner surface of the first wall 13 can be less than one-quarter of the thickness of the main body 22 of the second electrode assembly 2b; or the minimum distance between the first end 211 and the inner surface of the first wall 13 can be equal to one-quarter of the thickness of the main body 22 of the second electrode assembly 2b.

[0116] In the above embodiments, during the cycling process of the battery cell 10, as the number of cycles of the battery cell 10 increases, the electrolyte in the battery cell 10 decreases accordingly, causing the electrolyte level to drop. The distance between the first end 211 and the inner surface of the first wall 13 is less than or equal to one-quarter of the thickness of the main body 22 of the second electrode assembly 2b, making the position of the first end 211 even lower. When the electrolyte is at a lower position, the first end 211 is kept below the electrolyte level, further extending the time that the main body 22 of the first electrode assembly 2a can be wetted by the electrolyte, improving the wetting effect of the main body 22 of the first electrode assembly 2a, thereby improving the electrochemical reaction performance of the first electrode assembly 2a, and thus improving the performance of the battery cell 10.

[0117] In some embodiments, the first end 211 does not contact the inner surface of the first wall 13.

[0118] The first end 211 is the end of the tab 21 of the first electrode assembly 2a that is away from the main body 22 of the first electrode assembly 2a. The first end 211 does not contact the inner surface of the first wall 13, so that the tab 21 of the first electrode assembly 2a does not contact the inner surface of the first wall 13.

[0119] In the above embodiments, the outer casing 1 is easily deformed by the influence of the outer casing 1. The fact that the first end 211 does not contact the inner surface of the first wall 13 can reduce the risk of deformation due to contact with the first wall 13, thereby improving the structural stability of the battery cell 10. In addition, in embodiments where the outer casing 1 is a metal outer casing 1, the fact that the first end 211 does not contact the inner surface of the first wall 13 can reduce the risk of the outer casing 1 becoming charged, thereby improving the reliability of the battery cell 10.

[0120] In some embodiments, please continue to refer to Figure 6 The minimum distance between the first end 211 and the inner surface of the first wall 13 is 1mm-8mm.

[0121] The minimum distance L between the first end 211 and the inner surface of the first wall 13 can be any point value or a range value between any two of the following: 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, and 8mm.

[0122] In the above embodiments, when the distance between the first end 211 and the inner surface of the first wall 13 is greater than or equal to 1 mm, on the one hand, the distance between the first end 211 and the inner surface of the first wall 13 is not too small, reducing the risk of interference between the first end 211 and the first wall 13; on the other hand, it can save the material used for the tab 21 of the first electrode assembly 2a, reducing the manufacturing cost of the battery cell 10. When the distance between the first end 211 and the inner surface of the first wall 13 is less than or equal to 8 mm, the distance between the first end 211 and the inner surface of the first wall 13 is not too large, extending the time that the first end 211 is immersed in the electrolyte, thus extending the service life of the battery cell 10. Therefore, when the minimum distance between the first end 211 and the inner surface of the first wall 13 is 1 mm to 8 mm, the reliability, manufacturing cost, and service life of the battery cell 10 can be balanced.

[0123] In some embodiments, please refer to Figure 7 , Figure 7 This is an exploded view of a battery cell 10 provided in some embodiments of this application. The battery cell 10 also includes electrode terminals 3 and current collectors 4. The electrode terminals 3 are disposed on the housing 1, and the current collectors 4 correspond one-to-one with the electrode terminals 3. The current collectors 4 are connected to the electrode terminals 3, and the tabs 21 of the first electrode assembly 2a and the second electrode assembly 2b are both connected to the current collectors 4.

[0124] There can be two electrode terminals 3. Both electrode terminals 3 can be disposed on the housing 11; both electrode terminals 3 can be disposed on the end cap 12; or one electrode terminal 3 can be disposed on the housing 11 and the other electrode terminal 3 can be disposed on the end cap 12. One of the two electrode terminals 3 is the positive electrode terminal 3, and the other is the negative electrode terminal 3. For example, as shown... Figure 7 As shown, the housing 11 has an opening on one side along the second direction X, and the end cap 12 covers the opening. Both electrode terminals 3 are disposed on the end cap 12.

