Battery monomer, battery and electric device

Abstract

The invention discloses a battery monomer, a battery and a power utilization device. The battery monomer comprises an end cover, a shell and an electrode assembly, the shell is provided with an opening, the end cover covers the opening, the shell is matched with the end cover to form an internal environment of the battery monomer, and the electrode assembly is accommodated in the internal environment. The electrode assembly comprises a diaphragm, a pole piece and a winding needle. The winding needle is fixedly connected with one end of the diaphragm, the diaphragm separates the pole piece and the winding needle, and the diaphragm and the pole piece are wound on the winding needle. In the technical scheme of the embodiment of the invention, the winding needle is left in the electrode assembly, so that diaphragm wrinkling caused by extraction of the winding needle is avoided to a certain extent, and the flatness of the electrode assembly is ensured to a certain extent.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] In related technologies, battery cells may include a wound electrode assembly. During the manufacturing of a wound electrode assembly, one end of the separator is fixed to a winding pin, with the positive and negative electrode sheets located on opposite sides of the separator. After winding the electrode assembly, the winding pin needs to be removed. However, removing the winding pin can easily cause the separator connected to the winding pin to wrinkle, resulting in an uneven electrode assembly. Summary of the Invention

[0003] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can solve the problem of wrinkling of the diaphragm and unevenness of the electrode assembly caused by the withdrawal of the winding needle.

[0004] In a first aspect, an embodiment of the present application provides a battery cell, comprising an end cap, a housing, and an electrode assembly. The housing has an opening, the end cap is engaged with the opening, the housing and the end cap cooperate to form an internal environment of the battery cell, and the electrode assembly is accommodated in the internal environment. The electrode assembly comprises:

[0005] diaphragm;

[0006] Pole piece;

[0007] A winding needle is fixedly connected to one end of the diaphragm, the diaphragm separates the pole piece and the winding needle, and the diaphragm and the pole piece are wound on the winding needle.

[0008] In the technical solution of the embodiment of the present application, the winding needle remains in the electrode assembly, which to a certain extent avoids the wrinkling of the diaphragm caused by pulling out the winding needle, thereby ensuring the flatness of the electrode assembly to a certain extent.

[0009] In some embodiments, the diaphragm includes a first diaphragm and a second diaphragm, the electrode includes a first electrode and a second electrode with opposite polarities, the first diaphragm separates the first electrode and the second electrode, the second diaphragm separates the first electrode and the second electrode, and the connecting end of the first diaphragm and the connecting end of the second diaphragm are fixed on the same side of the winding needle along the thickness direction.

[0010] By arranging the first diaphragm and the second diaphragm on the same side of the winding needle to separate the first pole piece, the second pole piece and the winding needle, the first pole piece and the second pole piece are prevented from contacting each other to a certain extent, and the first pole piece and the second pole piece are prevented from contacting the winding needle to a certain extent to cause a short circuit.

[0011] In some embodiments, the connecting end of the first diaphragm and the connecting end of the second diaphragm are stacked and fixed on the same side of the winding needle along the thickness direction, and the second diaphragm is located between the first diaphragm and the winding needle, or the connecting end of the second diaphragm and the connecting end of the first diaphragm are both fixed on the same side of the winding needle along the thickness direction, and the connecting end of the second diaphragm is spaced apart from the connecting end of the first diaphragm.

[0012] The first and second diaphragms are fixed on the winding needle by stacking or spacing the connecting end of the second diaphragm and the connecting end of the first diaphragm on the same side of the winding needle in the thickness direction.

[0013] In some embodiments, the diaphragm includes a first diaphragm and a second diaphragm, the electrode includes a first electrode and a second electrode with opposite polarities, the first diaphragm separates the first electrode and the second electrode, the second diaphragm separates the first electrode and the second electrode, the connecting end of the first diaphragm and the connecting end of the second diaphragm are respectively fixed on two opposite sides of the winding needle along the thickness direction, and the winding needle is located between the connecting end of the first diaphragm and the connecting end of the second diaphragm.

[0014] By arranging the first diaphragm and the second diaphragm on two opposite sides of the winding needle to separate the first pole piece, the second pole piece and the winding needle, the first pole piece and the second pole piece can be prevented from contacting each other to a certain extent, and the first pole piece and the second pole piece can be prevented from contacting the winding needle to a certain extent to cause a short circuit.

[0015] In some embodiments, the winding needle includes a first side surface and a second side surface opposite to each other in the thickness direction, the connecting end of the first diaphragm is fixed to the first side surface, and the connecting end of the second diaphragm is fixed to the second side surface;

[0016] A projection of the connecting end of the first diaphragm along the thickness direction of the winding needle at least partially overlaps with a projection of the connecting end of the second diaphragm along the thickness direction of the winding needle, or;

[0017] A projection of the connecting end of the first diaphragm along the thickness direction of the winding needle is staggered from a projection of the connecting end of the second diaphragm along the thickness direction of the winding needle.

