Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly and a supporting piece, the electrode assembly is accommodated in the shell and comprises a first pole piece, the first pole piece comprises a first pole piece main body and a first pole lug, and the first pole piece main body comprises a first current collecting main body, a first active material layer and a first insulating layer; the first tab is connected to the end part of the first current collector main body along a first direction, the first current collector main body comprises two first surfaces which are oppositely arranged along the thickness direction of the first current collector main body, the first active material layer and the first insulating layer are arranged on the first surfaces, and the first insulating layer is positioned on one side, close to the first tab along the first direction, of the first active material layer; the first direction is perpendicular to the thickness direction. The supporting piece has elasticity, is connected to one side, close to the first insulating layer in the first direction, of the first tab, and covers at least part of the first tab in the thickness direction. According to the invention, the reliability of the battery can be effectively improved.

Description

Technical Field

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

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

[0003] In the development of battery technology, improving the reliability of individual battery cells is a continuous research direction. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can effectively improve the reliability of the battery.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, and a support member. The electrode assembly is housed within the casing and includes a first electrode plate. The first electrode plate includes a first electrode plate body and a first electrode tab. The first electrode plate body includes a first current collector body, a first active material layer, and a first insulating layer. The first electrode tab is connected to the end of the first current collector body along a first direction. The first current collector body includes two first surfaces disposed opposite to each other along its thickness direction. The first active material layer and the first insulating layer are both disposed on the first surfaces, and the first insulating layer is located on the side of the first active material layer near the first electrode tab along the first direction, which is perpendicular to the thickness direction. The support member is elastic and is connected to the side of the first electrode tab near the first insulating layer along the first direction, and covers at least a portion of the first electrode tab along the thickness direction.

[0006] In the process of bending or flattening the first electrode tab, the support member can undergo elastic deformation after being subjected to force, thereby applying elastic force to the first electrode tab to support it, reducing the possibility of wrinkles forming on the first electrode tab, thus reducing the risk caused by wrinkles and improving the reliability of the battery cell.

[0007] In some embodiments of the first aspect, the support is also connected to the first insulating layer and covers at least a portion of the first insulating layer in the thickness direction.

[0008] The above technical solution can, on the one hand, further increase the connection area between the support and the first electrode, reduce the risk of the support falling off, and improve reliability; on the other hand, the support can also support the first insulating layer, reducing the possibility of the first insulating layer producing problems such as powder shedding, cracking or wrinkling, so as to further improve the reliability of the battery cell.

[0009] In some embodiments of the first aspect, the first dimension d1 of the area of ​​the support member covering the first tab along the first direction and the second dimension d2 of the area of ​​the support member covering the first insulating layer along the first direction satisfy the relationship: d1≥d2 / 2.

[0010] The above technical solution can increase the connection area between the support and the first tab without increasing the space occupied by the support in the battery cell, so as to provide effective support for the first tab, further reduce the possibility of wrinkles in the first tab and the risk of the support falling off, thereby taking into account both the reliability and energy density of the battery cell.

[0011] In some embodiments of the first aspect, the first dimension d1 and the second dimension d2 satisfy the relationship: d1 ≥ d2. This can further increase the connection area between the support and the first electrode tab.

[0012] In some embodiments of the first aspect, the second dimension d2 of the area of ​​the support member covering the first insulating layer along the first direction and the third dimension d3 of the first insulating layer along the first direction satisfy the relationship: d2 ≥ d3 / 4. This can increase the connection area between the support member and the first insulating layer, thereby further reducing the risk of the support member falling off and further improving the support effect of the support member on the first insulating layer.

[0013] In some embodiments of the first aspect, the second dimension d2 and the third dimension d3 satisfy the relationship: d2 ≥ d3 / 2. This can further increase the connection area between the support and the first insulating layer.

[0014] In some embodiments of the first aspect, the support includes a substrate layer and an adhesive layer, the substrate layer being connected to the first electrode through the adhesive layer.

[0015] The substrate layer enhances the strength of the support and reduces deformation during the attachment process. The adhesive layer bonds the substrate layer to the first electrode, reducing the risk of the substrate layer detaching from the first electrode.

[0016] In some embodiments of the first aspect, the adhesive layer is disposed only on one side surface of the substrate layer along the thickness direction.

[0017] Bending or flattening the first tab can reduce the risk of unnecessary adhesion between the adhesive layer and other components, thereby reducing quality problems caused by excessive adhesion of the adhesive layer and improving the product yield of the battery cell.

[0018] In some embodiments of the first aspect, the support further includes a smoothing layer disposed on the side surface of the substrate layer facing away from the adhesive layer, and the coefficient of friction of the smoothing layer is less than the coefficient of friction of the substrate layer.

[0019] The smooth layer can reduce the frictional resistance when the support comes into contact with other components, and can reduce the wear caused by friction during the bending or flattening of the first electrode tab, thereby improving the product quality of the battery cell.

[0020] In some embodiments of the first aspect, the fourth dimension d4 of the support member along the first direction is 1mm-50mm.

[0021] Limiting the fourth dimension d4 to greater than or equal to 1 mm increases the connection area between the support and the first electrode, reducing the risk of the support detaching. Limiting the fourth dimension d4 to less than or equal to 50 mm reduces the amount of support required, decreasing the space occupied by the support within the battery cell and helping to improve the energy density of the battery cell.

[0022] In some embodiments of the first aspect, the fourth dimension d4 is 4mm-10mm. This can further improve the balance between the reliability of the support and the energy density of the battery cells.

[0023] In some embodiments of the first aspect, the dimension of the support member along the thickness direction is less than or equal to the dimension of the first insulating layer along the thickness direction.

[0024] Reducing the thickness of the support component can, on the one hand, reduce the risk of damage caused by excessive compression of the first electrode or the first insulating layer during the bending or flattening process of the first electrode; on the other hand, it can save internal space of the battery cell, improve the volume utilization efficiency of the battery cell, and thus increase the energy density of the battery.

[0025] In some embodiments of the first aspect, the dimension of the support member along the thickness direction is greater than or equal to the dimension of the first current collector body along the thickness direction. This reduces the risk that insufficient support for the first electrode tab may result from an excessively thin support member.

[0026] In some embodiments of the first aspect, the fifth dimension d5 of the support member along the thickness direction is 5μm-100μm.

