Battery monomer, battery device and electric device

Abstract

The embodiment of the utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a winding type electrode assembly, and the electrode assembly comprises a negative pole piece, a positive pole piece and an insulating layer. The first main body area of the negative pole piece is provided with a first edge, and the negative pole lug extends out of the first edge. A positive current collector of the positive pole piece is provided with a second edge on the same side as the first edge; the insulating layer is arranged on one side, facing the negative pole piece, of the positive pole piece, is close to the second edge and exceeds the first edge. Wherein in the winding direction of the electrode assembly, the electrode assembly comprises an initial area and an ending area which are sequentially arranged, in the direction from the initial area to the ending area, the maximum size of the insulating layer in the first direction is H1, the minimum size of the insulating layer in the first direction is H2, and the condition that H1-H2 is larger than 0 and smaller than or equal to 5 mm is met. According to the technical scheme, the reliability of the battery device can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery production, in particular to a battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] In the development of battery device technology, how to improve the reliability of the battery device is a technical problem that needs to be solved in battery device technology. Practical new type content

[0004] The present application provides a battery monomer, a battery device and a power utilization device, which can improve the reliability of the battery device.

[0005] The present application is realized by the following technical scheme:

[0006] In a first aspect, the present application provides a battery monomer, which comprises a wound electrode assembly, the electrode assembly comprising a negative electrode sheet, a positive electrode sheet and an insulating layer. The negative electrode sheet comprises a negative current collector and a negative active material layer, the negative current collector comprising a first main body region and a negative tab, the negative active material layer being arranged on the first main body region, the first main body region having a first edge in a first direction, the negative tab extending from the first edge, and the extension direction of the winding axis of the electrode assembly being parallel to the first direction. The positive electrode sheet comprises a positive current collector and a positive active material layer arranged on the surface of the positive current collector, the positive electrode sheet being arranged in a stack with the negative electrode sheet, the positive current collector having a second edge on the same side as the first edge in the first direction, and the second edge exceeding the first edge in the first direction. The insulating layer is arranged on the side of the positive electrode sheet facing the negative electrode sheet and is arranged close to the second edge, the orthographic projection of the first edge falls within the orthographic projection of the insulating layer on the projection plane perpendicular to the stacking direction of the positive electrode sheet and the negative electrode sheet, and the insulating layer exceeds the first edge in the direction from the first edge to the second edge. Wherein, in the winding direction of the electrode assembly, the electrode assembly comprises an initial region and a tail region arranged in sequence, the maximum size of the insulating layer in the first direction is H1 in the direction from the initial region to the tail region, the minimum size of the insulating layer in the first direction is H2, and 0 < H1-H2 ≤ 5mm is satisfied.

[0007] In the technical solution of this application embodiment, the first edge can be the edge of the negative electrode tab of the negative electrode sheet. On the projection plane perpendicular to the stacking direction of the positive electrode sheet and the negative electrode sheet, the orthogonal projection of the first edge falls into the orthogonal projection of the insulating layer. The burrs of the first edge can be blocked by the insulating layer after piercing the separator, which can reduce the risk of short circuit between the positive electrode sheet and the negative electrode sheet and improve the reliability of the battery cell. Meanwhile, in the direction from the initial region to the terminal region, the maximum and minimum dimensions of the insulating layer in the first direction satisfy the above conditions. The insulating layer in some regions is designed to have a larger dimension in the first direction, providing a larger blocking area relative to the first edge. This insulating layer in these regions can effectively block the first edge. Even during the charge-discharge cycle of the battery cell, or when the battery cell is subjected to vibration, the positive and negative electrode plates are prone to positional movement. On the projection plane perpendicular to the stacking direction of the positive and negative electrode plates, the orthogonal projection of the first edge can still fall into the orthogonal projection of the insulating layer. This reduces the risk of burrs at the first edge piercing the separator and causing a short circuit with the positive active material layer, improving the reliability of the battery cell. When H1-H2≤5mm, while ensuring the insulating layer provides good blocking effect on the first edge, the dimension of the insulating layer in the first direction can be designed to be smaller, allowing for more positive active material layers on the positive electrode plate, resulting in a higher energy density for the battery cell.

[0008] In some embodiments, 0.2mm ≤ H1 - H2 ≤ 0.5mm.

[0009] In the technical solution of this application embodiment, the size difference between the maximum and minimum dimensions of the insulating layer in the first direction satisfies the above conditions. When H1-H2≥0.2mm, the size of the insulating layer in a certain region in the first direction is further designed to be larger. This region of the insulating layer has a larger blocking area relative to the first edge in the first direction. The insulating layer in this region can play a good blocking effect on the first edge. Even during the charge and discharge cycle of the battery cell, or when the battery cell is vibrated, the positive and negative electrode plates are prone to positional movement. On the projection plane perpendicular to the stacking direction of the positive and negative electrode plates, the orthogonal projection of the first edge can still fall into the orthogonal projection of the insulating layer. This can reduce the risk of burrs on the first edge piercing the separator and short-circuiting the positive electrode active material layer, thereby improving the reliability of the battery cell. When H1-H2≤0.5mm, while satisfying the good blocking effect of the insulating layer on the first edge, the size of the insulating layer in the first direction is further designed to be smaller. More positive electrode active material layers can be set on the positive electrode plate, resulting in a higher energy density for the battery cell.

[0010] In some embodiments, the electrode assembly further includes an intermediate region that connects the initial region and the final region along the winding direction of the electrode assembly. The initial region has 1 to 3 turns, and the final region has 1 to 2 turns. In a first direction, the size of the insulating layer located in the initial region is larger than the size of the insulating layer located in the intermediate region.

[0011] The technical solution of this application embodiment sets the size of the insulating layer in the initial region to be larger than the size of the insulating layer in the middle region, that is, increases the size of the insulating layer in the initial region in the first direction, so that the size of the insulating layer in the initial region extends beyond the first edge by a large amount, which helps to reduce the risk of short circuit between the positive electrode and the negative electrode in the initial region, and further improves the reliability of the battery cell.

[0012] In some embodiments, in a first direction, the size of the insulating layer located in the initial region is equal to the size of the insulating layer located in the terminal region.

[0013] In the technical solution of this application embodiment, the size of the insulating layer in the initial region is equal to the size of the insulating layer in the terminal region. That is, the size of the insulating layer in the initial region and the terminal region in the first direction is increased, so that the size of the insulating layer in the initial region and the terminal region extending beyond the first edge is larger. This helps to reduce the risk of short circuit between the positive electrode and the negative electrode in the initial region and the terminal region, and further improves the reliability of the battery cell.

[0014] In some embodiments, in a first direction, the size of the insulating layer located in the initial region is larger than the size of the insulating layer located in the terminal region.

[0015] In the technical solution of this application embodiment, the size of the insulating layer in the initial region is larger than the size of the insulating layer in the terminal region. That is, the size of the insulating layer in the initial region in the first direction is increased, so that the size of the insulating layer in the initial region extending beyond the first edge is larger. This helps to reduce the risk of short circuit between the positive electrode and the negative electrode in the initial region and further improves the reliability of the battery cell.

[0016] In some embodiments, in a first direction, the size of the insulating layer located in the intermediate region is equal to the size of the insulating layer located in the terminal region.

[0017] In the technical solution of this application embodiment, the size of the insulating layer in the middle region is equal to the size of the insulating layer in the tail region. That is, the size of the insulating layer in the initial region in the first direction is increased, so that the size of the insulating layer in the initial region extending beyond the first edge is larger. This helps to reduce the risk of short circuit between the positive electrode and the negative electrode in the initial region and further improves the reliability of the battery cell.

[0018] In some embodiments, the electrode assembly further includes an intermediate region that connects the initial region and the final region along the winding direction of the electrode assembly. The initial region has 1 to 3 winding turns, and the final region has 1 to 2 winding turns. In a first direction, the size of the insulating layer in the initial region is equal to the size of the insulating layer in the intermediate region, and the size of the insulating layer in the initial region is larger than the size of the insulating layer in the final region.

[0019] In the technical solution of this application embodiment, in the first direction, the size of the insulating layer in the initial region is equal to the size of the insulating layer in the middle region, and the size of the insulating layer in the initial region is greater than the size of the insulating layer in the terminal region. That is, the size of the insulating layer in the initial region and the middle region in the first direction is increased, so that the size of the insulating layer in the initial region and the middle region extending beyond the first edge is larger. This helps to reduce the risk of short circuit between the positive electrode and the negative electrode in the initial region and the middle region, and further improves the reliability of the battery cell.

