Battery cell, battery device, and electric device

Abstract

The application belongs to the technical field of batteries, and provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell and an electrode assembly. The shell has a containing cavity; the electrode assembly is arranged in the containing cavity, and the electrode assembly comprises a wound cathode pole piece and anode pole piece; at least one of the cathode pole piece and the anode pole piece is a target pole piece, the target pole piece comprises a main body structure and a tab part arranged in sequence along a height direction, the main body structure has a coating, and the tab part does not have a coating; a part of the main body structure exceeds the tab part along a winding direction, and forms a target part. The battery monomer, the battery device and the power utilization device provided by the application can reduce the probability of excessive self-discharge of the battery monomer.

Description

Technical Field

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

[0002] In existing wound electrode assemblies with a full-tab structure, an insulating layer is applied to the edge of the cathode coating area, with the full tabs positioned above the insulating layer. The full tabs are flattened, and the current collector is welded to the flattened surface of the full tabs. However, battery cells using this electrode assembly are prone to excessive self-discharge. Utility Model Content

[0003] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device, which aims to reduce the probability of excessive self-discharge in the battery cell.

[0004] In a first aspect, embodiments of this application provide a battery cell, including a housing and an electrode assembly. The housing has a receiving cavity. The electrode assembly is disposed within the receiving cavity and includes a wound cathode electrode and an anode electrode. At least one of the cathode electrode and the anode electrode is a target electrode. The target electrode includes a main structure and an electrode tab arranged sequentially along the height direction. The main structure has a coating, while the electrode tab does not have a coating. A portion of the main structure extends beyond the electrode tab along its own winding direction to form a target portion.

[0005] The cathode and / or anode of the aforementioned battery cell form the target electrode. A portion of the main structure of the target electrode extends beyond the tab along its own winding direction, forming a target section. This target section consists only of a portion of the main structure and does not have a tab. The location of the target section can be determined based on areas prone to wrinkling. This reduces the risk of wrinkling in the electrode assembly of the battery cell during flattening or later in cycling, thereby reducing the risk of insulation layer detachment on the target electrode. Furthermore, it reduces the risk of overlap between the tab of the target electrode and adjacent electrodes, lowering the probability of excessive self-discharge and the risk of large voltage differentials in the battery device.

[0006] In some possible implementations of the first aspect, the target portion is located at the outer end of the main structure in the winding direction.

[0007] Since wrinkles are prone to occur at the outermost ends of the cathode electrode during the flattening process or in the later stages of the cycle, the target part is set at the outer end of the cathode electrode in the winding direction of the cathode electrode, which can reduce the risk of wrinkles.

[0008] In some possible implementations of the first aspect, the size of the target portion in the winding direction is 1 / 9 to 1 / 20 of the size of the main structure.

[0009] This reduces the risk of most wrinkles and makes the target part smaller, without affecting the normal operation of the battery cell.

[0010] In some possible implementations of the first aspect, the coating includes an active material layer and an insulating layer; the main structure includes a first part and a second part arranged sequentially along the height direction, the second part being located between the first part and the tab, and the surface of the second part being provided with an insulating layer; the surface of the first part is provided with an active material layer; the portion of the first part and / or the second part extending beyond the tab along the winding direction forms a target part; in the height direction, the size of the target part is greater than or equal to the size of the first part and less than or equal to the size of the main structure.

[0011] The battery cell provided in this embodiment has a complete first part, which can ensure that the electrochemical reaction of the battery cell is not affected. At the same time, it can reduce the risk of wrinkling, reduce the risk of the insulating layer on the cathode electrode peeling off, and further reduce the risk of overlap between the cathode electrode tab and the anode electrode, reduce the probability of excessive self-discharge, and reduce the risk of large voltage difference in the battery device.

[0012] In some possible implementations of the first aspect, the tab and the second part form a combined structure; a portion of the first part extends beyond the combined structure along the winding direction to form the target part.

[0013] In this way, regardless of whether wrinkles are likely to appear at the junction of the tab and the insulating layer or in the area covered by the insulating layer, the solution provided in this embodiment can reduce the risk of the insulating layer falling off the cathode electrode, thereby reducing the risk of overlap between the tab of the cathode electrode and the anode electrode, reducing the probability of excessive self-discharge, and reducing the risk of large voltage difference in the battery device.

[0014] In some possible implementations of the first aspect, a portion of the first part extends beyond the tab along the winding direction to form a first protrusion; at least a portion of the second part extends beyond the tab to form a second protrusion; the second protrusion and the first protrusion combine to form the target part.

[0015] The solution provided in this embodiment can retain at least part of the second part, which is suitable for situations where wrinkles are likely to appear at or near the junction of the tab and the insulating layer. At the same time, the retained second part can also prevent the part of the anode plate that extends beyond the first part from overlapping with the cathode plate, thereby reducing the probability of excessive self-discharge and the risk of large voltage difference in the battery device.

[0016] In some possible implementations of the first aspect, both the cathode electrode and the anode electrode include a main body structure and an electrode tab, and the electrode tabs of the cathode electrode and the anode electrode are located at both ends of the electrode assembly in the height direction; at least a portion of the second part of the cathode electrode extends beyond the anode electrode in the height direction.

[0017] This reduces the risk of the anode plate extending beyond the first part overlapping with the tab, thereby reducing the probability of excessive self-discharge and the risk of large voltage differences in the battery device.

[0018] In some possible implementations of the first aspect, the dimension of the portion of the second part extending beyond the anode electrode in the height direction is 0.1 mm to 1 mm.

[0019] The size of the portion of the second part that extends beyond the anode electrode sheet is within the range provided in this embodiment. This can reduce the risk of the portion of the anode electrode sheet extending beyond the first part overlapping with the tab, and can also reduce the probability of material waste caused by the second part extending too far beyond the anode electrode sheet, achieving multiple benefits in one fell swoop.

[0020] In some possible implementations of the first aspect, the thickness of the insulating layer is 30μm-50μm.

[0021] The thickness of the insulating layer can be any size from 30 micrometers to 50 micrometers, which can make the insulating layer have good insulation effect and not affect the electrochemical reaction of the battery cell.