[0027] Limiting the fifth dimension d5 to greater than or equal to 5 μm increases the range of elastic deformation of the support member and improves its support effect on the first electrode tab. Limiting the fifth dimension d5 to less than or equal to 100 μm can reduce the amount of support member used, reduce the occupancy rate of the support member in the internal space of the battery cell, and help improve the energy density of the battery cell.

[0028] In some embodiments of the first aspect, the fifth dimension d5 is 10μm-50μm. This can further improve the balance between the support effect of the support member and the energy density of the battery cell.

[0029] In some embodiments of the first aspect, the support is insulated. This reduces the risk of the support conducting between the positive and negative electrodes and causing a short circuit, thereby improving the reliability of the battery cell.

[0030] In some embodiments of the first aspect, the support member includes a first support portion and a second support portion connected together, and the first support portion and the second support portion are disposed along a first direction. The first support portion is connected to a first insulating layer and covers at least a portion of the first insulating layer along the thickness direction, and the second support portion is connected to a first electrode tab and covers at least a portion of the first electrode tab along the thickness direction.

[0031] In some embodiments of the first aspect, the first electrode is wound along a winding direction, and the winding axis of the first electrode is parallel to the first direction. The first tab is wound along the winding direction and includes multiple turns of the first tab layer, and the support extends along the winding direction.

[0032] The above technical solution can further increase the connection area between the support and the first pole piece, reduce the risk of the support falling off, and improve reliability.

[0033] In some embodiments of the first aspect, the multiple turns of the first tab layer are gathered in a direction close to the winding axis.

[0034] In the process of flattening the first tab, the support member can undergo elastic deformation after being subjected to force, thereby applying elastic force to the first tab to support it, reducing the possibility of wrinkles forming on the first tab, thus reducing the risk caused by wrinkles and improving the reliability of the battery cell.

[0035] In some embodiments of the first aspect, the electrode assembly further includes a second electrode, the first electrode having the opposite polarity to the second electrode. The second electrode includes a second electrode body and a second tab, the second electrode being connected to one end of the second electrode body along a first direction, and the second electrode and the first electrode being disposed opposite to each other along the first direction.

[0036] The second active material layer can provide more insertion sites for active ions that have been extracted from the first active material layer, thereby reducing the risk of active ion precipitation, improving the cycle performance of the battery cell, and increasing reliability.

[0037] In some embodiments of the first aspect, the battery cell is a cylindrical battery cell.

[0038] In the manufacturing process of cylindrical battery cells, it is generally necessary to flatten the tabs. The support component of the present application embodiment can greatly improve the reliability of cylindrical battery cells.

[0039] Secondly, this application provides a battery device that includes a battery cell provided in any of the embodiments of the first aspect.

[0040] Thirdly, this application provides an electrical device that includes a battery cell provided in any embodiment of the first aspect or a battery device provided in any embodiment of the second aspect, wherein the battery cell or battery device is used to store or provide electrical energy.

[0041] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0042] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0043] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application;

[0044] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application;

[0045] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application;

[0046] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in some embodiments of this application;

[0047] Figure 5 This is a schematic diagram of the structure of an electrode assembly for a battery cell provided in some embodiments of this application;

[0048] Figure 6 A schematic diagram of the structure of the electrode assembly provided in some embodiments of this application after the first electrode plate is connected to the support member;

[0049] Figure 7 for Figure 6 A partial sectional view along the AA direction;

[0050] Figure 8 This is a schematic diagram of the structure of the support member for the electrode assembly provided in some embodiments of this application.

[0051] The reference numerals in the detailed embodiments are as follows:

[0052] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing; 5b. Second housing; 6. Battery module; 7. Battery cell;

[0053] 10. Outer casing;

[0054] 20. Electrode assembly; 21. First electrode; 211. First electrode body; 2111. First current collector body; 2111a. First surface; 2112. First active material layer; 2113. First insulating layer; 212. First tab;

[0055] 22. Second electrode;

[0056] 23. Support component; 231. First support part; 232. Second support part; 233. Substrate layer; 234. Adhesive layer; 235. Smoothing layer;

[0057] 24. Isolation components;

[0058] X, first direction; Y, thickness direction; V, winding direction; K, winding axis. Detailed Implementation

[0059] 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 and completely 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.

[0060] 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 specification 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 specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] In this application, "multiple" means two or more (including two).

[0066] In this application, the term "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0067] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0068] In the development of battery technology, improving the reliability of individual battery cells is a continuous research direction.

[0069] During the fabrication of a single battery cell, an insulating layer is typically placed at the junction of the electrode body and the tab to reduce the risk of short circuits caused by the overlap of the positive and negative electrodes. However, the presence of the insulating layer often has a certain impact on the molding of the electrode assembly.

[0070] For example, during the forming process of electrode components, the tabs usually need to be bent or flattened. The thickness of the insulating layer itself will create a step between the tab and the insulating layer, i.e., a thickness difference. This makes it easy for wrinkles to form at the junction of the tab and the insulating layer during the bending or flattening process. These wrinkles may puncture the separator and conduct the positive and negative electrodes, causing a short circuit risk and affecting the reliability of the battery cell.

[0071] Based on the above considerations, this application designs a battery cell comprising a casing, an electrode assembly, and a support member. The electrode assembly is housed within the casing and includes a first electrode plate, which comprises a first electrode plate body and a first electrode tab. The first electrode plate body includes a first current collector body, a first active material layer, and a first insulating layer. The first electrode tab is connected to the end of the first current collector body along a first direction. The first current collector body includes two first surfaces disposed opposite each other along its thickness direction. The first active material layer and the first insulating layer are both disposed on the first surfaces, and the first insulating layer is located on the side of the first active material layer along the first direction near the first electrode tab. The first direction is perpendicular to the thickness direction. The support member is elastic and is connected to the side of the first electrode tab along the first direction near the first insulating layer, and covers at least a portion of the first electrode tab along the thickness direction.

[0072] During the bending or flattening process of the first tab, the support can undergo elastic deformation after being subjected to force, thereby applying elastic force to the first tab to support it, reducing the possibility of wrinkles forming on the first tab, thus reducing the risk caused by wrinkles and improving the reliability of the battery cell.