[0020] In some embodiments, the battery cell further includes a casing, a positive terminal, and a negative terminal. An electrode assembly is disposed within the casing, which includes a first wall whose thickness direction is parallel to a first direction. The positive terminal is disposed on the first wall. The negative terminal is disposed on the first wall. The positive current collector includes a second body region and a positive electrode tab. A positive active material layer is disposed in the second body region. The positive electrode tab extends from a second edge and is electrically connected to the positive terminal, and the negative electrode tab is electrically connected to the negative terminal. The first wall is configured to support the electrode assembly.

[0021] In the technical solution of this application embodiment, the first wall supports the electrode assembly, and the battery cell can be used in an inverted state to improve the applicability of the battery cell.

[0022] In some embodiments, the electrode assembly includes a main body, wherein a first main region, a negative electrode active material layer, a second main region, and a positive electrode active material layer constitute the main body. The battery cell also includes an insulating member and a supporting member. The insulating member is disposed on the side of the first wall facing the electrode assembly. The supporting member is disposed between the insulating member and the main body, and supports the main body.

[0023] In the technical solution of this application embodiment, the insulating member can separate the first wall and the electrode assembly, thereby reducing the risk of short circuit between the positive and negative electrodes. The support member supports the main body and can restrict the movement of the main body towards the first wall, reducing the impact of the movement of the main body on the connection stability of the positive and negative electrode tabs and their corresponding components, thus improving the reliability of the battery cell.

[0024] Secondly, this application also provides a battery device, including a battery cell as described in any of the above embodiments.

[0025] In some embodiments, the battery device includes a housing, and individual battery cells are disposed within the housing. Each individual battery cell includes a casing, a positive terminal, and a negative terminal. An electrode assembly is disposed within the casing. The casing includes a first wall, and both the positive and negative terminals are disposed on the first wall. The positive electrode tab of the electrode assembly is connected to the positive terminal, and the negative electrode tab of the electrode assembly is connected to the negative terminal. The first wall supports the electrode assembly.

[0026] In the technical solution of this application embodiment, the first wall supports the electrode assembly, and the battery cell can be used in an inverted state to improve the applicability of the battery cell.

[0027] Thirdly, this application also provides an electrical device, including a battery cell as described in any of the above embodiments or a battery device as described in any of the above embodiments, wherein the battery cell or battery device is used to provide electrical energy to the electrical device.

[0028] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0031] Figure 2 This is an exploded view of the structure of a battery device provided in some embodiments of this application;

[0032] Figure 3 This is an exploded view of the structure of a battery cell provided in some embodiments of this application;

[0033] Figure 4 This is a schematic diagram of the winding structure of an electrode assembly provided in some embodiments of this application;

[0034] Figure 5 A schematic diagram illustrating the stacked state of positive and negative electrode sheets provided in some embodiments of this application;

[0035] Figure 6 A cross-sectional view of a portion of the stacked structure of positive and negative electrode sheets provided in some embodiments of this application;

[0036] Figure 7A schematic diagram showing the unfolded state of the negative electrode sheet provided in some embodiments of this application;

[0037] Figure 8 A schematic diagram showing the unfolded state of the positive electrode sheet provided in some embodiments of this application;

[0038] Figure 9 for Figure 8 Enlarged view of point A in the image;

[0039] Figure 10 A schematic diagram showing the unfolded state of the positive electrode sheet provided in some other embodiments of this application;

[0040] Figure 11 A schematic diagram showing the unfolded state of the positive electrode sheet provided in some embodiments of this application;

[0041] Figure 12 Cross-sectional views of a battery cell provided in some embodiments of this application.

[0042] Icons: 1-Battery cell; 10-Electrode assembly; 11-Negative electrode; 111-Negative current collector; 1111-First main body region; 1112-Negative electrode tab; 1113-First edge; 112-Starting end of negative electrode winding; 113-Ending end of negative electrode winding; 114-Negative active material layer; 12-Positive electrode; 121-Positive current collector; 1211-Second edge; 1212-Second main body region; 1213-Positive electrode tab; 122-Positive active material layer; 123-Starting end of positive electrode winding; 124-Ending end of positive electrode winding; 13-Insulating layer; 14-Initial region; 15-Tailing region; 16-Intermediate region; 17-Main body; 18-Separating membrane; 20-Outer shell; 21-First wall; 22-Shell; 23-End cap; 30-Positive terminal; 40-Negative terminal; 50-Insulating component; 60-Supporting component; 100-Battery assembly; 110-Box; 120-First sub-box; 130-Second sub-box; 1000-Vehicle; 1100-Controller; 1200-Motor; X-First direction; Y-Winding direction of electrode assembly; Z-Direction from initial region to tailing region. Detailed Implementation

[0043] 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.

[0044] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0045] In this application, the reference to "embodiment" means that a specific 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0046] 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.

[0047] 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.

[0048] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0049] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0050] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0051] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0052] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0053] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0054] As an example, the enclosure may include a first sub-enclosure and a second sub-enclosure. The first and second sub-enclosures are interlocked to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or shutting down; it can be sealed or not sealed. The first sub-enclosure may be a top cover or a bottom plate.

[0055] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0056] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0057] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0058] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0059] The battery cell may be, but is not limited to, lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc.

[0060] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0061] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0062] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0063] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be made of stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium with a silver-plated surface. 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 alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0064] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.

[0065] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0066] As an example, the negative electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, or made of carbon, nickel, or titanium, etc.

[0067] In some embodiments, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0068] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in batteries. 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 for batteries may also be used.

[0069] These negative electrode active materials can be used alone or in combination of two or more.

[0070] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0071] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0072] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0073] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0074] In some implementations, the electrode assembly is a stacked structure.

[0075] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0076] In some embodiments, the housing includes an end cap and a casing, the casing having an opening, and the end cap closing the opening to form a sealed space for accommodating substances such as electrode assemblies and electrolytes. The casing may have one or more openings. The end cap may also be provided one or more times.

[0077] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab of the electrode assembly. The electrode terminal can be directly connected to the tab or indirectly connected to the tab via an adapter. The electrode terminal can be located on the end cap or on the housing.

[0078] In some implementations, an explosion-proof valve is provided on the housing. The explosion-proof valve is used to release the internal pressure of the battery cells.

[0079] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, it protects the electrode assembly and prevents leaks such as electrolyte leakage. When the housing is a non-sealed structure, it protects the electrode assembly, and a sealing bag may be included between the housing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film.

[0080] 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 batteries, such as hexagonal prismatic batteries.

[0081] Currently, judging from market trends, batteries are widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in power tools, drones, energy storage devices, and many other fields. As the applications of batteries continue to expand, the market demand is also constantly increasing.

[0082] The development of battery technology must take into account multiple design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate and other performance parameters. In addition, as environmental conditions and / or internal battery conditions change, battery reliability is also a key factor to consider.

[0083] Currently, electrode assemblies are mounted on the casing to form a battery cell. The electrode assembly includes stacked positive and negative electrode sheets. To reduce the risk of ion deposition from the negative electrode sheet, the projection of the negative active material layer overlaps the projection of the positive active material layer on a projection plane perpendicular to the stacking direction of the positive and negative electrode sheets. The negative electrode sheet includes a negative current collector with a first edge extending from the negative electrode tab. This first edge is the cut edge of the negative current collector that creates the negative electrode tab. The positive electrode sheet includes a positive current collector with a second edge extending from the positive electrode tab. Although an insulating layer is provided near the first edge of the positive electrode sheet, during battery cell charging and discharging, or when the battery cell is subjected to vibration, the positive and negative electrode sheets are prone to positional shifts. This can cause the first edge to overlap with the positive active material layer, potentially leading to burrs from the first edge piercing the separator and contacting the positive active material layer, resulting in a short circuit between the positive and negative electrodes. This affects the reliability of the battery cell and consequently, the reliability of the battery device.

[0084] Based on the above considerations, in order to reduce the risk of short circuits caused by contact between the positive and negative electrode sheets, and to address the problem of poor reliability of the battery cell and the battery, this application provides a battery cell. The battery cell includes a wound electrode assembly, which includes a negative electrode sheet, a positive electrode sheet, and an insulating layer. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative current collector includes a first body region and a negative electrode tab. The negative active material layer is disposed in the first body region. In a first direction, the first body region has a first edge, and the negative electrode tab extends from the first edge. The winding axis of the electrode assembly extends parallel to the first direction. The positive electrode sheet includes a positive current collector and a positive active material layer disposed on the surface of the positive current collector. The positive and negative electrode sheets are stacked. In the first direction, the positive current collector has a second edge on the same side as the first edge, and the second edge extends beyond the first edge along the first direction. An insulating layer is disposed on the side of the positive electrode facing the negative electrode and near the second edge. On a projection plane perpendicular to the stacking direction of the positive and negative electrodes, the orthographic projection of the first edge falls onto the orthographic projection of the insulating layer. In the direction from the first edge to the second edge, the insulating layer extends beyond the first edge. Along the winding direction of the electrode assembly, the electrode assembly includes an initial region and a final region arranged sequentially. In the direction from the initial region to the final region, the maximum dimension of the insulating layer in the first direction is H1, and the minimum dimension of the insulating layer in the first direction is H2, satisfying 0 < H1 - H2 ≤ 5 mm.