[0018] Thus, the connecting end of the first diaphragm and the connecting end of the second diaphragm can be fixedly connected to the winding needle at two opposite side surfaces of the winding needle along the thickness direction in the above manner.

[0019] In some embodiments, the electrode assembly includes a fastening mechanism that secures one end of the separator to the winding needle.

[0020] The fastening mechanism can fix one end of the diaphragm, thereby providing tension during subsequent winding, making it easier for the diaphragm to be wound on the winding needle.

[0021] In some embodiments, the fastening mechanism comprises tape.

[0022] By providing the adhesive tape, one end of the diaphragm can be easily adhered to the winding needle, which is highly practical.

[0023] In some embodiments, the fastening mechanism includes a fastener and a groove, the groove is provided on the winding needle, the side wall of the groove is provided with an elastic member, the fastener is at least partially accommodated in the groove, and the elastic member is connected to the fastener so that the fastener presses one end of the diaphragm into the groove.

[0024] The fastener is buckled into the groove, and the elastic member is connected to the fastener, so that the fastener presses one end of the diaphragm into the groove, thereby reducing the probability of separation of the diaphragm and the winding needle and improving the fixing and limiting effect on one end of the diaphragm.

[0025] In some embodiments, the winding needle includes a rigid body and an elastic body, and the elastic body is provided on at least one side of the rigid body along the thickness direction of the winding needle.

[0026] The rigid body can prevent the winding needle from bending, and the elastic body can balance the expansion force of the electrode assembly during charging and discharging, thereby increasing the service life of the electrode assembly.

[0027] In some embodiments, the rigid body includes a steel plate, an aluminum plate, a nickel plate, or a hard plastic, and the elastic member includes a polyethylene foam material or a polypropylene foam material.

[0028] Steel plates, aluminum plates, nickel plates or hard plastics have good bending strength, which helps prevent bending of the needle. Polyethylene foam materials or polypropylene foam materials have good toughness, flexibility and cushioning properties, which helps balance the expansion force of the electrode assembly during charging and discharging.

[0029] In some embodiments, both sides of the winding needle perpendicular to the thickness direction are in an outwardly convex arc shape.

[0030] The two side surfaces perpendicular to the thickness direction are arc-shaped to avoid scratching the diaphragm to a certain extent.

[0031] In some embodiments, the bending strength of the winding needle is greater than or equal to 50 Newtons.

[0032] As a result, the application scenarios of the needle coil are wider.

[0033] In a second aspect, an embodiment of the present application provides a battery, comprising a housing and a battery cell according to any one of the above embodiments, wherein the battery cell is accommodated in the housing.

[0034] In a third aspect, an embodiment of the present application provides an electrical device, which includes the battery of the above embodiment, and the battery is used to provide electrical energy.

[0035] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0037] Figure 1 A schematic structural diagram of a vehicle according to some embodiments of the present application;

[0038] Figure 2 Schematic diagram of the exploded structure of batteries according to some embodiments of the present application;

[0039] Figure 3 This is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0040] Figure 4 This is a schematic structural diagram of an electrode assembly according to some embodiments of the present application;

[0041] Figure 5 This is one of the partially exploded schematic diagrams of the electrode assembly according to some embodiments of the present application;

[0042] Figure 6 This is a second partially exploded schematic diagram of an electrode assembly according to some embodiments of the present application;

[0043] Figure 7 This is the third partially exploded schematic diagram of the electrode assembly according to some embodiments of the present application;

[0044] Figure 8 This is a fourth partially exploded schematic diagram of an electrode assembly according to some embodiments of the present application;

[0045] Figure 9 This is a fifth partially exploded schematic diagram of an electrode assembly according to some embodiments of the present application;

[0046] Figure 10 This is a schematic structural diagram of the winding needle of some embodiments of the present application.

[0047] The accompanying drawings in the specific implementation manner are as follows:

[0048] Vehicles 1000;

[0049] Battery 100;

[0050] Controller 200;

[0051] Motor 300;

[0052] Box body 10; first part 11; second part 12;

[0053] Battery cell 20;

[0054] End cap 21;

[0055] Electrode assembly 22;

[0056] Diaphragm 221; first diaphragm 2211; first connection end 22111; second diaphragm 2212; second connection end 22121;

[0057] Pole piece 222; first pole piece 2221; second pole piece 2222;

[0058] Winding needle 223; rigid body 2231; elastic body 2232; first side surface 2233; second side surface 2234; third side surface 2235; fourth side surface 2236;

[0059] Fastening mechanism 224; adhesive tape 2241; fastener 2242; fastening groove 22421; groove 2243; elastic member 2244;

[0060] Housing 23, opening 231, internal environment 232;

[0061] Electrode terminal 24;

[0062] Pressure relief mechanism 25. DETAILED DESCRIPTION

[0063] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0065] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0066] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0067] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0068] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0069] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0070] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0071] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0072] In related technologies, battery cells may include a wound electrode assembly. During the manufacturing of a wound electrode assembly, one end of the separator is fixed to a winding pin, with the positive and negative electrode sheets located on opposite sides of the separator. After winding the electrode assembly, the winding pin needs to be removed. However, removing the winding pin can easily cause the separator connected to the winding pin to wrinkle, resulting in an uneven electrode assembly.