[0022] In some possible implementations of the first aspect, in the height direction, the size of at least a portion of the second part within the target part is smaller than the size of the portion of the second part outside the target part.

[0023] Compared to removing the entire second portion within the preset area, this method reduces the amount of the second portion to be removed, thus lowering the risk of short circuits caused by overlap between the anode and cathode electrodes. Simultaneously, the insulating layer retained in the second portion within the target area can reduce the risk of burrs left after die-cutting the second portion piercing the diaphragm and causing overlap with the anode electrode.

[0024] In some possible implementations of the first aspect, the dimension of the second part within the target part in the height direction is less than or equal to 1 mm.

[0025] This reduces the likelihood of wrinkles occurring, thereby reducing the risk of short circuits caused by overlap between the anode and cathode electrodes.

[0026] In some possible implementations of the first aspect, the connecting surface between the first part and the second part is a first plane, the tab has a first end face in the winding direction, the first end face is disposed close to the target part, and the first end face and the portion of the first plane located within the target part are disposed at a first angle, wherein the first angle is an obtuse angle.

[0027] The first end face is set at an obtuse angle to the first plane, which can reduce the risk of the tab turning over during the winding or flattening process, so that the winding can be carried out smoothly, and can also reduce the risk of the tab overlapping with the anode plate.

[0028] In some possible implementations of the first aspect, the first included angle is greater than or equal to 150° and less than 180°.

[0029] The first included angle, within the range provided in this embodiment, can reduce the risk of the tab folding, thereby reducing the risk of the tab overlapping with the anode plate.

[0030] In some possible implementations of the first aspect, the tab has a first end face in the winding direction, the first end face is disposed close to the target portion, and the first end face is parallel to the height direction.

[0031] In this embodiment, the first end face is a plane, which facilitates design and fabrication.

[0032] In some possible implementations of the first aspect, the second part has a second end face in the winding direction, the second end face being located within or near the target part; the second end face is set at an obtuse angle to the portion of the first plane located within the target part, or is parallel to the height direction.

[0033] When the second end face is set at an obtuse angle to the first plane, the risk of the second part folding during the winding or flattening process can be reduced, making the winding process smooth, and reducing the risk of overlap between the tab and the anode plate.

[0034] When the second end face is parallel to the height direction, the second end face is a plane, which facilitates design and fabrication.

[0035] In some possible implementations of the first aspect, the first end face and the second end face are connected.

[0036] The first and second end faces can be connected using the same cutting process, eliminating the need for two separate operations and improving preparation efficiency.

[0037] In some possible implementations of the first aspect, the first end face and the second end face are spaced apart in the winding direction, and the second end face is located outside the first end face.

[0038] Compared to connecting the first and second end faces, this reduces the amount of material removed from the second part, lowering the risk of short circuits caused by overlap between the anode and cathode electrodes.

[0039] In some possible implementations of the first aspect, the battery cell is a cylindrical cell. This can reduce the likelihood of excessive self-discharge in cylindrical cells.

[0040] Secondly, embodiments of this application provide a battery device, including a battery cell provided by any of the above solutions.

[0041] Thirdly, embodiments of this application provide an electrical device, including a battery cell or battery device provided by any of the above solutions.

[0042] The effects of the second and third aspects are the same as those of the first aspect, and will not be elaborated here.

[0043] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0044] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

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

[0046] Figure 2 This is an exploded view of the battery device provided in some embodiments of this application;

[0047] Figure 3 A cross-sectional view of a single battery cell provided in some embodiments of this application;

[0048] Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;

[0049] Figure 5 This is a partial unfolded structural diagram of the electrode assembly in a battery cell provided in some embodiments of this application;

[0050] Figure 6 for Figure 5 A schematic diagram of the unfolded structure of the central cathode electrode;

[0051] Figure 7 A partially expanded structural schematic diagram of the electrode assembly in a battery cell provided in other embodiments of this application;

[0052] Figure 8 for Figure 7 A schematic diagram of the unfolded structure of the central cathode electrode;

[0053] Figure 9 A partially expanded structural schematic diagram of the electrode assembly in a battery cell provided in other embodiments of this application;

[0054] Figure 10 for Figure 9 A schematic diagram of the unfolded structure of the central cathode electrode;

[0055] Figure 11 This is a schematic diagram of the structure of the cathode and anode plates in a stacked state in a single battery cell provided in some embodiments of this application;

[0056] Figure 12 A partially expanded structural schematic diagram of the electrode assembly in a battery cell provided in other embodiments of this application;

[0057] Figure 13 for Figure 12 A schematic diagram of the unfolded structure of the central cathode electrode;

[0058] Figure 14 A schematic diagram showing the unfolded structure of the cathode electrode in a single battery cell provided in other embodiments of this application;

[0059] Figure 15 A partially expanded structural schematic diagram of the electrode assembly in a battery cell provided in other embodiments of this application;

[0060] Figure 16 for Figure 15 A schematic diagram of the unfolded structure of the central cathode electrode;

[0061] Figure 17 This is a partially expanded structural diagram of the electrode assembly in a battery cell provided in other embodiments of this application.

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

[0063] 1000, vehicles;

[0064] 100. Battery assembly; 200. Controller; 300. Motor;

[0065] 10. Box body; 11. Cover body; 12. Tray; 20. Battery cell; 21. End cap; 22. Housing; 23. Electrode assembly; 24. Insulating adhesive;

[0066] 211. Positive electrode top cover; 212. Negative electrode top cover; 213. Positive electrode tab adhesive; 214. Negative electrode tab adhesive; 231. Cathode electrode; 232. Anode electrode; 233. Diaphragm; 231a. Main structure; 231b. Electrode tab;

[0067] 2311. Part One; 2312. Part Two;

[0068] M1, first plane; M2, first end face; M3, second end face; X, winding direction; Y, thickness direction; Z, height direction. Detailed Implementation

[0069] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0071] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0072] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0073] In the description of the embodiments 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, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0074] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0075] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0076] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0077] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0078] The full-tab structure is a core structure in which the current collector serves as the tab. The tab is welded to the current collector plate. Because the current collector serves as both a carrier of the active material and a tab, the internal resistance of the full-tab structure is very low, and the rate performance is better, which can improve the rate performance of large-capacity battery cells.

