Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The single battery comprises a shell and an electrode assembly, the electrode assembly is contained in the shell and comprises a first pole piece, a second pole piece and an insulating part, and the polarity of the first pole piece is opposite to that of the second pole piece. The first pole piece comprises a first pole piece main body, the first pole piece main body comprises a first current collecting main body and a first active material layer, the first current collecting main body comprises two first surfaces which are oppositely arranged along the thickness direction of the first current collecting main body and a first end surface which is connected with the two first surfaces, and the first end surface is positioned at the end part of the first current collecting main body along the first direction; the first active material layer is arranged on the first surface, and the first direction is perpendicular to the thickness direction. The insulating part is connected to the first pole piece and used for separating the first end face from the second pole piece, and the light transmittance of the insulating part is 20%-95%. According to the invention, the product quality of the battery monomer 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 product quality 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, which can effectively improve the product quality of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a casing and an electrode assembly housed within the casing. The electrode assembly includes a first electrode, a second electrode, and an insulating member, with the first and second electrodes having opposite polarities. The first electrode includes a first electrode body, which comprises a first current collector and a first active material layer. The first current collector includes two first surfaces disposed opposite each other along its thickness direction and a first end face connecting the two first surfaces. The first end face is located at the end of the first current collector along a first direction. The first active material layer is disposed on the first surface, with the first direction perpendicular to the thickness direction. The insulating member is connected to the first electrode and serves to separate the first end face from the second electrode. The light transmittance of the insulating member is 20%-95%.

[0006] In this embodiment, the insulating component can separate the first end face from the second electrode, thereby reducing the risk of conductivity between the first end face and the second electrode, decreasing the risk of thermal runaway caused by short circuits, and improving the reliability of the battery cell. Furthermore, setting the light transmittance of the insulating component within the aforementioned range can improve the overall visibility of the first electrode during cutting or assembly, thereby improving the accuracy of visual inspection and recognition, and ultimately improving the product quality of the battery cell.

[0007] In some embodiments of the first aspect, the light transmittance of the insulating element is 65%-80%. This achieves a better balance between improving the visibility of the first electrode and the insulating element.

[0008] In some embodiments of the first aspect, the haze of the insulating element is 10%-70%.

[0009] In this embodiment of the application, setting the haze of the insulating component within the above-mentioned range can further improve the overall visibility of the first electrode during the cutting or assembly process, thereby further improving the accuracy of visual inspection and recognition, and thus further improving the product quality of the battery cell.

[0010] In some embodiments of the first aspect, the haze of the insulating element is 20%-30%. This achieves a balance between further improving the visibility of the first electrode and the insulating element.

[0011] In some embodiments of the first aspect, the second electrode includes a second electrode body, which is stacked with the first electrode body. In the first direction, the end of the insulating member away from the first end face does not extend beyond the second electrode body.

[0012] The above technical solution can reduce the space occupancy of the insulating component in the first direction, which helps to improve the structural compactness of the electrode assembly and increase the energy density of the battery cell.

[0013] In some embodiments of the first aspect, in the first direction, the end of the insulating member away from the first end face is flush with the end of the second electrode body.

[0014] It can improve the overall consistency of the electrode assembly, reduce the risk of damage to the second electrode due to the edge of the insulating component pressing against the second electrode body, and thus improve the reliability of the battery cell.

[0015] In some embodiments of the first aspect, the first electrode is a positive electrode and the second electrode is a negative electrode. The second electrode body 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. The second active material layer is disposed on the second surfaces. In the first direction, both ends of the second active material layer extend beyond the first electrode body.

[0016] The insulating component shields at least a portion of the first end face, making it less likely for the second active material layer to come into contact with burrs on the first end face even if the second active material layer overlaps with the first end face in the stacking direction. The second active material layer can provide more insertion sites for active ions that have 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.

[0017] In some embodiments of the first aspect, the insulating member includes two first insulating portions and a second insulating portion. The two first insulating portions are respectively located on both sides of the first electrode body along the thickness direction and connected to the first electrode body. The second insulating portion connects the two first insulating portions and is disposed on the outer side of the first end face along the first direction.

[0018] By providing two first insulating portions, the connection area between the insulating component and the main body of the first electrode plate can be increased, reducing the risk of the insulating component detaching. The second insulating portion can separate the burrs on the first end face from the second electrode plate, thereby reducing the risk of short circuit.

[0019] In some embodiments of the first aspect, the second insulating portion covers at least a portion of the first end face to cover burrs on the first end face, thereby further reducing the risk of short circuit.

[0020] In some embodiments of the first aspect, the first electrode further includes a first tab extending from a first end face and protruding from the second insulating portion along a first direction and away from the first current collector body.

[0021] The second insulating portion of the above-described technical solution can shield the burrs formed on the first end face during the molding process of the first electrode tab, thereby reducing the risk of short circuit. The first electrode tab protrudes from the second insulating portion to facilitate connection with other conductive structures and reduce the risk of interference between the second insulating portion and the conductive structures.

[0022] In some embodiments of the first aspect, a portion of the second insulating portion is connected to at least one side of the first electrode tab along the thickness direction.

[0023] The above technical solution enables the second insulating part to support the root of the first electrode near the first current collector body, reducing the risk of the first electrode being inserted upside down between the first and second electrodes when bent, thereby reducing the risk of short circuit and improving reliability.

[0024] In some embodiments of the first aspect, the first surface includes a coating area and an empty foil area disposed along a first direction. One end of the empty foil area is connected to the first end face, and the other end is connected to the coating area. The coating area is coated with a first active material layer, and the empty foil area is not coated with the first active material layer. At least a portion of the insulating member is connected to the empty foil area.

[0025] By setting up an empty foil area, the connection area between the first current collector and the insulating component can be increased, reducing the risk of the insulating component falling off and improving reliability.

[0026] In some embodiments of the first aspect, the insulating element completely covers the empty foil area to reduce the possibility of the empty foil area being connected to the second electrode, thereby reducing the risk of short circuit and improving reliability.