[0073] The battery cells described in this application are applicable to battery devices and electrical equipment using battery devices. Electrical equipment can be devices that use battery devices as a power source or various energy storage systems that use battery devices as energy storage elements. Electrical equipment can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0074] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0075] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0076] like Figure 1As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0077] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0078] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0079] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0080] In some embodiments, the battery device 2 may include one or more battery cell assemblies for providing voltage and capacity.

[0081] A battery cell assembly may include multiple battery cells ( Figure 2 (Not shown), multiple battery cells are connected in series, parallel, or mixed connection through a busbar. Mixed connection refers to multiple battery cells being connected in both series and parallel.

[0082] A battery cell can be a rechargeable battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0083] As an example, a single battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0084] As an example, a battery cell can be 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.

[0085] 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 6, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module 6 can be formed by bundling multiple battery cells together with cable ties.

[0086] In some embodiments, the battery device 2 may be a battery pack, which includes a housing 5 and one or more battery cell assemblies housed within the housing 5. As an example, the battery cell assembly may be a battery module 6, which can be housed within the housing by securing the battery module 6 to the housing. Alternatively, the battery cell assembly may be housed within the housing by directly securing multiple battery cells to the housing.

[0087] In some embodiments, the housing 5 is used to house individual battery cells, and the housing 5 can have various structures.

[0088] In some embodiments, the housing 5 may include a first housing 5a and a second housing 5b. The first housing 5a and the second housing 5b are fastened together to form a closed space inside the housing 5 to house the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0089] In some embodiments, the housing 5 may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, forming an enclosed space inside the housing to accommodate individual battery cells. As an example, the frame may include multiple side beams.

[0090] In some embodiments, the housing 5 may be part of the vehicle's chassis structure. For example, a portion of the housing 5 may be at least a portion of the vehicle's floor, or a portion of the housing 5 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0091] In some embodiments, the battery device 2 may be an energy storage device.

[0092] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0093] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0094] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application.

[0095] In some embodiments, such as Figure 3 As shown, there are multiple battery cells 7, which are first connected in series, parallel, or a combination of both to form a battery module 6. These battery modules 6 are then connected in series, parallel, or a combination of both to form a whole, which is housed within the casing.

[0096] Multiple battery cells 7 in battery module 6 can be electrically connected through a busbar to achieve parallel, series, or mixed connection of multiple battery cells 7 in battery module 6. There can be one or more busbars, each used to electrically connect at least two battery cells 7.

[0097] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0098] In some embodiments, the outer casing may be a steel casing, an aluminum casing, or a composite metal casing (such as a copper-aluminum composite casing).

[0099] The outer shell can be a hollow structure, with an internal cavity for accommodating the electrode assembly and electrolyte.

[0100] In some embodiments, the casing of the battery cell is a cylindrical casing, a square casing, a prismatic casing, or a casing of other shapes.

[0101] In some embodiments, the housing includes a housing and an end cap, the housing having an opening and the end cap being connected to the housing and covering the opening;

[0102] The housing is a component used to fit the end cap to form the internal cavity of the battery cell. The formed internal cavity can be used to house the electrode assembly, electrolyte, and other components.

[0103] The housing and end cap can be separate components. For example, an opening can be provided on the housing, and the end cap can be used to close the opening to form an internal cavity for the battery cell.

[0104] The housing can come in various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing can be determined based on the specific shape and size of the electrode assembly. The housing can be made of various materials, such as copper, iron, aluminum, stainless steel, and aluminum alloy.

[0105] The shape of the end cap can be adapted to the shape of the housing to fit the housing. The material of the end cap can be the same as or different from that of the housing. Optionally, the end cap can be made of a material with a certain degree of hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap is not easily deformed when subjected to compression and impact, enabling the battery cell to have higher strength and improve reliability.

[0106] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0107] The housing may be open at one end or at both ends. In some examples, the housing may be a structure with an opening on one side, with one end cap fitting over the housing. In other examples, the housing may be a structure with openings on both sides, with two end caps fitting over the two openings of the housing, respectively.

[0108] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0109] In some embodiments, the electrode assembly includes a positive electrode and a negative electrode, wherein the positive electrode and the negative electrode have opposite polarities.

[0110] In some embodiments, the positive electrode may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector.

[0111] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0112] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0113] As an example, the positive electrode film layer includes a positive electrode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0114] In some embodiments, the negative electrode may include a negative current collector.

[0115] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0116] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0117] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0118] As an example, the negative electrode film layer includes a negative electrode active material, which 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.

[0119] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0120] In some embodiments, the electrode assembly further includes a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrode plates, serving both to transport ions and to isolate the positive and negative electrodes.

[0121] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0122] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0123] As an example, inorganic solid electrolytes can be 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 phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0124] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0125] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0126] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0127] In some implementations, the electrode assembly is a stacked structure.

[0128] As an example, multiple positive and negative electrode plates can be set, with multiple positive and multiple negative electrode plates stacked alternately. As an example, multiple positive electrode plates can be set, and negative electrode plates are folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0129] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0130] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0131] In some embodiments, the positive current collector may include a positive tab, and the negative current collector may include a negative tab. The positive and negative tabs can be used to transmit current. As an example, at least a portion of the positive tab is not coated with a positive film layer, and at least a portion of the negative tab is not coated with a negative film layer.

[0132] In some embodiments, the electrode assembly is a wound structure. The positive electrode tab is wound multiple turns along the winding direction. Optionally, the end of the positive electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. Optionally, the positive electrode tab is annular.

[0133] In some embodiments, the negative electrode tab is wound multiple turns along the winding direction. Optionally, the end of the negative electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. The negative electrode tab is annular.

[0134] In some embodiments, the electrode assembly includes an electrode body. As an example, the electrode body includes a positive electrode film, a portion of a positive current collector covered by the positive electrode film, a negative electrode film, and a portion of a negative current collector covered by the negative electrode film.

[0135] The positive and negative tabs can be drawn from the same end of the electrode body, or they can be drawn from opposite ends of the electrode body.

[0136] In some embodiments, a battery cell includes a positive electrode lead and a negative electrode lead, wherein the positive electrode lead is electrically connected to a positive electrode plate and the negative electrode lead is electrically connected to a negative electrode plate.