[0079] In existing wound electrode assemblies with a full-tab structure, an insulating layer is applied to the edge of the cathode coating area, with the full tab positioned above the insulating layer. The full tab is produced using a flattening process, and the current collector is welded to the flattened surface of the full tab.

[0080] During the smoothing process of the aforementioned electrode assembly or in the later stages of cycling, wrinkles are prone to occur at the junction of the cathode tab and the insulating layer, or at the outermost few rings (e.g., the outermost two rings, the outermost three rings, etc.) and the innermost few rings (e.g., the innermost two rings, the innermost three rings, etc.) of the insulating layer covered by the insulating layer. Wrinkles reduce the adhesion between the insulating layer and the current collector (aluminum foil), making it easier for the insulating layer on the current collector to detach. After the insulating layer detaches, the tip of the wrinkled cathode tab can easily pierce the separator and overlap with the portion of the anode electrode that extends beyond the active material layer on the cathode electrode, forming a micro-short circuit. This micro-short circuit leads to localized leakage current, increasing the self-discharge rate of the battery cell with the aforementioned electrode assembly (or causing excessive self-discharge). Consequently, in battery devices with multiple battery cells, the self-discharge rates of different cells become inconsistent, causing voltage deviations and affecting the overall performance of the battery device.

[0081] Self-discharge rate refers to the rate at which a battery loses charge due to internal chemical reactions or micro-short circuits when it is in an open-circuit (unused) state. It is usually expressed as a percentage of capacity loss or voltage drop per unit time. Self-discharge refers to the natural loss of charge from a battery device when it is not connected to an external circuit due to internal chemical reactions or micro-short circuits. Reasonable self-discharge is a normal phenomenon, but an excessively high self-discharge rate will cause the battery device to experience a sharp drop in charge after storage, or even fail.

[0082] To address the aforementioned issues, this application provides a battery cell. In this battery cell, a portion of the main structure of the cathode electrode extends beyond the tab along its winding direction to form a target portion. This target portion consists only of a portion of the main structure and does not include the tab. The location of the target portion can be determined based on areas prone to wrinkling. This reduces the risk of wrinkling in the electrode assembly during flattening or later cycling, thereby reducing the risk of insulation layer detachment from the cathode electrode, further reducing the risk of overlap between the cathode tab and the anode electrode, lowering the probability of excessive self-discharge, and reducing the risk of large voltage differentials in the battery device.

[0083] The battery cells disclosed in this application can be used in battery devices and electrical devices that use the battery cells as a power source, or in various energy storage devices, energy storage systems, and charging networks that use batteries as energy storage elements. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0084] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0085] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. 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 provided 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. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0086] 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.

[0087] Please refer to Figure 2 , Figure 2 This is an exploded structural diagram of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 10 and battery cells 20, with the battery cells 20 housed within the housing 10.

[0088] The housing 10 provides a storage space for the battery cells 20, and can adopt various structures. In some embodiments, the housing 10 may include a cover 11 and a tray 12. The cover 11 covers the tray, and together with the tray 12, defines a storage space for accommodating the battery cells 20. The tray 12 may be a hollow structure with one open end, and the cover 11 may be a plate-like structure, covering the open side of the tray 12 so that the cover 11 and the tray 12 together define the storage space; the cover 11 and the tray 12 may also be hollow structures with side openings, with the open side of the cover 11 covering the open side of the tray 12. Of course, the housing 10 formed by the cover 11 and the tray 12 can be of various shapes, such as a circular through-hole, a cuboid, etc. The tray 12 is an important structural support component in the battery system, used to store and protect the battery cells, and also has a significant impact on the collision safety of the vehicle and the overall torsional and bending stiffness of the vehicle body.

[0089] Multiple battery cells 20 can be provided, and these cells can be connected in series, parallel, or mixed connection via a busbar. Mixed connection refers to a configuration where multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or mixed connection, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or mixed connection to form a battery module, and then multiple battery modules connected in series, parallel, or mixed connection to form a whole, housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar for electrical connection between the multiple battery cells 20. As an example, multiple battery cells 20 can form a battery module, which is an independent module formed by arranging and fixing multiple battery cells 20. As an example, a battery module can be formed by binding multiple battery cells 20 together with cable ties.

[0090] Each battery cell 20 can be a secondary battery or a primary battery. A secondary battery refers to a battery cell that can be recharged after discharge to activate the active materials and continue to be used. The battery cell 20 can be a 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., and this application embodiment is not limited to this. The battery cell can have a circular through-body, a flat body, a cuboid, or other shapes.

[0091] Please refer to Figure 3 , Figure 3 This is a cross-sectional structural diagram of a battery cell provided in some embodiments of this application. Battery cell 20 refers to the smallest unit that makes up a battery. For example... Figure 3 The battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0092] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved safety performance. Functional components such as electrode terminals can be provided on end cap 21. Electrode terminals can be used for electrical connection with electrode assembly 23 for outputting or inputting electrical energy into battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0093] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 22 can be integrated. Specifically, the end cap 21 and the housing 22 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 22, the end cap 21 closes the housing 22. The housing 22 can be of various shapes and sizes, such as cuboid, circular through-hole, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0094] Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. For example... Figure 3 and Figure 4 As shown, in this embodiment, the housing 22 has two openings. The end cap 21 includes a positive electrode top cap 211 and a negative electrode top cap 212. The positive electrode top cap 211 is sealed to the end of the housing 22 for the positive electrode to extend through a positive electrode tab adhesive 213. The negative electrode top cap 212 is sealed to the end of the housing 22 for the negative electrode to extend through a negative electrode tab adhesive 214.