[0027] In some embodiments of the first aspect, the insulating element is also connected to the first active material layer, which can further increase the connection area between the first electrode and the insulating element, reduce the risk of the insulating element falling off, and improve reliability.

[0028] In some embodiments of the first aspect, the peel strength between the insulating element and the empty foil region is higher than the peel strength between the insulating element and the first active material layer.

[0029] In this embodiment, the peel strength between the insulating component and the empty foil area is high, thereby reducing the risk of the insulating component falling off and improving reliability.

[0030] In some embodiments of the first aspect, the area of ​​the insulating element covering the first active material layer has a first dimension d1 along the first direction of 0.05 mm to 4 mm.

[0031] Limiting the first dimension d1 to greater than or equal to 0.05 mm increases the connection area between the insulating component and the first active material layer, reducing the risk of the insulating component detaching. Limiting the first dimension d1 to less than or equal to 4 mm reduces the amount of insulating component used, reduces the obstruction of the first insulating part to active ions, and reduces the capacity loss of the battery cell.

[0032] In some embodiments of the first aspect, the first dimension d1 is 0.1mm-2mm. This can further improve the balance between reducing the risk of insulation detachment and the capacity loss of individual battery cells.

[0033] In some embodiments of the first aspect, the second dimension d2 of the empty foil region along the first direction is 0.5 μm-8 μm.

[0034] Limiting the second dimension d2 to greater than or equal to 1.5 μm increases the space available for the empty foil area and reduces the difficulty of setting the insulating components. Limiting the second dimension d2 to less than or equal to 3.5 μm can reduce the proportion of the empty foil area on the first surface, increase the amount of the first active material layer, and help reduce the capacity loss of the battery cell.

[0035] In some embodiments of the first aspect, the second dimension d2 is 1.5μm-3.5μm. This can further improve the balance between reducing the difficulty of setting up the insulation and reducing the capacity loss of the battery cells.

[0036] In some embodiments of the first aspect, the third dimension d3 of the insulating element along the thickness direction is 4μm-100μm.

[0037] Limiting the third dimension d3 to greater than or equal to 4 μm improves the reliability of the insulating component, thereby enhancing its insulation protection effect. Limiting the third dimension d3 to less than or equal to 100 μm reduces the space occupied by the insulating component within the battery cell, thus increasing the energy density of the battery cell.

[0038] In some embodiments of the first aspect, the third dimension d3 is 9μm-30μm. This can further improve the insulation protection effect of the insulating component and the energy density of the battery cell.

[0039] In some embodiments of the first aspect, the fourth dimension d4 of the insulating element along the first direction is 2μm-30μm.

[0040] Limiting the fourth dimension d4 to greater than or equal to 2 μm improves the insulation protection effect of the insulating component. Limiting the fourth dimension d4 to less than or equal to 100 μm reduces the space occupied by the insulating component inside the battery cell, thereby increasing the energy density of the battery cell.

[0041] In some embodiments of the first aspect, the fourth dimension d4 is 4.5 μm-12 μm. This can further improve the insulation protection effect of the insulating component and the energy density of the battery cell.

[0042] In some embodiments of the first aspect, the insulating element includes a substrate layer and an adhesive layer, the substrate layer being connected to the first electrode through the adhesive layer.

[0043] The substrate layer can improve the strength of the insulation and reduce its deformation during the bonding process. The adhesive layer can bond the substrate layer to the first electrode, reducing the risk of the substrate layer detaching from the first electrode.

[0044] In some embodiments of the first aspect, the substrate layer is polyethylene terephthalate, polypropylene, or polyethylene and their block copolymers. The adhesive layer is a polyolefin, polyester, polyacrylate, styrene-butadiene rubber, polyisobutylene, or butyl rubber. These materials are readily available and help reduce costs.

[0045] Secondly, this application provides a battery device that includes a battery cell provided in any of the embodiments of the first aspect.

[0046] 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.

[0047] 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

[0048] 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:

[0049] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application;

[0050] Figure 2This is an exploded structural diagram of a battery device provided in some embodiments of this application;

[0051] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application;

[0052] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in some embodiments of this application;

[0053] Figure 5 A top view schematic diagram of an electrode assembly provided in some embodiments of this application;

[0054] Figure 6 for Figure 5 A partial sectional view along the AA direction;

[0055] Figure 7 A schematic diagram showing the first electrode of an electrode assembly connected to an insulating component, as provided in some embodiments of this application;

[0056] Figure 8 for Figure 7 A cross-sectional view along the BB direction;

[0057] Figure 9 for Figure 7 A sectional view taken along the CC direction;

[0058] Figure 10 A schematic diagram of the first electrode of an electrode assembly provided in some embodiments of this application in an unfolded state;

[0059] Figure 11 for Figure 10 The diagram shown is a schematic of the first electrode plate after it has been connected to the insulating component;

[0060] Figure 12 for Figure 11 A cross-sectional view along the DD direction;

[0061] Figure 13 This is a schematic diagram of the structure of the insulating component of the electrode assembly provided in some embodiments of this application.

[0062] The reference numerals in the detailed embodiments are as follows:

[0063] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing; 5b. Second housing; 6. Battery module; 7. Battery cell;

[0064] 10. Outer casing;

[0065] 20. Electrode assembly; 21. First electrode; 211. First electrode body; 2111. First current collector body; 2111a. First surface; 2111a1. Coated area; 2111a2. Empty foil area; 2111b. First end face; 2112. First active material layer; 212. First tab;

[0066] 22. Second electrode; 221. Second electrode body; 2211. Second current collector body; 2212. Second active material layer; 2212a. Second surface; 222. Second electrode tab;

[0067] 23. Insulating component; 231. First insulating part; 232. Second insulating part; 233. Substrate layer; 234. Adhesive layer;

[0068] 24. Isolation components;

[0069] X, first direction; Y, thickness direction. Detailed Implementation

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] In this application, "multiple" means two or more (including two).

[0077] 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.

[0078] 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.