[0137] The positive and negative leads are used to connect to the external circuit to enable charging or discharging of the battery cells.

[0138] In some embodiments, the positive lead-out portion includes a positive terminal. At least a portion of the positive terminal is exposed to the outside of the battery cell to facilitate connection with a busbar.

[0139] As an example, the positive terminal may be a separately molded component that is mounted on the housing. Alternatively, the positive terminal may also be part of the housing.

[0140] In some examples, the positive terminal is directly connected to the positive plate; in other examples, the positive terminal and the positive plate are indirectly connected through other conductive structures, such as a positive adapter plate.

[0141] In some embodiments, the positive terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0142] In some embodiments, the negative lead-out portion includes a negative terminal. At least a portion of the negative terminal is exposed to the outside of the battery cell to facilitate connection with a busbar.

[0143] As an example, the negative terminal can be a separately molded component that is mounted on the housing. Alternatively, the negative terminal can also be part of the housing.

[0144] In some examples, the negative terminal is directly connected to the negative electrode plate; in other examples, the negative lead-out section also includes other conductive structures connecting the negative terminal and the negative electrode plate, such as a negative electrode adapter plate.

[0145] In some embodiments, the negative terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0146] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in some embodiments of this application. Figure 5 This is a schematic diagram of the structure of an electrode assembly for a battery cell provided in some embodiments of this application. Figure 6 This is a schematic diagram of the structure of the electrode assembly provided in some embodiments of this application after the first electrode plate is connected to the support member. Figure 7 for Figure 6 A partial sectional view along the AA direction.

[0147] Continue to refer to Figures 4 to 7This application provides a battery cell 7, which includes a housing 10, an electrode assembly 20, and a support 23. The electrode assembly 20 is housed within the housing 10 and includes a first electrode 21. The first electrode 21 includes a first electrode body 211 and a first electrode tab 212. The first electrode body 211 includes a first current collector 2111, a first active material layer 2112, and a first insulating layer 2113. The first electrode tab 212 is connected to the end of the first current collector 2111 along the first direction X. The first current collector 2111 includes two first surfaces 2111a disposed opposite to each other along its own thickness direction Y. The first active material layer 2112 and the first insulating layer 2113 are both disposed on the first surfaces 2111a, and the first insulating layer 2113 is located on the side of the first active material layer 2112 along the first direction X close to the first electrode tab 212. The first direction X is perpendicular to the thickness direction Y. The support member 23 is elastic and is connected to the side of the first electrode tab 212 close to the first insulating layer 2113 along the first direction X, and covers at least part of the first electrode tab 212 along the thickness direction Y.

[0148] In some examples, the first electrode 21 is a positive electrode, the positive current collector may include a first current collector body 2111, and the first active material layer 2112 is a positive active material layer. In other examples, the first electrode 21 is a negative electrode, the negative current collector includes a first current collector body 2111, and the first active material layer 2112 is a negative active material layer.

[0149] The first active material layer 2112 can be integrally disposed on the first surface 2111a. Alternatively, a portion of the first active material layer 2112 can be disposed in other locations. For example, the first electrode 21 may also include a first tab 212 connected to the first current collector 2111, and a portion of the first active material layer 2112 may be disposed near the root of the first tab 212 close to the first current collector 2111.

[0150] In the embodiments of this application, the first active material layer 2112 may be provided on one first surface 2111a, or the first active material layer 2112 may be provided on both first surfaces 2111a.

[0151] The first insulating layer 2113 can be integrally disposed on the first surface 2111a. Alternatively, a portion of the first insulating layer 2113 can be disposed at other locations. For example, the first electrode 21 may also include a first tab 212 connected to the first current collector 2111, and a portion of the first insulating layer 2113 may be disposed at the root of the first tab 212 near the first current collector 2111.

[0152] In the embodiments of this application, the first insulating layer 2113 may be provided on one first surface 2111a, or the first insulating layer 2113 may be provided on both first surfaces 2111a.

[0153] In some examples, a first active material layer 2112 and a first insulating layer 2113 are provided on both first surfaces 2111a.

[0154] In the embodiments of this application, the first active material layer 2112 and the first insulating layer 2113 located on the same first surface 2111a can be spaced apart along the first direction X, or they can be closely connected along the first direction X.

[0155] The first insulating layer 2113 can be connected to the first current collector 2111 in various ways. For example, the first insulating layer 2113 can be connected to the first current collector 2111 by adhesive bonding; alternatively, the first insulating layer 2113 can also be connected to the first current collector 2111 by coating.

[0156] Optionally, the material of the first insulating layer 2113 may be, but is not limited to, at least one of polyethylene terephthalate, polypropylene or polyethylene and their block copolymers, polyolefins, polyesters, polyacrylates, styrene-butadiene rubber, polyisobutylene or butyl rubber.

[0157] In some examples, the first insulating layer 2113 may be an insulating ceramic coating.

[0158] In some examples, the first current collector body 2111 and the first tab 212 may be integrally formed; in other examples, the first tab 212 and the first current collector body 2111 may be formed independently and connected by welding or other means.

[0159] The first electrode 212 can be one or more.

[0160] In some examples, the first tab 212 is integrally formed with the first current collector body 2111. Exemplarily, the first tab 212 can be formed by a die-cutting process; during the forming of the first electrode 21, a portion of the first electrode 21 is removed by die-cutting to form the protruding first tab 212. Alternatively, the die-cutting process can be skipped, and the portion of the first current collector body 2111 not coated with the first active material layer 2112 and the first insulating layer 2113 can be directly used as the first tab 212, i.e., a full tab structure.

[0161] In some examples, the electrode assembly 20 is a wound structure. Optionally, the first direction X may be parallel to the winding axis of the electrode assembly 20.

[0162] In this embodiment, the support member 23 may be disposed on one side of the first electrode tab 212 along the thickness direction Y, or the support member 23 may be disposed on both sides of the first electrode tab 212 along the thickness direction Y.

[0163] The support member 23 can be directly connected to the first electrode 212, or it can be indirectly connected to the first electrode 212 through other components.

[0164] The support member 23 can be connected to the first electrode tab 212 in various ways. For example, the support member 23 can be connected to the first electrode tab 212 by adhesive bonding; alternatively, the support member 23 can also be connected to the first electrode tab 212 by attachment instead of adhesive bonding.