[0095] Electrode assembly 23 is the component in the battery cell 20 where electrochemical reactions occur. The housing 22 may contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding positive and negative electrode plates, and typically a separator is provided between the positive and negative electrode plates. The portions of the positive and negative electrode plates containing active material constitute the main body of the electrode assembly, while the portions of the positive and negative electrode plates without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery cell, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0096] An insulating adhesive 24 is provided between the electrode assembly 23 and the housing 22 to achieve insulation isolation between the two.

[0097] Figure 5 This is a partial unfolded structural diagram of the electrode assembly in a battery cell provided in some embodiments of this application; Figure 6 for Figure 5 A schematic diagram of the unfolded structure of the intermediate cathode electrode 231. Please refer to... Figure 5 and Figure 6 This application provides a battery cell. The battery cell includes a casing and an electrode assembly. The casing has a receiving cavity. The electrode assembly is disposed within the receiving cavity. The electrode assembly includes a wound cathode electrode 231 and an anode electrode 232. At least one of the cathode electrode 231 and the anode electrode 232 is a target electrode. The target electrode includes a main body structure 231a and a tab portion 231b arranged sequentially along the height direction Z of the target electrode. The main body structure 231a has a coating. The tab portion 231b does not have a coating. A portion of the main body structure 231a extends beyond the tab portion 231b along its own winding direction X, forming a target portion.

[0098] The outer casing includes the aforementioned end cap and housing, and the receiving cavity is a cavity formed by the end cap and housing for accommodating substances such as electrode components and electrolyte.

[0099] The winding arrangement refers to the stacking of the anode electrode 232 and the cathode electrode 231 in an unfolded state, with a separator 233 between them. The anode electrode 232, the cathode electrode 231 and the separator 233 are then wound to form a winding structure, which is the electrode assembly of a battery cell.

[0100] At least one of the cathode electrode 231 and the anode electrode 232 is the target electrode, including the following cases: First, only the cathode electrode 231 is the target electrode; second, only the anode electrode 232 is the target electrode; third, both the cathode electrode 231 and the anode electrode 232 are target electrodes.

[0101] The portion of the target electrode in the cathode electrode 231 and anode electrode 232 coated with a coating constitutes the main structure 231a, and the portion without coating constitutes the tab 231b. The tab 231b is located at one end of the main structure 231a in the height direction.

[0102] Generally, the main structure 231a has a coating on both surfaces that are opposite to each other in the thickness direction Y. In special cases, a portion of the main structure 231a may have a coating only on a surface perpendicular to the thickness direction Y, depending on the application requirements.

[0103] The coating includes both an active material layer and an insulating layer, which can be determined according to the application requirements.

[0104] The target portion is a part of the target electrode. For example... Figure 5 and Figure 6 As shown, the cathode electrode 231 is the target electrode, and the portion of the main structure 231a located to the right of the dashed line L is the target part. This part does not have a tab 231b and is entirely composed of a portion of the main structure 231a. The target part can be obtained by removing part of the tab 231b, or by removing part of the tab 231b and part of the main structure 231a. Alternatively, during the fabrication of the cathode electrode 231, the tab 231b of the cathode electrode 231 can be made shorter than the main structure 231a, or the tab 231b and part of the main structure 231a can be made shorter than the remaining portion of the main structure 231a. The specific choice depends on the application requirements.

[0105] It is understandable that the dashed line L is merely an auxiliary line drawn for ease of understanding, and is not a structural line of the cathode electrode 231.

[0106] For ease of description, the following explanation will use cathode electrode 231 as the target electrode, with the target portion being fabricated by removing part of its structure as an example. It is understandable that the design principle for directly fabricating the target portion is similar to that for fabricating the target portion by removing part of its structure.

[0107] The principle of the battery cell configuration provided in this application embodiment is as follows:

[0108] Generally, the target section is the portion extending beyond the tab 231b along the winding direction X after removing the parts of the original battery cell that are prone to wrinkling. Therefore, the location of the target section is generally determined based on the location where wrinkles are likely to occur.

[0109] For example, if wrinkles tend to appear at the junction of the tab 231b and the insulating layer, and are more likely to appear on the outermost ring of the electrode assembly formed by the anode electrode 232 and the cathode electrode 231, then the tab 231b on the outermost ring of the cathode electrode 231 can be removed to obtain the target portion described above. If wrinkles tend to appear in the area covered by the insulating layer, and are more likely to appear on the outermost two rings of the electrode assembly formed by the anode electrode 232 and the cathode electrode 231, then the tab 231b on the outermost two rings of the cathode electrode 231 and the portion covered by the insulating layer can be removed to obtain the target portion described above. If wrinkles tend to appear in the area covered by the insulating layer, and are more likely to appear on the innermost two rings of the electrode assembly formed by the anode electrode 232 and the cathode electrode 231, then the tab 231b on the innermost two rings of the cathode electrode 231 and the portion covered by the insulating layer can be removed to obtain the target portion described above.

[0110] When wrinkles tend to appear in other areas of the electrode assembly, the target portion can be obtained by removing the tab 231b in the corresponding area, at least part of the insulating layer, and the portion covered by the insulating layer.

[0111] The resulting battery cells are less prone to wrinkles, which reduces the risk of insulation layer detachment, thereby reducing the risk of overlap between the tab 231b and the anode plate 232, reducing the probability of excessive self-discharge, and reducing the risk of large voltage differences in the battery device.

[0112] Understandably, since the parts prone to wrinkles generally occupy a small area, the area where the tabs 231b or the main structure 231a need to be removed is also small. Most of the tabs 231b and the main structure 231a can be retained, so as not to affect the normal use of the battery cell.

[0113] The battery cell provided in this application embodiment forms a target electrode on the cathode electrode 231 and / or the anode electrode 232. A portion of the main structure 231a of the target electrode extends beyond the tab 231b along its own winding direction X, forming a target portion. This target portion consists only of a portion of the main structure 231a and does not have a tab 231b. The location of the target portion can be determined according to the location where wrinkles are likely to occur. This can reduce the risk of wrinkles appearing in the electrode assembly of the battery cell during flattening or in the later stages of cycling, thereby reducing the risk of the insulating layer on the target electrode peeling off. Furthermore, it can reduce the risk of overlap between the tab 231b of the target electrode and adjacent electrodes, reduce the probability of excessive self-discharge, and reduce the risk of large voltage differences in the battery device.