[0125] Each electrode terminal 3 is connected to a current collector 4. The first electrode assembly 2a includes a positive electrode tab and a negative electrode tab, and the second electrode assembly 2b includes a positive electrode tab and a negative electrode tab. The positive electrode tabs of the first electrode assembly 2a and the second electrode assembly 2b are both connected to a current collector 4, and the negative electrode tabs of the first electrode assembly 2a and the second electrode assembly 2b are both connected to another current collector 4.

[0126] In the above embodiments, the tabs 21 of the first electrode assembly 2a and the tabs 21 of the second electrode assembly 2b are connected to the electrode terminal 3 through the current collector 4, which reduces the difficulty of connecting the tabs 21 of the first electrode assembly 2a and the tabs 21 of the second electrode assembly 2b to the electrode terminal 3, and reduces the manufacturing difficulty of the battery cell 10.

[0127] In some embodiments, please refer to Figure 8 , Figure 8 This is a partial structural schematic diagram of a battery cell 10 provided in some embodiments of this application. The tab 21 of the first electrode assembly 2a is a first tab 21a, which is welded to the current collector 4 to form a first solder mark 5. Along the first direction Z, the main body 22 of the second electrode assembly 2b has a first surface 221b that is away from the first wall 13, and the first solder mark 5 is closer to the first wall 13 than the first surface 221b.

[0128] There can be one or more first solder marks 5. Only a portion of the first solder mark 5 may be closer to the first wall 13 than the first surface 221b; or the entire first solder mark 5 may be closer to the first wall 13 than the first surface 221b. In embodiments where there are multiple first solder marks 5, all of them are closer to the first wall 13 than the first surface 221b.

[0129] In this embodiment, the first solder mark 5 is located below the first surface 221b. When the electrolyte level is higher than the first surface 221b along the first direction Z, the first solder mark 5 is immersed in the electrolyte. The first tab 21a can reduce the influence of the first solder mark 5 on the electrolyte climbing on the first tab 21a by wetting the electrolyte through the part located above the first solder mark 5.

[0130] In some embodiments, the tab 21 of the second electrode assembly 2b is a second tab 21b, and the second tab 21b is welded to the current collector 4 to form a second solder mark 6.

[0131] In some embodiments, the second electrode assembly 2b has a mid-section 223b ( Figure 6 As shown in the figure, the mid-section 223b is perpendicular to the first direction Z, and along the first direction Z, the first solder mark 5 is located between the mid-section 223b and the inner surface of the first wall 13.

[0132] Along the first direction Z, the first electrode assembly 2a has a first surface 221b facing away from the first wall 13 and a second surface 222b facing the first wall 13. Figure 6 As shown in the figure, the distance between the mid-section 223b and the first surface 221b and the distance between the mid-section 223b and the second surface 222b are equal. In embodiments where there are multiple first solder marks 5, each of the multiple first solder marks 5 is located between the mid-section 223b and the inner surface of the first wall 13.

[0133] In this embodiment, when the electrolyte level is higher than the mid-section 223b of the second electrode assembly 2b, the first solder mark 5 can be located below the electrolyte level, and the electrolyte can climb to the main body 22 of the first electrode assembly 2a through the portion of the first tab 21a above the first solder mark 5, thereby reducing the influence of the first solder mark 5 on the electrolyte climbing on the first tab 21a.

[0134] In some embodiments, please continue to refer to Figure 8 Each first electrode tab 21a is welded to the current collector 4 to form multiple first solder marks 5, and the multiple first solder marks 5 are spaced apart.

[0135] The two adjacent first solder pads 5 do not contact each other, so that a flow channel is formed in the part of the first electrode tab 21a located between the two adjacent first solder pads 5. Under the action of capillary effect, the electrolyte rises to the main body 22 of the first electrode assembly 2a through the flow channel.

[0136] In this embodiment, by arranging multiple first solder marks 5 at intervals, the electrolyte can pass through the area welded by the first tab 21a between two adjacent first solder marks 5 to climb into the main body 22 of the first electrode assembly 2a, reducing the risk of poor wetting of the main body 22 of the first electrode assembly 2a and improving the performance of the battery cell 10.

