Battery cell, battery device, and electric device

Abstract

The application provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrolyte, a separator and a plurality of battery core groups. The plurality of battery core groups are accommodated in the shell. Each battery core group comprises at least one electrode assembly. The plurality of battery core groups are connected in series. The plurality of battery core groups are arranged along a first direction. The electrolyte is accommodated in the shell. The separator is arranged in the shell. Along the first direction, the separator is arranged between two adjacent battery core groups. The separator reduces the risk that the positive electrode and the negative electrode of the adjacent battery core groups form a conductive path through the electrolyte and cause electrolyte decomposition. The separator alleviates the problem of electrolyte decomposition of the high-voltage battery monomer and is beneficial to prolonging the service life of the battery monomer.

Description

Technical Field

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

[0002] Batteries are widely used in new energy vehicles, electronic devices, and other fields. As the demand for batteries increases, higher requirements are being placed on their lifespan. Summary of the Invention

[0003] This application provides a battery cell, a battery device, and an electrical device that can extend the service life of the battery cell.

[0004] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a casing, an electrolyte, a separator, and a plurality of cell groups; the plurality of cell groups are housed within the casing, each cell group including at least one electrode assembly, the plurality of cell groups are connected in series, and the plurality of cell groups are arranged along a first direction; the electrolyte is housed within the casing; the separator is disposed within the casing, and along the first direction, the separator is disposed between two adjacent cell groups.

[0005] In the above technical solution, multiple electrode groups in a single battery cell are connected in series, enabling the battery cell to have a high voltage. A separator is placed between adjacent cell groups to separate the electrolyte, reducing the risk of electrolyte decomposition caused by the formation of a conductive path between the positive and negative electrodes of adjacent cell groups through the electrolyte. This alleviates the problem of electrolyte decomposition in high-voltage battery cells and helps extend the lifespan of the battery cells.

[0006] In some embodiments of the first aspect of this application, the housing includes a first wall along a second direction, the first wall being located at the bottom of the battery cell assembly and supporting the battery cell assembly, the electrolyte level not higher than the end of the separator opposite to the first wall, and the second direction being perpendicular to the first direction.

[0007] In the above technical solution, if the electrolyte level is not higher than the end of the separator away from the first wall, the risk of the electrolyte crossing the end of the separator away from the first wall and connecting to the positive and negative electrodes of the adjacent cell group to form a conductive path is low. This alleviates the problem of electrolyte decomposition in high-voltage battery cells and helps to extend the service life of battery cells.

[0008] In some embodiments of the first aspect of this application, the electrode assembly includes a main body and a tab, the tab being disposed at at least one end of the main body along the second direction; the battery cell further includes an insulating member, the insulating member covering a plurality of the cell groups around an axis extending along the second direction, and at least one end of the separator abutting against or having a gap with the insulating member along a third direction, the first direction, the second direction and the third direction being perpendicular to each other.

[0009] In the above technical solution, at least one end of the main body along the second direction is provided with a tab, and the insulating member surrounds multiple cell groups around the axis extending along the second direction, which can insulate and isolate the outer casing and the cell groups, reduce the risk of internal short circuits in the battery cells, and improve the reliability of the battery cells. The insulating member can also bind multiple cell groups into a whole, reduce the risk of relative movement between the individual cell groups within the casing, and improve the reliability of the battery cells and the stability of the series connection between the individual cell groups.

[0010] In some embodiments of the first aspect of this application, the housing includes a first wall, the tab is disposed at one end of the main body away from the first wall, and the separator abuts against or has a gap with the first wall.

[0011] In the above technical solution, the separator abuts against the first wall to better separate the electrolyte, thereby reducing the risk of electrolyte decomposition caused by the formation of a conductive path between the positive and negative electrodes of adjacent cell groups through the electrolyte. This alleviates the problem of electrolyte decomposition in high-voltage battery cells and helps extend the service life of the battery cells. The tabs are located at the end of the main body away from the first wall, facilitating connection between the tabs and other structures. A gap exists between the separator and the first wall to facilitate the placement of the separator.

[0012] In some embodiments of the first aspect of this application, the housing includes a first wall along a second direction, the first wall being located at the bottom of the battery cell assembly and supporting the battery cell assembly; the electrode assembly includes a main body and a tab, the tab being disposed at the end of the main body opposite to the first wall, the main body including an insulating membrane, a first electrode and a second electrode with opposite polarities, the insulating membrane insulatingly separating the first electrode and the second electrode, along the second direction, the insulating membrane not extending beyond the end of the separator opposite to the first wall, the second direction being perpendicular to the first direction.

[0013] In the above technical solution, the electrode tab is located at the end of the main body away from the first wall. The separator membrane does not extend beyond the end of the separator away from the first wall, which can separate the electrolyte on both sides of the separator. This reduces the risk of the positive and negative electrodes of the two series-connected electrode assemblies forming a conductive path through the electrolyte, thus reducing the risk of electrolyte decomposition. This alleviates the problem of electrolyte decomposition in high-voltage battery cells and helps to extend the service life of battery cells.

[0014] In some embodiments of the first aspect of this application, along the second direction, the separator does not extend beyond the end of the tab that is away from the first wall.

[0015] In the above technical solution, by ensuring that the separator does not extend beyond the end of the electrode tab away from the first wall along the second direction, the risk of interference between the separator and the electrode tab is reduced, and the electrode tab is facilitated to be electrically connected to other structures.

[0016] In some embodiments of the first aspect of this application, the separator is made of an insulating material.

[0017] In the above technical solution, by using insulating material for the separator, the risk of internal short circuits in the battery cell is reduced, and the reliability of the battery cell is improved.

[0018] In some embodiments of the first aspect of this application, the housing includes a first wall, and a plurality of battery cell groups are disposed opposite to the first wall along a second direction. The first wall is provided with a plurality of pressure relief components, and each battery cell group is provided with at least one pressure relief component. The orthographic projection of the battery cell group along the second direction covers at least a portion of the corresponding pressure relief component, and the second direction is perpendicular to the first direction.

[0019] In the above technical solution, multiple cell groups are arranged opposite to the first wall in the second direction. By providing at least one pressure relief component for each cell group on the first wall, and the orthogonal projection of the cell group along the second direction covering at least a portion of the corresponding pressure relief component, the distance between the cell group and the pressure relief component can be reduced. This facilitates timely pressure relief for any exothermic reaction caused by any cell group inside the battery cell, thereby improving the reliability of the battery cell.

[0020] In some embodiments of the first aspect of this application, the electrode assembly in the battery cell assembly is one, or the electrode assembly in the battery cell assembly is multiple, and the multiple electrode assemblies are arranged along the first direction; each electrode assembly is provided with at least one pressure relief component, and the orthographic projection of the electrode assembly along the second direction covers at least a portion of the corresponding pressure relief component.

[0021] In the above technical solution, multiple cell groups are arranged opposite to the first wall in the second direction. By providing at least one pressure relief component for each electrode assembly on the first wall, and the orthogonal projection of the electrode assembly along the second direction covering at least a portion of the corresponding pressure relief component, the distance between the electrode assembly and the pressure relief component can be reduced. This facilitates timely pressure relief for any exothermic reaction caused by any electrode assembly inside the battery cell, thereby improving the reliability of the battery cell.

[0022] In some embodiments of the first aspect of this application, the electrode assembly in the battery cell assembly is one, or the electrode assembly in the battery cell assembly is multiple, and the multiple electrode assemblies are connected in parallel.

[0023] In the above technical solutions, if there is only one electrode assembly in the cell pack, then each electrode assembly is connected in series, which is beneficial for obtaining high voltage with a smaller number of electrode assemblies in the battery cell. If there are multiple electrode assemblies in the cell pack, and these multiple electrode assemblies are connected in parallel, then the battery cell can have a higher total capacity while still having a higher voltage.

[0024] In some embodiments of the first aspect of this application, the number of battery cells is greater than or equal to 3.

[0025] In the above technical solution, by having a cell group of 3 or more, the individual battery cells have a higher voltage.

[0026] In some embodiments of the first aspect of this application, the electrode assembly includes a first tab and a second tab with opposite polarities, the base metal of the first tab being different from the base metal of the second tab; the battery cell further includes an adapter connecting the first tab of one cell group and the second tab of another cell group, the adapter including a first portion and a second portion connected together, the first portion being connected to the first tab, the base metal of the first portion being the same as the base metal of the first tab, and the second portion being connected to the second tab, the base metal of the second portion being the same as the base metal of the second tab.