[0079] In the development of battery technology, improving the product quality of individual battery cells is a continuous research direction.

[0080] In the fabrication of battery cells, it is typically necessary to cut the electrodes (e.g., electrode slitting or tab die-cutting) to form the required size and shape, and to assemble the electrodes (e.g., winding or stacking) to form electrode assemblies. Furthermore, during the cutting or assembly process, a vision inspection system (e.g., an optical camera) is usually required to visually inspect and identify the size and structure of the electrodes to ensure the processing and assembly accuracy.

[0081] In related technologies, an insulating layer is typically applied to the die-cut edges of the electrode sheets for insulation protection, reducing the risk of short circuits caused by the overlap of the positive and negative electrode sheets. However, insufficient attention is currently paid to the visibility of the insulating layer, which affects the accuracy of visual inspection and identification during the cutting or assembly process of the electrode sheets. This leads to a decrease in the processing and assembly precision of the electrode sheets, which in turn can easily result in lower product quality of the battery cells.

[0082] For example, in the method of coating the electrode die-cutting edge with an insulating ceramic coating, the surface tension difference between the ceramic slurry and the active material slurry causes the two slurries to diffuse into each other, forming a fusion zone without a clear boundary, which affects the accuracy of visual inspection and recognition. As another example, in the method of coating the electrode die-cutting edge with transparent adhesive, the poor visibility of the transparent adhesive also affects the accuracy of visual inspection and recognition.

[0083] Based on the above considerations, this application designs a battery cell, which includes a casing and an electrode assembly housed within the casing. The electrode assembly includes a first electrode, a second electrode, and an insulating component. The first and second electrodes have opposite polarities. The first electrode includes a first electrode body, which comprises a first current collector and a first active material layer. The first current collector includes two first surfaces disposed opposite each other along its thickness direction and a first end face connecting the two first surfaces. The first end face is located at the end of the first current collector along a first direction. The first active material layer is disposed on the first surface, and the first direction is perpendicular to the thickness direction. The insulating component is connected to the first electrode and serves to separate the first end face from the second electrode. The light transmittance of the insulating component is 20%-95%.

[0084] In this embodiment, the insulating component can separate the first end face from the second electrode, thereby reducing the risk of conductivity between the first end face and the second electrode, decreasing the risk of thermal runaway caused by short circuits, and improving the reliability of the battery cell. Furthermore, setting the light transmittance of the insulating component within the aforementioned range can improve the overall visibility of the first electrode during cutting or assembly, thereby improving the accuracy of visual inspection and recognition, and ultimately improving the product quality of the battery cell.

[0085] 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.

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

[0087] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0088] like Figure 1 As 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.

[0089] 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.

[0090] 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.

[0091] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0092] In some embodiments, the battery device 2 may include one or more battery cell assemblies for providing voltage and capacity.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] In some embodiments, the housing 5 is used to house individual battery cells, and the housing 5 can have various structures.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] In some embodiments, the battery device 2 may be an energy storage device.

[0104] 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.

[0105] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0106] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application.

[0107] 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.

[0108] 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.

[0109] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0110] 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).

[0111] The outer shell can be a hollow structure, with an internal cavity for accommodating the electrode assembly and electrolyte.

[0112] 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.

[0113] 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;

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0119] 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.

[0120] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.).

[0125] 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 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 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.

[0126] In some embodiments, the negative electrode may include a negative current collector.

[0127] 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.).

[0128] 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.

[0129] 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.

[0130] 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.

[0131] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0132] 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.

[0133] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0134] 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.

[0135] 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.

[0136] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0137] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0138] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0139] In some implementations, the electrode assembly is a stacked structure.

[0140] 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.

[0141] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0142] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] The positive and negative leads are used to connect to the external circuit to enable charging or discharging of the battery cells.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] In some embodiments, the positive terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] In some embodiments, the negative terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0158] 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 top view schematic diagram of an electrode assembly provided in some embodiments of this application. Figure 6 for Figure 5A partial sectional view along the AA direction.

[0159] Continue to refer to Figures 4 to 6 This application provides a battery cell 7, which includes a housing 10 and an electrode assembly 20. The electrode assembly 20 is housed within the housing 10 and includes a first electrode 21, a second electrode 22, and an insulating member 23. The first electrode 21 and the second electrode 22 have opposite polarities. The first electrode 21 includes a first electrode body 211, which includes a first current collector 2111 and a first active material layer 2112. The first current collector 2111 includes two first surfaces 2111a disposed opposite each other along its own thickness direction Y and a first end face 211b connecting the two first surfaces 2111a. The first end face 211b is located at the end of the first current collector 2111 along the first direction X. The first active material layer 2112 is disposed on the first surface 2111a. The first direction X is perpendicular to the thickness direction Y. The insulating element 23 is connected to the first electrode 21 and is used to separate the first end face 211b from the second electrode 22. The light transmittance of the insulating element 23 is 20%-95%.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] For example, the first current collector 2111 has a small thickness, and the first end face 211b has a small dimension in the thickness direction Y, and the first end face 211b can be approximated as a line. Optionally, the thickness of the first current collector 2111 is 2μm-30μm. Optionally, the thickness of the first current collector 2111 is 5μm-15μm.

[0164] For example, at least a portion of the first end face 211b is formed in the cutting process of the first electrode 21.

[0165] For example, the first end face 211b is located at one end of the first current collector body 2111 along the first direction X. After the first electrode 21 is flattened, the first end face 211b may be located at one end of the first current collector body 2111 along the length direction of the first electrode 21, or it may be located at one end of the first current collector body 2111 along the width direction of the first electrode body 211.

[0166] In some embodiments, the first current collector 2111 has two first end faces 211b disposed opposite to each other along a first direction X. An insulating member 23 is disposed on at least one first end face 211b.

[0167] The insulating element 23 can be connected to the first electrode 21 in various ways. For example, the insulating element 23 can be connected to the first electrode 21 by adhesive bonding; alternatively, the insulating element 23 can also be connected to the first electrode 21 by attachment instead of adhesive bonding.