[0085] In the direction from the initial region to the terminal region, the maximum and minimum dimensions of the insulating layer in the first direction satisfy the above conditions. The insulating layer in some regions is designed to have a larger dimension in the first direction, providing a larger blocking area relative to the first edge. This portion of the insulating layer effectively blocks the first edge. Even during battery cell charge / discharge cycles or when the battery cell is subjected to vibration, the positive and negative electrode plates are prone to positional movement. On the projection plane perpendicular to the stacking direction of the positive and negative electrode plates, the orthogonal projection of the first edge still falls within the orthogonal projection of the insulating layer. This reduces the risk of burrs at the first edge piercing the separator and causing a short circuit with the positive active material layer, improving the reliability of the battery cell. When H1-H2≤5mm, while ensuring the insulating layer provides good blocking effect on the first edge, the dimension of the insulating layer in the first direction can be designed to be smaller. This allows for a larger positive active material layer on the positive electrode plate, resulting in a higher energy density for the battery cell.

[0086] The batteries disclosed in this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft, and can also be used to form the power system of such electrical equipment.

[0087] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric motorcycles, 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.

[0088] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0089] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000's electrical system, such as meeting the power requirements for starting, navigation, and operation of the vehicle 1000.

[0090] The vehicle 1000 may also include a controller 1100 and a motor 1200. The controller 1100 is used to control the battery device 100 to supply power to the motor 1200, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0091] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0092] Please refer to Figure 2 , Figure 2 This is an exploded view of the structure of a battery device provided in some embodiments of this application. The battery device 100 may further include a housing 110, within which a single battery cell 1 is housed. The housing 110 provides a space for housing the single battery cell 1, and the housing 110 may employ various structures. In some embodiments, the housing 110 may include a first sub-housing 120 and a second sub-housing 130, which overlap each other, and together define a space for housing the single battery cell 1. The second sub-box 130 can be a hollow structure with one end open, and the first sub-box 120 can be a plate-like structure. The first sub-box 120 covers the opening side of the second sub-box 130 so that the first sub-box 120 and the second sub-box 130 together define the accommodating space. Alternatively, the first sub-box 120 and the second sub-box 130 can both be hollow structures with one side open, and the opening side of the first sub-box 120 covers the opening side of the second sub-box 130.

[0093] In the battery device 100, there can be multiple battery cells 1, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 1 are connected in both series and parallel configurations. Multiple battery cells 1 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 1 is housed within the housing 110. Alternatively, the battery device 100 can also be composed of multiple battery cells 1 first connected in series, parallel, or in a mixed manner to form battery device 100 modules, which are then connected in series, parallel, or in a mixed manner to form a whole and housed within the housing 110. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 1.

[0094] Among them, the battery cell 1 can be a secondary battery or a primary battery; the battery cell 1 can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0095] Please refer to Figure 3 , Figure 3This is an exploded view of the structure of a battery cell provided in some embodiments of this application. The battery cell 1 includes a housing 20, an electrode assembly 10, and two electrode terminals, which may include a positive terminal 30 and a negative terminal 40. The housing 20 includes a casing 22 and an end cap 23. The casing 22 has an opening, and the end cap 23 closes the opening to isolate the internal environment of the battery cell 1 from the external environment.

[0096] The housing 22 is a component used to cooperate with the end cap 23 to form the internal environment of the battery cell 1, wherein the formed internal environment can accommodate the electrode assembly 10, electrolyte, and other components. The housing 22 and the end cap 23 can be independent components. The housing 22 can have various shapes and sizes. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 10. The housing 22 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0097] End cap 23 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 1 from the external environment. The shape of end cap 23 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 23 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 23 is less prone to deformation under pressure and impact, allowing battery cell 1 to have higher structural strength and improved reliability. Functional components such as electrode terminals can be provided on end cap 23. Electrode terminals can be used for electrical connection with electrode assembly 10 to output or input electrical energy to battery cell 1. The material of end cap 23 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating member 50 can also be provided on the inner side of end cap 23. The insulating member 50 can be used to isolate the electrical connection components inside housing 22 from end cap 23 to reduce the risk of short circuit. For example, the insulating element 50 may be made of plastic, rubber, etc.

[0098] Please refer to Figure 4 and refer to Figures 5 to 9 , Figure 4 This is a schematic diagram of the winding structure of an electrode assembly provided in some embodiments of this application. Figure 5 This is a schematic diagram illustrating the stacked state of the positive and negative electrode sheets provided in some embodiments of this application. Figure 6 This is a partial cross-sectional view of the stacked structure of the positive and negative electrode sheets provided in some embodiments of this application. Figure 7 This is a schematic diagram showing the unfolded state of the negative electrode sheet provided in some embodiments of this application. Figure 8 This is a schematic diagram showing the unfolded state of the positive electrode sheet provided in some embodiments of this application. Figure 9 for Figure 8A magnified view of point A in the image. Among them, Figure 7 and Figure 8 The boundary lines between the initial region, the intermediate region, and the final region are shown by dashed lines. This application provides a battery cell 1, which includes a wound electrode assembly 10. The electrode assembly 10 includes a negative electrode 11, a positive electrode 12, and an insulating layer 13. The negative electrode 11 includes a negative current collector 111 and a negative active material layer 114. The negative current collector 111 includes a first main body region 1111 and a negative electrode tab 1112. The negative active material layer 114 is disposed in the first main body region 1111. In a first direction X, the first main body region 1111 has a first edge 1113, and the negative electrode tab 1112 extends from the first edge 1113. The extension direction of the winding axis of the electrode assembly 10 is parallel to the first direction X. The positive electrode 12 includes a positive current collector 121 and a positive active material layer 122 disposed on the surface of the positive current collector 121. The positive electrode 12 and the negative electrode 11 are stacked. In the first direction X, the positive current collector 121 has a second edge 1211 on the same side as the first edge 1113. Along the first direction X, the second edge 1211 extends beyond the first edge 1113. An insulating layer 13 is disposed on the side of the positive electrode 12 facing the negative electrode 11 and is disposed close to the second edge 1211. On a projection plane perpendicular to the stacking direction of the positive electrode 12 and the negative electrode 11, the orthogonal projection of the first edge 1113 falls into the orthogonal projection of the insulating layer 13. In the direction from the first edge 1113 to the second edge 1211, the insulating layer 13 extends beyond the first edge 1113. Along the winding direction Y of the electrode assembly, the electrode assembly 10 includes an initial region 14 and a closing region 15 arranged sequentially. In the direction Z from the initial region to the closing region, the maximum dimension of the insulating layer 13 in the first direction X is H1, and the minimum dimension of the insulating layer 13 in the first direction X is H2, satisfying that 0 < H1 - H2 ≤ 5 mm.

[0099] In some embodiments, the negative electrode sheet 11 may include a negative electrode current collector 111 and a negative electrode active material layer 114, wherein the negative electrode active material layer 114 may be disposed on two surfaces of the negative electrode current collector 111 in its thickness direction.

[0100] In some embodiments, the positive electrode 12 may include a positive current collector 121 and a positive active material layer 122, wherein the positive active material layer 122 may be disposed on two surfaces of the positive current collector 121 in its thickness direction.

[0101] In some embodiments, the negative electrode current collector 111 may have a first edge 1113, which may be located on the side of the negative electrode current collector 111 that extends out of the negative electrode tab 1112, and the negative electrode active material layer 114 may extend to the first edge 1113.

[0102] In some embodiments, the positive current collector 121 may have a second edge 1211, which may be located on the side of the positive current collector 121 that extends out of the positive electrode tab 1213, and the positive active material layer 122 extends in a direction close to the second edge 1211.

[0103] The insulating layer 13 can be disposed between the edge of the positive electrode active material layer 122 near the second edge 1211 and the second edge 1211, and the insulating layer 13 can extend to the second edge 1211.