[0027] In the above technical solution, the adapter includes a first part and a second part connected together. The base metal of the first part is the same as the base metal of the first tab of the cell assembly connected to it, and the base metal of the second part is the same as the base metal of the second tab of the cell assembly connected to it. This is beneficial to improve the connection quality between the first part and the first tab, as well as the connection quality between the second part and the second tab. It can reduce the contact resistance of the electrical connection between the first tab and the first part, and the contact resistance of the electrical connection between the second tab and the second part. It reduces the contact resistance difference caused by different materials, thereby improving the conductivity efficiency. It can also reduce the risk of electrochemical corrosion at the connection position between the first part and the first tab, and the connection position between the second part and the second tab due to different materials, thereby improving the reliability of the battery cell and extending the service life of the battery cell.

[0028] In some embodiments of the first aspect of this application, the first part and the second part are connected by a connecting portion; the battery cell further includes a protective member, the protective member being made of insulating material, the protective member covering a portion of the first part and a portion of the second part, and covering the connecting portion.

[0029] In the above technical solution, by covering a portion of the first part and a portion of the second part with a protective component, and also covering the connecting portion, the problem of contact resistance difference caused by the different materials of the first part and the second part can be alleviated. This helps to improve conductivity efficiency and reduces the risk of electrochemical corrosion at the connection point of the first part and the second part due to material differences, thereby improving the reliability of the battery cell and extending its service life. Furthermore, by using an insulating material for the protective component, the risk of internal short circuits within the battery cell can be reduced.

[0030] In some embodiments of the first aspect of this application, the first portion and the second portion are welded to form a solder mark, the solder mark being at least a portion of the connecting portion.

[0031] In the above technical solution, the welded connection of the first and second parts forms a weld stamp, which facilitates the connection between the first and second parts and ensures high connection stability. The weld stamp is at least a part of the connection, and by covering the connection with a protective component, the problem of contact resistance differences caused by the different materials of the first and second parts can be mitigated. This helps improve conductivity, reduces the risk of electrochemical corrosion at the connection point of the first and second parts, improves the reliability of the battery cell, extends the service life of the battery cell, and also reduces the risk of internal short circuits caused by burrs in the weld stamp, further improving the reliability of the battery cell.

[0032] In some embodiments of the first aspect of this application, the assembly formed by multiple battery cells connected in series has a first output electrode and a second output electrode with opposite polarities. The battery cell also includes a first electrode terminal and a second electrode terminal, both of which are disposed on the housing. The first electrode terminal and the second electrode terminal are electrically connected to the first output electrode and the second output electrode, respectively. The battery cell also includes a data acquisition terminal, which is disposed on the housing. At least one of the adapters is connected to the data acquisition terminal.

[0033] In the above technical solution, the battery cell also includes a data acquisition terminal, and at least one adapter is connected to the data acquisition terminal to facilitate voltage acquisition of the cell group within the battery cell.

[0034] In some embodiments of the first aspect of this application, each of the adapters is connected to the acquisition terminal.

[0035] In the above technical solution, by connecting a data acquisition terminal to each adapter, it is possible to acquire the voltage of each cell group, as well as the voltage of any number of cell groups, which facilitates accurate detection of the voltage of each part inside the battery cell.

[0036] In some embodiments of the first aspect of this application, the solvent of the electrolyte is a carbonate, and the electrode assembly includes a negative electrode sheet containing a polymer that swells or crosslinks with the carbonate.

[0037] In the above technical solution, the negative electrode sheet contains a polymer that swells or cross-links with a carbonate solvent, which can reduce the free electrolyte in the battery cell, reduce the risk of electrolyte decomposition caused by the formation of a conductive path between the positive and negative electrodes of adjacent battery cells through the electrolyte, alleviate the problem of electrolyte decomposition in high-voltage battery cells, and help extend the service life of battery cells.

[0038] In some embodiments of the first aspect of this application, the polymer includes one or more of carboxylic acid polymers, vinylidene fluoride polymers, ether polymers, ester polymers, and polymers containing cyano groups.

[0039] In the above technical solution, the negative electrode sheet includes a carboxylic acid polymer. This polymer significantly improves the problems of electrode rebound and adhesion failure caused by volume changes in the negative electrode material, thereby enhancing the cycle performance of the lithium battery. The carboxylic acid polymer also significantly inhibits the growth of lithium dendrites in the negative electrode, improving the reliability and stability of the battery cell. Furthermore, the carboxylic acid polymer significantly improves the high-temperature cycle performance of the battery cell, making it perform better in high-temperature environments. Fluoropolymers can increase the cohesive force of the negative electrode sheet and reduce the rebound rate after cold pressing, thus improving the quality of the negative electrode sheet. The negative electrode sheet includes a polyvinylidene fluoride (PVDF) polymer, which enhances the contact between the active material and conductive agent and the current collector, thereby stabilizing the negative electrode sheet structure. The PVDF polymer also helps prevent the active material from detaching during charge and discharge, improving the cycle stability and lifespan of the battery cell. Furthermore, the PVDF polymer exhibits good chemical stability and corrosion resistance, remaining stable in organic electrolyte environments without dissolving or swelling, contributing to improved battery capacity and safety, and reducing performance degradation caused by electrolyte corrosion. The PVDF polymer also improves low-temperature performance, thus enhancing the performance of the battery cell in low-temperature environments. The negative electrode sheet includes ether polymers, which are beneficial for improving the rate performance, cycle performance, reliability, and stability of the battery cell. The negative electrode sheet includes ester polymers, which are beneficial for improving the cohesive force of the negative electrode sheet, reducing the rebound force after cold pressing, and improving the overall quality of the negative electrode sheet. The negative electrode sheet includes polymers containing cyano groups, which can reduce the risk of internal short circuits within the battery cell and improve the reliability of the battery cell.

[0040] Secondly, embodiments of this application provide a battery device, which includes the battery cell provided in any embodiment of the first aspect.

[0041] In the above technical solutions, the battery cell provided in any embodiment of the first aspect has a long service life, which also extends the service life of the battery device including the battery cell.

[0042] Thirdly, embodiments of this application provide an electrical device, which includes a battery cell provided in any embodiment of the first aspect or a battery device provided in any embodiment of the second aspect.

[0043] In the above technical solutions, the battery cell provided in any embodiment of the first aspect and the battery device provided in any embodiment of the second aspect have a long service life, which can reduce the replacement frequency and maintenance cost of electrical equipment powered by the battery cell or battery device, improve the reliability of power supply, and enhance the user experience. Attached Figure Description

[0044] 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.

[0045] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0046] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0047] Figure 3 Exploded views of a single battery cell provided in some embodiments of this application;

[0048] Figure 4 A view of a battery cell along a first direction provided for some embodiments of this application;

[0049] Figure 5 for Figure 4 A sectional view along line A1-A1;

[0050] Figure 6 This is a schematic diagram showing an insulating element surrounding the outer periphery of multiple battery cell assemblies, as provided in some embodiments of this application.

[0051] Figure 7 Cross-sectional views of a battery cell provided for other embodiments of this application;

[0052] Figure 8 This is a schematic diagram showing the relative positional relationship between the separator and the partition.

[0053] Figure 9 for Figure 5 Enlarged view at point B1;

[0054] Figure 10 Axonometric views of a battery cell provided in some further embodiments of this application;

[0055] Figure 11 for Figure 4 A sectional view along line A2-A2;

[0056] Figure 12 for Figure 11 Enlarged view at B2;

[0057] Figure 13 This is a schematic diagram of the structure of the adapter provided in some embodiments of this application;

[0058] Figure 14 This is a schematic diagram of the structure of the adapter provided in other embodiments of this application;

[0059] Figure 15 Exploded view of the first and second parts of the adapter;

[0060] Figure 16 A cross-sectional view of a battery cell provided for some embodiments of this application;

[0061] Figure 17 for Figure 16 Enlarged view at B3;

[0062] Figure 18 This is a schematic diagram of the structure of the adapter provided in some embodiments of this application;

[0063] Figure 19 This is a schematic diagram showing the structure where the first and second parts of the adapter are not connected by a connecting part.

[0064] Figure 20 A schematic diagram of a battery cell provided in some embodiments of this application;

[0065] Figure 21 for Figure 20 The battery cells in the design do not have end caps.