[0168] The insulating component 23 can be directly connected to the first electrode body 211, or directly connected to the first electrode tab 212, or simultaneously directly connected to both the first electrode body 211 and the first electrode tab 212.

[0169] As an example, when the insulating element 23 is directly connected to the first electrode body 211, the insulating element 23 can be directly connected to the first active material layer 2112, or directly connected to the first current collector body 2111, or simultaneously directly connected to both the first active material layer 2112 and the first current collector body 2111.

[0170] The insulating element 23 can be a one-piece molded structure. Alternatively, the insulating element 23 can be assembled from at least two separately molded parts.

[0171] There may be one or more insulating components 23.

[0172] Light transmittance measures the ability of light to pass through a material. It's easy to understand that the lower the light transmittance of the insulating element 23, the more difficult it is for light to penetrate it, making it difficult for the visual inspection system to clearly capture the parts of the electrode covered by the insulation, such as the die-cut edge of the tab, the junction of the first current collector 2111 and the first tab 212, or the junction of the first current collector 2111 and the first active material layer 2112. At the same time, the lower the light transmittance of the insulating element 23, the easier it is for the visual inspection system to clearly capture the details of the insulating element 23 itself, such as its shape, edges, or position.

[0173] The higher the light transmittance of the insulating component 23, the easier it is for light to penetrate the insulating component 23, making it easier for the visual inspection system to clearly capture the part of the electrode covered by the insulation; at the same time, the higher the light transmittance of the insulating component 23, the more difficult it is for the visual inspection system to clearly capture the details of the insulating component 23 itself.

[0174] Thus, in this embodiment, by setting the light transmittance of the insulating member 23 within the aforementioned range, the structure of the electrode itself (especially the portion of the electrode covered by insulation) can be easily and clearly detected, while the structure of the insulating member 23 itself can also be easily and clearly detected, thereby improving the overall visibility of the first electrode 21 during cutting or assembly. In other words, by setting the light transmittance of the insulating member 23 within the aforementioned range, the visibility of both the first electrode 21 and the insulating member 23 can be balanced.

[0175] As an example, the light transmittance of the insulating element 23 may be, but is not limited to, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, etc.

[0176] As an example, light transmittance can be tested according to GB / T2410-2009 "Determination of Light Transmittance of Plastics and Rubber".

[0177] In this embodiment, the insulating member 23 can separate the first end face 211b from the second electrode 22, thereby reducing the risk of the first end face 211b and the second electrode 22 becoming conductive, reducing the risk of thermal runaway caused by short circuits, and improving the reliability of the battery cell 7. Furthermore, setting the light transmittance of the insulating member 23 within the aforementioned range can improve the overall visibility of the first electrode 21 during cutting or assembly, thereby improving the accuracy of visual inspection and recognition, and ultimately improving the product quality of the battery cell 7.

[0178] In some embodiments, at least a portion of the insulating member 23 is disposed on the outer side of the first end face 211b along the first direction X, which is perpendicular to the thickness direction Y.

[0179] For example, "at least a portion of the insulating member 23 is disposed on the outer side of the first end face 211b along the first direction X" does not require that the insulating member 23 overlaps with the first end face 211b in the first direction X, as long as at least a portion of the insulating member 23 protrudes from the first end face 211b in the first direction XZ.

[0180] For example, at least a portion of the first end face 211b overlaps with the insulating member 23 in the thickness direction Y.

[0181] The first current collector 2111 may have one first end face 211b or multiple first end faces 211b. Optionally, the first current collector 2111 has multiple first end faces 211b, and an insulating member 23 is correspondingly provided on the outer side of each first end face 211b.

[0182] In some embodiments, the electrode assembly 20 further includes a separator 24 for separating the first electrode 21 from the second electrode 22.

[0183] It is easy to understand that during the preparation of electrodes (positive or negative electrodes), cutting (such as electrode slitting or tab die-cutting) is usually required to form the desired size and shape. However, after cutting, burrs are easily generated at the cutting location of the current collector. During the charging and discharging process of the battery cell 7, the burrs may puncture the separator 24 and conduct electricity between the positive and negative electrodes, causing a short circuit risk and affecting the reliability of the battery cell 7.

[0184] In this embodiment, the insulating member 23 can separate the burrs on the first end face 211b from the second electrode 22, thereby reducing the risk of the burrs and the second electrode 22 conducting together, reducing the possibility of thermal runaway caused by short circuit, and improving the reliability of the battery cell 7.

[0185] For example, the insulating member 23 can separate the burr from the insulating member 24, reducing the risk of the burr piercing the insulating member 24.

[0186] In some embodiments, the light transmittance of the insulating element 23 is 65%-80%. This achieves a balance between improving the visibility of the first electrode 21 and the insulating element 23.

[0187] As an example, the light transmittance of the insulating element 23 may be, but is not limited to, 65%, 68%, 70%, 73%, 75%, 78%, 80%, etc.

[0188] In some embodiments, the haze of the insulating element 23 is 10%-70%.

[0189] Haze measures the ability of a material to scatter light from its interior or surface. It's easy to understand that the lower the haze of the insulating element 23, the less light is scattered when it passes through, making it easier for the visual inspection system to clearly capture the portion of the electrode covered by the insulation. Conversely, the lower the haze of the insulating element 23, the more difficult it is for the visual inspection system to capture the insulating element 23 itself.

[0190] The higher the haze of the insulating component 23, the easier it is for light to be scattered when it passes through, making it more difficult for the visual inspection system to clearly capture the part of the electrode covered by the insulation; at the same time, the higher the haze of the insulating component 23, the easier it is for the visual inspection system to capture the insulating component 23 itself.

[0191] Thus, in this embodiment of the application, setting the haze of the insulating component 23 within the above-mentioned range can further improve the overall visibility of the first electrode 21 during the cutting or assembly process, thereby further improving the accuracy of visual inspection and recognition, and thus further improving the product quality of the battery cell 7.