[0104] It should be noted that the first edge 1113 here is the edge of the negative current collector 111 excluding the negative electrode tab 1112, and the second edge 1211 is the edge of the positive current collector 121 excluding the positive electrode tab 1213.

[0105] In some embodiments, the first direction can be represented by the direction indicated by the letter X in the figure.

[0106] In some embodiments, the extension direction of the winding axis of the electrode assembly 10 is parallel to the first direction X.

[0107] In some embodiments, the direction from the initial region to the ending region can be represented by the direction indicated by the letter Z in the figure.

[0108] In some embodiments, in the first direction X, the second edge 1211 extends beyond the first edge 1113, the size of the negative electrode active material layer 114 is set to be larger than the size of the positive electrode active material layer 122, and the negative electrode active material layer 114 extends beyond the edge of the positive electrode active material layer 122 to form an overhang, thereby reducing the risk of metal ions being deposited on the surface of the negative electrode sheet 11, and an insulating layer 13 is provided on the positive electrode current collector 121 where the positive electrode active material layer 122 is not provided.

[0109] In some embodiments, the insulating layer 13 may be disposed on the side of the positive electrode 12 facing the negative electrode 11, wherein the insulating layer 13 may be disposed on the side of the positive current collector 121 facing the negative electrode 11.

[0110] In some embodiments, the insulating layer 13 is disposed near the second edge 1211, wherein the insulating layer 13 may be connected to the positive electrode active material layer 122 or may not be connected to the positive electrode active material layer 122.

[0111] In some embodiments, the stacking direction of the positive electrode 12 and the negative electrode 11 can be the direction indicated by the letter Y in the figure. The stacking direction of the positive electrode 12 and the negative electrode 11 can be parallel to the thickness direction of the positive electrode 12, and the stacking direction of the positive electrode 12 and the negative electrode 11 can be parallel to the thickness direction of the negative electrode 11.

[0112] It should be noted that in the wound electrode assembly 10, the electrode assembly 10 may include a flat region and a bent region. In the flat region, the stacking direction of the positive electrode 12 and the negative electrode 11 remains unchanged. In the bent region, the stacking direction of the positive electrode 12 and the negative electrode 11 in each bent region is different.

[0113] In some embodiments, the stacking direction of the positive electrode 12 and the negative electrode 11 is used as the projection direction. The positive electrode 12 and the negative electrode 11 are projected onto a projection plane perpendicular to the stacking direction of the positive electrode 12 and the negative electrode 11, thus obtaining the orthographic projection of the positive electrode 12 and the orthographic projection of the negative electrode 11. The orthographic projection of the negative electrode active material layer 114 covers the orthographic projection of the positive electrode active material layer 122, that is, the orthographic projection of the negative electrode active material layer 114 covers the orthographic projection of the edge of the positive electrode active material layer 122. A portion of the orthographic projection of the insulating layer 13 overlaps with the orthographic projection of the negative electrode active material layer 114, while another portion of the orthographic projection of the insulating layer 13 does not overlap with the orthographic projection of the negative electrode active material layer 114. The connection point of the two portions of the orthographic projection of the insulating layer 13 overlaps with the orthographic projection of the first edge 1113.

[0114] In some embodiments, the insulating layer 13 can be an electrical insulating structure that can be blocked by the insulating layer 13 after the burrs of the first edge 1113 pass through the isolation membrane 18.

[0115] Along the stacking direction of the positive electrode 12 and the negative electrode 11, the insulating layer 13 is located between the negative electrode 11 and the positive current collector 121. The insulating layer 13 can prevent the burrs of the first edge 1113 from contacting and short-circuiting with the positive current collector 121.

[0116] The insulating layer 13 can be entirely coated on the surface of the positive current collector 121, or a portion of the insulating layer 13 can be coated on the surface of the positive current collector 121, and another portion of the insulating layer 13 can be coated on the surface of the positive active material layer 122. When a portion of the insulating layer 13 is coated on the positive active material layer 122, the insulating layer 13 can also prevent the burrs of the first edge 1113 from contacting and short-circuiting with the positive active material layer 122.

[0117] In some embodiments, the insulating layer 13 may be made of an insulating material as an insulating slurry, which is applied to the surface of the positive current collector 121 and solidifies to form the insulating layer 13.

[0118] In some embodiments, the insulating layer 13 may be coated or adhered to the surface of the positive current collector 121 by a mixture of insulating material and adhesive.

[0119] In some embodiments, the insulating layer 13 may be made of burlite, alumina, ceramic, polyvinylidene fluoride, or aramid.

[0120] In some embodiments, the winding direction of the electrode assembly can be represented by the direction indicated by the letter Y in the figure.

[0121] In some embodiments, the initial region 14 and the ending region 15 are sequentially distributed along the winding direction Y of the electrode assembly. The initial region 14 can be the starting segment of the winding of the electrode assembly 10, and the ending region 15 can be the ending segment of the winding of the electrode assembly 10.

[0122] The initial region 14 can be one or more turns of the positive electrode 12 near the starting end 123 of the positive electrode winding, and one or more turns of the negative electrode 11 near the starting end 112 of the negative electrode winding.

[0123] The finishing area 15 can be one or more turns of the positive electrode 12 near the finishing end 124 of the positive electrode, and one or more turns of the negative electrode 11 near the finishing end 113 of the negative electrode.

[0124] In some embodiments, the insulating layer 13 has a maximum size H1 in the first direction X, and the insulating layer 13 with the maximum size can be located in the initial region 14 or the terminal region 15.

[0125] In some embodiments, in the first direction X, the insulating layer 13 has a minimum dimension H2, and the insulating layer 13 with the minimum dimension can be located in the intermediate region 16 or in the terminal region 15.

[0126] In some embodiments, the insulating layer 13 may include a body and a widening portion. The widening portion is disposed on one side of a portion of the body in the first direction X, along a direction Z from the initial region to the terminal region. The dimension of the body in the first direction X is such that the insulating layer 13 has a minimum dimension H2, and the region where the widening portion is disposed has a maximum dimension H1, where the maximum dimension is the sum of the dimension of the widening portion in the first direction X and the dimension of the body in the first direction X; that is, H1-H2 is the dimension of the widening portion.

[0127] Alternatively, the initial region 14 can be provided with a widened portion, the middle region 16 can be provided with a widened portion, and the ending region 15 can be provided with a widened portion, wherein the size of the widened portion in the first direction X is different for each region.

[0128] In some embodiments, the maximum dimension H1 and the minimum dimension H2 of the insulating layer 13 in the first direction X satisfy the condition: 0 < H1 - H2 ≤ 5 mm. That is, H1 - H2 can be any one of 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or any value between any two of them.

[0129] It should be noted that, in the direction Z from the initial region to the terminal region, the size of the insulating layer 13 in the first direction X is at least partially different, so the second edge 1211 is not flush in the first direction X.

[0130] In some embodiments, the method for measuring the size of the insulating layer 13 in the first direction X may be to remove the electrode assembly 10 from the battery cell 1, at which time the insulating layer 13 is squeezed and deformed, and the main body 17 is fixed by pressing or clamping, the deformed insulating layer 13 is flattened to restore its original shape as much as possible, and the size of the insulating layer 13 in the first direction X is measured.

[0131] In some embodiments, the method for measuring the size of the insulating layer 13 in the first direction X can also be battery CT inspection, battery X-RAY inspection, etc.

[0132] In the technical solution of this application embodiment, the first edge 1113 can be the edge of the negative electrode tab 1112 cut by the negative electrode sheet 11. On the projection plane perpendicular to the stacking direction of the positive electrode sheet 12 and the negative electrode sheet 11, the orthogonal projection of the first edge 1113 falls into the orthogonal projection of the insulating layer 13. The burrs of the first edge 1113 can be blocked by the insulating layer 13 after piercing the separator 18, which can reduce the risk of short circuit between the positive electrode sheet 12 and the negative electrode sheet 11 and improve the reliability of the battery cell 1. Meanwhile, in the direction Z from the initial region to the terminal region, the maximum size and minimum size of the insulating layer 13 in the first direction X satisfy the above conditions. The size of the insulating layer 13 in the first direction X is designed to be larger in some regions. The insulating layer 13 in these regions has a larger blocking area relative to the first edge 1113 in the first direction X. The insulating layer 13 in these regions can play a better blocking effect on the first edge 1113. Even if the positive electrode 12 and the negative electrode 11 are easily moved during the charge and discharge cycle of the battery cell 1 or when the battery cell 1 is vibrated, the orthogonal projection of the first edge 1113 can still fall into the orthogonal projection of the insulating layer 13 on the projection plane perpendicular to the stacking direction of the positive electrode 12 and the negative electrode 11. This can reduce the risk of the burrs of the first edge 1113 piercing the separator 18 and short-circuiting the positive active material layer 122, thereby improving the reliability of the battery cell 1. When H1-H2≤5mm, while ensuring that the insulating layer 13 provides a good blocking effect on the first edge 1113, the size of the insulating layer 13 in the first direction X can be designed to be smaller, and the positive electrode sheet 12 can be provided with more positive active material layers 122, so that the battery cell 1 has a higher energy density.

