Battery monomer, battery device and electric equipment

Abstract

The utility model discloses a battery monomer, a battery device and electric equipment. The battery monomer comprises a shell, a winding pole piece group and an additional pole piece. The winding pole piece set is arranged in the shell and comprises a first pole piece and a second pole piece which are arranged in a stacked mode. The tail end of the first pole piece along the winding direction is formed by winding the first pole piece and the second pole piece along the winding direction, and at least part of the tail end of the first pole piece along the winding direction is positioned on the outermost side of the winding pole piece group. The additional pole piece is arranged in the shell, the additional pole piece and at least part of the tail end of the first pole piece in the winding direction are oppositely arranged, and the polarity of the additional pole piece is opposite to that of the first pole piece. According to the battery monomer, the battery device and the electric equipment, the utilization rate of the electrode plates in the electrode assembly can be improved, and waste is reduced.

Description

Technical Field

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

[0002] Batteries are widely used in various electronic devices, such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy airplanes, electric toy ships, power tools, and energy storage systems, etc.

[0003] Currently, improving the energy density of individual battery cells is also one of the research issues in this field. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can improve the utilization rate of electrode plates in the electrode assembly and reduce waste.

[0005] In a first aspect, this application provides a battery cell, including a casing, a wound electrode assembly, and an additional electrode. The wound electrode assembly is disposed within the casing and includes a first electrode and a second electrode stacked together. The first and second electrode are wound along a winding direction, with at least a portion of the end of the first electrode along the winding direction located on the outermost side of the wound electrode assembly. The additional electrode is disposed within the casing, and is disposed opposite to at least a portion of the end of the first electrode along the winding direction, with the polarity of the additional electrode being opposite to that of the first electrode.

[0006] In the technical solution of this application embodiment, a shell is provided to offer a stable environment for the wound electrode assembly and additional electrodes, reducing damage caused by external impurities and moisture. The wound electrode assembly is housed within the shell, where positive and negative electrodes are stacked and wound, improving the compactness of the electrode assembly and the utilization rate of the internal space of the shell, thereby increasing the energy density of the battery cell. Additional electrodes are placed outside the wound electrode assembly, where lithium insertion / extraction reactions occur with the outermost electrode of the wound electrode assembly, fully utilizing the active material layer of the outermost electrode of the wound electrode assembly, reducing waste and increasing utilization. Furthermore, the above structure is convenient to manufacture and has high assembly efficiency.

[0007] In some embodiments, the wound electrode assembly includes a flat region and bent regions at both ends of the flat region. The end of the first electrode along the winding direction is located in the flat region, and the additional electrode is disposed opposite to the flat region. In the above structure, the wound electrode assembly forms the flat and bent regions by pressure shaping, which can better adapt to the structure of the square shell and improve the utilization rate of the internal space of the shell. Furthermore, it simplifies the manufacturing process and improves production efficiency. Placing the additional electrode in the flat region increases the contact area with the outer electrode of the wound electrode assembly and facilitates the placement of the additional electrode.

[0008] In some embodiments, the first electrode is a negative electrode, the second electrode is a positive electrode, and an additional electrode is a positive electrode. In the above structure, placing a negative electrode on the outermost layer of the wound electrode assembly increases the total area of ​​the negative electrode in the assembly, providing more lithium-ion insertion and extraction sites, thereby improving the capacity and energy density of the battery cell. Placing a positive electrode as an additional electrode corresponding to the outermost negative electrode fully utilizes the material of the outermost negative electrode, reducing waste and improving material utilization.

[0009] In some embodiments, the first electrode includes a first current collector and a first active material layer disposed on opposite sides of the first current collector, and the second electrode includes a second current collector and a second active material layer disposed on opposite sides of the second current collector. In the above structure, configuring the first electrode and the second electrode as having active material layers on both sides increases the total mass of the active material, thereby improving the energy density of the battery cell.

[0010] In some embodiments, the additional electrode includes a third current collector and a third active material layer. The third active material layer is disposed on at least one side of the third current collector and on the surface of the third current collector facing the end of the first electrode in the winding direction. In the above structure, the active material is disposed on the side of the additional electrode facing the wound electrode assembly, reducing material waste and increasing the energy density of the battery cell.