[0192] As an example, the haze of the insulating element 23 may be, but is not limited to, 10%, 20%, 30%, 40%, 50%, 60%, 70%, etc.

[0193] As an example, haze can be tested according to GB / T9750-2009 "Method for Determination of Haze in Transparent Materials".

[0194] In some embodiments, the haze of the insulating element 23 is 20%-30%. This achieves a balance between further improving the visibility of the first electrode 21 and the insulating element 23.

[0195] As an example, the haze of the insulating element 23 may be, but is not limited to, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc.

[0196] In some embodiments, the second electrode 22 includes a second electrode body 221, which is stacked with the first electrode body 211. In the first direction X, the end of the insulating member 23 away from the first end face 211b does not extend beyond the second electrode body 221.

[0197] For example, the projection of the second electrode body 221 along the thickness direction Y covers the projection of the insulating member 23 along the thickness direction Y.

[0198] The above technical solution can reduce the space occupancy of the insulating component 23 in the first direction X, which helps to improve the structural compactness of the electrode assembly 20 and increase the energy density of the battery cell 7.

[0199] In some embodiments, in the first direction X, the end of the insulating member 23 away from the first end face 211b is flush with the end of the second electrode body 221.

[0200] This can improve the overall consistency of the electrode assembly 20, reduce the risk of damage to the second electrode 22 caused by the edge of the insulating component 23 pressing against the second electrode body 221, and thus improve the reliability of the battery cell 7.

[0201] In some embodiments, the first electrode 21 is a positive electrode and the second electrode 22 is a negative electrode. The second electrode body 221 includes a second current collector 2211 and a second active material layer 2212. The second current collector 2211 includes two second surfaces 2212a disposed opposite each other along the thickness direction Y. The second active material layer 2212 is disposed on the second surface 2212a. In the first direction X, both ends of the second active material layer 2212 extend beyond the first electrode body 211.

[0202] In the embodiments of this application, the second active material layer 2212 may be provided on one second surface 2212a, or the second active material layer 2212 may be provided on both second surfaces 2212a.

[0203] The insulating element 23 shields at least a portion of the first end face 211b, making it less likely to come into contact with burrs on the first end face 211b even if the second active material layer 2212 overlaps with the first end face 211b in the stacking direction. The second active material layer 2212 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.

[0204] In some embodiments, the second electrode 22 further includes a second electrode tab 222, which is connected to the second electrode body 221. The projection of the second electrode tab 222 along the thickness direction Y and the projection of the first electrode tab 212 along the thickness direction Y are spaced apart.

[0205] Figure 7 This is a schematic diagram showing the first electrode of the electrode assembly connected to the insulating member according to some embodiments of this application. Figure 8 for Figure 7 A cross-sectional view along the BB direction. Figure 9 for Figure 7 A sectional view taken along the CC direction.

[0206] Continue to refer to Figures 7 to 9 In some embodiments, the insulating member 23 includes two first insulating portions 231 and a second insulating portion 232. The two first insulating portions 231 are respectively located on both sides of the first electrode body 211 along the thickness direction Y and connected to the first electrode body 211. The second insulating portion 232 connects the two first insulating portions 231 and is disposed on the outer side of the first end face 211b along the first direction X.

[0207] For example, in the thickness direction Y, the projection of the first insulating portion 231 is located within the projection of the first electrode body 211, and the projection of the second insulating portion 232 does not overlap with the projection of the first electrode body 211.

[0208] The two first insulating parts 231 may have the same shape or different shapes.

[0209] The first insulating part 231 can be connected to the first active material layer 2112 or to the first current collector 2111.

[0210] By providing two first insulating portions 231, the connection area between the insulating member 23 and the first electrode body 211 can be increased, reducing the risk of the insulating member 23 falling off. The second insulating portion 232 can separate the burrs on the first end face 211b from the second electrode 22, thereby reducing the risk of short circuit.

[0211] In some embodiments, the second insulating portion 232 covers at least a portion of the first end face 211b to cover burrs on the first end face 211b, thereby further reducing the risk of short circuit.

[0212] In the first direction X, the second insulating portion 232 at least partially overlaps with the first end face 211b to cover at least a portion of the first end face 211b.

[0213] The second insulating portion 232 may completely cover the first end face 211b, or it may only cover a portion of the first end face 211b.

[0214] In some embodiments, the first electrode 21 further includes a first electrode tab 212, which extends from the first end face 211b and protrudes from the second insulating portion 232 along the first direction X and away from the first current collector 2111.

[0215] 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.

[0216] The first electrode 212 can be one or more.

[0217] 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 process of the first electrode 21, a portion of the first electrode 21 is removed by a die-cutting process to form the protruding first tab 212.

[0218] 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.

[0219] For example, the first collector body 2111 has two first end faces 211b, and all the first tabs 212 extend outward from the same first end face 211b. Alternatively, there may be multiple first tabs 212, with some of the first tabs 212 extending outward from one first end face 211b and others extending outward from another first end face 211b.

[0220] The second insulating portion 232 of the above-described technical solution can shield the burrs formed on the first end face 211b during the molding process of the first tab 212, thereby reducing the risk of short circuit. The first tab 212 protrudes from the second insulating portion 232 to facilitate connection with other conductive structures and reduce the risk of interference between the second insulating portion 232 and the conductive structures.

[0221] In some embodiments, the first end face 211b includes a tab lead-out area and a non-tab lead-out area, and the first tab 212 extends only from the tab lead-out area and protrudes from the second insulating portion 232 in a direction away from the first current collector body 2111 along the first direction X.

[0222] There can be one or more tab exit areas. For example, the number of tab exit areas corresponds to the number of first tabs 212. After the first tabs 212 are removed, the tab exit areas are exposed.

[0223] There can be one or more non-electrode venting regions.

[0224] In some examples, there are multiple tab lead-out areas and multiple non-tab lead-out areas, with multiple tab lead-out areas and multiple non-tab lead-out areas alternately set.

[0225] In some embodiments, the second insulation portion 232 covers at least a portion of the non-tab lead-out area. The second insulation can separate the burrs in the non-tab lead-out area from the second electrode 22, thereby reducing the risk of short circuit.