[0133] Please refer to Figure 9 In some embodiments, 0.2mm≤H1-H2≤0.5mm.

[0134] In some embodiments, the maximum dimension H1 and the minimum dimension H2 of the insulating layer 13 in the first direction X satisfy the condition: 0.2mm ≤ H1 - H2 ≤ 0.5mm. That is, H1-H2 can be any one of 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, or any value between any two.

[0135] In the technical solution of this application embodiment, the size difference between the maximum and minimum dimensions of the insulating layer 13 in the first direction X satisfies the above conditions. When H1-H2≥0.2mm, the size of the insulating layer 13 in a certain area in the first direction X is further designed to be larger. The insulating layer 13 in this certain area has a larger blocking area relative to the first edge 1113 in the first direction X. The insulating layer 13 in this certain area can play a better blocking effect on the first edge 1113. Even during the charge and discharge cycle of the battery cell 1, or when the battery cell 1 is vibrated, the positive electrode 12 and the negative electrode 11 are prone to positional movement. On the projection plane perpendicular to the stacking direction of the positive electrode 12 and the negative electrode 11, the orthogonal projection of the first edge 1113 can still fall into the orthogonal projection of the insulating layer 13. This can reduce the risk of the burrs of the first edge 1113 piercing the separator 18 and short-circuiting the positive active material layer 122, thereby improving the reliability of the battery cell 1. When H1-H2≤0.5mm, while ensuring that the insulating layer 13 provides a good blocking effect on the first edge 1113, the size of the insulating layer 13 in the first direction X is further designed to be smaller, so that the positive electrode sheet 12 can be provided with more positive electrode active material layers 122, so that the battery cell 1 has a higher energy density.

[0136] Please refer to Figure 8 In some embodiments, the electrode assembly 10 further includes an intermediate region 16. Along the winding direction Y of the electrode assembly, the intermediate region 16 connects the initial region 14 and the final region 15. The number of winding turns in the initial region 14 is in the range of 1 to 3 turns, and the number of winding turns in the final region 15 is in the range of 1 to 2 turns. In the first direction X, the size of the insulating layer 13 located in the initial region 14 is larger than the size of the insulating layer 13 located in the intermediate region 16.

[0137] In some embodiments, the number of turns of the initial region 14 can be 1 turn, 2 turns, or 3 turns.

[0138] In some embodiments, the number of turns in the finishing region 15 can be 1 turn or 2 turns.

[0139] In some embodiments, the intermediate region 16 can be one or more turns of the structure connecting the initial region 14 and the final region 15 of the positive electrode 12.

[0140] In some embodiments, the number of turns of the intermediate region 16 can be 1 turn, 2 turns, 3 turns, 4 turns, or 5 turns, etc.

[0141] In some embodiments, the insulating layer 13 of the initial region 14 may have the same size in the first direction X, the insulating layer 13 of the intermediate region 16 may have the same size in the first direction X, and the insulating layer 13 of the initial region 14 may have a larger size in the first direction X than the insulating layer 13 of the intermediate region 16.

[0142] In some embodiments, the dimensions of the insulating layer 13 in the initial region 14 in the first direction X may be partially unequal, the dimensions of the insulating layer 13 in the intermediate region 16 in the first direction X may be partially unequal, and the minimum dimension of the insulating layer 13 in the initial region 14 in the first direction X may be greater than the maximum dimension of the insulating layer 13 in the intermediate region 16 in the first direction X.

[0143] In some embodiments, the size of the insulating layer 13 in the initial region 14 in the first direction X can be the maximum size of the insulating layer 13 in the first direction X, and the size of the insulating layer 13 in the intermediate region 16 in the first direction X can be the minimum size of the insulating layer 13 in the first direction X.

[0144] When setting the insulating layer 13, an insulating layer 13 of the same size as the insulating layer 13 in the first direction X can be set in the direction Z from the initial region to the terminal region. Then, a widening portion is set on the insulating layer 13 in the initial region 14, so that the size of the insulating layer 13 in the initial region 14 in the first direction X is larger than the size of the insulating layer 13 in the middle region 16 in the first direction X.

[0145] The size of the widened portion can be the difference between the maximum size H1 of the insulating layer 13 in the first direction X and the minimum size H2 of the insulating layer 13 in the first direction X, that is, the size of the widened portion satisfies the above conditions.

[0146] In some embodiments, the size of the widened portion of the initial region 14 in the first direction X can be 0.5 mm.

[0147] The technical solution of this application embodiment sets the size of the insulating layer 13 located in the initial region 14 to be larger than the size of the insulating layer 13 located in the middle region 16, that is, increases the size of the insulating layer 13 located in the initial region 14 in the first direction X, so that the insulating layer 13 located in the initial region 14 extends beyond the first edge 1113 by a larger size, which helps to reduce the risk of short circuit between the positive electrode 12 and the negative electrode 11 located in the initial region 14, and further improves the reliability of the battery cell 1.

[0148] Please refer toFigure 10 , Figure 10 This is a schematic diagram showing the unfolded state of the positive electrode sheet provided in other embodiments of this application. Figure 10 The boundary lines between the initial region, the intermediate region, and the final region are shown by dashed lines. In some embodiments, in the first direction X, the size of the insulating layer 13 located in the initial region 14 is equal to the size of the insulating layer 13 located in the final region 15.

[0149] In some embodiments, the insulating layer 13 of the initial region 14 may have the same size in the first direction X, the insulating layer 13 of the terminal region 15 may have the same size in the first direction X, and the insulating layer 13 of the initial region 14 may have the same size in the first direction X as the insulating layer 13 of the terminal region 15 in the first direction X.

[0150] In some embodiments, the size of the insulating layer 13 of the initial region 14 in the first direction X may be larger than the size of the insulating layer 13 of the intermediate region 16 in the first direction X, and the size of the insulating layer 13 of the initial region 14 in the first direction X may be equal to the size of the insulating layer 13 of the terminal region 15 in the first direction X, that is, the size of the insulating layer 13 of the terminal region 15 in the first direction X may be larger than the size of the insulating layer 13 of the intermediate region 16 in the first direction X.

[0151] In some embodiments, when setting the insulating layer 13, an insulating layer 13 of the same size in the first direction X can be set in the direction Z from the initial region to the terminal region. Then, a widening portion is set on the insulating layer 13 of the initial region 14 and the terminal region 15, so that the size of the insulating layer 13 of the initial region 14 and the terminal region 15 in the first direction X is larger than the size of the insulating layer 13 of the intermediate region 16 in the first direction X.

[0152] The size of the widened portion can be the difference between the maximum size H1 of the insulating layer 13 in the first direction X and the minimum size H2 of the insulating layer 13 in the first direction X, that is, the size of the widened portion satisfies the above conditions.

[0153] In some embodiments, the widened portion of the initial region 14 and the closing region 15 may have a dimension of 0.5 mm in the first direction X.

[0154] It should be noted that during the winding process of the electrode assembly 10, the tension of the electrode assembly 10 is relatively small at the feeding and cutting positions, which easily leads to a greater risk of misalignment between the initial region 14 and the final region 15 of the electrode assembly 10. When the electrode assembly 10 is misaligned, the insulating layer 13 may not extend beyond the first edge 1113, which may easily lead to a short circuit between the positive electrode 12 and the negative electrode 11.

[0155] By increasing the size of the insulating layer 13 in the initial region 14 and the final region 15 in the first direction X, the risk of short circuit due to contact between the positive electrode 12 and the negative electrode 11 caused by misalignment during winding is reduced.

[0156] Furthermore, by not increasing the size of the insulating layer 13 in the first direction X of the intermediate region 16, the material of the insulating layer 13 can be saved.

[0157] In the technical solution of this application embodiment, the size of the insulating layer 13 located in the initial region 14 is equal to the size of the insulating layer 13 located in the terminal region 15. That is, the size of the insulating layer 13 located in the initial region 14 and the terminal region 15 in the first direction X is increased, so that the size of the insulating layer 13 located in the initial region 14 and the terminal region 15 extending beyond the first edge 1113 is larger. This helps to reduce the risk of short circuit between the positive electrode 12 and the negative electrode 11 located in the initial region 14 and the terminal region 15, and further improves the reliability of the battery cell 1.