[0011] In some embodiments, the additional electrode further includes a thermistor layer disposed on the side of the third active material layer facing the third current collector. The thermistor layer can release heat when energized. In the above structure, by providing the thermistor layer, rapid temperature rise can be achieved in the initial stage of battery cell operation, thereby improving the fast-charging performance of the battery cell.

[0012] In some embodiments, the thermistor layer includes at least one of a polyvinylidene fluoride layer, a graphene heating film layer, and a ceramic electrothermal layer. The above structure utilizes readily available raw materials and is easy to manufacture, while also enabling rapid heating of the thermistor layer, thus improving the fast-charging performance of the battery cell.

[0013] In some embodiments, the additional electrode and the wound electrode assembly are arranged along a first direction. The wound electrode assembly further includes a first electrode tab connected to a first current collector, a second electrode tab connected to a second current collector, and a third electrode tab connected to a third current collector. The third electrode tab and the first electrode tab at least partially overlap in the first direction. In the above structure, the third electrode tab is stacked with the first electrode tab, which facilitates the connection of the first electrode tab, the third electrode tab, and the electrode terminal, improving the convenience and efficiency of assembly.

[0014] In some embodiments, the wound electrode assembly further includes a separator film disposed between the first electrode and the second electrode. The separator film has a connecting segment at its end along the winding direction. At least a portion of the connecting segment is located on the outermost side of the wound electrode assembly, and the connecting segment completely covers the end of the first electrode along the winding direction to insulate the end of the first electrode along the winding direction from the additional electrode. In the above structure, the separator film provides insulation between the first and second electrodes, improving the stability of the battery cell operation. Furthermore, the connecting segment formed on the outermost side of the wound electrode assembly insulates the additional electrode from the wound electrode assembly, improving the insulation performance between the additional electrode and the wound electrode assembly. Simultaneously, the above structure can be completed in a single winding operation, resulting in high production efficiency.

[0015] In some embodiments, there are two wound electrode groups. The first electrodes of the two wound electrode groups are arranged opposite each other at their ends along the winding direction. An additional electrode is disposed between the two wound electrode groups, and a third active material layer is disposed on opposite sides of the third current collector. In the above structure, by setting two wound electrode groups, the energy density of the battery cell is improved. By setting an additional electrode between the two wound electrode groups, the outermost electrode of the two wound electrode groups can be utilized with as few additional electrodes as possible, effectively improving the utilization rate of the internal space of the casing and the energy density of the battery cell.

[0016] In some embodiments, there are two wound electrode groups and two corresponding additional electrode sheets, with the two wound electrode groups positioned between the two additional electrode sheets. In the above structure, each wound electrode group corresponds to one additional electrode sheet, allowing the wound electrode groups and additional electrode sheets to be pre-assembled, thus improving assembly accuracy and efficiency.

[0017] Secondly, this application provides a battery device that includes the battery cell described in the above embodiments.

[0018] Thirdly, this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0019] 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

[0020] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the structure of a vehicle according to one embodiment of this application;

[0022] Figure 2 This is an exploded view of the battery device provided in some embodiments of this application;

[0023] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;

[0024] Figure 4 This is a schematic diagram of the structure of the electrode plates provided in some embodiments of this application;

[0025] Figure 5 This is a schematic diagram of the structure of the wound electrode assembly provided in some embodiments of this application;

[0026] Figure 6 This is a schematic diagram of the structure of the first electrode provided in some embodiments of this application;

[0027] Figure 7 This is a schematic diagram of the structure of the second electrode provided in some embodiments of this application;

[0028] Figure 8 This is a schematic diagram of the structure of the additional electrode provided in some embodiments of this application;

[0029] Figure 9 This is a schematic diagram of the structure of additional electrode plates provided in other embodiments of this application;

[0030] Figure 10 This is a schematic diagram of the structure of the wound electrode assembly provided in other embodiments of this application;

[0031] Figure 11 Schematic diagrams of the structure of the wound electrode assembly provided in some embodiments of this application;

[0032] Figure 12 This is a schematic diagram of the structure of a wound electrode assembly provided in some embodiments of this application.