[0165] The support member 23 can be a one-piece molded structure. Alternatively, the support member 23 can be assembled from at least two separately molded parts.

[0166] There can be one or more support members 23.

[0167] The support member 23 is connected to the side of the first electrode tab 212 along the first direction X near the first insulating layer 2113. In other words, the support member 23 is connected to the root of the first electrode tab 212 along the first direction X near the first insulating layer 2113.

[0168] Optionally, the material of the support member 23 may be, but is not limited to, at least one of rubber, polyolefin, polyester, polyacrylate, silicone or polyester fiber.

[0169] In some examples, the support 23 may be a sheet-like structure.

[0170] It is understandable that when the first tab 212 is bent or flattened, an external force is applied to the first tab 212. The external force is transmitted to the support member 23 through the first tab 212. The support member 23 can produce elastic deformation after being subjected to the force, thereby applying an elastic force to the first tab 212 to support the first tab 212 and reduce the possibility of the first tab 212 wrinkling.

[0171] In the process of bending or flattening the first tab 212, the support member 23 can undergo elastic deformation after being subjected to force, thereby applying elastic force to the first tab 212 to support it, reducing the possibility of wrinkles in the first tab 212, thereby reducing the risk caused by wrinkles and improving the reliability of the battery cell 7.

[0172] In some embodiments, the support member 23 is also connected to the first insulating layer 2113 and covers at least a portion of the first insulating layer 2113 along the thickness direction Y.

[0173] The support member 23 may cover a portion of the first insulating layer 2113 along the thickness direction Y, or it may cover the entire first insulating layer 2113 along the thickness direction Y.

[0174] It is understandable that during the bending or flattening of the first tab 212, the first insulating layer 2113 may also be subjected to some external force, which may cause problems such as powder shedding, cracking or wrinkling of the first insulating layer 2113.

[0175] The above technical solution can, on the one hand, further increase the connection area between the support member 23 and the first electrode 21, reduce the risk of the support member 23 falling off, and improve reliability; on the other hand, the support member 23 can simultaneously support the first insulating layer 2113, reduce the possibility of the first insulating layer 2113 producing problems such as powder shedding, cracking or wrinkling, so as to further improve the reliability of the battery cell 7.

[0176] In some embodiments, the peel strength between the support member 23 and the first tab 212 is higher than the peel strength between the support member 23 and the first insulating layer 2113.

[0177] As an example, the support member 23 can be fixed on a tensile testing machine and pulled 180°. During the pulling process, the support member 23 peels off from the first insulating layer 2113, while the support member 23 remains connected to the first tab 212.

[0178] As an example, peel strength can be tested according to GB / T2792-2014 Test Method for Peel Strength of Adhesive Tapes.

[0179] In this embodiment, the peel strength between the support member 23 and the first insulating layer 2113 is high, thereby reducing the risk of the support member 23 falling off and improving reliability.

[0180] In some embodiments, the battery cell 7 includes an electrolyte contained within the housing 10. The support 23 remains stable in the electrolyte.

[0181] For example, after immersion in the electrolyte for 1000 hours, the peel strength between the support member 23 and the first tab 212 is greater than or equal to 2 N / m. Optionally, after immersion in the electrolyte for 1000 hours, the peel strength between the support member 23 and the first tab 212 is 15 N / m to 200 N / m.

[0182] In some embodiments, the support member 23 has good insulation properties, will not break down under 200V voltage, and has a resistance greater than or equal to 9999 megohms.

[0183] In some embodiments, the support member 23 extends beyond both ends of the first electrode 21 along its length direction, with the first direction X, thickness direction Y, and length direction being perpendicular to each other. This further increases the coverage area of ​​the support member 23, thereby further improving the support effect of the support member 23 on the first electrode tab 212.

[0184] In some embodiments, the first dimension d1 of the area of ​​the support member 23 covering the first tab 212 along the first direction X and the second dimension d2 of the area of ​​the support member 23 covering the first insulating layer 2113 along the first direction X satisfy the relationship: d1≥d2 / 2.

[0185] In other words, the first dimension d1 is greater than or equal to half of the second dimension d2.

[0186] It is understandable that the larger the first dimension d1 and the second dimension d2 are, the larger the connection area between the support member 23 and the first electrode 212 and the connection area between the support member 23 and the first insulating layer 2113 will be, and the better the support effect of the support member 23 on the first electrode 212 and the first insulating layer 2113 will be. At the same time, it will also lead to a larger dimension of the support member 23 along the first direction X, and the larger the space occupied by the support member 23 in the internal space of the battery cell 7.

[0187] During the bending or flattening process of the first tab 212, the risk of wrinkles in the first tab 212 is relatively greater than the risk of powder shedding, cracking or wrinkling in the first insulating layer 2113.

[0188] Thus, the above technical solution can increase the connection area between the support member 23 and the first tab 212 without increasing the space occupied by the support member 23 inside the battery cell 7, so as to provide effective support for the first tab 212, further reduce the possibility of the first tab 212 wrinkling and the risk of the support member 23 falling off, thereby taking into account both the reliability and energy density of the battery cell 7.

[0189] In some embodiments, the first dimension d1 and the second dimension d2 satisfy the relationship: d1 ≥ d2. This can further increase the connection area between the support member 23 and the first tab 212.

[0190] In some embodiments, the second dimension d2 of the area of ​​the support member 23 covering the first insulating layer 2113 along the first direction X and the third dimension d3 of the first insulating layer 2113 along the first direction X satisfy the relationship: d2≥d3 / 4.

[0191] This can increase the connection area between the support member 23 and the first insulating layer 2113, thereby further reducing the risk of the support member 23 falling off and further improving the support effect of the support member 23 on the first insulating layer 2113.

[0192] In some embodiments, the second dimension d2 and the third dimension d3 satisfy the relationship: d2 ≥ d3 / 2. This can further increase the connection area between the support member 23 and the first insulating layer 2113.

[0193] Figure 8 This is a schematic diagram of the structure of the support member for the electrode assembly provided in some embodiments of this application.

[0194] Continue to refer to Figure 8 In some embodiments, the support member 23 includes a substrate layer 233 and an adhesive layer 234, wherein the substrate layer 233 is connected to the first electrode 21 through the adhesive layer 234.