[0158] Please refer to Figure 8 In some embodiments, in the first direction X, the size of the insulating layer 13 located in the initial region 14 is larger than the size of the insulating layer 13 located in the terminal region 15.

[0159] In some embodiments, the insulating layer 13 of the initial region 14 may have the same size in the first direction X, the insulating layer 13 of the terminal region 15 may have the same size in the first direction X, and the insulating layer 13 of the initial region 14 may have a larger size in the first direction X than the insulating layer 13 of the terminal region 15.

[0160] In some embodiments, the dimensions of the insulating layer 13 in the initial region 14 in the first direction X may be partially unequal, the dimensions of the insulating layer 13 in the terminal region 15 in the first direction X may be partially unequal, and the minimum dimension of the insulating layer 13 in the initial region 14 in the first direction X may be greater than the maximum dimension of the insulating layer 13 in the terminal region 15 in the first direction X.

[0161] In some embodiments, the size of the insulating layer 13 in the initial region 14 in the first direction X can be the maximum size of the insulating layer 13 in the first direction X, the size of the insulating layer 13 in the middle region 16 in the first direction X can be the minimum size of the insulating layer 13 in the first direction X, or the size of the insulating layer 13 in the terminal region 15 in the first direction X can be the minimum size of the insulating layer 13 in the first direction X.

[0162] When setting the insulating layer 13, an insulating layer 13 of the same size as the insulating layer 13 in the first direction X can be set in the direction Z from the initial region to the terminal region. Then, a widening portion is set on the insulating layer 13 in the initial region 14, so that the size of the insulating layer 13 in the initial region 14 in the first direction X is larger than the size of the insulating layer 13 in the middle region 16 in the first direction X.

[0163] The size of the widened portion of the initial region 14 can be the difference between the maximum size H1 of the insulating layer 13 in the first direction X and the minimum size H2 of the insulating layer 13 in the first direction X, that is, the size of the widened portion satisfies the above conditions.

[0164] In some embodiments, the size of the widened portion of the initial region 14 in the first direction X can be 0.5 mm.

[0165] Alternatively, when setting the insulating layer 13, an insulating layer 13 of the same size in the first direction X can be set in the direction Z from the initial region to the terminal region. Then, a first widening portion is set on the insulating layer 13 in the initial region 14, and a second widening portion is set on the insulating layer 13 in the terminal region 15, so that the size of the insulating layer 13 in the first direction X of the initial region 14 is larger than the size of the insulating layer 13 in the first direction X of the intermediate region 16, and the size of the insulating layer 13 in the first direction X of the terminal region 15 is larger than the size of the insulating layer 13 in the first direction X of the intermediate region 16.

[0166] In some embodiments, the first widening portion may have a dimension of 0.5 mm in the first direction X, and the second widening portion may have a dimension of 0.3 mm in the first direction X.

[0167] In the technical solution of this application embodiment, the size of the insulating layer 13 located in the initial region 14 is larger than the size of the insulating layer 13 located in the terminal region 15. That is, the size of the insulating layer 13 located in the initial region 14 in the first direction X is increased, so that the size of the insulating layer 13 located in the initial region 14 extending beyond the first edge 1113 is larger. This helps to reduce the risk of short circuit between the positive electrode 12 and the negative electrode 11 located in the initial region 14, and further improves the reliability of the battery cell 1.

[0168] Please refer to Figure 8 In some embodiments, in the first direction X, the size of the insulating layer 13 located in the intermediate region 16 is equal to the size of the insulating layer 13 located in the terminal region 15.

[0169] In some embodiments, the dimensions of the insulating layer 13 in the terminal region 15 in the first direction X can be equal, the dimensions of the insulating layer 13 in the middle region 16 in the first direction X can be equal, and the dimensions of the insulating layer 13 in the terminal region 15 in the first direction X can be equal to the dimensions of the insulating layer 13 in the middle region 16 in the first direction X.

[0170] In some embodiments, since the size of the insulating layer 13 in the initial region 14 in the first direction X is larger than the size of the insulating layer 13 in the intermediate region 16 in the first direction X, and the size of the insulating layer 13 in the intermediate region 16 in the first direction X is equal to the size of the insulating layer 13 in the terminal region 15, that is, the size of the insulating layer 13 in the initial region 14 in the first direction X is larger than the size of the insulating layer 13 in the terminal region 15 in the first direction X.

[0171] The size of the insulating layer 13 in the initial region 14 in the first direction X can be the maximum size of the insulating layer 13 in the first direction X, and the size of the insulating layer 13 in the middle region 16 and the terminal region 15 in the first direction X can be the minimum size of the insulating layer 13 in the first direction X.

[0172] In some embodiments, when setting the insulating layer 13, an insulating layer 13 of the same size in the first direction X can be set in the direction Z from the initial region to the terminal region. Then, a widening portion is set on the insulating layer 13 in the initial region 14, so that the size of the insulating layer 13 in the initial region 14 in the first direction X is larger than the size of the insulating layer 13 in the middle region 16 in the first direction X, and the size of the insulating layer 13 in the initial region 14 in the first direction X is larger than the size of the insulating layer 13 in the terminal region 15 in the first direction X.

[0173] In some embodiments, the dimension of the widened portion in the first direction X can be 0.5 mm.

[0174] Alternatively, when setting the insulating layer 13, an insulating layer 13 of the same size in the first direction X can be set in the direction Z from the initial region to the terminal region. Then, a first widening portion is set on the insulating layer 13 in the initial region 14, and a second widening portion is set on the insulating layer 13 in the intermediate region 16 and the terminal region 15. The size of the insulating layer 13 in the initial region 14 in the first direction X is larger than the size of the insulating layer 13 in the intermediate region 16 in the first direction X, and the size of the insulating layer 13 in the initial region 14 in the first direction X is larger than the size of the insulating layer 13 in the terminal region 15 in the first direction X.

[0175] In some embodiments, the first widening portion may have a dimension of 0.5 mm in the first direction X, and the second widening portion may have a dimension of 0.3 mm in the first direction X.

[0176] In the technical solution of this application embodiment, the size of the insulating layer 13 located in the middle region 16 is equal to the size of the insulating layer 13 located in the terminal region 15. That is, the size of the insulating layer 13 located in the initial region 14 in the first direction X is increased, so that the size of the insulating layer 13 located in the initial region 14 extending beyond the first edge 1113 is larger. This helps to reduce the risk of short circuit between the positive electrode 12 and the negative electrode 11 located in the initial region 14, and further improves the reliability of the battery cell 1.

[0177] Please refer to Figure 11 , Figure 11 This is a schematic diagram showing the unfolded state of the positive electrode sheet provided in some embodiments of this application. Figure 11 The boundary lines between the initial region, the intermediate region, and the final region are shown by dashed lines. In some embodiments, the electrode assembly 10 further includes an intermediate region 16, which connects the initial region 14 and the final region 15 along the winding direction Y of the electrode assembly. The number of winding turns in the initial region 14 is in the range of 1 to 3 turns, and the number of winding turns in the final region 15 is in the range of 1 to 2 turns. In the first direction X, the size of the insulating layer 13 located in the initial region 14 is equal to the size of the insulating layer 13 located in the intermediate region 16, and the size of the insulating layer 13 located in the initial region 14 is larger than the size of the insulating layer 13 located in the final region 15.

[0178] In some embodiments, the insulating layer 13 of the initial region 14 may have the same size in the first direction X, the insulating layer 13 of the intermediate region 16 may have the same size in the first direction X, and the insulating layer 13 of the initial region 14 may have the same size in the first direction X as the insulating layer 13 of the intermediate region 16 in the first direction X.

[0179] In some embodiments, the insulating layer 13 of the initial region 14 may have equal dimensions in the first direction X, the insulating layer 13 of the terminal region 15 may have equal dimensions in the first direction X, and the insulating layer 13 of the initial region 14 may have dimensions greater than or equal to the insulating layer 13 of the terminal region 15 in the first direction X.

[0180] In some embodiments, the dimensions of the insulating layer 13 in the initial region 14 in the first direction X may be partially unequal, the dimensions of the insulating layer 13 in the terminal region 15 in the first direction X may be partially unequal, and the minimum dimension of the insulating layer 13 in the initial region 14 in the first direction X may be greater than the maximum dimension of the insulating layer 13 in the terminal region 15 in the first direction X.