[0033] Detailed Explanation of Reference Numerals

[0034] 1. Vehicle; 2. Battery assembly; 3. Controller; 4. Motor; 5. Housing; 51. First housing section; 52. Second housing section; X, First direction; Z, Winding direction; 6. Battery cell; 10. Electrode assembly; 11. Straight area; 12. Bending area; 20. Housing; 25. Electrode terminal; 30. End cap; 40. Outer shell; 50. Winded electrode assembly; 501. First electrode; 502. Second electrode; 503. First current collector; 504. First active material layer; 505. Second current collector; 506. Second active material layer; 507. First tab; 508. Second tab; 60. Additional electrode; 601. Third current collector; 602. Third active material layer; 603. Thermistor layer; 604. Third tab. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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).

[0041] 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.

[0042] 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.

[0043] 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.

[0044] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0045] The electrode assembly is a crucial component of a battery cell, converting electrical energy into chemical energy. The electrode assembly includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrode plates. Optionally, the electrode assembly also includes a separator disposed between the positive and negative electrode plates. This separator reduces the risk of short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0046] To improve the compactness of the electrode arrangement and increase the energy density of a battery cell, the electrode sheets and separators are typically stacked sequentially before being wound. After winding, the outermost electrode sheets face the inner wall of the casing. This portion of the electrode sheets cannot participate in the charge-discharge reaction, resulting in material waste.

[0047] To address the aforementioned issues, this application provides a battery cell with a casing that provides a stable environment for the wound electrode assembly and additional electrodes, reducing damage caused by external impurities and moisture. The wound electrode assembly is housed within the casing, where positive and negative electrodes are stacked and wound, improving electrode compactness and internal space utilization, thereby increasing the battery cell's energy density. Additional electrodes are placed outside the wound electrode assembly, allowing for lithium insertion / extraction reactions with the outermost electrode layer of the wound electrode assembly, fully utilizing the active material layer of the outermost electrode layer, reducing waste, and increasing utilization. Furthermore, this structure is convenient to manufacture and offers high assembly efficiency.

[0048] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0049] 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 together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0050] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0051] 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.

[0052] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0053] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0054] Battery cells may include, but are not limited to, lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-metal hydride battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0055] As an example, the battery cell can be a cylindrical battery cell, a prismatic 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. This application does not have any particular limitations.

[0056] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0057] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0058] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0059] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0060] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0061] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0062] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0063] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0064] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0065] The housing 5 is used to accommodate the battery cell 6, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 51 and a second housing portion 52, which cover each other, and the first housing portion 51 and the second housing portion 52 together define a receiving space 53 for accommodating the battery cell.

[0066] In the battery device 2, there can be one or more battery cells 6. If there are multiple battery cells 6, they can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel. Multiple battery cells 6 can be directly connected in series, in parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 6 is housed in the housing 5. Alternatively, multiple battery cells can first be connected in series, in parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, in parallel, or in a mixed manner to form a whole assembly, which is then housed in the housing 5.

[0067] In some alternative embodiments, the battery cell 6 can also be directly housed within the housing 5 to reduce the number of connecting or supporting components required to assemble the battery module and improve the energy density of the battery device 2.

[0068] For example, the battery cell 6 may be the smallest unit that makes up the battery device 2.

[0069] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application.

[0070] like Figure 3 As shown, in some embodiments, the battery cell 6 includes a housing 40 and an electrode assembly 10 housed within the housing 40.

[0071] The electrode assembly 10 includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell 6, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrodes. Optionally, the electrode assembly 10 also includes a separator disposed between the positive and negative electrodes, which can reduce the risk of short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0072] The housing 40 is used to encapsulate the electrode assembly 10 and electrolyte components. The housing 40 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite housing 40), or aluminum-plastic film, etc.

[0073] In some embodiments, the housing 40 includes a housing 20 and an end cap 30, the housing 20 having an opening and the end cap 30 for closing the opening.

[0074] In some embodiments, the battery cell 6 further includes an electrolyte housed within the casing 40. The electrolyte acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid.

[0075] In some embodiments, the battery cell 6 includes electrode terminals 25. The electrode terminals 25 are electrically connected to the electrode assembly 10 for outputting or inputting electrical energy into the battery cell 6.