[0073] Based on the above considerations, and in order to solve the problem of wrinkled diaphragms and uneven electrode assemblies caused by the withdrawal of a winding needle, the present application provides a battery cell, which includes an end cap, a housing, and an electrode assembly. The housing has an opening, the end cap is fitted over the opening, and the housing and the end cap cooperate to form an internal environment for the battery cell, in which the electrode assembly is housed. The electrode assembly includes a diaphragm, an electrode sheet, and a winding needle. The winding needle is fixedly connected to one end of the diaphragm, which separates the electrode sheet and the winding needle, and the diaphragm and the electrode sheet are wound around the winding needle.

[0074] In such a battery cell, the winding needle remains in the electrode assembly, which to a certain extent prevents the separator from wrinkling due to the withdrawal of the winding needle, thereby ensuring the flatness of the electrode assembly to a certain extent.

[0075] The battery disclosed in the embodiments of the present application can be applied to electrical devices used as power sources or various energy storage systems using batteries as energy storage elements. The electrical devices may be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric vehicles, ships, spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0076] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device in an embodiment of the present application.

[0077] Please refer to Figure 1 , Figure 1A schematic structural diagram of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, to meet the power requirements for starting, navigating and driving the vehicle 1000.

[0078] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0079] Please refer to Figure 2 , Figure 2 An exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and battery cells 20, with the battery cells 20 housed within the housing 10. The housing 10 is used to provide a storage space for the battery cells 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for the battery cells 20. The second portion 12 can be a hollow structure with one end open. The first portion 11 can be a plate-like structure, with the first portion 11 overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. The first portion 11 and the second portion 12 can also be hollow structures with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0080] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 100 may be housed within the housing 10. Of course, the battery 100 may also be in the form of a battery module 100, in which multiple battery cells 20 are first connected in series, in parallel, or in a hybrid connection, and then the multiple battery modules 100 are further connected in series, in parallel, or in a hybrid connection to form an entire battery 100, and then housed within the housing 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for electrically connecting the multiple battery cells 20.

[0081] Each battery cell 20 may be a secondary battery cell 20 or a primary battery cell 20; it may also be a lithium-sulfur battery cell 20, a sodium-ion battery cell 20, or a magnesium-ion battery cell 20, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or have other shapes.

[0082] Please refer to Figure 3 , Figure 3 The schematic diagram of the exploded structure of the battery cell 20 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit that constitutes the battery 100. Figure 3 The battery cell 20 includes an end cap 21, an electrode assembly 22, a shell 23 and other functional components.

[0083] The housing 23 has an opening 231. The end cap 21 is a component that fits over the opening of the housing 23 to isolate the internal environment 232 of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 23 to fit the housing 23. Optionally, the end cap 21 can be made of a material with a certain degree of hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming when subjected to compression or collision, thereby enhancing the structural strength and reliability of the battery cell 20. Functional components such as electrode terminals 24 can be provided on the end cap 21. The electrode terminals 24 can be used to electrically connect to the electrode assembly 22 for inputting or outputting electrical energy to the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism 25 for relieving internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can be made of a variety of materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, and plastic. In some embodiments, an insulating member may be provided inside the end cap 21 to isolate the electrical connection components in the housing 23 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0084] The housing 23 is a component that cooperates with the end cap 21 to form the internal environment 232 of the battery cell 20. This internal environment 232 can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 23 and end cap 21 can be separate components. An opening can be provided in the housing 23, and the end cap 21 is placed over the opening to form the internal environment 232 of the battery cell 20. Alternatively, the end cap 21 and housing 23 can be integrated. Specifically, the end cap 21 and housing 23 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 23 needs to be enclosed, the end cap 21 is placed over the housing 23. The housing 23 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the housing 23 can be determined based on the specific shape and size of the electrode assembly 22. Materials for the housing 23 include, but are not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0085] According to some embodiments of this application, please refer to Figures 4 to 10 The embodiment of the present application provides a battery cell 20, which includes an end cap 21, a shell 23, and an electrode assembly 22. The shell 23 has an opening 231, and the end cap 21 covers the opening 231. The shell 23 cooperates with the end cap 21 to form an internal environment 232 of the battery cell 20. The electrode assembly 22 is accommodated in the internal environment 232. The electrode assembly 22 includes a diaphragm 221, a pole piece 222, and a winding needle 223. The winding needle 223 is fixedly connected to one end of the diaphragm 221. The diaphragm 221 separates the pole piece 222 and the winding needle 223. The diaphragm 221 and the pole piece 222 are wound on the winding needle 223.