[0137] In some embodiments, please continue to refer to Figure 8 Multiple first solder marks 5 are arranged in multiple rows and columns. Each row of first solder marks 5 is spaced apart along the third direction Y, and each column of first solder marks 5 is spaced apart along the second direction X. The first direction Z, the second direction X and the third direction Y are perpendicular to each other.

[0138] The number of rows in the plurality of first solder pads 5 can be two, three, four, five, six, seven, eight, etc. The number of columns in the plurality of first solder pads 5 can be two, three, four, five, six, seven, eight, etc. For example, such as... Figure 8 As shown, multiple first solder marks 5 are arranged in seven rows and three columns.

[0139] In this embodiment, on the one hand, the solder area between the multiple first tabs 21a can be increased, thereby improving the connection stability between the multiple first tabs 21a; on the other hand, the multiple first solder parts 5 are arranged in multiple rows and columns, and a channel for conducting electrolyte can be formed between two adjacent first solder parts 5, which is beneficial for the electrolyte to rise.

[0140] In some embodiments, along the third direction Y, the ratio of the sum of the dimensions of each row of first solder pads 5 to the dimension of the first tab 21a is 1 / 3 to 2 / 3.

[0141] In each row of first solder joints 5, the ratio of the sum of the dimensions of multiple first solder joints 5 along the third direction Y to the dimension of the first tab 21a is 1 / 3 to 2 / 3. This ratio can be any one of 1 / 3, 0.37, 0.41, 0.44, 0.48, 0.52, 0.56, 0.59, 0.63, 2 / 3, or any value between two of them.

[0142] In this embodiment, the ratio of the sum of the dimensions of the first solder marks 5 in each row to the dimensions of the first tabs 21a is greater than or equal to 1 / 3, which can increase the dimensions of the solder marks on the multiple first tabs 21a along the third direction Y, thereby improving the connection strength between the multiple first tabs 21a; the ratio of the sum of the dimensions of the first solder marks 5 in each row to the dimensions of the first tabs 21a is less than or equal to 2 / 3, which can reserve a climbing channel for the electrolyte at the positions of the multiple first tabs 21a where the first solder marks 5 are not soldered, thus improving the wetting effect of the electrolyte into the main body 22 of the first electrode assembly 2a; therefore, the ratio of the sum of the dimensions of the first solder marks 5 in each row to the dimensions of the first tabs 21a is 1 / 3-2 / 3, which can balance the connection strength between the multiple first tabs 21a and improve the wetting effect of the electrolyte into the main body 22 of the first electrode assembly 2a.

[0143] In some embodiments, please refer to Figure 9 , Figure 9 This is a schematic diagram of the structure of the electrode assembly 2 provided in some embodiments of this application. The tab 21 of the first electrode assembly 2a is the first tab 21a, the main body 22 of the first electrode assembly 2a is the first main body 22a, the first tab 21a includes a plurality of first sub-tabs 211a, the plurality of first sub-tabs 211a are stacked, the first sub-tabs 211a have a connecting end 2111a and a free end 2112a, the connecting end 2111a is connected to the first main body 22a, and the free end 2112a closest to the first wall 13 is the first end 211.

[0144] Multiple first sub-tabs 211a are stacked, and a flow channel for electrolyte uplift is formed between two adjacent first sub-tabs 211a. Each first sub-tab 211a has a connecting end 2111a and a free end 2112a, and the connecting end 2111a of each first sub-tab 211a is connected to the first main body 22a. Among the free ends 2112a of the multiple first sub-tabs 211a, the free end 2112a closest to the first wall 13 is the first end 211. In an embodiment where the free ends 2112a of the multiple first sub-tabs 211a are flush along the first direction Z, all the free ends 2112a of the multiple first sub-tabs 211a are the first end 211.

[0145] In this embodiment, the electrolyte can wet multiple first sub-tabs 211a through the free end 2112a closest to the first wall 13. The stacked first sub-tabs 211a form a channel to facilitate the rise of the electrolyte, reduce the difficulty of wetting the first main body 22a, and improve the wetting effect of the electrolyte into the first main body 22a.