[0076] Please refer to the reference. Figures 3 to 5 , Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. Figure 4 This is a schematic diagram of the structure of the electrode plates provided in some embodiments of this application. Figure 5 This is a schematic diagram of the structure of a wound electrode assembly provided in some embodiments of this application.

[0077] As shown in the figure, an embodiment of this application provides a battery cell 6, including a housing 40, a wound electrode assembly 50, and an additional electrode 60. The wound electrode assembly 50 is disposed within the housing 40 and includes a first electrode 501 and a second electrode 502 stacked together. The first electrode 501 and the second electrode 502 are wound along a winding direction Z, with at least a portion of the end of the first electrode 501 along the winding direction Z located on the outermost side of the wound electrode assembly 50. The additional electrode 60 is disposed within the housing 40, and is disposed opposite to at least a portion of the end of the first electrode 501 along the winding direction Z. The polarity of the additional electrode 60 is opposite to that of the first electrode 501.

[0078] The wound electrode assembly 50 also includes an isolation component, which is disposed between the first electrode 501 and the second electrode 502 to insulate them. Furthermore, an isolation element is also provided on the side of the first electrode 501 facing away from the second electrode 502 to insulate the first electrode 501 from the housing 40. An isolation element is also provided on the side of the second electrode 502 facing away from the first electrode 501 to insulate the second electrode 502 from the inside of the first electrode 501 after it is wound around the first electrode 502.

[0079] For example, the end of the first electrode 501 along the winding direction Z may surround the other part of the wound electrode group 50 by 1 turn or 1.25 turns. The end of the first electrode 501 along the winding direction Z is an extension of the body of the first electrode 501, which has the same structure as the body of the first electrode 501.

[0080] The structure of the additional electrode 60 can be similar to that of the second electrode 502, and it can be manufactured using the same materials, thereby improving the manufacturing efficiency of the battery cell 6. For example, the additional electrode 60 can be disposed between the wound electrode assembly 50 and the housing 40.

[0081] The first electrode 501 and the second electrode 502 have opposite polarities, meaning that the two electrodes have opposite properties in terms of charge distribution; one is a positive electrode, and the other is a negative electrode. The additional electrode 60 has the opposite polarity to the end of the first electrode 501 along the winding direction Z, which can compensate for the vacancy of active material on the outer side of the end of the first electrode 501 along the winding direction Z, thereby improving material utilization.

[0082] In the technical solution of this application embodiment, a housing 40 is provided to provide a stable environment for the wound electrode assembly 50 and the additional electrode 60, reducing damage to the wound electrode assembly 50 and the additional electrode 60 caused by external impurities and moisture. The wound electrode assembly 50 is disposed within the housing 40, where positive and negative electrode sheets are stacked and wound, improving the compactness of the electrode sheets and the utilization rate of the internal space of the housing 40, thereby increasing the energy density of the battery cell 6. An additional electrode 60 is disposed outside the wound electrode assembly 50, and a lithium insertion / extraction reaction occurs between it and the outermost electrode sheet of the wound electrode assembly 50, fully utilizing the active material layer of the outermost electrode sheet of the wound electrode assembly 50, reducing waste and improving utilization. Furthermore, the above structure is convenient to manufacture and has high assembly efficiency.

[0083] In some embodiments of this application, the wound electrode assembly 50 includes a flat region 11 and a bending region 12 disposed at both ends of the flat region 11. The end of the first electrode 501 along the winding direction Z is disposed in the flat region 11, and the additional electrode 60 is disposed opposite to the flat region 11.

[0084] In the above structure, the wound electrode assembly 50 is formed into a flat area 11 and a bent area 12 by pressure shaping, which can better adapt to the structure of the square shell 20 and improve the utilization rate of the internal space of the shell 20. The additional electrode 60 is set in the flat area 11, which increases the contact area with the outer electrode of the wound electrode assembly 50 and facilitates the setting of the additional electrode 60.

[0085] In some embodiments of this application, the first electrode 501 is a negative electrode, the second electrode 502 is a positive electrode, and the additional electrode 60 is a positive electrode.