[0195] For example, the adhesive layer 234 may be disposed on one of the two opposite surfaces of the substrate layer 233 along the thickness direction Y, or the adhesive layer 234 may be disposed on both opposite surfaces of the substrate layer 233 along the thickness direction Y.

[0196] The substrate layer 233 can improve the strength of the support member 23 and reduce the deformation of the support member 23 during the attachment process. The adhesive layer 234 can bond the substrate layer 233 to the first electrode 21, reducing the risk of the substrate layer 233 falling off the first electrode 21.

[0197] In some embodiments, the adhesive layer 234 is disposed only on one side surface of the substrate layer 233 along the thickness direction Y.

[0198] During the bending or flattening process of the first tab 212, the risk of unnecessary adhesion between the adhesive layer 234 and other components can be reduced, thereby reducing quality problems caused by excessive adhesion of the adhesive layer 234 and improving the product yield of the battery cell 7.

[0199] In some embodiments, the support member 23 further includes a smooth layer 235, which is disposed on the side surface of the substrate layer 233 facing away from the adhesive layer 234, and the coefficient of friction of the smooth layer 235 is less than the coefficient of friction of the substrate layer 233.

[0200] For example, a smooth layer 235 may be formed by smoothing the surface of the substrate layer 233, or the smooth layer 235 and the substrate layer 233 may be two independently formed components and connected by means of bonding or the like.

[0201] Optionally, the material of the smooth layer 235 may be, but is not limited to, polytetrafluoroethylene, polyurethane coating, polyethylene, polypropylene, or silicone rubber or other polymeric materials with lubricating properties.

[0202] As an example, the peel strength can be tested in accordance with GB / T20877-2007 "Test Methods for Friction Properties of Rubber, Plastics and Metal Materials".

[0203] The smooth layer 235 can reduce the frictional resistance when the support 23 comes into contact with other components, and can reduce the wear caused by friction during the bending or flattening process of the first tab 212, thereby improving the product quality of the battery cell 7.

[0204] In some embodiments, the fourth dimension d4 of the support member 23 along the first direction X is 1mm-50mm.

[0205] For example, the fourth dimension d4 of the support member 23 along the first direction X can also be understood as the width of the support member 23. After the first pole piece 21 on which the support member 23 is provided is flattened, the fourth dimension d4 of the support member 23 along the first direction X is obtained by measurement.

[0206] As an example, the fourth dimension d4 can be, but is not limited to, 1mm, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, etc.

[0207] Limiting the fourth dimension d4 to greater than or equal to 1 mm increases the connection area between the support member 23 and the first electrode 21, reducing the risk of the support member 23 detaching. Limiting the fourth dimension d4 to less than or equal to 50 mm reduces the amount of support member 23 used, lowers the occupancy rate of the support member 23 on the internal space of the battery cell 7, and helps to improve the energy density of the battery cell 7.

[0208] In some embodiments, the fourth dimension d4 is 4mm-10mm. This can further improve the balance between the reliability of the support member 23 and the energy density of the battery cell 7.

[0209] As an example, the fourth dimension d4 can be, but is not limited to, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc.

[0210] In some embodiments, the dimension of the support member 23 along the thickness direction Y is less than or equal to the dimension of the first insulating layer 2113 along the thickness direction Y.

[0211] The thickness of the support member 23 can be reduced. On the one hand, during the bending or flattening process of the first tab 212, the risk of damage caused by excessive compression of the first tab 212 or the first insulating layer 2113 by the support member 23 can be reduced. On the other hand, it can save the internal space of the battery cell 7, improve the volume utilization efficiency of the battery cell 7, and thus improve the energy density of the battery.

[0212] In some embodiments, the dimension of the support member 23 along the thickness direction Y is greater than or equal to the dimension of the first current collector body along the thickness direction Y. This reduces the risk that the support member 23 is too thin, resulting in insufficient support for the first electrode tab 212.

[0213] In some embodiments, the fifth dimension d5 of the support member 23 along the thickness direction Y is 5μm-100μm.

[0214] For example, the fifth dimension d5 of the support member 23 along the thickness direction Y can also be understood as the thickness of the support member 23. After the first pole piece 21 on which the support member 23 is provided is flattened, the fifth dimension d5 of the support member 23 along the thickness direction Y is obtained by measurement.

[0215] The support member 23 can be disposed on one of the two sides of the first electrode 21 along the thickness direction Y, or it can be disposed on both sides of the first electrode 21 along the thickness direction Y.

[0216] In some examples, there is one support member 23, which is disposed on one of the two sides of the first electrode 21 along the thickness direction Y. In the embodiments of this application, the fifth dimension d5 of the support member 23 along the thickness direction Y refers to the thickness of this support member 23.

[0217] In some examples, there are two supports 23, which can be attached to the first electrode 21 from both sides along the thickness direction Y. In the embodiments of this application, the fifth dimension d5 of the support 23 along the thickness direction Y refers to the thickness of one of the two supports 23.

[0218] As an example, the fifth dimension d5 can be, but is not limited to, 5μm, 10μm, 20μm, 50μm, 80μm, 100μm, etc.

[0219] Limiting the fifth dimension d5 to greater than or equal to 5 μm increases the range of elastic deformation of the support member 23 and improves the support effect of the support member 23 on the first tab 212. Limiting the fifth dimension d5 to less than or equal to 100 μm can reduce the amount of support member 23 used, reduce the occupancy rate of the support member 23 on the internal space of the battery cell 7, and help improve the energy density of the battery cell 7.

[0220] In some embodiments, the fifth dimension d5 is 10μm-50μm. This can further improve the balance between the support effect of the support member 23 and the energy density of the battery cell 7.

[0221] As an example, the fifth dimension d5 can be, but is not limited to, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, etc.

[0222] In some embodiments, the support member 23 is insulated. This reduces the risk of short circuits caused by the support member 23 conducting between the positive and negative terminals, thereby improving the reliability of the battery cell 7.

[0223] In some embodiments, the support member 23 includes a first support portion 231 and a second support portion 232 connected together, and the first support portion 231 and the second support portion 232 are disposed along a first direction X. The first support portion 231 is connected to a first insulating layer 2113 and covers at least a portion of the first insulating layer 2113 along the thickness direction Y, and the second support portion 232 is connected to a first electrode tab 212 and covers at least a portion of the first electrode tab 212 along the thickness direction Y.