[0086] By keeping the winding needle 223 in the electrode assembly 22 , wrinkling of the diaphragm 221 caused by withdrawing the winding needle 223 can be avoided to a certain extent, thereby ensuring the flatness of the electrode assembly 22 to a certain extent.

[0087] Optionally, the electrode assembly 22 is a component where electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 22 may be contained in the housing 23.

[0088] The separator 221 is a thin film that provides insulation. The material of the separator 221 is not specifically limited; the separator 221 can be made of polyethylene, polypropylene, or other materials. The electrode assembly 22 can be provided with two electrode sheets 222 , one of which can be a positive electrode sheet 222 and the other can be a negative electrode sheet 222 .

[0089] The winding needle 223 can have a long, rounded structure. One end of the diaphragm 221 can be fixedly connected to a side surface of the winding needle 223 along the thickness direction D, near the middle of the side surface of the winding needle 223. During the installation of the electrode assembly 22, after fixing one end of the diaphragm 221 to the winding needle 223, the two sides of the winding needle 223 along the D direction can be wrapped along the winding direction A, and then the electrode piece 222 can be placed on the two opposite sides of the diaphragm 221. Finally, the diaphragm 221 and the electrode piece 222 can be wound around the winding needle 223 along the winding direction A. After the winding is completed, the winding needle 223 and the electrode piece 222 are located inside the electrode assembly 22, and a portion of the diaphragm 221 is wrapped around the outermost side of the electrode assembly 22. Optionally, during the process of winding the diaphragm 221 around the winding needle 223, the winding needle 223 can be fixed and then the diaphragm 221 can be wrapped around the winding needle 223 along the winding direction A, so that the winding needle 223 remains in the electrode assembly 22. It can be understood that the installation method of the winding needle 223 remaining in the electrode assembly 22 includes but is not limited to the above methods.

[0090] By leaving the winding needle 223 in the electrode assembly 22, wrinkling of the diaphragm 221 caused by withdrawing the winding needle 223 can be avoided to a certain extent, thereby ensuring the flatness of the electrode assembly 22 to a certain extent and improving production efficiency. In addition, along the length direction L of the winding needle 223, the winding needle 223 can increase the curvature of the electrode piece 222 at both ends of the length direction L of the winding needle 223, thereby preventing the electrode piece 222 from breaking to a certain extent and reducing the risk of internal short circuits caused by breaking the electrode piece 222. In addition, leaving the winding needle 223 in the electrode assembly 22 can support the electrode piece 222, preventing the corner gap of the electrode piece 222 from being too large during winding, and reducing the risk of lithium deposition caused by excessive corner gaps of the electrode piece 222.

[0091] Please refer to Figures 4 to 6 In some embodiments, the diaphragm 221 includes a first diaphragm 2211 and a second diaphragm 2212, the electrode 222 includes a first electrode 2221 and a second electrode 2222 with opposite polarities, the first diaphragm 2211 separates the first electrode 2221 and the second electrode 2222, the second diaphragm 2212 separates the first electrode 2221 and the second electrode 2222, and the connecting end of the first diaphragm 2211 and the connecting end of the second diaphragm 2212 are fixed on the same side of the winding needle 223 along the thickness direction D.

[0092] By arranging the first diaphragm 2211 and the second diaphragm 2212 on the same side of the winding needle 223 to separate the first electrode piece 2221, the second electrode piece 2222 and the winding needle 223, the first electrode piece 2221 and the second electrode piece 2222 can be prevented from contacting each other to a certain extent, and the first electrode piece 2221 and the second electrode piece 2222 can be prevented from contacting the winding needle 223 to a certain extent to cause a short circuit.

[0093] Optionally, the first diaphragm 2211 is a thin film having an insulating and isolating function. The material of the first diaphragm 2211 includes, but is not limited to, polyethylene or polypropylene. The second diaphragm 2212 is a thin film having an insulating and isolating function. The material of the second diaphragm 2212 includes, but is not limited to, polyethylene or polypropylene.

[0094] One of the first electrode piece 2221 and the second electrode piece 2222 can be a positive electrode piece 222, and the other can be a negative electrode piece 222. The polarity of the first electrode piece 2221 and the second electrode piece 2222 are opposite. For example, when the first electrode piece 2221 is a positive electrode piece 222, the second electrode piece 2222 is a negative electrode piece 222. When the first electrode piece 2221 is a negative electrode piece 222, the second electrode piece 2222 is a positive electrode piece 222.