[0146] In some embodiments, please continue to refer to Figure 9The first sub-taper 211a extends from the connecting end 2111a to the free end 2112a by a dimension equal to the extension length of the first sub-taper 211a. The connecting ends 2111a of the multiple first sub-tapers 211a are arranged along the first direction Z. In two adjacent first sub-tapers 211a, the extension length of the first sub-taper 211a whose connecting end 2111a is further away from the first wall 13 is greater than the extension length of the first sub-taper 211a whose connecting end 2111a is closer to the first wall 13.

[0147] The extension lengths of the multiple first sub-taper 211a are not equal. In any two adjacent first sub-taper 211a, the extension length of the first sub-taper 211a whose connecting end 2111a is further away from the first wall 13 is greater than the extension length of the first sub-taper 211a whose connecting end 2111a is closer to the first wall 13.

[0148] In this embodiment, the free end 2112a of the first sub-tab 211a, which is further away from the first wall 13, can be brought closer to the first wall 13, so that the two adjacent first sub-tabs 211a have more overlapping areas, which is beneficial for the electrolyte to climb to the first main body 22a through the overlapping area, thereby improving the wetting effect of the electrolyte in the first main body 22a.

[0149] In some embodiments, along the first direction Z, the free ends 2112a of the plurality of first sub-taperes 211a are aligned.

[0150] The free ends 2112a of the multiple first sub-pole ears 211a are aligned, so that the free ends 2112a of the multiple first sub-pole ears 211a as a whole constitute the first end 211.

[0151] In this embodiment, on the one hand, the processing difficulty of the first sub-tab 211a is reduced, and the processing cost of the first sub-tab 211a is reduced; on the other hand, the free ends 2112a of the multiple first sub-tabs 211a are the first ends 211, so that the free ends 2112a of the multiple first sub-tabs 211a can all be immersed in the electrolyte, which is beneficial for the electrolyte to climb to the first main body 22a through the multiple first sub-tabs 211a, thereby improving the wetting effect of the electrolyte in the first main body 22a.

[0152] In some embodiments, please refer to Figure 10 , Figure 10 This is a schematic diagram of the structure of an electrode assembly 2 provided in some embodiments of this application. The first electrode tab 21a is provided with a through hole 212a, which passes through multiple first sub-electrodes 211a.

[0153] Along the thickness direction of the first sub-tab 211a, the first sub-tab 211a has two opposing surfaces, and the through hole 212a penetrates the two surfaces. A flow channel can be formed between the two first sub-tabs 211a, and the through hole 212a can communicate with the flow channel. Electrolyte can remain in the through hole 212a to facilitate the entry of electrolyte into the flow channel and its ascent towards the first main body 22a through capillary action.

[0154] The number of through holes 212a can be one or more.

[0155] In this embodiment, the electrolyte can enter the through hole 212a and wet the two adjacent first sub-electrode tabs 211a through the through hole 212a, which is conducive to the electrolyte climbing to the first main body 22a, thereby improving the wetting effect of the electrolyte in the first main body 22a.

[0156] In some embodiments, please continue to refer to Figure 10 Along the first direction Z, the main body 22 of the second electrode assembly 2b has a first surface 221b facing away from the first wall 13, and along the first direction Z, the through hole 212a is closer to the first wall 13 than the first surface 221b.

[0157] Along the first direction Z, the through hole 212a is located between the first surface 221b and the first wall 13. In embodiments where there are multiple through holes 212a, each through hole 212a is located between the first surface 221b and the first wall 13.

[0158] In this embodiment, the through hole 212a is positioned at a lower position and is located closer to the first wall 13, which facilitates the entry of electrolyte into the through hole 212a and the upward movement of electrolyte through the multiple first tabs 21a to the first main body 22a, thereby improving the wetting effect of electrolyte in the first main body 22a.

[0159] In some embodiments, the diameter of the through hole 212a is 0.5mm-1.5mm.

[0160] The diameter of the through hole 212a can be any one of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, or 1.5mm, or any value between two of them.