[0066] Icons: 1000 - Vehicle; 100 - Battery assembly; 10 - Housing; 11 - First housing; 12 - Second housing; 20 - Battery cell; 20a - First output terminal; 20b - Second output terminal; 21 - Housing; 2111 - Shell; 2111 - Opening; 212 - End cap; 213 - First wall; 2131 - Pressure relief component; 22 - Cell assembly; 22a - First cell assembly; 22b - Second cell assembly; 22c - Third cell assembly; 22d - Fourth cell assembly; 221 - Electrode assembly; 2211 - Main body; 22111 - Separator; 22112 - First electrode; 22113 - Second electrode; 2212 - Tab; 2212a - First tab; 2212b - Second tab; 23 - Electrode terminal; 231 - First electrode terminal ; 232-Second electrode terminal; 24-Current collector; 25-Electrolyte; 26-Separator; 27-Insulating component; 271-Insulating part; 28-Adapter; 28a-First adapter; 28b-Second adapter; 28c-Third adapter; 281-First part; 2811-First region; 2812-Second region; 282-Second part; 2821-Third region; 2822-Fourth region; 29-Protective component; 210-Connecting part; 2101-Acquisition terminal; 21011-First acquisition terminal; 21012-Second acquisition terminal; 21013-Third acquisition terminal; 200-Controller; 300-Motor; X-First direction; Y-Second direction; Z-Third direction; Q1-First receiving part; Q2-Second receiving part. Detailed Implementation

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] In this application, "multiple" means two or more (including two).

[0074] 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.

[0075] 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.

[0076] 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.

[0077] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0078] 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.

[0079] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0080] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3Mn 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 0.2O2 (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.

[0081] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0082] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0083] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0084] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0085] 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.

[0086] 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 negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0087] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0095] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0096] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0097] 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.

[0098] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0099] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0100] In some implementations, the electrode assembly is a stacked structure.

[0101] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0102] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0103] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0104] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0105] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0106] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0107] 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.

[0108] 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.

[0109] 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 battery cells, such as hexagonal prismatic battery cells.

[0110] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0111] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0112] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0113] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cells housed within the housing.

[0114] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0115] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0116] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0117] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0118] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0119] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0120] In related technologies, to achieve high voltage in a single battery cell, multiple electrode components within the cell are connected in series to form a high-voltage battery cell. However, in high-voltage battery cells, the electrolyte can easily connect the positive and negative electrodes, causing a short circuit within the cell and leading to electrolyte decomposition, thus shortening the cell's lifespan.

[0121] Based on the above considerations, in order to improve the service life of high-voltage battery cells, this application provides a battery cell, which includes a casing, an electrolyte, a separator, and multiple cell groups; the multiple cell groups are housed in the casing, each cell group includes at least one electrode assembly, the multiple cell groups are connected in series, and the multiple cell groups are arranged along a first direction; the electrolyte is housed in the casing; the separator is disposed in the casing, and a separator is disposed between two adjacent cell groups along the first direction.

[0122] Multiple electrode groups in a single battery cell are connected in series, enabling the cell to have a high voltage. A separator is placed between adjacent cell groups to separate the electrolyte, reducing the risk of electrolyte decomposition caused by conductive pathways formed between the positive and negative electrodes of adjacent cell groups. This mitigates the electrolyte decomposition problem in high-voltage battery cells and helps extend their lifespan.

[0123] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0124] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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 10 and a battery cell 20, wherein the housing 10 is used to house the battery cell 20.

[0129] The housing 10 has an enclosed space inside for accommodating the battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first housing 11 and a second housing 12, which are interlocked. The first housing 11 and the second housing 12 can have various shapes, such as cuboids or cylinders. The first housing 11 can be a hollow structure open on one side, and the second housing 12 can also be a hollow structure open on one side. The open side of the second housing 12 interlocks with the open side of the first housing 11, thus forming a housing 10 with an enclosed space. Alternatively, the first housing 11 can be a hollow structure open on one side, and the second housing 12 can be a plate-like structure, with the second housing 12 interlocked with the open side of the first housing 11, thus forming a housing 10 with an accommodating space.

[0130] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0131] In some embodiments, the battery device 100 may further include a busbar (not shown in the figure), through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of multiple battery cells 20. The busbar can be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0132] Please refer to Figure 3 , Figure 3 This is an exploded view of a battery cell 20 provided in some embodiments of this application. The battery cell 20 may include a housing 21 and a plurality of cell groups 22, which are housed within the housing 21. Each cell group 22 includes at least one electrode assembly 221, and the plurality of cell groups 22 are connected in series.

[0133] like Figure 3 As shown, in some embodiments, the housing 21 may include a housing 211 and an end cap 212. The housing 211 has an opening 2111, and the end cap 212 closes the opening 2111 of the housing 211. Here, "closed" means to cover or shut, and can be either sealed or unsealed.

[0134] The housing 211 is a component used to house the battery cell assembly 22. The housing 211 can be a hollow structure with an opening 2111 at one end, or it can be a hollow structure with openings 2111 at both opposite ends. The housing 211 can have various shapes, such as cylindrical or cuboid. The housing 211 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The battery cell assembly 22 can be partially or completely housed within the housing 211.

[0135] End cap 212 and housing 211 together define a receiving space for accommodating battery cell assembly 22 and other components. End cap 212 can be connected to housing 211 by welding, roll sealing, or other methods to close the opening 2111 of housing 211. The shape of end cap 212 can be adapted to the shape of housing 211. For example, if housing 211 is a cuboid structure, end cap 212 can be a rectangular plate structure adapted to housing 211; or if housing 211 is a cylindrical structure, end cap 212 can be a circular plate structure adapted to housing 211. The material of end cap 212 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The materials of end cap 212 and housing 211 can be the same or different.

[0136] In an embodiment where the housing 211 has an opening 2111 at one end, one end cap 212 may be provided accordingly. In an embodiment where the housing 211 has openings 2111 at both opposite ends, two end caps 212 may be provided accordingly. The two end caps 212 respectively close the two openings 2111 of the housing 211, and the two end caps 212 and the housing 211 together define the receiving space.

[0137] In some embodiments, the battery cell 20 may further include electrode terminals 23, which are disposed on the housing 21 and are used for electrical connection with the tabs 2212 of the electrode assembly 221 to input or output electrical energy of the battery cell 20. The electrode terminals 23 may be disposed on the housing 211 of the housing 21 or on the end cap 212 of the housing 21. The electrode terminals 23 and the tabs 2212 may be directly connected, for example, by welding. Alternatively, the electrode terminals 23 and the tabs 2212 may be indirectly connected, for example, through a current collector 24. The current collector 24 may be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy.

[0138] As an example, such as Figure 3 As shown, one end of the housing 211 forms an opening 2111, and there is one end cap 212 in the housing 21, which closes one opening 2111 of the housing 211. Two electrode terminals 23 are provided on the end cap 212, which are a positive electrode terminal 23 and a negative electrode terminal 23, respectively. The end of the electrode assembly 221 facing the end cap 212 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.

[0139] like Figure 3As shown, the battery cell 20 includes a casing 21, an electrolyte 25, a separator 26, and multiple cell groups 22; the multiple cell groups 22 are housed within the casing 21, each cell group 22 includes at least one electrode assembly 221, the multiple cell groups 22 are connected in series, and the multiple cell groups 22 are arranged along a first direction X; the electrolyte 25 is housed within the casing 21; the separator 26 is disposed within the casing 21, and a separator 26 is disposed between two adjacent cell groups 22 along the first direction X.

[0140] The cell assembly 22 may include an electrode assembly 221, and the electrode assemblies 221 of the individual cells 20 are connected in series.

[0141] The cell assembly 22 may include multiple electrode components 221, which are connected in parallel to form a cell assembly 22, and then the cell assemblies 22 are connected in series.

[0142] In the multiple cell groups 22, each cell group 22 may include an electrode assembly 221, or some cell groups 22 may include an electrode assembly 221 and other cell groups 22 may include multiple electrode assemblies 221.

[0143] In a plurality of battery cell groups 22, each battery cell group 22 may include a plurality of electrode assemblies 221. The plurality of electrode assemblies 221 of the battery cell group 22 may be arranged along a first direction X or along other directions.

[0144] A separator 26 is provided between any two battery cell groups 22, and the electrolyte 25 is separated on both sides of the separator 26, which helps to prevent the electrolyte 25 from contacting the positive and negative electrodes of the battery cell group 22 to form a conductive path.

[0145] Multiple electrode groups in the battery cell 20 are connected in series, enabling the battery cell 20 to have a high voltage. A separator 26 is provided between two adjacent cell groups 22. The separator 26 can separate the electrolyte 25, reducing the risk of electrolyte 25 decomposition caused by the formation of a conductive path between the positive and negative electrodes of adjacent cell groups 22 through the electrolyte 25. This alleviates the problem of electrolyte 25 decomposition in the high-voltage battery cell 20 and helps to extend the service life of the battery cell 20.

[0146] like Figure 4 , Figure 5 As shown, in some embodiments, the outer casing 21 includes a first wall 213 along the second direction Y. The first wall 213 is located at the bottom of the cell assembly 22 and supports the cell assembly 22. The electrolyte level 25 is not higher than the end of the separator 26 away from the first wall 213. The second direction Y is perpendicular to the first direction X.