[0095] The connection end of the first diaphragm 2211 is hereinafter referred to as the first connection end 22111. The connection end of the second diaphragm 2212 is hereinafter referred to as the second connection end 22121. The first diaphragm 2211 and the second diaphragm 2212 can be connected to the same side of the winding needle 223 along the thickness direction D via the first connection end 22111 and the second connection end 22121, respectively. At the connection point where the first diaphragm 2211 and the second diaphragm 2212 connect to the winding needle 223, the second connection end 22121 is in close contact with the side of the winding needle 223. The first connection end 22111 is connected to the second connection end 22121, and the second connection end 22121 is disposed between the first connection end 22111 and the winding needle 223. The first electrode 2221, the second electrode 2222 and the winding needle 223 are separated by the first diaphragm 2211 and the second diaphragm 2212, which to a certain extent prevents the first electrode 2221 and the second electrode 2222 from contacting each other, and to a certain extent prevents the first electrode 2221 and the second electrode 2222 from contacting the winding needle 223 to cause a short circuit.

[0096] Please refer to Figure 4 、 Figure 5 and Figure 7 In some embodiments, the connecting end of the first diaphragm 2211 and the connecting end of the second diaphragm 2212 are stacked and fixed on the same side of the winding needle 223 along the thickness direction D, and the second diaphragm 2212 is located between the first diaphragm 2211 and the winding needle 223, or the connecting end of the second diaphragm 2212 and the connecting end of the first diaphragm 2211 are both fixed on the same side of the winding needle 223 along the thickness direction D, and the connecting end of the second diaphragm 2212 is spaced apart from the connecting end of the first diaphragm 2211.

[0097] The first diaphragm 2211 and the second diaphragm 2212 are fixed on the winding needle by stacking or spacing the connecting end of the second diaphragm 2212 and the connecting end of the first diaphragm 2211 on the same side of the winding needle 223 along the thickness direction D.

[0098] Optionally, in one embodiment, on the same side of the winding needle 223 along the thickness direction D, the first connection end 22111 can be connected to the second connection end 22121, the second connection end 22121 can be connected to the winding needle 223, and the second connection end 22121 is located between the first connection end 22111 and the winding needle 223 (such as Figure 5 In one embodiment, on the same side of the winding needle 223 along the thickness direction D, the first connection end 22111 can be connected to the winding needle 223, and the second connection end 22121 can be connected to the winding needle 223, and the first connection end 22111 and the second connection end 22121 are spaced apart (as shown in FIG. Figure 7 The first diaphragm 2211 and the second diaphragm 2212 are fixed to the winding needle 223 by stacking or spacing the first connecting end 22111 and the second connecting end 22121 on the same side of the winding needle 223 along the thickness direction D.

[0099] Please refer to Figure 4 、 Figure 8 and Figure 9 In some embodiments, the diaphragm 221 includes a first diaphragm 2211 and a second diaphragm 2212, and the electrode 222 includes a first electrode 2221 and a second electrode 2222 with opposite polarities. The first diaphragm 2211 separates the first electrode 2221 and the second electrode 2222, and the second diaphragm 2212 separates the first electrode 2221 and the second electrode 2222. The connecting end of the first diaphragm 2211 and the connecting end of the second diaphragm 2212 are respectively fixed on two opposite sides of the winding needle 223 along the thickness direction D, and the winding needle 223 is located between the connecting end of the first diaphragm 2211 and the connecting end of the second diaphragm 2212.

[0100] By arranging the first diaphragm 2211 and the second diaphragm 2212 on two opposite sides of the winding needle 223 to separate the first electrode piece 2221, the second electrode piece 2222 and the winding needle 223, the first electrode piece 2221 and the second electrode piece 2222 can be prevented from contacting each other to a certain extent, and the first electrode piece 2221 and the second electrode piece 2222 can be prevented from contacting the winding needle 223 to a certain extent to cause a short circuit.

[0101] Optionally, in the thickness direction D of the winding needle 223, the first connecting end 22111 can be connected to one side of the winding needle 223, and the second connecting end 22121 can be connected to the other side opposite to the one side, thereby realizing that the first diaphragm 2211 and the second diaphragm 2212 are fixedly connected to the winding needle 223, so that the first electrode piece 2221, the second electrode piece 2222 and the winding needle 223 can be separated by arranging the first diaphragm 2211 and the second diaphragm 2212 on two opposite sides of the winding needle 223, thereby avoiding contact between the first electrode piece 2221 and the second electrode piece 2222 to a certain extent, and avoiding contact between the first electrode piece 2221 and the second electrode piece 2222 and the winding needle 223 to a certain extent to cause a short circuit.