[0224] For example, the portion of the support member 23 covering the first insulating layer 2113 along the thickness direction Y serves as the first support portion 231, and the portion of the support member 23 covering the first tab 212 along the thickness direction Y serves as the second support portion 232.

[0225] In some examples, the first support portion 231 and the second support portion 232 can be formed independently. The first support portion 231 and the second support portion 232 are respectively connected to the first insulating layer 2113 and the first tab 212 to form the support member 23, which can simplify the assembly process.

[0226] In some examples, the first support portion 231 and the second support portion 232 may also be integrally formed.

[0227] In some embodiments, the first electrode 21 is wound along the winding direction V, and the winding axis K of the first electrode 21 is parallel to the first direction X. The first tab 212 is wound along the winding direction V and includes multiple turns of the first tab layer, and the support member 23 extends along the winding direction V.

[0228] The first electrode 21 is wound together along the winding direction V to form a wound structure. The wound structure can be a cylindrical structure, a flat structure, or other shapes.

[0229] The first tab 212 has an inner end and an outer end at its two ends along the winding direction V. In this embodiment, the first tab layer is divided based on the inner end of the first tab 212. The winding direction V is perpendicular to the winding axis K.

[0230] Specifically, the inner end of the first tab 212 is the beginning end of the first loop of the first tab layer, and the tail end of the first loop of the first tab layer is aligned radially with the beginning end of the first loop of the first tab layer. The first loop of the first tab layer wraps around the winding axis K once. Correspondingly, the tail end of the first loop of the first tab layer is the beginning end of the second loop of the first tab layer, and so on, with multiple loops of the first tab layer connected end-to-end along the winding direction V. When dividing the first tab layer, the beginning end of each loop of the first tab layer is aligned radially with the inner end of the first tab 212. The radial direction of the first tab 212 is perpendicular to and passes through the winding axis K.

[0231] For example, the inner and outer ends of the first tab 212 are aligned radially on the first tab 212, such that each tab layer wraps around the winding axis K once.

[0232] Of course, alternatively, the tail of the first tab 212 may have a portion that wraps around the winding axis K less than one turn, for example, the portion may wrap around 1 / 3 turn, 1 / 2 turn, 2 / 3 turn or 3 / 4 turn of the winding axis K.

[0233] After winding, the first tab 212 is generally cylindrical, with gaps between adjacent first tab layers, and the support 23 is placed in the gaps.

[0234] The support member 23 extends along the winding direction V, that is, after the first electrode 21 is flattened, the support member 23 extends along the length direction of the first electrode 21.

[0235] The above technical solution can further increase the connection area between the support member 23 and the first pole piece 21, reduce the risk of the support member 23 falling off, and improve reliability.

[0236] In some embodiments, the multiple turns of the first tab layer are gathered together in a direction close to the winding axis K.

[0237] For example, the first tab 212 can be processed to reduce the gaps between the layers of the first tab 212, facilitating the connection between the first tab 212 and the current collector. For instance, in embodiments of this application, the first tab 212 can be flattened to gather and aggregate the multiple layers of the first tab together. The flattening process involves shaping the first tab 212 using a flattening device to compact it and form a dense structure, thereby reducing the gaps between the multiple layers of the first tab 212.

[0238] In the process of flattening the first tab 212, the support member 23 can undergo elastic deformation after being subjected to force, thereby applying elastic force to the first tab 212 to support it, reducing the possibility of wrinkles in the first tab 212, thereby reducing the risk caused by wrinkles and improving the reliability of the battery cell 7.

[0239] In some embodiments, the electrode assembly 20 further includes a second electrode 22, wherein the first electrode 21 and the second electrode 22 have opposite polarities. The second electrode 22 includes a second electrode 22 body and a second tab, the second electrode 22 being connected to one end of the second electrode 22 body along a first direction X, and the second electrode 22 and the first electrode 21 being disposed opposite to each other along the first direction X.

[0240] For example, the electrode assembly 20 includes an electrode body and tabs. The electrode body includes a first electrode body 211 and a second electrode body 22, and the tabs include a first tab 212 and a second tab. The first tab 212 and the second tab are arranged opposite to each other along the first direction X, meaning that the first tab 212 and the second tab are respectively led out from opposite ends of the electrode body along the first direction X.

[0241] In some embodiments, the first electrode 21 is a positive electrode and the second electrode 22 is a negative electrode. The main body of the second electrode 22 includes a second current collector and a second active material layer. The second current collector includes two second surfaces disposed opposite to each other along the thickness direction Y. The second active material layer is disposed on the second surface. In the first direction X, both ends of the second active material layer extend beyond the first electrode body 211.

[0242] For example, the second active material layer may be provided on one second surface, or the second active material layer may be provided on both second surfaces.

[0243] The second active material layer can provide more insertion sites for active ions extracted from the first active material layer 2112, thereby reducing the risk of active ion precipitation, improving the cycle performance of the battery cell 7, and increasing reliability.

[0244] In some embodiments, the electrode assembly 20 further includes a spacer 24 disposed between the first electrode 21 and the second electrode 22 and used to separate the first electrode body 211 from the second electrode 22.

[0245] In some embodiments, the separator 24 is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0246] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator 24 can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0247] In some embodiments, the separator 24 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.

[0248] During the bending or flattening process of the first tab 212, the support member 23 can undergo elastic deformation after being subjected to force, thereby applying elastic force to the first tab 212 to support it, reducing the possibility of wrinkles forming on the first tab 212, thereby reducing the risk of wrinkles puncturing the separator 24 and conducting positive and negative electrodes, and improving the reliability of the battery cell 7.

[0249] In some embodiments, the battery cell 7 is a cylindrical battery cell.

[0250] In the manufacturing process of cylindrical battery cells, it is generally necessary to flatten the tabs. The support member 23 in this embodiment can greatly improve the reliability of cylindrical battery cells.

[0251] According to some embodiments of this application, this application also provides a battery device including a battery cell 7 of any of the above schemes.

[0252] According to some embodiments of this application, this application also provides an electrical device, including a battery cell 7 or a battery device of any of the above schemes, wherein the battery cell 7 or the battery device is used to store or provide electrical energy.