[0114] like Figure 6As shown, in some embodiments, the coating includes an active material layer and an insulating layer. The main structure 231a includes a first portion 2311 and a second portion 2312 arranged sequentially along the height direction. The second portion 2312 is located between the first portion 2311 and the tab portion 231b, and the surface of the second portion 2312 is provided with an insulating layer. The surface of the first portion 2311 is provided with an active material layer. The portions of the first portion 2311 and / or the second portion 2312 extending beyond the tab portion 231b along the winding direction form the target portion.

[0115] In the height direction, the size of the target part is greater than or equal to the size of the first part 2311, and less than or equal to the size of the main structure 231a.

[0116] The first part 2311 and the second part 2312 are both part of the main structure 231a. The first part 2311 is the part of the main structure 231a that has an active material layer. The second part 2312 is the part of the main structure 231a that has an insulating layer, and it is also the part that connects the first part 2311 and the tab 231b.

[0117] The active material layer is generally coated on both sides of the current collector in the first part 2311 that are opposite to each other in the thickness direction Y. In special cases, the active material layer may be applied only to a certain surface of the current collector perpendicular to the thickness direction Y in a certain area of ​​the first part 2311, depending on the application requirements.

[0118] The insulating layer is a coating that serves an insulating function and can be a ceramic coating, an AT11 coating, or other coatings. The insulating layer is generally applied to both sides of the current collector in the second part 2312 that are opposite to each other in the thickness direction Y. In special cases, a portion of the second part 2312 may have an insulating layer applied only to a specific surface of the current collector perpendicular to the thickness direction Y, depending on the application requirements.

[0119] In the height direction, the size of the target portion is greater than or equal to the size of the first portion 2311, and less than or equal to the size of the main structure 231a. This means that the target portion can be obtained by removing the tab 231b and the second portion 2312 within a preset area, or by removing the tab 231b and part of the second portion 2312 within the preset area, or by removing the tab 231b within the preset area. The aforementioned preset area is an area prone to wrinkling.

[0120] It is understandable that when the target portion is obtained by removing the tab 231b and the second portion 2312 within the preset area, the portion of the first portion 2311 that extends beyond the tab 231b in the winding direction forms the target portion, and in the height direction, the size of the target portion is equal to the size of the first portion 2311. When the target portion is obtained by removing the tab 231b and a portion of the second portion 2312 within a preset area, a portion of the first portion 2311 and the second portion 2312 extending beyond the tab 231b along the winding direction forms the target portion. If only a portion of the structure connected to the tab 231b is removed from the second portion 2312, then in the height direction, the size of the target portion is larger than the size of the first portion 2311 and smaller than the size of the main structure 231a. If a portion of the target portion completely removes the second portion 2312, and another portion does not remove the second portion 2312, then in the height direction, the size of the portion of the target portion from which the second portion 2312 is removed is equal to the size of the first portion 2311, and the size of the portion of the target portion from which the second portion 2312 is not removed is equal to the size of the main structure 231a. When the target portion is obtained by removing the tab 231b within a preset area, the portion of the first portion 2311 and the second portion 2312 extending beyond the tab 231b along the winding direction forms the target portion, and in the height direction, the size of the target portion is equal to the size of the main structure 231a.

[0121] The battery cell provided in this embodiment has a complete first part 2311, which can ensure that the electrochemical reaction of the battery cell is not affected. At the same time, it can reduce the risk of wrinkles and the risk of the insulating layer on the cathode electrode 231 falling off. This can reduce the risk of overlap between the tab 231b of the cathode electrode 231 and the anode electrode 232, reduce the probability of excessive self-discharge, and reduce the risk of large voltage difference in the battery device.

[0122] In some embodiments, the target portion is located at the outer end of the main body structure 231a in the winding direction X.

[0123] The outer end refers to the end of the outermost ring after the main structure 231a is wound and formed.

[0124] Since the outermost two rings of the main structure 231a are prone to wrinkling during the kneading process or the later stages of the cycle, the target part is set at the outer end of the main structure 231a in the winding direction X, which can reduce the risk of wrinkling.

[0125] In some embodiments, in the winding direction X, the size b1 of the target portion is 1 / 9 to 1 / 20 of the size b2 of the main structure.

[0126] For example, in the winding direction X, the size b1 of the target portion is 1 / 9, 1 / 20, 1 / 10, 1 / 11, 1 / 15, etc. of the size b2 of the cathode electrode 231.

[0127] This reduces the risk of most wrinkles and makes the target part smaller, without affecting the normal operation of the battery cell.

[0128] like Figure 6 As shown, in some embodiments, the tab 231b and the second portion 2312 form a combined structure. A portion of the first portion 2311 extends beyond the combined structure along the winding direction X to form a target portion.

[0129] In this embodiment, the target portion is entirely composed of the first portion 2311, which can be obtained by removing the tab portion 231b and the second portion 2312 within the preset area.

[0130] In this way, regardless of whether wrinkles are likely to appear at the junction of the tab 231b and the insulating layer or in the area covered by the insulating layer, the solution provided in this embodiment can reduce the risk of the insulating layer falling off the cathode electrode 231, thereby reducing the risk of overlap between the tab 231b of the cathode electrode 231 and the anode electrode 232, reducing the probability of excessive self-discharge and the risk of large voltage difference in the battery device.

[0131] In some embodiments, a portion of the first portion 2311 extends beyond the tab 231b along the winding direction X to form a first protrusion. At least a portion of the second portion 2312 extends beyond the tab 231b to form a second protrusion. The second protrusion and the first protrusion combine to form the target portion.

[0132] In this embodiment, the target portion consists of a first portion 2311 and a second portion 2312. The target portion can be obtained by removing the tab portion 231b within a preset area, such as... Figure 7 and Figure 8 As shown, it can also be obtained by removing the tab portion 231b and part of the second portion 2312 within the preset area, as shown. Figure 9 and Figure 10 As shown.