[0102] Please refer to Figure 4 、 Figure 8 and Figure 9 In some embodiments, the two opposite side surfaces of the winding needle 223 along the thickness direction D include a first side surface 2233 and a second side surface 2234 , the connecting end of the first diaphragm 2211 is fixed to the first side surface 2233 , and the connecting end of the second diaphragm 2212 is fixed to the second side surface 2234 ;

[0103] The projection of the connecting end of the first diaphragm 2211 along the thickness direction of the winding needle 223 at least partially overlaps with the projection of the connecting end of the second diaphragm 2212 along the thickness direction of the winding needle 223 , or;

[0104] The projection of the connecting end of the first diaphragm 2211 along the thickness direction of the winding needle 223 is staggered with the projection of the connecting end of the second diaphragm 2212 along the thickness direction of the winding needle 223 .

[0105] Optionally, the winding needle 223 includes a third side surface 2235 and a fourth side surface 2236 opposite to each other along the length direction L. In the embodiment shown in the figure, the length direction L of the winding needle 223 is perpendicular to the thickness direction D. The connecting end of the first diaphragm 2211 and the connecting end of the second diaphragm 2212 are fixedly connected to the winding needle 223 on the two opposite sides of the winding needle 223 along the thickness direction D by means including but not limited to two methods. One method is that the connecting end of the first diaphragm 2211 is connected to the first side surface 2233, and the connecting end of the second diaphragm 2212 is connected to the second side surface 2234, and the projection of the connecting end of the first diaphragm 2211 along the thickness direction of the winding needle 223 at least partially overlaps with the projection of the connecting end of the second diaphragm 2212 along the thickness direction of the winding needle 223. Specifically, please refer to Figure 8 The connecting end of the first diaphragm 2211 and the connecting end of the second diaphragm 2212 are both close to the third side surface 2235 .

[0106] Another way is that the connection end of the first diaphragm 2211 is connected to the first side surface 2233, the connection end of the second diaphragm 2212 is connected to the second side surface 2234, and the projection of the connection end of the first diaphragm 2211 along the thickness direction of the winding needle 223 is staggered with the projection of the connection end of the second diaphragm 2212 along the thickness direction of the winding needle 223. Figure 9 The connection end of the first diaphragm 2211 is close to the third side surface 2235 , and the connection end of the second diaphragm 2212 is close to the fourth side surface 2236 .

[0107] Optionally, the winding needle 223 has a first side surface 2233 and a second side surface 2234 along a thickness direction D, where the thickness direction D may include a left-right direction. The first side surface 2233 may be located on the left side of the winding needle 223, and the second side surface 2234 may be located on the right side of the winding needle 223. The winding needle 223 has a third side surface 2235 and a fourth side surface 2236 along a length direction L, where the length direction L may include an up-down direction. The third side surface 2235 may be located on the upper side of the winding needle 223, and the fourth side surface 2236 may be located on the lower side of the winding needle 223.

[0108] In one embodiment, please combine Figure 8 The first connecting end 22111 is fixed to the first side surface 2233, and the second connecting end 22121 is fixed to the second side surface 2234. The projection of the first connecting end 22111 along the thickness direction of the winding needle 223 completely overlaps with the projection of the second connecting end 22121 along the thickness direction of the winding needle 223. It is understood that in other embodiments, the projection of the first connecting end 22111 along the thickness direction of the winding needle 223 and the projection of the second connecting end 22121 along the thickness direction of the winding needle 223 may also partially overlap.

[0109] Specifically, compared to the fourth side surface 2236 , the first connection end 22111 and the second connection end 22121 are both closer to the third side surface 2235 , so that the first diaphragm 2211 and the second diaphragm 2212 can be fixedly connected to the winding needle 223 .

[0110] In one embodiment, the first connection end 22111 is fixed to the first side surface 2233 , the second connection end 22121 is fixed to the second side surface 2234 , and the projection of the first connection end 22111 along the thickness direction of the winding needle 223 is staggered with the projection of the second connection end 22121 along the thickness direction of the winding needle 223 .

[0111] Specifically, compared to the fourth side 2236 , the first connection end 22111 is closer to the third side 2235 . Compared to the third side 2235 , the second connection end 22121 is closer to the fourth side 2236 , thereby fixing the first diaphragm 2211 and the second diaphragm 2212 to the winding needle 223 .

[0112] The first connection end 22111 and the second connection end 22121 are fixedly connected to the winding needle 223, including but not limited to being bonded to the winding needle 223 through tape 2241, or being fixed to the winding needle 223 through the cooperation of the fastener 2242 and the groove 22421, or other feasible fixing methods.