[0086] In the wound electrode assembly 50, the main function of the positive electrode is to provide electrons. When current flows through the battery, electrons flow from the positive electrode to the negative electrode through the wires, forming a current. The main function of the negative electrode is to receive electrons transferred from the positive electrode. To provide enough electron insertion sites, more negative electrode sheets are usually placed in the battery cell 6 to ensure that the charging and discharging reactions in the battery are complete and rapid. Therefore, the outermost part of the wound electrode assembly 10 is usually set as the negative electrode.

[0087] In the above structure, placing a negative electrode on the outermost layer of the wound electrode assembly 50 significantly increases the total area of ​​the negative electrode. A larger negative electrode provides more lithium-ion insertion and extraction sites, thereby improving the capacity and energy density of the battery cell 6. Placing a positive electrode as an additional electrode 60 corresponding to the outermost negative electrode fully utilizes the material of the outermost negative electrode. This reduces material waste, improves material utilization, and thus lowers the battery production cost. Furthermore, the larger negative electrode area helps disperse current density, reducing the risk of localized overheating and short circuits. Especially in high-power and high-energy-density applications, this enhances the operational stability of the battery cell 6.

[0088] like Figure 6 as well as Figure 7 As shown, in some embodiments of this application, the first electrode 501 includes a first current collector 503 and a first active material layer 504 disposed on opposite sides of the first current collector 503, and the second electrode 502 includes a second current collector 505 and a second active material layer 506 disposed on opposite sides of the second current collector 505.

[0089] In the above structure, by providing active material layers on both sides of the first electrode 501 and the second electrode 502, the total mass of the active material can be increased. More active material means more energy storage and release sites, thereby improving the energy density of the battery cell 6.

[0090] like Figure 8 As shown, in some embodiments of this application, the additional electrode 60 includes a third current collector 601 and a third active material layer 602. The third active material layer 602 is disposed on at least one side of the third current collector 601, and the third active material layer 602 is disposed on the surface of the third current collector 601 facing the end of the first electrode 501 in the winding direction Z.

[0091] In the above structure, the third current collector 601 serves as a carrier for the active material layer. By setting the active material layer on the surface of the additional electrode 60 facing the end of the first electrode 501 along the winding direction Z, this space can be fully utilized, reducing material waste and increasing the energy density of the battery cell 6.

[0092] like Figure 9 As shown, in some embodiments of this application, the additional electrode 60 further includes a thermistor layer 603, which is disposed on the side of the third active material layer 602 facing the third current collector 601. The thermistor layer 603 can release heat after being energized.

[0093] The thermistor layer 603 is a special material layer that can release heat when an electric current is applied. This material typically has specific resistivity and thermal conductivity to effectively generate heat when an electric current is applied. In the initial stage of operation of the battery cell 6, the internal temperature of the battery can be rapidly increased by applying an electric current to the thermistor layer 603.

[0094] This helps improve battery performance in low-temperature environments, especially during fast charging, reducing charging time and increasing charging efficiency. Low temperatures negatively impact fast charging performance because they reduce the rate of ion diffusion within the battery, thus increasing charging time. The rapid heating achieved through the thermistor layer 603 effectively mitigates this issue, enhancing the battery's fast charging performance in low-temperature environments.

[0095] Besides improving fast charging performance, rapid heating also helps improve other battery performance aspects, such as cycle stability and capacity retention. This is because a high-temperature environment helps accelerate chemical reactions inside the battery, thereby increasing its activity.

[0096] It is understandable that a heat exchange component is usually provided on the outer side of the casing 40 of the battery cell 6, which can exchange heat with the battery cell 6, reduce the internal temperature of the battery cell 6 when the temperature of the battery cell 6 is too high, and maintain the operation of the battery cell 6 within a stable and efficient range.

[0097] In the above structure, by setting the thermal layer 603, rapid heating can be achieved in the initial stage of operation of the battery cell 6, thereby improving the fast charging performance of the battery cell 6.

[0098] In some embodiments of this application, the thermistor layer 603 includes at least one of a polyvinylidene fluoride layer, a graphene heating film layer, and a ceramic electrothermal layer.