[0147] The first wall 213 is located at the bottom of the cell assembly 22 and supports the cell assembly 22, thus the first wall 213 can bear the weight of the cell assembly 22. The first wall 213 is also located at the bottom of the electrolyte 25, and the first wall 213 can also support the cell and bear the weight of the electrolyte 25.

[0148] The first wall 213 may be an end cap 212. In some embodiments, the first wall 213 may be part of a wall portion of the housing 211. For example, the first wall 213 may be a wall portion of the housing 211 opposite to the end cap 212. Along the second direction Y, the partition 26 may abut against the end cap 212 or there may be a gap between it and the first wall 213.

[0149] The electrolyte level 25 is the position where the electrolyte 25 is located away from the first wall 213. Along the second direction Y, the electrolyte level 25 is not higher than the end of the separator 26 away from the first wall 213. That is, along the second direction Y, the electrolyte level 25 can be flush with the end of the separator 26 away from the first wall 213, and the electrolyte level 25 is closer to the first wall 213 than the end of the separator 26 away from the first wall 213. Figure 5 The diagram shows the electrolyte 25 level being closer to the first wall 213 than the end of the separator 26 that is away from the first wall 213, with the separator 26 extending beyond the surface of the electrolyte 25 away from the first wall 213.

[0150] If the electrolyte level 25 is not higher than the end of the separator 26 away from the first wall 213, the risk of the electrolyte 25 passing over the end of the separator 26 away from the first wall 213 and connecting to the positive and negative electrodes of the adjacent cell group 22 to form a conductive path is low. This alleviates the problem of electrolyte 25 decomposition in the high-voltage battery cell 20 and helps to extend the service life of the battery cell 20.

[0151] Combined with reference Figure 3 , Figure 6 In some embodiments, the electrode assembly 221 includes a main body 2211 and a tab 2212. The tab 2212 is provided at least one end of the main body 2211 along the second direction Y. The battery cell 20 also includes an insulating member 27, which covers a plurality of cell groups 22 around an axis extending along the second direction Y. Along the third direction Z, at least one end of the separator 26 abuts against or has a gap with the insulating member 27. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0152] The electrode assembly 221 includes two tabs 2212 with opposite polarities, one of which is a positive tab and the other is a negative tab.

[0153] The main body 2211 may have a tab 2212 at one end along the second direction Y, that is, two tabs 2212 with opposite polarities are both provided at the same end of the main body 2211 along the second direction Y, which can reduce the size of the electrode assembly 221 in the second direction Y and increase the energy density of the battery cell 20.

[0154] The main body 2211 may also have tabs 2212 respectively provided at opposite ends along the second direction Y, that is, two tabs 2212 with opposite polarities are respectively provided at opposite ends along the second direction Y of the main body 2211, reducing the risk of internal short circuit of the battery cell 20.

[0155] An insulating member 27 covers the outer periphery of the integral formed by multiple battery cell assemblies 22. The insulating member 27 may be a one-piece molded structure. Alternatively, the insulating member 27 may include multiple separately arranged insulating portions 271, which are sequentially connected around an axis extending along a second direction Y, and cover the integral formed by the multiple battery cell assemblies 22. Figure 3 , Figure 6 As shown, the insulating member 27 includes two separately disposed insulating parts 271, one end of one insulating part 271 overlaps with one end of the other insulating part 271, and the other end of the other insulating part 271 overlaps with the other end of the other insulating part 271, so that the two insulating parts 271 together wrap around the axis extending along the second direction Y to enclose multiple battery cell groups 22, thereby improving the stability of the connection between the two insulating parts 271.

[0156] In an embodiment where tabs 2212 are respectively provided at opposite ends of the main body 2211 along the second direction Y, the insulating member 27 may simply cover the entire assembly of multiple battery cell groups 22 around the axis extending along the second direction Y.

[0157] In an embodiment where a tab 2212 is provided at one end of the main body 2211 along the second direction Y, the insulating member 27 can cover the entire assembly formed by multiple battery cell groups 22 around the axis extending along the second direction Y, and can also cover the end face of the entire assembly formed by multiple battery cell groups 22 away from the tab 2212.

[0158] Along the third direction Z, the separator 26 can extend beyond the main body 2211 of the electrode assembly 221, or it can be flush with the end of the main body 2211 of the electrode assembly 221. This allows the separator 26 to have a larger separating area, further reducing the risk of electrolyte 25 decomposition caused by the formation of a conductive path between the positive and negative electrodes of adjacent cell groups 22 through the electrolyte 25. This alleviates the problem of electrolyte 25 decomposition in the high-voltage battery cell 20 and helps extend the service life of the battery cell 20. In this embodiment, the insulating member 27 can abut or contact the end of the separator 26 along the third direction Z.

[0159] Along the third direction Z, the main body 2211 of the electrode assembly 221 may extend beyond the separator 26. In this embodiment, the insulating member 27 may have a gap with the end of the separator 26 in the third direction Z, reducing wear on the separator 26 and the insulating member 27 and extending the service life of the insulating member 27.

[0160] The insulating component 27 can be made of polypropylene, polyethylene terephthalate, etc.

[0161] Along the second direction Y, the two ends of the main body 2211 can be wrapped by the insulating member 27 or can extend beyond the insulating member 27.

[0162] The main body 2211 has a tab 2212 at at least one end along the second direction Y. An insulating member 27 surrounds multiple cell groups 22 along an axis extending along the second direction Y, insulating and isolating the outer casing 21 and the cell groups 22, reducing the risk of internal short circuits in the battery cell 20, and improving the reliability of the battery cell 20. The insulating member 27 also binds the multiple cell groups 22 into a whole, reducing the risk of relative movement between the individual cell groups 22 within the outer casing 21, and improving the reliability of the battery cell 20 and the stability of the series connection between the individual cell groups 22.

[0163] like Figure 5 , Figure 7 As shown, in some embodiments, the outer casing 21 includes a first wall 213, a tab 2212 is disposed at one end of the main body 2211 away from the first wall 213, and the separator 26 abuts against the first wall 213 or has a gap.

[0164] The electrode assembly 221 has two tabs 2212 with opposite polarities, both disposed at one end of the main body 2211 away from the first wall 213, or the two tabs 2212 are respectively disposed at opposite ends of the main body 2211 along the second direction Y. Along the second direction Y, the separator 26 can abut against the first wall 213, the separator 26 can be connected to the first wall 213, or it can only contact but not connect, in order to reduce the connection process. Figure 5 The diagram shows the situation where the separator 26 abuts against the first wall 213.

[0165] Along the second direction Y, the separator 26 has a gap with the first wall 213, and the separator 26 does not contact the first wall 213. Figure 7 The diagram shows a situation where the separator 26 has a gap with the first wall 213.

[0166] The separator 26 abuts against the first wall 213, allowing it to better separate the electrolyte 25. This reduces the risk of electrolyte 25 decomposition caused by the formation of a conductive path between the positive and negative electrodes of adjacent cell groups 22 through the electrolyte 25, mitigating the problem of electrolyte 25 decomposition in the high-voltage battery cell 20 and extending its service life. The tab 2212 is located at the end of the main body 2211 facing away from the first wall 213, facilitating connection between the tab 2212 and other structures. A gap exists between the separator 26 and the first wall 213 to facilitate its placement.

[0167] like Figure 8 As shown, in some embodiments, the outer casing 21 includes a first wall 213 along the second direction Y. The first wall 213 is located at the bottom of the cell assembly 22 and supports the cell assembly 22. The electrode assembly 221 includes a main body 2211 and a tab 2212. The tab 2212 is disposed at one end of the main body 2211 away from the first wall 213. The main body 2211 includes an insulating membrane 22111, a first electrode 22112 and a second electrode 22113 with opposite polarities. The insulating membrane 22111 insulates and isolates the first electrode 22112 and the second electrode 22113. Along the second direction Y, the insulating membrane 22111 does not extend beyond the end of the separator 26 away from the first wall 213. The second direction Y is perpendicular to the first direction X.

[0168] One of the first electrode 22112 and the second electrode 22113 is a positive electrode, and the other is a negative electrode. A tab 2212 is disposed at the end of the main body 2211 opposite to the first wall 213; that is, both tabs 2212 of the electrode assembly 221 are disposed at the end of the main body 2211 opposite to the first wall 213. The electrode assembly 221 includes two tabs 2212 with opposite polarities, namely a first tab 2212a and a second tab 2212b. Along the second direction Y, the first tab 2212a is connected to the end of the first electrode 22112 opposite to the first wall 213, and the second tab 2212b is connected to the end of the second electrode 22113 opposite to the first wall 213. The current collector of the first electrode 22112 and the first tab 2212a can be separately disposed and connected, or they can be integrally formed. The current collector of the second electrode 22113 and the second electrode tab 2212b can be separately configured and connected, or they can be integrally formed.