[0253] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. All technical features and optional technical features of this application can be combined to form new technical solutions.

[0254] To better understand the battery cell 7 provided in the embodiments of this application, based on the same inventive concept, embodiments of the battery cell 7 in practical applications are provided here for illustration.

[0255] This application provides a battery cell 7, which is a cylindrical battery cell. The battery cell 7 includes a housing 10, an electrode assembly 20, and a support member 23. The electrode assembly 20 is housed within the housing 10 and includes a first electrode 21. The first electrode 21 includes a first electrode body 211 and a first electrode tab 212. The first electrode 21 is wound along a winding direction V, and the winding axis K of the first electrode 21 is parallel to a first direction X. The first electrode tab 212 is wound along the winding direction V and includes multiple turns of the first electrode tab 212 layer. The multiple turns of the first electrode tab 212 layer converge in a direction close to the winding axis K. The support member 23 extends along the winding direction V.

[0256] The first electrode body 211 includes a first current collector 2111, a first active material layer 2112, and a first insulating layer 2113. The first electrode tab 212 is connected to the end of the first current collector 2111 along the first direction X. The first current collector 2111 includes two first surfaces 2111a disposed opposite to each other along its own thickness direction Y. The first active material layer 2112 and the first insulating layer 2113 are both disposed on the first surface 2111a, and the first insulating layer 2113 is located on the side of the first active material layer 2112 along the first direction X close to the first electrode tab 212. The first direction X is perpendicular to the thickness direction Y.

[0257] The support member 23 is elastic and insulated, and is connected to the side of the first tab 212 close to the first insulating layer 2113 along the first direction X and the first insulating layer 2113, and covers at least a portion of the first tab 212 and at least a portion of the first insulating layer 2113 along the thickness direction Y.

[0258] The support member 23 includes a substrate layer 233 and an adhesive layer 234. The adhesive layer 234 is disposed only on one side surface of the substrate layer 233 along the thickness direction Y. The substrate layer 233 is connected to the first electrode 21 through the adhesive layer 234.

[0259] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0260] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The application relates to a battery, comprising: a shell; an electrode assembly accommodated in the shell, the electrode assembly comprising a first tab, the first tab comprising a first tab body and a first lug, the first tab body comprising a first current collector body, a first active material layer and a first insulating layer, the first lug being connected to an end of the first current collector body in a first direction, the first current collector body comprising two first surfaces arranged opposite to each other in a thickness direction of the first current collector body, the first active material layer and the first insulating layer being arranged on the first surfaces, and the first insulating layer being arranged on a side of the first active material layer close to the first lug in the first direction, the first direction being perpendicular to the thickness direction; a support member having elasticity, the support member being connected to a side of the first lug close to the first insulating layer in the first direction and covering at least part of the first lug in the thickness direction.

2. The battery cell of claim 1, wherein, The support member is also connected to the first insulating layer and covers at least part of the first insulating layer in the thickness direction.

3. The battery cell of claim 2, wherein, A first size d1 of an area of the first lug covered by the support member in the first direction and a second size d2 of an area of the first insulating layer covered by the support member in the first direction satisfy the relationship d1 >= d2 / 2.

4. The battery cell of claim 3, wherein, The first size d1 and the second size d2 satisfy the relationship d1 >= d2.

5. The battery cell of claim 2, wherein, The second size d2 of the area of the first insulating layer covered by the support member in the first direction and a third size d3 of the first insulating layer in the first direction satisfy the relationship d2 >= d3 / 4.

6. The battery cell of claim 5, wherein, The second size d2 and the third size d3 satisfy the relationship d2 >= d3 / 2.

7. The battery cell of claim 1, wherein, The support member comprises a substrate layer and a glue layer, the substrate layer being connected to the first tab through the glue layer.

8. The battery cell of claim 7, wherein, The glue layer is arranged only on one side surface of the substrate layer in the thickness direction.

9. The battery cell of claim 8, wherein, The support member further comprises a smooth layer, the smooth layer being arranged on a side surface of the substrate layer away from the glue layer, the smooth layer having a friction coefficient smaller than that of the substrate layer.

10. The battery cell of claim 1, wherein, A fourth size d4 of the support member in the first direction is 1 mm-50 mm.

11. The battery cell of claim 10, wherein, The fourth size d4 is 4 mm-10 mm.

12. The battery cell of claim 1, wherein, A size of the support member in the thickness direction is smaller than or equal to a size of the first insulating layer in the thickness direction.

13. The battery cell of claim 12, wherein, The size of the support member in the thickness direction is greater than or equal to a size of the first current collector body in the thickness direction.

14. The battery cell of claim 1, wherein, A fifth size d5 of the support member in the thickness direction is 5 mu m-100 mu m.

15. The battery cell of claim 14, wherein, The fifth size d5 is 10 mu m-50 mu m.

16. The battery cell of claim 1, wherein, The support member is insulated.

17. The battery cell of claim 1, wherein, The support member comprises a first support part and a second support part connected to each other, and the first support part and the second support part are arranged in the first direction. The first support part is connected to the first insulating layer and covers at least part of the first insulating layer in the thickness direction, and the second support part is connected to the first lug and covers at least part of the first lug in the thickness direction.

18. The battery cell of claim 1, wherein, The first tab is arranged in a winding direction, and a winding axis of the first tab is parallel to the first direction. The first tab is wound along the winding direction and comprises a plurality of layers of first tabs, and the support is disposed extending along the winding direction.

19. The battery cell of claim 18, wherein, The plurality of layers of first tabs are gathered in a direction close to the winding axis.

20. The battery cell of claim 1, wherein, The electrode assembly further comprises a second tab, the first tab and the second tab being opposite in polarity; The second tab comprises a second tab body and a second tab, the second tab being connected to one end of the second tab body in the first direction, and the second tab and the first tab being disposed opposite in the first direction.

21. The battery cell of any one of claims 1-20, wherein, The battery cell is a cylindrical battery cell.

22. A battery device, characterized by A plurality of battery cells as claimed in any of claims 1 to 21.

23. An electrical device, comprising: A battery cell as claimed in any of claims 1 to 21 or a battery device as claimed in claim 22, for storing or providing electrical energy.

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