[0181] In some embodiments, when setting the insulating layer 13, an insulating layer 13 of the same size as in the first direction X can be set in the direction Z from the initial region to the terminal region. Then, a widening portion is set on the insulating layer 13 of the initial region 14 and the intermediate region 16, so that the size of the insulating layer 13 of the initial region 14 and the intermediate region 16 in the first direction X is greater than the size of the insulating layer 13 of the terminal region 15 in the first direction X.

[0182] In some embodiments, the dimension of the widened portion in the first direction X can be 0.5 mm.

[0183] Alternatively, when setting the insulating layer 13, an insulating layer 13 of the same size in the first direction X can be set in the direction Z from the initial region to the terminal region. Then, a first widening portion can be set on the insulating layer 13 in the initial region 14 and the intermediate region 16, and a second widening portion can be set on the insulating layer 13 in the terminal region 15. The size of the insulating layer 13 in the initial region 14 and the intermediate region 16 in the first direction X is larger than the size of the insulating layer 13 in the terminal region 15 in the first direction X.

[0184] In some embodiments, the first widening portion may have a dimension of 0.5 mm in the first direction X, and the second widening portion may have a dimension of 0.3 mm in the first direction X.

[0185] By not increasing the size of the insulating layer 13 in the first direction X of the terminal region 15, or by increasing the size of the insulating layer 13 in the first direction X of the terminal region 15 to a smaller value, material of the insulating layer 13 can be saved.

[0186] In the technical solution of this application embodiment, in the first direction X, the size of the insulating layer 13 located in the initial region 14 is equal to the size of the insulating layer 13 located in the intermediate region 16. The size of the insulating layer 13 located in the initial region 14 is larger than the size of the insulating layer 13 located in the terminal region 15. That is, the size of the insulating layer 13 located in the initial region 14 and the intermediate region 16 in the first direction X is increased, so that the size of the insulating layer 13 located in the initial region 14 and the intermediate region 16 extending beyond the first edge 1113 is larger. This helps to reduce the risk of short circuit between the positive electrode 12 and the negative electrode 11 located in the initial region 14 and the intermediate region 16, and further improves the reliability of the battery cell 1.

[0187] Please refer to Figure 3 and refer to Figure 12 , Figure 3This is a cross-sectional view of a battery cell provided in some embodiments of this application. In some embodiments, the battery cell 1 further includes a housing 20, a positive terminal 30, and a negative terminal 40. An electrode assembly 10 is disposed within the housing 20, which includes a first wall 21 whose thickness direction is parallel to a first direction X. The positive terminal 30 is disposed on the first wall 21. The negative terminal 40 is disposed on the first wall 21. The positive current collector 121 includes a second body region 1212 and a positive electrode tab 1213. A positive active material layer 122 is disposed in the second body region 1212. The positive electrode tab 1213 extends from a second edge 1211 and is electrically connected to the positive terminal 30. The negative electrode tab 1112 is electrically connected to the negative terminal 40. The first wall 21 is configured to support the electrode assembly 10.

[0188] In some embodiments, the first wall 21 may be an end cap 23.

[0189] In some embodiments, the thickness direction of the first wall 21 may be parallel to the first direction X.

[0190] In some embodiments, the first direction X may be parallel to the height direction of the battery cell 1.

[0191] In some embodiments, the positive terminal 30 and the negative terminal 40 are respectively disposed on the first wall 21. The first wall 21 is provided with a first electrode lead-out hole corresponding to the positive terminal 30 and a second electrode lead-out hole corresponding to the negative terminal 40. The positive terminal 30 is electrically connected to the positive electrode tab 1213 through the positive electrode lead-out hole, and the negative terminal 40 is electrically connected to the negative electrode tab 1112 through the negative electrode lead-out hole.

[0192] In some embodiments, during the use of the battery cell 1, the first wall 21 may be located at the bottom of the electrode assembly 10, the first wall 21 supports the electrode assembly 10 and bears at least part of the weight of the electrode assembly 10.

[0193] In some embodiments, when the first wall 21 supports the electrode assembly 10, the insulating layer 13 is in contact with the insulating member 50 first. At least part of the gravity of the electrode assembly 10 acts on the insulating layer 13, making the insulating layer 13 easy to be squeezed and deformed. Therefore, the size of part of the insulating layer 13 in the first direction X is increased, so that the size of part of the insulating layer 13 extending beyond the first edge 1113 is larger, reducing the probability of the insulating layer 13 contacting the negative electrode plate 11, that is, reducing the probability of the positive current collector 121 with the insulating layer 13 contacting the negative electrode plate 11. This helps to reduce the risk of short circuit between the positive electrode plate 12 and the negative electrode plate 11, and further improves the reliability of the battery cell 1.

[0194] In the technical solution of this application embodiment, the first wall 21 supports the electrode assembly 10, and the battery cell 1 can be used in an inverted state to improve the applicability of the battery cell 1.

[0195] Please refer to Figure 12 and Figure 2 In some embodiments, the electrode assembly 10 includes a main body 17, which is composed of a first main body region 1111, a negative electrode active material layer 114, a second main body region 1212, and a positive electrode active material layer 122. The battery cell 1 also includes an insulating member 50 and a support member 60. The insulating member 50 is disposed on the side of the first wall 21 facing the electrode assembly 10. The support member 60 is disposed between the insulating member 50 and the main body 17 and supports the main body 17.

[0196] In some embodiments, the portions of the positive electrode 12 and the negative electrode 11 having active material constitute the main body 17 of the electrode assembly 10, and the portions of the positive electrode 12 and the negative electrode 11 not having active material each constitute the positive electrode tab 1213 and the negative electrode tab 1112.

[0197] The positive electrode tab 1213 and the negative electrode tab 1112 can be located together at one end of the main body 17.

[0198] In some embodiments, the support member 60 is disposed within the housing 20 and between the insulating member 50 and the main body 17. The support member 60 is capable of bearing at least a portion of the weight of the main body 17 to support the main body 17.

[0199] The positive electrode tab 1213 is electrically connected to the positive terminal 30 after bypassing the support member 60, and the negative electrode tab 1112 is electrically connected to the negative terminal 40 after bypassing the support member 60.

[0200] In some embodiments, the positive electrode tab 1213 is fixed to the support member 60, and the negative electrode tab 1112 is fixed to the support member 60, so as to fix the positions of the positive electrode tab 1213 and the negative electrode tab 1112, thereby improving the connection reliability between the positive electrode tab 1213 and the positive terminal 30, and the connection reliability between the negative electrode tab 1112 and the negative terminal 40.

[0201] In the technical solution of this application embodiment, the insulating member 50 can separate the first wall 21 and the electrode assembly 10, so as to reduce the risk of short circuit between the positive and negative electrodes. The support member 60 supports the main body 17 and can restrict the movement of the main body 17 toward the first wall 21, thereby reducing the impact of the movement of the main body 17 on the connection stability of the positive electrode tab 1213 and the negative electrode tab 1112 with the corresponding components, and thus improving the reliability of the battery cell 1.

[0202] Please refer to Figure 12 This application also provides a battery device 100, including a battery cell 1 as described in any of the above embodiments.

[0203] Please refer to Figure 1In some embodiments, the battery device 100 includes a housing 110, and a battery cell 1 is disposed within the housing 110. The battery cell 1 includes a casing 20, a positive terminal 30, and a negative terminal 40. An electrode assembly 10 is disposed within the casing 20. The casing 20 includes a first wall 21. Both the positive terminal 30 and the negative terminal 40 are disposed on the first wall 21. The positive electrode tab 1213 of the electrode assembly 10 is connected to the positive terminal 30, and the negative electrode tab 1112 of the electrode assembly 10 is connected to the negative terminal 40. The first wall 21 supports the electrode assembly 10.

[0204] In some embodiments, the positive terminal 30 can be electrically connected to the positive electrode tab 1213, and the negative terminal 40 can be electrically connected to the negative electrode tab 1112.

[0205] In some embodiments, in the direction of gravity, the housing 110 may include a bottom wall located below, and a first wall 21 may be disposed opposite to the bottom wall, with the first wall 21 located between the electrode assembly 10 and the bottom wall.

[0206] In the technical solution of this application embodiment, the first wall 21 supports the electrode assembly 10, and the battery cell 1 can be used in an inverted state to improve the applicability of the battery cell 1.

[0207] Please refer to Figure 3 This application also provides an electrical device, including a battery cell 1 as described in any of the above embodiments or a battery device 100 as described in any of the above embodiments, wherein the battery cell 1 or the battery device 100 is used to provide electrical energy to the electrical device.