[0133] Understandable, Figure 8 and Figure 10 The first part 2311, located to the right of the dashed line L, is the first convex part, and the second part 2312, located to the right of the dashed line L, is the second convex part.

[0134] By adopting the solution provided in this embodiment, at least part of the second part 2312 can be retained, which is suitable for situations where wrinkles are likely to appear at the junction of the tab 231b and the insulating layer, or near the junction. At the same time, the retained second part 2312 can also prevent the portion of the anode plate 232 that extends beyond the first part 2311 from overlapping with the cathode plate 231, thereby reducing the probability of excessive self-discharge and the risk of large voltage difference in the battery device.

[0135] like Figure 11 As shown, in some embodiments, both the cathode electrode 231 and the anode electrode 232 include a main body structure 231a and an electrode tab 231b. The electrode tabs 231b of the cathode electrode 231 and the anode electrode 232 are respectively disposed at both ends of the electrode assembly in the height direction. At least a portion of the second part 2312 of the cathode electrode 231 extends beyond the anode electrode 232 in the height direction.

[0136] The tabs 231b of the cathode electrode 231 and the anode electrode 232 are respectively disposed at both ends of the electrode assembly. Specifically, the electrode assembly has a first end and a second end in the height direction. If the tab 231b of the cathode electrode 231 is located at the first end, then the tab 231b of the anode electrode 232 is located at the second end. If the tab 231b of the cathode electrode 231 is located at the second end, then the tab 231b of the anode electrode 232 is located at the first end.

[0137] At least a portion of the second part 2312 extends beyond the anode plate 232 in the height direction, meaning that the projection pattern of the portion of the anode plate 232 extending beyond the first part onto the second part 2312 along the thickness direction Y completely falls within the pattern enclosed by the edge of the second part 2312.

[0138] This reduces the risk of the portion of the anode plate 232 extending beyond the first part 2311 overlapping with the tab portion 231b, thereby reducing the probability of excessive self-discharge and the risk of large voltage differences in the battery device.

[0139] like Figure 11 As shown, in some embodiments, the dimension h0 of the portion of the second portion 2312 extending beyond the anode electrode 232 in the height direction is 0.1mm-1mm. For example, the dimension of the portion of the second portion 2312 extending beyond the anode electrode 232 in the height direction can be 0.1mm, 0.3mm, 0.5mm, 0.8mm, or 1mm, etc.

[0140] The size of the portion of the second part 2312 that extends beyond the anode electrode 232 within the range provided in this embodiment can reduce the risk of overlap between the portion of the anode electrode 232 that extends beyond the first part 2311 and the tab 231b, and can also reduce the probability of material waste caused by the second part 2312 extending too far beyond the anode electrode 232, achieving multiple benefits in one fell swoop.

[0141] In some embodiments, the thickness of the insulating layer is 30μm-50μm.

[0142] For example, the thickness of the insulating layer can be 30 micrometers, 32 micrometers, 35 micrometers, 40 micrometers, 45 micrometers, 47 micrometers, 50 micrometers, etc.

[0143] The thickness of the insulating layer refers to the dimension of the insulating layer in the thickness direction Y of the cathode electrode 231, which is also the dimension in the Y direction perpendicular to the Z and X directions.

[0144] The thickness of the insulating layer can be any size from 30 micrometers to 50 micrometers, which can make the insulating layer have good insulation effect and not affect the electrochemical reaction of the battery cell.

[0145] like Figure 12 and Figure 13 As shown, in some embodiments, in the height direction, the size of at least a portion of the second portion 2312 within the target portion is smaller than the size of the portion of the second portion 2312 outside the target portion.

[0146] In this embodiment, the target portion can be obtained by removing the tab 231b within a preset area and a portion of the second portion 2312 near the tab 231b. For example... Figure 13 As shown, the height of the part to the right of the dashed line L in the second part 2312 is h1, and the height of the part to the left of the dashed line L in the second part 2312 is h2, where h1 is less than h2.

[0147] Compared to removing the entire second portion 2312 within the preset area, this method reduces the amount of second portion 2312 removed, thus reducing the risk of short circuits caused by overlap between the anode electrode 232 and the cathode electrode 231. Simultaneously, the insulating layer retained in the second portion 2312 within the target area can be used to reduce the risk of burrs left after die-cutting the second portion 2312 piercing the diaphragm 233 and causing overlap with the anode electrode 232.

[0148] In some embodiments, in the height direction, the dimension h1 of the second portion 2312 within the target portion is less than or equal to 1 mm.

[0149] For example, in the height direction, the dimension h1 of the second part 2312 within the target part can be 1 mm, 0.8 mm, 0.5 mm, 0.4 mm, 0.3 mm, etc.

[0150] This reduces the likelihood of wrinkles occurring, thereby reducing the risk of short circuits caused by overlap between the anode electrode 232 and the cathode electrode 231.

[0151] like Figure 13 As shown, in some embodiments, the connecting surface between the first portion 2311 and the second portion 2312 is a first plane M1. The tab portion 231b has a first end face M2 in the winding direction X. The first end face M2 is disposed close to the target portion. The first end face M2 and the portion of the first plane M1 located within the target portion are disposed at a first angle α1. The first angle is an obtuse angle.

[0152] The first end face M2 is an end face of the tab portion 231b in the winding direction X, and this end face is disposed adjacent to the target portion.

[0153] An obtuse angle is an angle greater than 90 degrees and less than 180 degrees. For example, the first end face M2 and the first plane M1 can be set at angles of 120°, 135°, 140°, 150°, 170°, etc.

[0154] The first end face M2 and the first plane M1 are set at an obtuse angle within the target portion, which can reduce the risk of the tab 231b folding during the winding or flattening process, so that the winding can proceed smoothly, and can also reduce the risk of the tab 231b overlapping with the anode plate 232.

[0155] like Figure 13 As shown, in some embodiments, the first included angle a1 is greater than or equal to 150° and less than 180°.

[0156] For example, the obtuse angle can be 150°, 155°, 160°, 165°, 175°, etc.