[0161] In this embodiment, the aperture of the through hole 212a is greater than or equal to 0.5 mm, which can increase the capacity of the through hole 212a. The through hole 212a can accommodate more electrolyte, which is beneficial for the electrolyte to climb and improve the wetting effect of the electrolyte into the first main body 22a. The aperture of the through hole 212a is less than or equal to 1.5 mm, which can improve the strength of the first electrode 21a and reduce the risk of damage to the first electrode 21a. Therefore, the aperture of the through hole 212a is 0.5 mm-1.5 mm, which can balance improving the capacity of the through hole 212a and the strength of the first electrode 21a, improving the wetting effect of the electrolyte into the first main body 22a and reducing the risk of damage to the first electrode 21a.

[0162] In some embodiments, please refer to Figure 11 and Figure 12 , Figure 11 This is a schematic diagram of the structure of electrode assembly 2 provided in some embodiments of this application. Figure 12 This is a schematic diagram of the structure of the first electrode assembly 2a provided in some embodiments of this application. The first sub-electrode 211a has a liquid-conducting layer 213a on at least one surface in its thickness direction, the liquid-conducting layer 213a being used to guide the electrolyte to the first main body portion 22a.

[0163] The first sub-tab 211a may have a liquid-conducting layer 213a on only one surface in its thickness direction; alternatively, the first sub-tab 211a may have a liquid-conducting layer 213a on both surfaces in its thickness direction. The liquid-conducting layer 213a may be disposed close to the first main body portion 22a to guide the electrolyte to the first main body portion 22a. The liquid-conducting layer 213a may also extend into the electrolyte to allow the electrolyte to directly enter the first main body portion 22a through the liquid-conducting layer 213a.

[0164] In this embodiment, the liquid-conducting layer 213a can enhance the climbing ability of the electrolyte on the first tab 21a and improve the wetting effect of the electrolyte into the first main body 22a.

[0165] In some embodiments, the liquid-conducting layer 213a has a porous structure. In this embodiment, the electrolyte rises to the first main body 22a through the porous structure of the liquid-conducting layer 213a, which helps to improve the electrolyte's ability to rise on the first tab 21a.

[0166] In some embodiments, the liquid-conducting layer 213a is an inorganic particle coating, a sponge layer, or a porous organic polymer layer. In this embodiment, by using any of the above materials to manufacture the liquid-conducting layer 213a, it is beneficial to improve the guiding ability of the liquid-conducting layer 213a to guide the electrolyte to the first main body portion 22a, and to improve the wetting effect of the electrolyte infiltrating the first main body portion 22a.

[0167] In some embodiments, please continue to refer to Figure 12 The first main body 22a includes a first electrode segment 221a, a second electrode segment 222a, and an isolation segment 223a. Along a first direction Z, the first electrode segment 221a and the second electrode segment 222a are stacked, and the isolation segment 223a is disposed between the first electrode segment 221a and the second electrode segment 222a. The first electrode segment 221a and the second electrode segment 222a have opposite polarities. The first electrode segment 221a is provided with a first sub-electrode tab 211a, and multiple first sub-electrode tabs 211a on the first electrode segments 221a are stacked to form a first electrode tab 21a. At least a portion of the isolation segment 223a extends between two adjacent first sub-electrode tabs 211a in the first electrode tab 21a to form a liquid-conducting layer 213a.

[0168] The first electrode segment 221a and the first sub-electrode tab 211a can be integrally formed or separately configured and connected. Only a portion of a single insulating segment 223a may extend between two adjacent first sub-electrode tabs 211a within the first electrode tab 21a; alternatively, portions of multiple insulating segments 223a may extend between multiple pairs of adjacent first sub-electrode tabs 211a within the first electrode tab 21a. The insulating segment 223a may extend into the electrolyte or above the electrolyte surface.