[0169] Along the second direction Y, the isolation membrane 22111 does not extend beyond the end of the separator 26 that is away from the first wall 213. The end of the isolation membrane 22111 that is away from the separator 26 can be flush with the end of the separator 26 that is away from the first wall 213. The separator 26 can extend beyond the end of the isolation membrane 22111 that is away from the first wall 213.

[0170] The material of the separator 22111 can include PP (polypropylene) or PE (polyethylene), etc.

[0171] The tab 2212 is located at the end of the main body 2211 away from the first wall 213. The separator 22111 does not extend beyond the end of the separator 26 away from the first wall 213. It can separate the electrolyte 25 on both sides of the separator 26, reducing the risk of the positive and negative electrodes of the two series-connected electrode assemblies 221 forming a conductive path through the electrolyte 25, which would lead to the decomposition of the electrolyte 25. This alleviates the problem of electrolyte 25 decomposition in the high-voltage battery cell 20 and helps to extend the service life of the battery cell 20.

[0172] Combined with reference Figure 5 , Figure 9 In some embodiments, along the second direction Y, the separator 26 does not extend beyond the end of the tab 2212 that is away from the first wall 213.

[0173] Understandably, along the second direction Y, the separator 26 is flush with the end of the tab 2212 that is away from the first wall 213, and the tab 2212 may also extend beyond the end of the tab 2212 that is away from the first wall 213.

[0174] By ensuring that the separator 26 does not extend beyond the end of the tab 2212 away from the first wall 213 along the second direction Y, the risk of interference between the separator 26 and the tab 2212 is reduced, and the tab 2212 is made easier to connect electrically to other structures.

[0175] In some embodiments, the separator 26 is made of insulating material.

[0176] For example, the separator 26 can be made of polypropylene board, ceramic board, etc.

[0177] By using insulating material for the separator 26, the risk of internal short circuits in the battery cell 20 is reduced, thereby improving the reliability of the battery cell 20.

[0178] like Figure 10 As shown, in some embodiments, the housing 21 includes a first wall 213. Along the second direction Y, a plurality of battery cell groups 22 are disposed opposite to the first wall 213. The first wall 213 is provided with a plurality of pressure relief components 2131. Each battery cell group 22 is provided with at least one pressure relief component 2131. The orthographic projection of the battery cell group 22 along the second direction Y covers at least a portion of the corresponding pressure relief component 2131. The second direction Y is perpendicular to the first direction X.

[0179] The pressure relief component 2131 can be located on any wall portion of the housing 21 in a direction other than the first direction X.

[0180] The pressure relief component 2131 refers to an element or component that is actuated to release internal pressure or temperature when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold. This threshold design varies depending on design requirements. The threshold may depend on one or more materials of the positive electrode, negative electrode, electrolyte 25, and separator 22111 in the battery cell 20. The pressure relief component 2131 can take the form of an explosion-proof valve, explosion-proof disc, gas valve, pressure relief valve, or safety valve, and can specifically employ pressure-sensitive or temperature-sensitive elements or structures. That is, when the internal pressure or temperature of the battery cell 20 reaches the predetermined threshold, the pressure relief component 2131 actuates or a weak structure in the pressure relief mechanism is destroyed, thereby forming an opening 2111 or channel for releasing internal pressure or temperature.

[0181] For example, the pressure relief component 2131 can be a weak part formed by grooves in the bottom wall. When the temperature or pressure inside the battery cell 20 reaches a threshold, the weak part tears to form a pressure relief channel.

[0182] The term "actuation" as used in this application refers to the activation or actuation of the pressure relief component 2131 to a certain state, thereby releasing the internal pressure and temperature of the battery cell 20. The action of the pressure relief component 2131 may include, but is not limited to, at least a portion of the pressure relief component 2131 rupturing, breaking, tearing, or opening, etc. When the pressure relief component 2131 is actuated, the high-temperature, high-pressure substances inside the battery cell 20 are discharged outwards from the actuated portion as waste. In this way, the battery cell 20 can be depressurized and de-temperatureed under controllable pressure or temperature, thereby preventing potentially more serious accidents.

[0183] The emissions from the battery cell 20 mentioned in this application include, but are not limited to: electrolyte 25, dissolved or split positive and negative electrode plates, fragments of separator 22111, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0184] Each cell group 22 can be provided with a corresponding pressure relief component 2131. The positive projection of the cell group 22 in the second direction Y can either cover a part of the corresponding pressure relief component 2131 or completely cover the pressure relief component 2131.

[0185] Each cell group 22 can be provided with multiple pressure relief components 2131. The positive projection of the cell group 22 in the second direction Y can cover part of the corresponding pressure relief component 2131, or can completely cover the pressure relief component 2131.

[0186] Multiple cell groups 22 are arranged opposite to the first wall 213 in the second direction Y. By providing at least one pressure relief component 2131 for each cell group 22 on the first wall 213, and by having the orthogonal projection of the cell group 22 along the second direction Y cover at least a portion of the corresponding pressure relief component 2131, the distance between the cell group 22 and the pressure relief component 2131 can be reduced. This facilitates timely pressure relief in the event of an exothermic reaction caused by any cell group 22 inside the battery cell 20, thereby improving the reliability of the battery cell 20.

[0187] Please continue to refer to Figure 10 In some embodiments, the electrode assembly 221 in the battery cell assembly 22 is one, or the electrode assembly 221 in the battery cell assembly 22 is multiple, and the multiple electrode assemblies 221 are arranged along the first direction X; each electrode assembly 221 is provided with at least one pressure relief component 2131, and the orthographic projection of the electrode assembly 221 along the second direction Y covers at least a portion of the corresponding pressure relief component 2131.

[0188] Each electrode assembly 221 can be provided with a corresponding pressure relief component 2131. The orthogonal projection of the electrode assembly 221 in the second direction Y can either cover a part of the corresponding pressure relief component 2131 or completely cover the pressure relief component 2131.

[0189] Each electrode assembly 221 can be provided with multiple pressure relief components 2131. The orthogonal projection of the electrode assembly 221 in the second direction Y can either cover a part of the corresponding pressure relief component 2131 or completely cover the pressure relief component 2131.

[0190] Multiple cell groups 22 are arranged opposite to the first wall 213 in the second direction Y. By providing at least one pressure relief component 2131 for each electrode assembly 221 on the first wall 213, and by having the orthogonal projection of the electrode assembly 221 along the second direction Y cover at least a portion of the corresponding pressure relief component 2131, the distance between the electrode assembly 221 and the pressure relief component 2131 can be reduced. This facilitates timely pressure relief in the event of an exothermic reaction caused by any electrode assembly 221 inside the battery cell 20, thereby improving the reliability of the battery cell 20.

[0191] In some embodiments, the electrode assembly 221 in the battery cell assembly 22 is one, or the electrode assembly 221 in the battery cell assembly 22 is multiple, and the multiple electrode assemblies 221 are connected in parallel.

[0192] In an embodiment where the electrode assembly 221 in each cell group 22 is one, each cell group 22 may have one electrode assembly 221, or some cell groups 22 may have only one electrode assembly 221. In an embodiment where each cell group 22 has one electrode assembly 221, the cell groups 22 are connected in series, that is, the electrode assemblies 221 are connected in series.

[0193] In embodiments where there are multiple electrode assemblies 221 in the cell assembly 22, each cell assembly 22 may have multiple electrode assemblies 221, or some cell assemblies 221 may have multiple electrode assemblies 221.

[0194] If there is only one electrode assembly 221 in the cell pack 22, then each electrode assembly 221 is connected in series, which is beneficial for the battery cell 20 to obtain a high voltage using a smaller number of electrode assemblies 221. If there are multiple electrode assemblies 221 in the cell pack 22, and the multiple electrode assemblies 221 are connected in parallel, then the battery cell 20 can have a higher total capacity while having a higher voltage.

[0195] like Figure 1 As shown, in some embodiments, the number of battery cell groups 22 is greater than or equal to 3.

[0196] For example, the number of cell groups 22 is four, and each cell group 22 includes an electrode assembly 221, with the four electrode assemblies 221 connected in series.

[0197] Of course, in other embodiments, the number of battery cell packs 22 can be three, five, or more.

[0198] By having a cell group 22 of 3 or more, the individual battery cell 20 has a higher voltage.

[0199] like Figures 11-13 As shown, in some embodiments, the electrode assembly 221 includes a first tab 2212a and a second tab 2212b with opposite polarities. The base metal of the first tab 2212a is different from the base metal of the second tab 2212b. The battery cell 20 also includes an adapter 28, which connects the first tab 2212a of one cell group 22 and the second tab 2212b of another cell group 22. The adapter 28 includes a first part 281 and a second part 282 connected together. The first part 281 is connected to the first tab 2212a, and the base metal of the first part 281 is the same as the base metal of the first tab 2212a. The second part 282 is connected to the second tab 2212b, and the base metal of the second part 282 is the same as the base metal of the second tab 2212b.