[0157] The first included angle a1 is within the range provided in this embodiment, which can reduce the risk of the tab 231b folding over, thereby reducing the risk of the tab 231b overlapping with the anode plate 232.

[0158] like Figure 8 As shown, in some embodiments, the tab portion 231b has a first end face M2 in the winding direction X. The first end face M2 is disposed close to the target portion. The first end face M2 is parallel to the height direction.

[0159] In this embodiment, the first end face M2 is a plane, which facilitates design and fabrication.

[0160] In some embodiments, the second portion 2312 has a second end face M3 in the winding direction X. The second end face M3 is located within or near the target portion. The second end face M3 is positioned at a second angle α2 with the portion of the first plane M1 located within the target portion, or is parallel to the height direction Z. The second angle α2 is an obtuse angle.

[0161] The second end face M3 is an end face of the second part 2312 in the winding direction X, and this end face is located within the target part.

[0162] The angle and range of the second included angle a2 and the first included angle a1 can be the same or different, depending on the specific needs of use.

[0163] This embodiment includes multiple solutions:

[0164] like Figure 6 and Figure 8 As shown, in some embodiments, the second end face M3 is located within or near the target portion. The second end face M3 is parallel to the height direction. This makes the second end face M3 planar, which facilitates design and fabrication.

[0165] like Figure 10 As shown, in some embodiments, the second end face M3 is located within the target portion. The portion of the second end face M3 and the portion of the first plane M1 located within the target portion are set at an obtuse angle. In this embodiment, the second included angle α2 can be the same as the first included angle α1, and the second end face M3 and the first end face M2 are located on the same inclined plane, such as... Figure 10 As shown; alternatively, the second included angle a2 and the first included angle a1 can be different, and the second end face M3 and the first end face M2 can be misaligned, such as... Figure 14 As shown.

[0166] Regardless of which setting method is adopted, the solution provided in this embodiment can reduce the risk of the second part 2312 folding during the winding or flattening process, so that the winding can proceed smoothly, and can reduce the risk of overlap between the tab 231b and the anode plate 232.

[0167] In other embodiments, the second end face M3 may also have other configurations, which can be determined according to the usage requirements.

[0168] like Figure 6 and Figure 10 As shown, in some embodiments, the first end face M2 and the second end face M3 are connected.

[0169] In this embodiment, the first end face M2 and the second end face M3 can be set in the same way, such as both being inclined planes set at an obtuse angle to the first plane M1, or both being planes parallel to the height direction; or they can be set in different ways, such as the first end face M2 being an inclined plane and the second end face M3 being a plane, or the first end face M2 being a plane and the second end face M3 being an inclined plane, or both the first end face M2 and the second end face M3 being inclined planes, but with different inclination angles.

[0170] The first end face M2 and the second end face M3 are connected, and both can be completed by the same cutting process, without the need for two operations, which can improve the preparation efficiency.

[0171] like Figures 14 to 16 As shown, in some embodiments, the first end face M2 and the second end face M3 are spaced apart in the winding direction X, and the second end face M3 is located outside the first end face M2.

[0172] In this embodiment, the first end face M2 and the second end face M3 can be configured in the same or different ways. "Interval configuration" means that the first end face M2 and the second end face M3 have a certain distance between them in the winding direction X. "The second end face M3 is located outside the first end face M2" means that the second end face M3 is closer to the tail end face of the cathode electrode 231 than the first end face M2.

[0173] Compared to connecting the first end face M2 and the second end face M3, this reduces the amount of material removed from the second part 2312, thus lowering the risk of short circuit caused by overlap between the anode electrode 232 and the cathode electrode 231.

[0174] Figure 17 This is a partially expanded structural diagram of the electrode assembly in a battery cell provided for other embodiments of this application. For example... Figure 17 As shown, in some embodiments, the anode electrode 232 also has a target portion.

[0175] Figure 17 The portion of the anode electrode 232 located to the right of the dashed line K is the target portion. It can be understood that when both the cathode electrode 231 and the anode electrode 232 have target portions, the arrangement of the two target portions can be the same (e.g., ...). Figure 17 As shown), they can also be different (e.g. Figure 15 As shown in the figure, the specific details can be determined according to the usage requirements.

[0176] The anode plate 232 also has a target portion that can reduce the risk of wrinkling of the anode plate 232, thereby reducing the risk of the insulating layer on the anode plate 232 falling off.

[0177] In some embodiments, the battery cell is a cylindrical cell. This reduces the likelihood of excessive self-discharge in cylindrical cells.

[0178] According to some embodiments of this application, this application also provides a battery device. The battery device includes a single battery cell provided by any of the above solutions.

[0179] The electrical device provided in this application embodiment includes the above-mentioned battery cell and can achieve the same effect, which will not be described in detail here.

[0180] According to some embodiments of this application, this application also provides an electrical device, including a battery cell or battery device provided by any of the above solutions. The battery cell or battery device is used to store or provide electrical energy.

[0181] The electrical device can be any of the aforementioned devices or systems that utilize individual battery cells.

[0182] The electrical device provided in this application embodiment includes the above-mentioned battery cell or battery device, and can achieve the same effect, which will not be described in detail here.

[0183] like Figures 5 to 17 As shown, one embodiment of this application provides a battery cell. The battery cell is a cylindrical battery, including a wound cathode electrode 231 and an anode electrode 232. The cathode electrode 231 includes a main body structure 231a and a tab portion 231b arranged sequentially along the height direction. The main body structure 231a has a coating. A portion of the main body structure 231a extends beyond the tab portion 231b along its own winding direction X, forming a target portion.

[0184] The coating includes an active material layer and an insulating layer. The main structure 231a includes a first part 2311 and a second part 2312 arranged sequentially along the height direction. The second part 2312 is located between the first part 2311 and the tab part 231b, and the surface of the second part 2312 is provided with an insulating layer. The surface of the first part 2311 is provided with an active material layer.

[0185] In the height direction, the size of the target portion is greater than or equal to the size of the first portion 2311, and less than or equal to the size of the main structure 231a. At least a portion of the second portion 2312 extends beyond the anode plate 232 in the height direction, and the size of the portion of the second portion 2312 extending beyond the anode plate 232 is 0.1 mm to 1 mm. The thickness of the insulating layer is 30 μm to 50 μm.