[0169] In some embodiments, the first main body 22a includes a first electrode segment 221a, a second electrode segment 222a, and an isolation segment 223a. Along a first direction Z, the first electrode segment 221a and the second electrode segment 222a are stacked, and the isolation segment 223a is disposed between the first electrode segment 221a and the second electrode segment 222a. The first electrode segment 221a and the second electrode segment 222a have opposite polarities. The second electrode segment 222a is provided with a first sub-electrode tab 211a, and multiple first sub-electrode tabs 211a on the second electrode segments 222a are stacked to form a first electrode tab 21a. At least a portion of the isolation segment 223a extends between two adjacent first sub-electrode tabs 211a in the first electrode tab 21a to form a liquid-conducting layer 213a.

[0170] The second pole segment 222a can be integrally formed with the first sub-pole tab 211a, or it can be set separately and connected.

[0171] In this embodiment, the isolation section 223a between two adjacent first sub-electrode tabs 211a can guide the electrolyte to the part of the isolation section 223a located between the first electrode segment 221a and the second electrode segment 222a. On the one hand, this reduces the processing difficulty of the liquid guiding layer 213a, and on the other hand, it improves the wetting effect of the electrolyte infiltrating into the first main body 22a.

[0172] In some embodiments, the tabs 21 of the first electrode assembly 2a and the tabs 21 of the second electrode assembly 2b are arranged along a third direction Y, and the first direction Z, the second direction X and the third direction Y are perpendicular to each other.

[0173] The tabs 21 of the first electrode assembly 2a and the tabs 21 of the second electrode assembly 2b are located on the same side of the first main body 22a along the second direction X, and the tabs 21 of the first electrode assembly 2a and the tabs 21 of the second electrode assembly 2b are arranged along the third direction Y.

[0174] In this embodiment, the tabs 21 of the first electrode assembly 2a and the second electrode assembly 2b can be located on the same side of the first electrode assembly 2a along the second direction X. This is beneficial to reduce the size of the battery cell 10 along the second direction X occupied by the tabs 21 of the first electrode assembly 2a and the second electrode assembly 2b, thereby improving the space utilization rate of the battery cell 10 and increasing the volumetric energy density of the battery cell 10.

[0175] This application provides a battery device 100, which includes a battery cell 10 provided in any of the above embodiments.

[0176] This application provides an electrical device, including a battery cell 10 or a battery device 100 provided in any of the above embodiments.

[0177] Please continue to refer to Figure 4 , Figure 6 , Figure 8 , Figure 10 and Figure 12This application provides a battery cell 10, including a casing 1, an electrolyte, and multiple electrode assemblies 2. The casing 1 has a first wall 13, the electrolyte is contained within the casing 1, and the multiple electrode assemblies 2 are contained within the casing 1 and supported by the first wall 13 along a first direction Z. Each electrode assembly 2 includes a tab 21 and a body portion 22. The body portions 22 of the multiple electrode assemblies 2 are stacked along the first direction Z, and at least one end of the body portion 22 is provided with a tab 21 along a second direction X, the second direction X being perpendicular to the first direction Z. Multiple electrode assemblies 2 include a first electrode assembly 2a and a second electrode assembly 2b. Along the first direction Z, the main body 22 of the second electrode assembly 2b is the part closest to the first wall 13. The main body 22 of the first electrode assembly 2a is located on the side of the main body 22 of the second electrode assembly 2b away from the first wall 13. The end of the tab 21 of the first electrode assembly 2a furthest from the main body 22 is designated as a first end 211. The first end 211 extends into the electrolyte, and the minimum distance between the first end 211 and the inner surface of the first wall 13 is less than or equal to half the thickness of the main body 22 of the second electrode assembly 2b. Each first tab 21a is welded to a current collector 4 to form multiple spaced first solder marks 5. Along the first direction Z, the maximum distance between the first solder marks 5 and the inner surface of the first wall 13 is less than or equal to half the thickness of the main body 22 of the second electrode assembly 2b. The first electrode tab 21a is provided with a through hole 212a, which passes through multiple first sub-electrode tabs 211a. The main body 22 of the first electrode assembly 2a includes a first electrode segment 221a, a second electrode segment 222a, and an isolation segment 223a. Along the first direction Z, the first electrode segment 221a and the second electrode segment 222a are stacked and have opposite polarities. The isolation segment 223a is disposed between the first electrode segment 221a and the second electrode segment 222a. The first electrode segment 221a is provided with a first sub-electrode tab 211a. Multiple first sub-electrode tabs 211a on the first electrode segment 221a are stacked to form one first electrode tab 21a. The second electrode segment 222a is provided with a first sub-electrode tab 211a. Multiple first sub-electrode tabs 211a on the second electrode segment 222a are stacked to form another first electrode tab 21a. At least a portion of the isolation segment 223a extends between two adjacent first sub-taps 211a in the first tab 21a to form a liquid-conducting layer 213a.