[0208] Please refer to Figure 12 and Figures 4 to 9 In some embodiments, the battery cell 1 includes a housing 20 and an electrode assembly 10, with the electrode assembly 10 disposed within the housing 20. The electrode assembly 10 includes a main body 17, a positive electrode tab 1213, and a negative electrode tab 1112. The housing 20 includes an end cap 23, which is provided with a positive terminal 30 and a negative terminal 40. The positive terminal 30 is electrically connected to the positive electrode tab 1213, and the negative terminal 40 is electrically connected to the negative electrode tab 1112.

[0209] In some embodiments, the end cap 23 supports the main body 17.

[0210] Please refer to ​In some embodiments, the electrode assembly 10 includes a positive electrode 12, a negative electrode 11, and an insulating layer 13. The negative electrode 11 includes a negative current collector 111 and a negative active material layer 114 disposed on the surface of the negative current collector 111. The positive electrode 12 includes a positive current collector 121 and a positive active material layer 122 disposed on the surface of the positive current collector 121. The portions of the positive electrode 12 and the negative electrode 11 with active material constitute the main body 17 of the electrode assembly 10, and the portions of the positive electrode 12 and the negative electrode 11 without active material respectively constitute a positive electrode tab 1213 and a negative electrode tab 1112.

[0211] In the first direction X, the negative current collector 111 has a first edge 1113 extending out of the negative electrode tab 1112, and the positive current collector 121 has a second edge 1211 extending out of the positive electrode tab 1213.

[0212] The insulating layer 13 is disposed on the side of the positive electrode 12 facing the negative electrode 11 and is disposed close to the second edge 1211. On the projection plane perpendicular to the stacking direction of the positive electrode 12 and the negative electrode 11, the orthogonal projection of the first edge 1113 falls into the orthogonal projection of the insulating layer 13. In the direction from the first edge 1113 to the second edge 1211, the insulating layer 13 extends beyond the first edge 1113.

[0213] Along the winding direction Y of the electrode assembly, the electrode assembly 10 includes an initial region 14, an intermediate region 16, and a terminal region 15 arranged sequentially. In the direction Z from the initial region to the terminal region, the maximum dimension of the insulating layer 13 of the initial region 14 and the terminal region 15 in the first direction X is H1, and the minimum dimension of the insulating layer 13 of the intermediate region 16 in the first direction X is H2, satisfying that 0 < H1 - H2 ≤ 5 mm.

[0214] In some embodiments, H1-H2 can be 0.5 mm.

[0215] In the technical solution of this application embodiment, the first edge 1113 can be the edge of the negative electrode tab 1112 cut by the negative electrode sheet 11. On the projection plane perpendicular to the stacking direction of the positive electrode sheet 12 and the negative electrode sheet 11, the orthogonal projection of the first edge 1113 falls into the orthogonal projection of the insulating layer 13. The burrs of the first edge 1113 can be blocked by the insulating layer 13 after piercing the separator 18, which can reduce the risk of short circuit between the positive electrode sheet 12 and the negative electrode sheet 11 and improve the reliability of the battery cell 1. Meanwhile, in the direction Z from the initial region to the terminal region, the maximum size and minimum size of the insulating layer 13 in the first direction X satisfy the above conditions. The size of the insulating layer 13 in the first direction X is designed to be larger in some regions. The insulating layer 13 in these regions has a larger blocking area relative to the first edge 1113 in the first direction X. The insulating layer 13 in these regions can play a better blocking effect on the first edge 1113. Even if the positive electrode 12 and the negative electrode 11 are easily moved during the charge and discharge cycle of the battery cell 1 or when the battery cell 1 is vibrated, the orthogonal projection of the first edge 1113 can still fall into the orthogonal projection of the insulating layer 13 on the projection plane perpendicular to the stacking direction of the positive electrode 12 and the negative electrode 11. This can reduce the risk of the burrs of the first edge 1113 piercing the separator 18 and short-circuiting the positive active material layer 122, thereby improving the reliability of the battery cell 1. When H1-H2≤5mm, while ensuring that the insulating layer 13 provides a good blocking effect on the first edge 1113, the size of the insulating layer 13 in the first direction X can be designed to be smaller, and the positive electrode sheet 12 can be provided with more positive active material layers 122, so that the battery cell 1 has a higher energy density.

[0216] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. 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 in that, Includes a wound electrode assembly, the electrode assembly comprising: A negative electrode sheet includes a negative current collector and a negative active material layer. The negative current collector includes a first main body region and a negative electrode tab. The negative active material layer is disposed in the first main body region. In a first direction, the first main body region has a first edge. The negative electrode tab extends from the first edge. The extension direction of the winding axis of the electrode assembly is parallel to the first direction. A positive electrode sheet includes a positive current collector and a positive active material layer disposed on the surface of the positive current collector. The positive electrode sheet and the negative electrode sheet are stacked together. In the first direction, the positive current collector has a second edge on the same side as the first edge. Along the first direction, the second edge extends beyond the first edge. An insulating layer is disposed on the side of the positive electrode sheet facing the negative electrode sheet and close to the second edge. On a projection plane perpendicular to the stacking direction of the positive electrode sheet and the negative electrode sheet, the orthogonal projection of the first edge falls into the orthogonal projection of the insulating layer. In the direction from the first edge to the second edge, the insulating layer extends beyond the first edge. Along the winding direction of the electrode assembly, the electrode assembly includes an initial region and a closing region arranged sequentially. In the direction from the initial region to the closing region, the maximum dimension of the insulating layer in the first direction is H1, and the minimum dimension of the insulating layer in the first direction is H2, satisfying that 0 < H1 - H2 ≤ 5 mm.

2. The battery cell according to claim 1, characterized in that, 0.2mm≤H1-H2≤0.5mm.

3. The battery cell according to claim 1, characterized in that, The electrode assembly further includes an intermediate region. Along the winding direction of the electrode assembly, the intermediate region connects the initial region and the final region. The number of winding turns in the initial region is in the range of 1 to 3 turns, and the number of winding turns in the final region is in the range of 1 to 2 turns. In the first direction, the size of the insulating layer located in the initial region is larger than the size of the insulating layer located in the intermediate region.

4. The battery cell according to claim 3, characterized in that, In the first direction, the size of the insulating layer located in the initial region is equal to the size of the insulating layer located in the closing region.

5. The battery cell according to claim 3, characterized in that, In the first direction, the size of the insulating layer located in the initial region is larger than the size of the insulating layer located in the closing region.

6. The battery cell according to claim 3, characterized in that, In the first direction, the size of the insulating layer located in the intermediate region is equal to the size of the insulating layer located in the terminal region.

7. The battery cell according to claim 1, characterized in that, The electrode assembly further includes an intermediate region. Along the winding direction of the electrode assembly, the intermediate region connects the initial region and the final region. The number of winding turns in the initial region is in the range of 1 to 3 turns, and the number of winding turns in the final region is in the range of 1 to 2 turns. In the first direction, the size of the insulating layer located in the initial region is equal to the size of the insulating layer located in the intermediate region, and the size of the insulating layer located in the initial region is greater than the size of the insulating layer located in the terminal region.

8. The battery cell according to claim 1, characterized in that, The battery cell also includes: The housing contains the electrode assembly disposed within it, and the housing includes a first wall whose thickness direction is parallel to the first direction. The positive terminal is disposed on the first wall; The negative terminal is disposed on the first wall; The positive current collector includes a second main body region and a positive electrode tab. The positive active material layer is disposed in the second main body region. The positive electrode tab extends from the second edge and is electrically connected to the positive terminal. The negative electrode tab is electrically connected to the negative terminal. The first wall is configured to support the electrode assembly.

9. The battery cell according to claim 8, characterized in that, The electrode assembly includes a main body portion, wherein the first main body region, the negative electrode active material layer, the second main body region, and the positive electrode active material layer constitute the main body portion; The battery cell also includes: An insulating element is disposed on the side of the first wall facing the electrode assembly; A support member is disposed between the insulating member and the main body portion, and supports the main body portion.

10. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-9.

11. The battery device according to claim 10, characterized in that, The battery device includes a housing, and the individual battery cells are disposed within the housing; The battery cell includes a casing, a positive terminal, and a negative terminal. The electrode assembly is disposed inside the casing. The casing includes a first wall. The positive terminal and the negative terminal are both disposed on the first wall. The positive electrode tab of the electrode assembly is connected to the positive terminal, and the negative electrode tab of the electrode assembly is connected to the negative terminal. The first wall supports the electrode assembly.

12. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-9 or a battery device as described in any one of claims 10-11, wherein the battery cell or the battery device is used to provide electrical energy to the electrical device.

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