[0200] "The base metal of the first part 281 and the first tab 2212a is the same" means that the main components of the first part 281 and the first tab 2212a are the same. Specifically, the main component of the first part 281 constitutes 50% or more of its composition, and similarly, the main component of the first tab 2212a constitutes 50% or more of its composition. The material of the first tab 2212a can also be various, such as copper or aluminum. If the first tab 2212a is a positive tab, the material is usually aluminum, and the main component of the first part 281 is also aluminum, with a content of 50% or more. If the first tab 2212a is a negative tab, the material is usually copper, and the main component of the first part 281 is also copper, with a content of 50% or more. In other words, the fact that the base metal of the first part 281 and the first electrode 2212a is the same means that the main components of the first part 281 and the first electrode 2212a are the same. For example, if the first part 281 and the first electrode 2212a are both made of a single material, such as copper or aluminum, then the materials of the first part 281 and the first electrode 2212a are composed of the same metallic elements. If the first part 281 and the first electrode 2212a are made of an alloy or mixed material, such as aluminum alloy or steel, then the fact that the base metal of the first part 281 and the first electrode 2212a is the same means that the main components of the first part 281 and the first electrode 2212a are the same, that is, the components with a content of more than 50% in the alloy or mixed material are the same.

[0201] "The base metal of the second part 282 and the second tab 2212b is the same" means that the main components of the second part 282 and the second tab 2212b are the same. Specifically, the main component of the second part 282 constitutes 50% or more of its composition, and similarly, the main component of the second tab 2212b constitutes 50% or more of its composition. The material of the second tab 2212b can also be various, such as copper or aluminum. If the second tab 2212b is a positive tab, the material is usually aluminum, and the main component of the second part 282 is also aluminum, with a content of 50% or more. If the second tab 2212b is a negative tab, the material is usually copper, and the main component of the second part 282 is also copper, with a content of 50% or more. In other words, the fact that the base metal of the second part 282 and the second tab 2212b is the same means that the main components of the second part 282 and the second tab 2212b are the same. For example, if the second part 282 and the second tab 2212b are both made of a single material, such as copper or aluminum, then the materials of the second part 282 and the second tab 2212b are composed of the same metallic elements. If the second part 282 and the second tab 2212b are made of an alloy or mixed material, such as aluminum alloy or steel, then the fact that the base metal of the second part 282 and the second tab 2212b is the same means that the main components of the second part 282 and the second tab 2212b are the same, that is, the components with a content of more than 50% in the alloy or mixed material are the same.

[0202] The first tab 2212a of the two battery cell groups 22 is connected to the first part 281, and the second tab 2212b of the two battery cell groups 22 is connected to the second part 282. The first part 281 and the second part 282 are connected to achieve series connection of the two battery cell groups 22.

[0203] The first part 281 and the first tab 2212a can be connected by welding, conductive adhesive, etc. The second part 282 and the second tab 2212b can also be connected by welding, conductive adhesive, etc. In this embodiment, the first part 281 is welded to the first tab 2212a, and the second part 282 is welded to the second tab 2212b. Since the base metal of the first part 281 and the base metal of the first tab 2212a are the same, welding the first part 281 and the first tab 2212a together improves the welding quality of the first part 281 and the first tab 2212a, as well as the welding quality of the second part 282 and the second tab 2212b, thereby improving the current carrying capacity.

[0204] The adapter 28 includes a first part 281 and a second part 282 connected together. The base metal of the first part 281 is the same as the base metal of the first tab 2212a of the cell assembly 22 connected thereto, and the base metal of the second part 282 is the same as the base metal of the second tab 2212b of the cell assembly 22 connected thereto. This is beneficial to improving the connection quality between the first part 281 and the first tab 2212a, as well as the connection quality between the second part 282 and the second tab 2212b. It can reduce the contact resistance of the electrical connection between the first tab 2212a and the first part 281, and the electrical connection between the second tab 2212b and the second part 282. It reduces the contact resistance difference caused by different materials, thereby improving the conductivity efficiency. It can also reduce the risk of electrochemical corrosion at the connection positions of the first part 281 and the first tab 2212a, and the second part 282 and the second tab 2212b due to different materials, thereby improving the reliability of the battery cell 20 and extending the service life of the battery cell 20.

[0205] like Figures 11-13 As shown, in some embodiments, the first part 281 and the second part 282 are connected by a connecting part 210; the battery cell 20 also includes a protective member 29, which is made of insulating material, and the protective member 29 covers a part of the first part 281 and a part of the second part 282, and covers the connecting part 210.

[0206] There are several ways to connect the first part 281 and the second part 282, such as welding the first part 281 and the second part 282 together, or using conductive adhesive. In the embodiment where the first part 281 and the second part 282 are welded together, the solder mark is the connecting part 210. In the embodiment where the first part 281 and the second part 282 are connected by conductive adhesive, the conductive adhesive is the connecting part 210.

[0207] The portion of the first part 281 near the connecting portion 210, the portion of the second part 282 near the connecting portion 210, and the connecting portion 210 are covered by the protective member 29. Exemplarily, the portions of the first part 281 and the second part 282 not covered by the protective member 29 are distributed on both sides of the connecting portion 210. The portions of the first part 281 and the second part 282 not covered by the protective member 29 extend in mutually opposite directions and are respectively connected to the first tab 2212a and the second tab 2212b. The protective member 29 covers a portion of the first part 281 and a portion of the second part 282, and also covers the connecting portion 210. This not only increases the connection area between the protective member 29 and the adapter 28, making it easier to install the protective member 29 on the adapter 28, but also increases the distance between the areas of the first part 281 and the second part 282 not covered by the protective member 29, reducing the risk of electrochemical corrosion of the adapter 28.

[0208] By covering a portion of the first part 281 and a portion of the second part 282 with the protective component 29, and also covering the connection portion 210, the problem of contact resistance difference caused by the different materials of the first part 281 and the second part 282 can be mitigated. This helps to improve conductivity efficiency and reduces the risk of electrochemical corrosion at the connection point of the first part 281 and the second part 282 due to material differences, thereby improving the reliability of the battery cell 20 and extending its service life. Furthermore, by using an insulating material for the protective component 29, the risk of internal short circuits in the battery cell 20 can be reduced.

[0209] Of course, in other embodiments, the protective member 29 may only cover the connecting portion 210.

[0210] In some embodiments, the protective member 29 can also seal the connection portion 210 to prevent the connection portion 210 from contacting the electrolyte 25. The protective member 29 can also connect the first portion 281 and the second portion 282, thereby increasing the connection strength between the first portion 281 and the second portion 282.

[0211] In an embodiment where the adapter 28 is provided with a protective member 29, the first part 281 and the second part 282 may not be connected by the connecting part 210. A portion of the first part 281 and a portion of the second part 282 are covered by the protective member 29 so that the protective member 29 connects the first part 281 and the second part 282.

[0212] like Figures 11-14 As shown, in some embodiments, the first portion 281 and the second portion 282 are welded to form a solder mark, which is at least a portion of the connecting portion 210.

[0213] The first part 281 and the second part 282 can be laser welded, ultrasonic welded, etc. The first part 281 and the second part 282 can be connected by welding alone, and the weld mark is the connecting part 210.

[0214] The first part 281 and the second part 282 can also be connected by welding or other means. For example, if the first part 281 and the second part 282 are connected by welding and conductive adhesive, the solder joint and the conductive adhesive together form the connection part 210, and the solder joint is part of the connection part 210.

[0215] The welded connection of the first part 281 and the second part 282 forms a weld mark, which facilitates the connection between the first part 281 and the second part 282 and ensures high connection stability. The weld mark is at least a portion of the connecting part 210. By covering the connecting part 210 with the protective member 29, the difference in contact resistance caused by the different materials of the first part 281 and the second part 282 can be mitigated. This helps improve conductivity, reduces the risk of electrochemical corrosion at the connection point of the first part 281 and the second part 282, improves the reliability of the battery cell 20, extends the service life of the battery cell 20, and also reduces the risk of internal short circuits in the battery cell 20 caused by burrs in the weld mark, further improving the reliability of the battery cell 20.

[0216] like Figure 14 , Figure 15 As shown, in some embodiments, the first portion 281 includes a first region 2811 and a second region 2812 connected together, and the second portion 282 includes a third region 2821 and a fourth region 2822 connected together.