[0178] In this embodiment, by extending the first end 211 into the electrolyte, and the distance between the first end 211 and the inner surface of the first wall 13 is less than or equal to half the thickness of the main body 22 of the second electrode assembly 2b, the electrolyte can climb through the tab 21 of the first electrode assembly 2a to the main body 22 of the first electrode assembly 2a, thereby improving the effect of the first electrode assembly 2a being wetted by the electrolyte. When half of the main body 22 of the second electrode assembly 2b is below the surface of the electrolyte and the first electrode assembly 2a is above the surface of the electrolyte, the first end 211 can be located below the surface of the electrolyte, and the tab 21 of the first electrode assembly 2a can guide the electrolyte to the main body 22 of the first electrode assembly 2a, extending the time that the main body 22 of the first electrode assembly 2a can be wetted by the electrolyte, improving the wettability of the main body 22 of the first electrode assembly 2a, thereby improving the electrochemical reaction performance of the first electrode assembly 2a, and thus improving the performance of the battery cell 10. By spaced apart multiple first solder marks 5, the electrolyte can pass through the welding area of ​​the first tab 21a between two adjacent first solder marks 5 to climb into the main body 22 of the first electrode assembly 2a, reducing the risk of poor wetting of the main body 22 of the first electrode assembly 2a. The first solder marks 5 can be positioned closer to the inner surface of the first wall 13, allowing them to be immersed in the electrolyte for a longer period. The first tab 21a can be partially wetted by the electrolyte above the first solder marks 5, reducing the impact of the first solder marks 5 on the electrolyte's climbing effect on the first tab 21a. The electrolyte can enter the through hole 212a and wet between two adjacent first sub-tabs 211a, facilitating the electrolyte's climbing into the first main body 22a and improving the wetting effect of the electrolyte within the first main body 22a. The isolation section 223a between two adjacent first sub-electrode tabs 211a can guide the electrolyte to the part of the isolation section 223a located between the first electrode segment 221a and the second electrode segment 222a. On the one hand, this reduces the processing difficulty of the liquid guiding layer 213a, and on the other hand, it improves the wetting effect of the electrolyte into the first main body 22a.

[0179] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0180] 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 shell has a first wall; Electrolyte, contained within the outer casing; Multiple electrode assemblies are housed within the housing. The first wall supports the multiple electrode assemblies along a first direction. Each electrode assembly includes a tab and a main body. The main bodies of the multiple electrode assemblies are stacked along the first direction. The tab is provided at at least one end of each main body along a second direction, which is perpendicular to the first direction. The plurality of electrode assemblies include a first electrode assembly and a second electrode assembly. Along the first direction, the main body portion of the second electrode assembly is the main body portion closest to the first wall. The main body portion of the first electrode assembly is located on the side of the main body portion of the second electrode assembly facing away from the first wall. The end of the tab of the first electrode assembly away from the main body portion of the first electrode assembly is a first end. The first end extends into the electrolyte, and the minimum distance between the first end and the inner surface of the first wall is less than or equal to half the thickness of the main body portion of the second electrode assembly.

2. The battery cell as described in claim 1, characterized in that, Along the first direction, the minimum distance between the first end and the inner surface of the first wall is less than or equal to one-quarter of the thickness of the main body of the second electrode assembly.

3. The battery cell as described in claim 1, characterized in that, The first end does not contact the inner surface of the first wall.

4. The battery cell as described in claim 1, characterized in that, The minimum distance between the first end and the inner surface of the first wall is 1mm-8mm.