[0226] In some embodiments, the second insulating portion 232 completely covers the non-tab lead-out area. The second insulating portion 232 can completely cover the non-tab lead-out area, thereby covering the burrs in the non-tab lead-out area and reducing the risk of short circuit.

[0227] In some embodiments, the second insulating portion 232 has a channel through which the first tab 212 passes, and the second insulating portion 232 completely covers the non-tab lead-out area.

[0228] By setting up a channel, the first tab 212 can be avoided, reducing the risk of interference between the insulating component 23 and the first tab 212.

[0229] In some embodiments, a portion of the second insulating portion 232 is connected to at least one side of the first tab 212 along the thickness direction Y.

[0230] For example, a portion of the second insulating portion 232 may be connected to one side of the first tab 212 along the thickness direction Y, and a portion of the second insulating portion 232 may be connected to both sides of the first tab 212 along the thickness direction Y.

[0231] The above technical solution enables the second insulating part 232 to support the root of the first electrode 212 near the first current collector 2111, reducing the risk that the first electrode 212 will be inserted upside down between the first electrode 21 and the second electrode 22 when bent, thereby reducing the risk of short circuit and improving reliability.

[0232] For example, in the battery cell 7, in order to save the space occupied by the first tab 212, the first tab 212 can be bent; during the bending process, the root of the first tab 212 may deform and be inserted upside down between the first electrode 21 and the second electrode 22; a portion of the second insulating portion 232 is connected to at least one side of the first tab 212 along the thickness direction Y, so that the second insulating portion 232 can support the root of the first tab 212 near the first current collector 2111, reducing the risk that the first tab 212 will be inserted upside down between the first electrode 21 and the second electrode 22 when bent.

[0233] Figure 10 This is a schematic diagram of the first electrode plate of an electrode assembly provided in some embodiments of this application in its unfolded state. Figure 11 for Figure 10 The diagram shown is a schematic of the first electrode after it has been connected to the insulating component. Figure 12 for Figure 11 A cross-sectional view along the DD direction.

[0234] Continue to refer to Figures 10 to 12 In some embodiments, the first surface 2111a includes a coating area 2111a1 and an empty foil area 2111a2 disposed along a first direction X. One end of the empty foil area 2111a2 is connected to the first end face 211b, and the other end is connected to the coating area 2111a1. The coating area 2111a1 is coated with a first active material layer 2112, while the empty foil area 2111a2 is not coated with the first active material layer 2112. At least a portion of the insulating member 23 is connected to the empty foil area 2111a2.

[0235] By setting an empty foil area 2111a2, the connection area between the first current collector 2111 and the insulating component 23 can be increased, reducing the risk of the insulating component 23 falling off and improving reliability.

[0236] In some embodiments, the first end face 211b and the first active material layer 2112 are spaced apart along the first direction X, which can reduce the risk of cutting the first active material layer 2112 during the cutting process of the first electrode 21 and reduce the waste of active material.

[0237] In some embodiments, the first current collector 2111 includes two first end faces 211b, with one end of the empty foil region 2111a2 away from the coating region 2111a1 connected to one first end face 211b, and the other end of the coating region 2111a1 away from the empty foil region 2111a2 connected to the other first end face 211b. A first insulating portion 231 of one insulating member 23 is connected to the empty foil region 2111a2, and a first insulating portion 231 of another insulating member 23 is connected to the coating region 2111a1.

[0238] In some embodiments, the insulating element 23 completely covers the empty foil area 2111a2. This reduces the possibility of the empty foil area 2111a2 becoming conductive with the second electrode 22, thereby reducing the risk of short circuits and improving reliability.

[0239] In some embodiments, the insulating element 23 is also connected to the first active material layer 2112. This can further increase the connection area between the first electrode 21 and the insulating element 23, reduce the risk of the insulating element 23 falling off, and improve reliability.

[0240] In some embodiments, the peel strength between the insulating element 23 and the empty foil region 2111a2 is higher than the peel strength between the insulating element 23 and the first active material layer 2112.

[0241] As an example, the insulating element 23 can be fixed on a tensile testing machine and pulled 180°. During the pulling process, the insulating element 23 peels off from the first active material layer 2112, while the insulating element 23 remains connected to the empty foil area 2111a2.

[0242] As an example, peel strength can be tested according to GB / T2792-2014 Test Method for Peel Strength of Adhesive Tapes.

[0243] In this embodiment, the peel strength between the insulating element 23 and the empty foil area 2111a2 is high, thereby reducing the risk of the insulating element 23 falling off and improving reliability.

[0244] In some embodiments, the battery cell 7 includes an electrolyte contained within the housing 10. The insulating element 23 remains stable in the electrolyte.

[0245] For example, after immersion in the electrolyte for 1000 hours, the peel strength between the insulating element 23 and the first active material layer 2112 and the peel strength between the insulating element 23 and the empty foil area 2111a2 are both greater than or equal to 2 N / m. Optionally, after immersion in the electrolyte for 1000 hours, the peel strength between the insulating element 23 and the first active material layer 2112 and the peel strength between the insulating element 23 and the empty foil area 2111a2 are both 15 N / m to 200 N / m.

[0246] In some embodiments, the insulating element 23 has good insulation properties, the insulating element 23 will not break down under a voltage of 200V, and the resistance of the insulating element 23 is greater than or equal to 9999 megohms.

[0247] In some embodiments, the area of ​​the insulating member 23 covering the first active material layer 2112 has a first dimension d1 along the first direction X of 0.05mm-4mm.

[0248] As an example, the first dimension d1 can be, but is not limited to, 0.05mm, 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, etc.

[0249] The first dimension d1 is limited to 0.05 mm or greater to increase the connection area between the insulating member 23 and the first active material layer 2112, thereby reducing the risk of the insulating member 23 falling off. The first dimension d1 is limited to 4 mm or less to reduce the amount of insulating member 23 used, reduce the obstruction of the first insulating part 231 to active ions, and reduce the capacity loss of the battery cell 7.