[0099] The polyvinylidene fluoride (PVDF) layer is a novel polymeric piezoelectric material layer with unique properties such as piezoelectricity, dielectricity, and thermoelectricity. In the thermistor layer 603, PVDF can serve as a highly efficient heat conductor, enabling rapid heat transfer. Simultaneously, PVDF also possesses good flexibility, impact resistance, and chemical stability, contributing to the stability and durability of the thermistor layer 603.

[0100] Graphene is an ultrathin material composed of a single layer of tightly packed carbon atoms, possessing extremely high electrical and thermal conductivity. Graphene heating films can rapidly convert electrical energy into heat energy, enabling rapid heat generation and transfer. Furthermore, graphene exhibits excellent flexibility and stability, maintaining its original performance even in extreme environments.

[0101] Ceramic heating layers are typically made of thermistor ceramic materials, such as PTC (positive temperature coefficient) ceramics or NTC (negative temperature coefficient) ceramics. These ceramic materials are sensitive to temperature changes, allowing for adjustments to their resistivity and heat generation as needed. Ceramic heating layers offer advantages such as high temperature resistance, corrosion resistance, and good stability, making them suitable for battery cells operating in high-temperature environments.

[0102] The above structure allows for easy access to raw materials and facilitates production, while also enabling rapid heating of the thermal layer 603 and improving the fast-charging performance of the battery cell 6.

[0103] like Figure 10 As shown, in some embodiments of this application, the additional electrode 60 and the wound electrode group 50 are arranged along the first direction X. The wound electrode group 50 further includes a first electrode tab 507 connected to the first current collector 503, a second electrode tab 508 connected to the second current collector 505, and a third electrode tab 604 connected to the third current collector 601. The third electrode tab 604 and the first electrode tab 507 at least partially overlap in the first direction X.

[0104] Optionally, the second tab 508 is staggered with the first tab 507 and the third tab 604 in the first direction X. This structure increases the creepage distance between the second tab 508 and the other tabs, improving insulation performance.

[0105] In the above structure, the third tab 604 is stacked on top of the first tab 507, which facilitates the connection of the first tab 507, the third tab 604 and the electrode terminal 25, and reduces the length of the current transmission path inside the battery cell 6. The overlapping design makes the wound electrode assembly 50 and the additional electrode 60 more compact in structure, reduces unnecessary space waste, and improves the convenience and efficiency of assembly.

[0106] In some embodiments of this application, the wound electrode assembly 50 further includes a separator film disposed between the first electrode 501 and the second electrode 502. The separator film has a connecting segment at its end along the winding direction Z. At least a portion of the connecting segment is located on the outermost side of the wound electrode assembly 50, and the connecting segment completely covers the end of the first electrode 501 along the winding direction Z to insulate the end of the first electrode 501 along the winding direction Z from the additional electrode 60.

[0107] In the above structure, the first electrode 501 and the second electrode 502 are insulated and isolated by a separator, which improves the operational stability of the battery cell 6. Furthermore, a connecting section is formed on the outermost side of the wound electrode assembly 50 to insulate the additional electrode 60 from the wound electrode assembly 50, improving the insulation performance between the additional electrode 60 and the wound electrode assembly 50. Moreover, the above structure can be completed in a single winding operation, resulting in high production efficiency.

[0108] like Figure 11 As shown, in some embodiments of this application, there are two wound electrode groups 50, the first electrode 501 of the two wound electrode groups 50 are arranged opposite each other at the ends along the winding direction Z, the additional electrode 60 is disposed between the two wound electrode groups 50, and the third active material layer 602 is disposed on opposite sides of the third current collector 601.

[0109] In the above structure, by setting two wound electrode groups 50, the energy density of the battery cell 6 is improved. By setting an additional electrode 60 between the two wound electrode groups 50, the outermost electrode of the two wound electrode groups 50 can be utilized with as few additional electrode 60s as possible, which effectively improves the utilization rate of the internal space of the casing 40 and the energy density of the battery cell 6.

[0110] like Figure 12 As shown, in some embodiments of this application, there are two wound electrode groups 50 and two additional electrode groups 60, with the two wound electrode groups 50 disposed between the two additional electrode groups 60.

[0111] In the above structure, each wound electrode group 50 is respectively provided with an additional electrode 60, which can pre-assemble the wound electrode group 50 and the additional electrode 60, thereby improving the assembly accuracy and assembly efficiency.