[0217] The third region 2821 is stacked on one side of the first region 2811 in the thickness direction and is connected to the first region 2811 through the connecting part 210. The second region 2812 is connected to the first tab 2212a, and the fourth region 2822 is connected to the second tab 2212b.

[0218] Optionally, the thickness of the second region 2812 is greater than the thickness of the first region 2811, and the second region 2812 protrudes from the surface of the first region 2811 facing the third region 2821. The thickness of the fourth region 2822 is greater than the thickness of the third region 2821, and the fourth region 2822 protrudes from the surface of the third region 2821 facing the first region 2811. In this way, the second region 2812 and the first region 2811 define a first receiving portion Q1 that accommodates the third region 2821, and the third region 2821 and the fourth region 2822 define a second receiving portion Q2 that accommodates the first region 2811, thereby reducing the overall thickness of the first region 2811 and the third region 2821 in their stacking direction.

[0219] In other embodiments, the first portion 281 and the second portion 282 of the adapter 28 employ other connection methods, such as... Figures 16-19 As shown, Figure 19 As shown, one end of the first part 281 and one end of the second part 282 are positioned opposite each other and connected by the connecting part 210 to form a shape as shown. Figure 18 The structure shown. One end of the first part 281 and one end of the second part 282 can be welded together to form a solder mark, which is the connecting part 210. Of course, one end of the first part 281 and one end of the second part 282 can also be connected by conductive adhesive or the like.

[0220] like Figure 20 , Figure 21 As shown, in some embodiments, the overall structure formed by multiple electrode groups connected in series has a first output electrode 20a and a second output electrode 20b with opposite polarities. The battery cell 20 also includes a first electrode terminal 231 and a second electrode terminal 232. The first electrode terminal 231 and the second electrode terminal 232 are both disposed on the housing 21. The first electrode terminal 231 and the second electrode terminal 232 are electrically connected to the first output electrode 20a and the second output electrode 20b, respectively. The battery cell 20 also includes a data acquisition terminal 2101, which is disposed on the housing 21. At least one adapter 28 is connected to the data acquisition terminal 2101.

[0221] The first output terminal 20a and the second output terminal 20b are the total positive and total negative terminals formed by connecting all the cell groups 22 in series, respectively. The first tab 2212a of one cell group 22 forms the first output terminal 20a, and the second tab 2212b of the other cell group 22 forms the second output terminal 20b.

[0222] Both the first electrode terminal 231 and the second electrode terminal 232 are insulated from the outer casing 21. One of the first electrode terminal 231 and the second electrode terminal 232 is a positive electrode terminal, and the other is a negative electrode terminal.

[0223] The first electrode terminal 231 and the first tab 2212a can be directly connected, for example, by welding the first electrode terminal 231 and the first tab 2212a together. Alternatively, the first electrode terminal 231 and the first tab 2212a can be indirectly connected through a current collector 24. The second electrode terminal 232 and the second tab 2212b can be directly connected, for example, by welding the second electrode terminal 232 and the second tab 2212b together. Alternatively, the second electrode terminal 232 and the second tab 2212b can be indirectly connected through another current collector 24.

[0224] The first electrode terminal 231 and the second electrode terminal 232 can be disposed on the same wall of the housing 21, for example, the first electrode terminal 231 and the second electrode terminal 232 can both be disposed on the same end cap 212 of the housing 21.

[0225] The first electrode terminal 231 and the second electrode terminal 232 can be disposed on different parts of the outer casing 21.

[0226] The acquisition terminal 2101 can be used to acquire the voltage of the battery cell group 22 to monitor the voltage of the battery cell group 22 and provide a reference for balancing the voltage of the battery cell group 22.

[0227] The acquisition terminal 2101 is insulated from the housing 21. The adapter 28 is directly connected to the corresponding acquisition terminal 2101, such as by welding or direct contact.

[0228] The connectors may be connected to the acquisition terminals 2101, or each connector may be connected to an acquisition terminal 2101. In embodiments where the battery cell 20 includes multiple acquisition terminals 2101, the multiple acquisition terminals 2101 can cooperate in pairs to detect the voltage of the cell assembly 22, and the acquisition terminals 2101 can also cooperate with the first electrode terminal 231 or the second electrode terminal 232 to detect the voltage of the cell assembly 22.

[0229] The battery cell 20 also includes a data acquisition terminal 2101, and at least one adapter 28 is connected to the data acquisition terminal 2101 to facilitate voltage acquisition of the cell group 22 in the battery cell 20 through the data acquisition terminal 2101.

[0230] In some embodiments, each adapter 28 is connected to a data acquisition terminal 2101.

[0231] For example, such as Figure 16 , Figure 17As shown, the battery cell 20 includes four cell groups 22, three adapters 28, and three data acquisition terminals 2101. Each cell group 22 includes an electrode assembly 221, and each adapter 28 is connected to a data acquisition terminal 2101. The four cell groups 22 are defined as first cell group 22a, second cell group 22b, third cell group 22c, and fourth cell group 22d, and the three adapters 28 are defined as first adapter 28a, second adapter 28b, and third adapter 28c. The three data acquisition terminals 2101 are defined as first data acquisition terminal 21011, second data acquisition terminal 21012, and third data acquisition terminal 21013. The first adapter 28a connects the first tab 2212a of the first cell group 22a and the second tab 2212b of the second cell group 22b. The second adapter 28b connects the first tab 2212a of the second cell group 22b and the second tab 2212b of the third cell group 22c. The third adapter 28c connects the first tab 2212a of the third cell group 22c and the second tab 2212b of the fourth cell group 22d. The first tab 2212a of the fourth cell group 22d and the second tab 2212b of the first cell group 22a form the first output electrode 20a and the second output electrode 20b, respectively, and are electrically connected to the first electrode terminal 231 and the second electrode terminal 232. The first acquisition terminal 21011 is connected to the first adapter 28a, the second acquisition terminal 21012 is connected to the second adapter 28b, and the third acquisition terminal 21013 is connected to the third adapter 28c.

[0232] When detecting voltage, the second electrode terminal 232 and the first acquisition terminal 21011 cooperate to detect the voltage of the first battery cell group 22a, the first acquisition terminal 21011 and the second acquisition terminal 21012 cooperate to detect the voltage of the second battery cell group 22b, the second acquisition terminal 21012 and the third acquisition terminal 21013 cooperate to detect the voltage of the third battery cell group 22c, and the third acquisition terminal 21013 and the first electrode terminal 231 cooperate to detect the voltage of the fourth battery cell group 22d.

[0233] With each adapter 28 connected to a data acquisition terminal 2101, voltage acquisition of each cell group 22 can be achieved, as well as voltage acquisition of any number of cell groups 22, facilitating accurate detection of voltage in various parts of the battery cell 20.

[0234] In some embodiments, the solvent of the electrolyte 25 is a carbonate, and the electrode assembly 221 includes a negative electrode sheet containing a polymer that has swollen or crosslinked with the carbonate.

[0235] The negative electrode includes a polymer that swells or cross-links with a carbonate solvent, which can reduce the amount of free electrolyte 25 in the battery cell 20, reduce the risk of electrolyte 25 decomposition caused by the formation of a conductive path between the positive and negative electrodes of adjacent cell groups 22 through electrolyte 25, alleviate the problem of electrolyte 25 decomposition in high-voltage battery cells 20, and help extend the service life of battery cells 20.

[0236] In some embodiments, the polymer includes one or more of carboxylic acid polymers, vinylidene fluoride polymers, ether polymers, ester polymers, and polymers containing cyano groups.

[0237] The negative electrode sheet can be made of polymers that can swell or crosslink with carbonates, including any one of carboxylic acid polymers, vinylidene fluoride polymers, ether polymers, ester polymers, and cyanide-containing polymers, or a combination of carboxylic acid polymers, vinylidene fluoride polymers, ether polymers, ester polymers, and cyanide-containing polymers.

[0238] For example, the polymer of the negative electrode sheet that can swell or crosslink with carbonates can be at least one of polyacrylic acid, polyacrylonitrile, polyvinylidene fluoride, polyethylene oxide, polylactic acid, hexafluoropropylene, polymethyl methacrylate, polyvinyl chloride, polyvinyl chloride, polystyrene, and polybutadiene.

[0239] The content of polymers that can swell or cross-link with carbonates in the negative electrode sheet can be 0.5% to 5% to reduce the extrusion of electrolyte 25 from the negative electrode sheet, thereby reducing the amount of free electrolyte 25 in the battery cell 20.

[0240] The negative electrode sheet includes carboxylic acid polymers. These polymers can significantly improve the problems of electrode rebound and adhesion failure caused by volume changes in the negative electrode material, thereby improving the cycle performance of the lithium battery. Carboxylic acid polymers can also significantly inhibit the growth of lithium dendrites in the negative electrode, improving the reliability and stability of the battery cell 20. Furthermore, carboxylic acid polymers can significantly improve the high-temperature cycle performance of the battery cell 20, making it perform better in high-temperature environments.