[0250] In some embodiments, the first dimension d1 is 0.1mm-2mm. This can further improve the balance between reducing the risk of insulation component 23 detachment and the capacity loss of battery cell 7.

[0251] As an example, the first dimension d1 can be, but is not limited to, 0.1mm, 0.2mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.6mm, 1.8mm, 2mm, etc.

[0252] In some embodiments, the second dimension d2 of the empty foil region 2111a2 along the first direction X is 0.5μm-8μm.

[0253] As an example, the second size d2 can be, but is not limited to, 0.5μm, 1μm, 4μm, 5μm, 6μm, 7μm, 8μm, etc.

[0254] Limiting the second dimension d2 to greater than or equal to 1.5 μm increases the available space for the empty foil region 2111a2 and reduces the difficulty of setting the insulating member 23. Limiting the second dimension d2 to less than or equal to 3.5 μm can reduce the proportion of the empty foil region 2111a2 on the first surface 2111a, increase the amount of the first active material layer 2112, and help reduce the capacity loss of the battery cell 7.

[0255] In some embodiments, the second dimension d2 is 1.5μm-3.5μm. This can further improve the balance between reducing the difficulty of setting the insulating element 23 and reducing the capacity loss of the battery cell 7.

[0256] As an example, the second size d2 can be, but is not limited to, 1.5μm, 1.8μm, 2μm, 2.5μm, 1.8μm, 3μm, 3.5μm, etc.

[0257] In some embodiments, the insulating element 23 includes two independently formed insulating layers, which can be attached to the first electrode 21 from both sides along the thickness direction Y to form the insulating element 23. The embodiments of this application can simplify the assembly process.

[0258] In this embodiment, the third dimension d3 of the insulating member 23 along the thickness direction Y refers to the thickness of one of the two insulating layers.

[0259] In some embodiments, the third dimension d3 of the insulating element 23 along the thickness direction Y is 4μm-100μm.

[0260] As an example, the third size d3 can be, but is not limited to, 4μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.

[0261] Limiting the third dimension d3 to greater than or equal to 4 μm improves the reliability of the insulator 23, thereby enhancing its insulation protection effect. Limiting the third dimension d3 to less than or equal to 100 μm reduces the space occupied by the insulator 23 within the battery cell 7, thereby increasing the energy density of the battery cell 7.

[0262] In some embodiments, the third dimension d3 is 9μm-30μm. This can further improve the insulation protection effect of the insulator 23 and the energy density of the battery cell 7.

[0263] As an example, the third dimension d3 can be, but is not limited to, 9μm, 15μm, 20μm, 25μm, 30μm, etc.

[0264] In some embodiments, the fourth dimension d4 of the insulating member 23 along the first direction X is 2μm-30μm.

[0265] As an example, the fourth dimension d4 can be, but is not limited to, 2μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, etc.

[0266] Limiting the fourth dimension d4 to greater than or equal to 2 μm improves the insulation protection effect of the insulator 23. Limiting the fourth dimension d4 to less than or equal to 100 μm reduces the space occupied by the insulator 23 within the battery cell 7, thereby increasing the energy density of the battery cell 7.

[0267] In some embodiments, the fourth dimension d4 is 4.5μm-12μm. This can further improve the insulation protection effect of the insulator 23 and the energy density of the battery cell 7.

[0268] As an example, the fourth size d4 can be, but is not limited to, 4.5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, etc.

[0269] Figure 13 This is a schematic diagram of the structure of the insulating component of the electrode assembly provided in some embodiments of this application.

[0270] Continue to refer to Figure 13 In some embodiments, the insulating element 23 includes a substrate layer 233 and an adhesive layer 234, with the substrate layer 233 connected to the first electrode 21 via the adhesive layer 234.

[0271] The substrate layer 233 can improve the strength of the insulating component 23 and reduce the deformation of the insulating component 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.

[0272] In some embodiments, the substrate layer 233 is at least one of polyethylene terephthalate, polypropylene, or polyethylene and their block copolymers. The adhesive layer 234 is at least one of polyolefin, polyester, polyacrylate, styrene-butadiene rubber, polyisobutylene, or butyl rubber. These materials are readily available and help reduce costs.

[0273] In some embodiments, the insulating element 23 includes two insulating layers, each insulating layer including a substrate layer 233 and an adhesive layer 234. The adhesive layers 234 of the two insulating layers are bonded together. Optionally, the insulating layer is a pressure-sensitive adhesive tape.

[0274] In some embodiments, the elastic modulus of the substrate layer 233 is greater than that of the adhesive layer 234.

[0275] As an example, the elastic modulus of the insulating component 23 can be tested with reference to the national standard GB / T 22315-2008 "Test Method for Elastic Modulus and Poisson's Ratio of Metallic Materials".

[0276] 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.

[0277] 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.

[0278] 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.

[0279] 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.

[0280] This application provides a battery cell 7, which includes a housing 10 and an electrode assembly 20. The electrode assembly 20 is housed within the housing 10 and includes a first electrode 21, a second electrode 22, and an insulating member 23. The first electrode 21 and the second electrode 22 have opposite polarities. The first electrode 21 includes a first electrode body 211 and a first tab 212. The first electrode body 211 includes a first current collector 2111 and a first active material layer 2112. The first current collector 2111 includes two first surfaces 2111a disposed opposite each other along its own thickness direction Y and a first end face 211b connecting the two first surfaces 2111a. The first end face 211b is located at the end of the first current collector 2111 along the first direction X. The first active material layer 2112 is disposed on the first surface 2111a. The first direction X is perpendicular to the thickness direction Y.