[0112] This application provides a battery device 2, which includes the battery cell 6 described in the above embodiments. This application also provides an electrical device, which includes the battery device 2 described in the above embodiments. The battery device 2 is used to provide electrical energy. In both the battery device 2 and the electrical device, a housing 40 is provided to provide a stable environment for the wound electrode assembly 50 and the additional electrode 60, reducing damage to the wound electrode assembly 50 and the additional electrode 60 caused by external impurities and moisture. The wound electrode assembly 50 is disposed within the housing 40, where positive and negative electrode sheets are stacked and wound, improving the compactness of the electrode sheets and the utilization rate of the internal space of the housing 40, thereby increasing the energy density of the battery cell 6. An additional electrode 60 is disposed outside the wound electrode assembly 50, and a lithium insertion / extraction reaction occurs between it and the outermost electrode sheet of the wound electrode assembly 50, fully utilizing the active material layer of the outermost electrode sheet of the wound electrode assembly 50, reducing waste and improving utilization. Furthermore, the above structure is convenient to manufacture and has high assembly efficiency.

[0113] 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: shell; A wound electrode assembly is disposed within the housing. The wound electrode assembly includes a first electrode and a second electrode stacked together. The first electrode and the second electrode are wound in a winding direction, and the end of the first electrode along the winding direction is located at the outermost edge of the wound electrode assembly. An additional electrode is disposed within the housing, and is disposed opposite to at least a portion of the end of the first electrode along the winding direction, wherein the polarity of the additional electrode is opposite to that of the first electrode.

2. The battery cell according to claim 1, characterized in that, The wound electrode assembly includes a flat region and bending regions at both ends of the flat region. The end of the first electrode along the winding direction is located in the flat region, and the additional electrode is disposed opposite to the flat region.

3. The battery cell according to claim 1, characterized in that, The first electrode is a negative electrode, the second electrode is a positive electrode, and the additional electrode is a positive electrode.

4. The battery cell according to claim 1, characterized in that, The first electrode includes a first current collector and a first active material layer disposed on opposite sides of the first current collector, and the second electrode includes a second current collector and a second active material layer disposed on opposite sides of the second current collector.

5. The battery cell according to claim 4, characterized in that, The additional electrode includes: The third volume, fluids; and A third active material layer is disposed on at least one side of the third current collector, and the third active material layer is disposed on the surface of the third current collector facing the end of the first electrode sheet along the winding direction.

6. The battery cell according to claim 5, characterized in that, The additional electrode also includes a thermistor layer, which is disposed on the side of the third active material layer facing the third current collector. The thermistor layer can release heat when energized.

7. The battery cell according to claim 6, characterized in that, The thermosensitive layer includes at least one of a polyvinylidene fluoride layer, a graphene heating film layer, and a ceramic heating layer.

8. The battery cell according to claim 5, characterized in that, The additional electrode and the wound electrode group are arranged along a first direction. The wound electrode group further includes a first electrode tab connected to the first current collector, a second electrode tab connected to the second current collector, and a third electrode tab connected to the third current collector. The third electrode tab and the first electrode tab at least partially overlap in the first direction.

9. The battery cell according to claim 5, characterized in that, The wound electrode assembly further includes a separator film disposed between the first electrode and the second electrode. The separator film has a connecting segment at its end along the winding direction. At least a portion of the connecting segment is located on the outermost side of the wound electrode assembly, and the connecting segment completely covers the end of the first electrode along the winding direction to insulate the end of the first electrode along the winding direction from the additional electrode.

10. The battery cell according to any one of claims 5-9, characterized in that, The number of the wound electrode groups is two, the first electrode of the two wound electrode groups is arranged opposite to each other along the winding direction, the additional electrode is disposed between the two wound electrode groups, and the third active material layer is disposed on opposite sides of the third current collector.

11. The battery cell according to any one of claims 1-9, characterized in that, The number of wound electrode groups is two, and the number of additional electrode sheets is also two, with the two wound electrode groups disposed between the two additional electrode sheets.

12. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-11.

13. An electrical appliance, characterized in that, The electrical equipment includes the battery device as described in claim 12, the battery device being used to provide electrical energy.

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