[0113] Please refer to Figures 4 to 6 In some embodiments, the electrode assembly 22 includes a fastening mechanism 224 , which secures the connection end of the diaphragm 221 to the winding needle 223 .

[0114] The fastening mechanism 224 can fix the connection end of the diaphragm 221 , thereby providing tension during subsequent winding, making it easier for the diaphragm 221 to be wound on the winding needle 223 .

[0115] Optionally, the fastening mechanism 224 may be a component wound around the outside of the winding needle 223, and the fastening mechanism 224 may include an insulating tape, a silk thread, etc. The fastening mechanism 224 may wind the connecting end of the diaphragm 221 around the winding needle 223, thereby fixing the connecting end of the diaphragm 221. The fastening mechanism 224 may also include a buckle, a plug, etc. A corresponding snap-fit ​​groove may be provided on the winding needle 223, and the fastening mechanism 224 may be fixedly connected in the snap-fit ​​groove, thereby achieving the purpose of fixing the connecting end of the diaphragm 221, and further providing tension during subsequent winding, so as to facilitate winding the diaphragm 221 around the winding needle 223. It can be understood that the connection method of the fastening mechanism 224 includes but is not limited to the above connection methods.

[0116] Please refer to Figure 4 and Figure 5 In some embodiments, the fastening mechanism 224 includes a tape 2241 .

[0117] By providing the adhesive tape 2241 , the connection end of the diaphragm 221 can be easily bonded to the winding needle 223 , which is highly practical.

[0118] Optionally, the fastening mechanism 224 can be arranged in sequence along the D direction with the first connection end 22111, the second connection end 22121, and the winding needle 223 by adhesively attaching one end of the adhesive tape 2241 to cover and adhere the side of the first connection end 22111 facing the adhesive tape 2241, so that the first connection end 22111 is in close contact with the second connection end 22121, and the second connection end 22121 is in close contact with the side of the winding needle 223. The other end of the adhesive tape 2241 can be adhered to the side of the winding needle 223, thereby fixing the first connection end 22111 and the second connection end 22121 to the winding needle 223. During installation, the first and second diaphragms 2211 and 2212 are first fixedly attached to the winding needle 223 via the adhesive tape 2241, and then the first and second electrode pieces 2221 and 2222 are respectively arranged between the first and second diaphragms 2211 and 2212.

[0119] Furthermore, adhesive tape may be provided on the side of the winding needle 223, and the adhesive tape 2241 may be adhered to the adhesive tape by a gluing mechanism. Optionally, the thickness of the adhesive tape may be less than 30 microns.

[0120] Please refer to Figure 4 and Figure 6 In some embodiments, the fastening mechanism 224 includes a fastener 2242 and a groove 2243. The winding needle 223 is provided with a groove 2243, and the side wall of the groove 2243 is provided with an elastic member 2244. The fastener 2242 is at least partially accommodated in the groove 2243. The elastic member 2244 is connected to the fastener 2242 so that the fastener 2242 presses the connecting end of the diaphragm 221 into the groove 2243.

[0121] By fastening the fastener 2242 into the groove 2243, the elastic member 2244 connects the fastener 2242, and the fastener 2242 presses the connecting end of the diaphragm 221 into the groove 2243, thereby reducing the probability of separation of the diaphragm 221 and the winding needle 223, and improving the fixing and limiting effect of the connecting end of the diaphragm 221.

[0122] Optionally, the fastening mechanism 224 can be nested, with the first connection end 22111, the second connection end 22121 and the winding needle 223 arranged in sequence along the D direction, and then the fastener 2242 is pressed onto the first connection end 22111, the first connection end 22111 is close to the second connection end 22121, and the second connection end 22121 is close to the bottom of the groove 2243, and finally the fastener 2242 is inserted into the groove 2243, and the elastic member 2244 connects the fastener 2242 so that the fastener 2242 presses the first connection end 22111 and the second connection end 22121 into the groove 2243.

[0123] Optionally, in Figure 6 In the embodiment, the fastener 2242 may be a plate-like structure, with fastening grooves 22421 defined on both side walls of the fastener 2242. When the fastener 2242 is inserted into the groove 2243, the two elastic members 2244 located on the side walls of the groove 2243 may be respectively engaged in the two fastening grooves 22421, thereby causing the fastener 2242 to press the first connecting end 22111 and the second connecting end 22121 into the groove 2243, thereby reducing the probability of separation between the diaphragm 221 and the winding needle 223 and improving the fixing and limiting effect of the connecting end of the diaphragm 221.

[0124] Furthermore, the fastener 2242 can be pushed into the groove 2243 by the pushing mechanism until the elastic member 2244 locks the fastener 2242 .

[0125] Please refer to Figure 10In some embodiments, the winding needle 223 includes a rigid body 2231 and an elastic body 2232 , and the elastic body 2232 is provided on at least one side of the rigid body 2231 along the thickness direction D of the winding needle 223 .