[0281] An insulating member 23 is connected to the first electrode 21 and serves to separate the first end face 211b from the second electrode 22. The light transmittance of the insulating member 23 is 65%-80%, and the haze of the insulating member 23 is 20%-30%. The insulating member 23 includes a substrate layer 233 and an adhesive layer 234. The substrate layer 233 is connected to the first electrode 21 through the adhesive layer 234. The insulating member 23 includes two first insulating portions 231 and a second insulating portion 232. The two first insulating portions 231 are located on both sides of the first electrode body 211 along the thickness direction Y and are connected to the first electrode body 211. The second insulating portion 232 connects the two first insulating portions 231 and is disposed on the outer side of the first end face 211b along the first direction X. The second insulating portion 232 covers at least a portion of the first end face 211b.

[0282] The first tab 212 extends from the first end face 211b and protrudes from the second insulating portion 232 along the first direction X and away from the first current collector 2111. A portion of the second insulating portion 232 is connected to at least one side of the first tab 212 along the thickness direction Y.

[0283] The first surface 2111a includes a coating area 2111a1 and an empty foil area 2111a2 disposed along a first direction X. One end of the empty foil area 2111a2 is connected to the first end face 211b, and the other end is connected to the coating area 2111a1. The coating area 2111a1 is coated with a first active material layer 2112, while the empty foil area 2111a2 is not coated with the first active material layer 2112. An insulating member 23 is connected to the empty foil area 2111a2 and the first active material layer 2112. The peel strength between the insulating member 23 and the empty foil area 2111a2 is higher than the peel strength between the insulating member 23 and the first active material layer 2112.

[0284] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0285] 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 electrode tab, a second electrode tab and an insulating piece, the first electrode tab and the second electrode tab being opposite in polarity; the first electrode tab comprises a first electrode tab body, the first electrode tab body comprising a first current collecting body and a first active material layer, the first current collecting body comprising two first surfaces oppositely arranged along a thickness direction of the first current collecting body and a first end surface connecting the two first surfaces, the first end surface being located at an end of the first current collecting body along a first direction, the first direction being perpendicular to the thickness direction, and the first active material layer being arranged on the first surfaces; the insulating piece is connected to the first electrode tab and used for separating the first end surface from the second electrode tab, the light transmittance of the insulating piece being 20%-95%.

2. The battery cell of claim 1, wherein, The light transmittance of the insulating piece is 65%-80%.

3. The battery cell of claim 1, wherein, The haze of the insulating piece is 10%-70%.

4. The battery cell of claim 3, wherein, The haze of the insulating piece is 20%-30%.

5. The battery cell of claim 1, wherein, the second electrode tab comprises a second electrode tab body, the second electrode tab body being arranged in a stack with the first electrode tab body; in the first direction, an end of the insulating piece away from the first end surface does not exceed an end of the second electrode tab body.

6. The battery cell of claim 5, wherein, in the first direction, an end of the insulating piece away from the first end surface is flush with the end of the second electrode tab body.

7. The battery cell of claim 5, wherein, the first electrode tab is a positive electrode tab, and the second electrode tab is a negative electrode tab; the second electrode tab body comprises a second current collecting body and a second active material layer, the second current collecting body comprising two second surfaces oppositely arranged along the thickness direction, and the second active material layer being arranged on the second surfaces, both ends of the second active material layer exceeding the first electrode tab body in the first direction.

8. The battery cell of claim 1, wherein, the insulating piece comprises two first insulating parts and a second insulating part, the two first insulating parts being respectively located on both sides of the first electrode tab body along the thickness direction and connected to the first electrode tab body; the second insulating part connects the two first insulating parts and is arranged on the outside of the first end surface along the first direction.

9. The battery cell of claim 8, wherein, the second insulating part covers at least part of the first end surface.

10. The battery cell of claim 8, wherein, the first electrode tab further comprises a first tab, the first tab being led out from the first end surface and protruding from the second insulating part in the first direction and away from the first current collecting body.

11. The battery cell of claim 10, wherein, a part of the second insulating part is connected to at least one side of the first tab along the thickness direction.

12. The battery cell of claim 1, wherein, the first surface comprises a coated area and an uncoated area arranged along the first direction, one end of the uncoated area being connected to the first end surface, and the other end being connected to the coated area, the coated area being coated with the first active material layer, and the uncoated area being not coated with the first active material layer; at least part of the insulating piece is connected to the uncoated area.

13. The battery cell of claim 12, wherein, the insulating piece completely covers the uncoated area.

14. The battery cell of claim 12, wherein, the insulating piece is further connected to the first active material layer.

15. The battery cell of claim 14, wherein, the peeling strength between the insulating piece and the uncoated area is higher than the peeling strength between the insulating piece and the first active material layer.

16. The battery cell of claim 14, wherein, The first dimension d1 of the insulating member in the first direction is 0.05 mm to 4 mm.

17. The battery cell of claim 16, wherein, The first dimension d1 is 0.1 mm to 2 mm.

18. The battery cell of claim 12, wherein, The second dimension d2 of the empty-foil region in the first direction is 0.5 μm to 8 μm.

19. The battery cell of claim 18, wherein, The second dimension d2 is 1.5 μm to 3.5 μm.

20. The battery cell of claim 1, wherein, The third dimension d3 of the insulating member in the thickness direction is 4 μm to 100 μm.

21. The battery cell of claim 20, wherein, The third dimension d3 is 9 μm to 30 μm.

22. The battery cell of claim 1, wherein, The fourth dimension d4 of the insulating member in the first direction is 2 μm to 30 μm.

23. The battery cell of claim 22, wherein, The fourth dimension d4 is 4.5 μm to 12 μm.

24. The battery cell of any one of claims 1-23, wherein, The insulating member includes a base material layer and a glue layer, and the base material layer is connected to the first tab through the glue layer.

25. The battery cell of claim 24, wherein, The base material layer is polyethylene terephthalate, polypropylene, or polyethylene, and block copolymers thereof. The glue layer is polyolefin, polyester, polyacrylate, styrene butadiene rubber, polyisobutylene, or butyl rubber.

26. A battery device, characterized by A plurality of the battery cell according to any one of claims 1 to 25 is included.

27. An electrical device, comprising: The battery cell according to any one of claims 1 to 25 or the battery device according to claim 26 is used for storing or providing electric energy.

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