[0186] The target portion is located at the outer end of the main structure 231a in the winding direction X. In the winding direction X, the size of the target portion is 1 / 9 to 1 / 20 of the size of the main structure 231a.

[0187] The target section can have multiple settings.

[0188] In some embodiments, the tab portion 231b and the second portion 2312 form a combined structure. A portion of the first portion 2311 extends beyond the combined structure along the winding direction X to form a target portion.

[0189] In other embodiments, a portion of the first portion 2311 extends beyond the tab 231b along the winding direction X to form a first protrusion. At least a portion of the second portion 2312 extends beyond the tab 231b to form a second protrusion. The second protrusion and the first protrusion combine to form the target portion.

[0190] Based on the above embodiments, the connecting surface between the first part 2311 and the second part 2312 is a first plane M1. The tab part 231b has a first end face M2 in the winding direction X. The first end face M2 is disposed close to the target part, and the first end face M2 may be disposed at an obtuse angle to the first plane M1 or may be parallel to the height direction.

[0191] The second part 2312 has a second end face M3 in the winding direction X, and the second end face M3 is located inside or near the target part. The second end face M3 may be set at an obtuse angle to the first plane M1, or it may be parallel to the height direction.

[0192] The first end face M2 can be connected to the second end face M3, or it can be spaced apart from the second end face M3 in the winding direction X. When the first end face M2 and the second end face M3 are spaced apart, the second end face M3 is located outside the first end face M2.

[0193] In the height direction, at least a portion of the second part 2312 within the target part has a dimension smaller than the dimensions of the other parts. Furthermore, in the height direction, the dimension of the second part 2312 within the target part is less than or equal to 1 mm.

[0194] The anode plate 232 can be configured with a target section or not.

[0195] By using the battery cell provided in this embodiment, the risk of the tab 231b of the cathode electrode 231 bending and overlapping with the anode electrode 232 can be reduced. The risk of the tab 232 bending and overlapping with the tab 231b of the cathode electrode 231 can also be reduced. This can reduce the probability of excessive self-discharge and thus reduce the risk of large voltage difference in the battery device.

[0196] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer shell has a receiving cavity; An electrode assembly is disposed within the receiving cavity, the electrode assembly comprising a wound cathode electrode and an anode electrode; At least one of the cathode electrode and the anode electrode is a target electrode. The target electrode includes a main structure and an electrode tab arranged sequentially along the height direction of the target electrode. The main structure has a coating, and the electrode tab does not have a coating. A portion of the main structure extends beyond the electrode tab along the winding direction to form a target portion.

2. The battery cell as described in claim 1, characterized in that, The target portion is located at the outer end of the main structure in the winding direction.

3. The battery cell as described in claim 2, characterized in that, In the winding direction, the size of the target portion is 1 / 9 to 1 / 20 of the size of the main structure.

4. The battery cell according to any one of claims 1-3, characterized in that, The coating includes an active material layer and an insulating layer; the main structure includes a first part and a second part arranged sequentially along the height direction, the second part being located between the first part and the tab, and the insulating layer being provided on the surface of the second part; the active material layer being provided on the surface of the first part; the portion of the first part and / or the second part extending beyond the tab along the winding direction forms a target portion; In the height direction, the size of the target part is greater than or equal to the size of the first part, and less than or equal to the size of the main structure.

5. The battery cell as described in claim 4, characterized in that, The tab and the second portion form a combined structure; a portion of the first portion extends beyond the combined structure along the winding direction to form the target portion.

6. The battery cell as described in claim 4, characterized in that, A portion of the first part extends beyond the tab to form a first protrusion along the winding direction; at least a portion of the second part extends beyond the tab to form a second protrusion; the second protrusion and the first protrusion combine to form the target part.

7. The battery cell as described in claim 4, characterized in that, Both the cathode electrode and the anode electrode include the main body structure and the tab portion, and the tab portion of the cathode electrode and the tab portion of the anode electrode are disposed at both ends of the electrode assembly in the height direction; at least a portion of the second portion of the cathode electrode extends beyond the anode electrode in the height direction.

8. The battery cell as described in claim 4, characterized in that, In the height direction, the portion of the second part that extends beyond the anode electrode has a dimension of 0.1 mm to 1 mm.

9. The battery cell as described in claim 4, characterized in that, The thickness of the insulating layer is 30μm-50μm.

10. The battery cell as described in claim 4, characterized in that, In the height direction, the size of at least a portion of the second part within the target part is smaller than the size of the portion of the second part outside the target part.

11. The battery cell as described in claim 4, characterized in that, In the height direction, the dimension of the second part within the target part is less than or equal to 1 mm.

12. The battery cell as described in claim 4, characterized in that, The connecting surface between the first part and the second part is a first plane, the tab has a first end face in the winding direction, the first end face is disposed close to the target part, and the first end face and the portion of the first plane located within the target part are disposed at a first angle, wherein the first angle is an obtuse angle.

13. The battery cell as described in claim 12, characterized in that, The first included angle is greater than or equal to 150° and less than 180°.

14. The battery cell as described in claim 4, characterized in that, The tab has a first end face in the winding direction, the first end face is disposed close to the target portion, and the first end face is parallel to the height direction.

15. The battery cell as described in claim 12, characterized in that, The second portion has a second end face in the winding direction, the second end face being located within or near the target portion; the second end face is arranged at a second angle with the portion of the first plane located within the target portion, or is parallel to the height direction; the second angle is an obtuse angle.

16. The battery cell as described in claim 15, characterized in that, The first end face and the second end face are connected.

17. The battery cell as described in claim 15, characterized in that, The first end face and the second end face are spaced apart in the winding direction, and the second end face is located outside the first end face.

18. The battery cell according to any one of claims 1-3, characterized in that, The battery cell is a cylindrical battery.

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

20. An electrical device, characterized in that, Includes a battery cell according to any one of claims 1-18 or a battery device according to claim 19.

Images