5. The battery cell as described in claim 1, characterized in that, The battery cell also includes electrode terminals and current collectors, the electrode terminals are disposed on the housing, and the current collectors correspond one-to-one with the electrode terminals; The current collector is connected to the electrode terminal, and the tabs of the first electrode assembly and the second electrode assembly are both connected to the current collector.

6. The battery cell as described in claim 5, characterized in that, The first electrode assembly has a first electrode tab, which is welded to the current collector to form a first solder mark. Along the first direction, the main body of the second electrode assembly has a first surface facing away from the first wall, and the first solder mark is closer to the first wall than the first surface.

7. The battery cell as described in claim 6, characterized in that, The second electrode assembly has a mid-section perpendicular to the first direction, and along the first direction, the first solder mark is located between the mid-section and the inner surface of the first wall.

8. The battery cell as described in claim 6, characterized in that, Each first electrode tab is welded to the current collector to form a plurality of first solder marks, and the plurality of first solder marks are spaced apart.

9. The battery cell as described in claim 8, characterized in that, Multiple first solder marks are arranged in multiple rows and columns. Each row of first solder marks is spaced apart along a third direction, and each column of first solder marks is spaced apart along a second direction. The first direction, the second direction, and the third direction are perpendicular to each other.

10. The battery cell as described in claim 9, characterized in that, Along the third direction, the ratio of the sum of the dimensions of the first solder marks in each row to the dimensions of the first tab is 1 / 3 to 2 / 3.

11. The battery cell according to any one of claims 1-10, characterized in that, The tab of the first electrode assembly is a first tab, the main body of the first electrode assembly is a first main body, the first tab includes a plurality of first sub-tabs, the plurality of first sub-tabs are stacked, the first sub-tab has a connecting end and a free end, the connecting end is connected to the first main body, and the free end closest to the first wall is the first end.

12. The battery cell as described in claim 11, characterized in that, The dimension by which the first sub-electrode extends from the connecting end to the free end is the extension length of the first sub-electrode. The connecting ends of the plurality of first sub-electrodes are arranged along the first direction. In two adjacent first sub-electrodes, the extension length of the first sub-electrode whose connecting end is further away from the first wall is greater than the extension length of the first sub-electrode whose connecting end is closer to the first wall.

13. The battery cell as described in claim 11, characterized in that, Along the first direction, the free ends of multiple first sub-pole ears are aligned.

14. The battery cell as described in claim 11, characterized in that, The first electrode tab is provided with a through hole, and the through hole passes through multiple first sub-electrodes.

15. The battery cell as described in claim 14, characterized in that, Along the first direction, the main body of the second electrode assembly has a first surface facing away from the first wall, and along the first direction, the through hole is closer to the first wall than the first surface.

16. The battery cell as described in claim 14, characterized in that, The diameter of the through hole is 0.5mm-1.5mm.

17. The battery cell as described in claim 11, characterized in that, The first sub-tab has a liquid-conducting layer on at least one surface in its thickness direction, the liquid-conducting layer being used to guide the electrolyte to the first main body.

18. The battery cell as described in claim 17, characterized in that, The liquid-conducting layer has a porous structure.

19. The battery cell as described in claim 17, characterized in that, The liquid guiding layer is an inorganic particle coating, a sponge layer, or a porous organic polymer layer.

20. The battery cell as described in claim 17, characterized in that, The first main body includes a first pole segment, a second pole segment, and an isolation segment. Along the first direction, the first pole segment and the second pole segment are stacked, and the isolation segment is disposed between the first pole segment and the second pole segment. The first pole segment and the second pole segment have opposite polarities. The first pole segment is provided with a first sub-pole tab, and multiple first sub-pole tabs on the first pole segment are stacked to form a first pole tab. And / or the second pole segment is provided with a first sub-pole tab, and multiple first sub-pole tabs on the second pole segment are stacked to form a first pole tab. At least a portion of the isolation section extends between two adjacent first sub-tabs in the first tab to form the liquid-conducting layer.

21. The battery cell according to any one of claims 1-10, characterized in that, The tabs of the first electrode assembly and the tabs of the second electrode assembly are arranged along a third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

22. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-21.

23. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-21 or a battery device as described in claim 22.

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