[0241] Fluoropolymers can improve the cohesiveness of the negative electrode and reduce the rebound rate after cold pressing, thereby improving the quality of the negative electrode. The negative electrode includes a polyvinylidene fluoride (PVDF) polymer, which enhances the contact between the active material and conductive agent and the current collector, thus stabilizing the negative electrode structure. The PVDF polymer also helps prevent the active material from detaching during charging and discharging, improving the cycle stability and lifespan of the battery cell 20. Furthermore, the PVDF polymer exhibits good chemical stability and corrosion resistance, remaining stable in the organic electrolyte environment 25 without dissolving or swelling, contributing to improved battery capacity and safety, and reducing performance degradation caused by electrolyte 25 corrosion. The PVDF polymer also helps improve low-temperature performance, thereby improving the performance of the battery cell 20 in low-temperature environments.

[0242] The negative electrode sheet includes ether polymers, which is beneficial to improving the rate performance, cycle performance, reliability and stability of the battery cell 20.

[0243] The negative electrode sheet includes ester polymers, which helps to improve the cohesive force of the negative electrode sheet, reduce the rebound force after cold pressing, and improve the quality of the negative electrode sheet. The negative electrode sheet also includes polymers containing cyano groups, which can reduce the risk of internal short circuits in the battery cell 20 and improve the reliability of the battery cell 20.

[0244] This application also provides a battery device 100, which includes the battery cell 20 provided in any of the above embodiments.

[0245] The battery cell 20 provided in any of the above embodiments has a long service life, which also extends the service life of the battery device 100 including the battery cell 20.

[0246] This application also provides an electrical device, which includes the battery cell 20 or the battery device 100 provided in any of the above embodiments.

[0247] The battery cell 20 and the battery device 100 provided in any of the above embodiments have a long service life, which can reduce the replacement frequency and maintenance cost of electrical equipment powered by the battery cell 20 or the battery device 100, improve the reliability of power supply, and enhance the user experience.

[0248] This application provides a battery cell 20, which includes a casing 21, an electrolyte 25, three separators 26, an insulator 27, four cell groups 22, three adapters 28, three acquisition terminals 2101, a first electrode terminal 231, and a second electrode terminal 232. The four cell groups 22 are arranged and connected in series along a first direction X, and each cell group 22 includes an electrode assembly 221. The casing 21 includes a housing 211 and an end cap 212, which covers the opening 2111 of the housing 211. Along a second direction Y, the housing 211 has a first wall 213 opposite to the end cap 212, which is located on the bottom wall of the cell group 22 and supports the cell group 22. The electrode assembly 221 includes a main body 2211 and two tabs 2212 with opposite polarities, both tabs 2212 being located at the end of the main body 2211 opposite to the first wall 213. In adjacent electrode assemblies 221, the first tab 2212a of one electrode assembly 221 is connected to the second tab 2212b of another electrode assembly 221 via an adapter 28. A separator 26 is provided between adjacent cell groups 22. Three acquisition terminals 2101, the first electrode terminal 231, and the second electrode terminal 232 are insulated from the end cap 212 of the housing 21. Each adapter 28 is connected to one acquisition terminal 2101. The first tabs 2212a and 2212b in all cell groups 22 that are not connected to the adapter 28 form the first output pole 20a and the second output pole 20b, respectively. The first output pole 20a is connected to the first tab 2212a via a current collector 24, and the second output pole 20b is connected to the second tab 2212b via a current collector 24.

[0249] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0250] 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: shell; Multiple battery cell groups are housed within the housing, each battery cell group includes at least one electrode assembly, the multiple battery cell groups are connected in series, and the multiple battery cell groups are arranged along a first direction; Electrolyte, contained within the outer casing; A separator is disposed inside the housing, and the separator is disposed between two adjacent battery cell groups along the first direction.

2. The battery cell as described in claim 1, characterized in that, The outer casing includes a first wall along a second direction. The first wall is located at the bottom of the battery cell assembly and supports the battery cell assembly. The electrolyte level is not higher than the end of the separator opposite to the first wall. The second direction is perpendicular to the first direction.

3. The battery cell as described in claim 1, characterized in that, The electrode assembly includes a main body and an electrode tab, wherein the electrode tab is disposed at at least one end of the main body along a second direction; The battery cell further includes an insulating member that covers a plurality of the cell groups around an axis extending along the second direction. Along the third direction, at least one end of the separator abuts against or has a gap with the insulating member. The first direction, the second direction, and the third direction are perpendicular to each other.

4. The battery cell as described in claim 3, characterized in that, The outer casing includes a first wall, the electrode tab is disposed at one end of the main body away from the first wall, and the separator abuts against the first wall or has a gap therebetween.

5. The battery cell as described in claim 1, characterized in that, The outer casing includes a first wall along a second direction, the first wall being located at the bottom of the battery cell assembly and supporting the battery cell assembly; The electrode assembly includes a main body and a tab. The tab is disposed at the end of the main body away from the first wall. The main body includes a separating membrane, a first electrode and a second electrode with opposite polarities. The separating membrane insulates and isolates the first electrode and the second electrode. Along the second direction, the separating membrane does not extend beyond the end of the separator away from the first wall. The second direction is perpendicular to the first direction.

6. The battery cell as described in claim 5, characterized in that, Along the second direction, the separator does not extend beyond the end of the tab that is away from the first wall.

7. The battery cell as described in claim 1, characterized in that, The separator is made of insulating material.

8. The battery cell as described in claim 1, characterized in that, The outer casing includes a first wall. Along a second direction, a plurality of battery cell groups are disposed opposite to the first wall. The first wall is provided with a plurality of pressure relief components. Each battery cell group is provided with at least one pressure relief component. The orthographic projection of the battery cell group along the second direction covers at least a portion of the corresponding pressure relief component. The second direction is perpendicular to the first direction.

9. The battery cell as described in claim 8, characterized in that, The electrode assembly in the battery cell assembly is one, or the electrode assembly in the battery cell assembly is multiple, and the multiple electrode assemblies are arranged along the first direction; Each of the electrode assemblies is provided with at least one of the pressure relief components, and the orthographic projection of the electrode assembly along the second direction covers at least a portion of the corresponding pressure relief component.

10. The battery cell as described in claim 1, characterized in that, The electrode assembly in the battery cell assembly may be one, or the electrode assembly in the battery cell assembly may be multiple, with the multiple electrode assemblies connected in parallel.

11. The battery cell as described in claim 10, characterized in that, The number of battery cells in the assembly is greater than or equal to 3.

12. The battery cell according to any one of claims 1-11, characterized in that, The electrode assembly includes a first electrode and a second electrode with opposite polarities, wherein the base metal of the first electrode is different from the base metal of the second electrode. The battery cell also includes an adapter, which connects the first tab of one battery cell group and the second tab of another battery cell group. The adapter includes a first part and a second part connected together. The first part is connected to the first tab, and the base metal of the first part is the same as the base metal of the first tab. The second part is connected to the second tab, and the base metal of the second part is the same as the base metal of the second tab.

13. The battery cell as described in claim 12, characterized in that, The first part and the second part are connected by a connecting part; The battery cell also includes a protective component made of insulating material. The protective component covers a portion of the first part and a portion of the second part, and covers the connecting portion.

14. The battery cell as described in claim 13, characterized in that, The first part and the second part are welded together to form a weld mark, which is at least a part of the connecting part.

15. The battery cell as described in claim 12, characterized in that, The assembly formed by multiple battery cells connected in series has a first output electrode and a second output electrode with opposite polarities. The battery cell also includes a first electrode terminal and a second electrode terminal. The first electrode terminal and the second electrode terminal are both disposed on the outer casing. The first electrode terminal and the second electrode terminal are electrically connected to the first output electrode and the second output electrode, respectively. The battery cell also includes a data acquisition terminal, which is disposed on the housing, and at least one of the adapters is connected to the data acquisition terminal.

16. The battery cell as described in claim 15, characterized in that, Each of the adapters is connected to the acquisition terminal.

17. The battery cell according to any one of claims 1-11, characterized in that, The electrolyte is a carbonate solvent, and the electrode assembly includes a negative electrode sheet containing a polymer that swells or crosslinks with the carbonate solvent.

18. The battery cell as described in claim 17, characterized in that, The polymer includes one or more of the following: carboxylic acid polymers, vinylidene fluoride polymers, ether polymers, ester polymers, and polymers containing cyano groups.

19. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-18.

20. An electrical appliance, characterized in that, Includes the battery cell as described in any one of claims 1-18 or the battery device as described in claim 19.

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