[0126] The rigid body 2231 can prevent the winding needle 223 from bending, and the elastic body 2232 can balance the expansion force of the electrode assembly 22 during charging and discharging, thereby increasing the service life of the electrode assembly 22.

[0127] Optionally, in Figure 10 In the embodiment, the winding needle 223 can be designed as a three-layer structure. The winding needle 223 can be provided with two elastic bodies 2232 and a rigid body 2231. Along the thickness direction D of the winding needle 223, the rigid body 2231 can be arranged between the two elastic bodies 2232. It is understood that in other embodiments, the winding needle 223 can also be designed as a two-layer structure, with a layer of elastic body 2232 arranged on one side of a layer of rigid body 2231 along the thickness direction D of the winding needle 223.

[0128] In one embodiment, optionally, the bending strength of the winding needle 223 is greater than or equal to 50 Newtons (N).

[0129] Bending strength refers to the force required to resist bending without breaking. The bending strength of the winding needle 223 is greater than or equal to 50 Newtons. This means that the winding needle 223 can withstand a bending force of 50 Newtons or more without breaking. The bending strength of the winding needle 223 can be customized to meet specific needs, expanding its application scenarios.

[0130] Alternatively, the bending strength of the winding needle 223 may be measured by a three-point bending test.

[0131] In some examples, the bending strength of the winding needle 223 can be 50 Newtons, 150 Newtons, 250 Newtons, 350 Newtons, 800 Newtons, 1000 Newtons, 1500 Newtons, or other values ​​greater than or equal to 50 Newtons.

[0132] In one embodiment, optionally, the bending strength of the winding needle 223 is greater than or equal to 50 Newtons and less than or equal to 5000 Newtons. Thus, the bending strength of the winding needle 223 is more easily achieved.

[0133] In some examples, the bending strength of the winding needle 223 can be 50 Newtons, 150 Newtons, 250 Newtons, 350 Newtons, 800 Newtons, 1000 Newtons, 1500 Newtons, 2000 Newtons, 2500 Newtons, 3000 Newtons, 3500 Newtons, 4000 Newtons, 4500 Newtons, 5000 Newtons, or other values ​​greater than or equal to 50 Newtons and less than or equal to 5000 Newtons.

[0134] Optionally, the thickness H of the winding needle 223 can be set to 0.5 mm ≤ H ≤ 3 mm. The above value range of H can, to a certain extent, ensure that the winding needle 223 has a certain degree of bending resistance while also reducing the impact on the volume energy density of the battery cell 20.

[0135] In one embodiment, optionally, the winding needle 223 may be composed of a rigid body 2231 and an elastic body 2232, the thickness H1 of the rigid body 2231, and the value range of H1 is 0

[0136] In one embodiment, optionally, combine Figure 10 The winding needle 223 consists of a rigid body 2231 and two elastic bodies 2232, with the rigid body 2231 positioned between the two elastic bodies 2232. The thickness H1 of the rigid body 2231 is in the range of 0 < H1 ≤ 50% × H. The thickness H2 of the elastic body 2232 is in the range of 25% × H ≤ H2 < 50% × H. The total thickness H3 of the two elastic bodies 2232 is 2 × H2, where 50% × H ≤ H3 < 100% × H. When H1 is within this range, the winding needle 223 has a certain degree of rigidity, and when H2 is within this range, the winding needle 223 has a certain degree of elasticity on both sides.

[0137] Optionally, the thicknesses of the two elastic bodies 2232 may be the same or different.

[0138] In one embodiment, the winding needle 223 may be composed of two rigid bodies 2231 and an elastic body 2232, with the elastic body 2232 positioned between the two rigid bodies 2231. The thickness H1 of the rigid body 2231 is in the range of 0 < H1 ≤ 25% × H, and the thickness H2 of the elastic body 2232 is in the range of 50% × H ≤ H2 < 100% × H. The total thickness H4 of the two rigid bodies 2231 is 2 × H1, where 0 < H4 ≤ 50% × H. Having H1 within this range can impart a certain degree of rigidity to the winding needle 223, and having H2 within this range can impart a certain degree of elasticity to the winding needle 223.

[0139] Optionally, the thicknesses of the two rigid bodies 2231 may be the same or different.

[0140] ​In some embodiments, the rigid body 2231 includes but is not limited to a steel plate, an aluminum plate, a nickel plate or a hard plastic, and the elastic member 2244 includes but is not limited to a polyethylene foam material or a polypropylene foam material.

[0141] Steel plates, aluminum plates, nickel plates or hard plastics have good bending strength, which helps prevent the winding needle 223 from bending. Polyethylene foam materials or polypropylene foam materials have good toughness, flexibility and cushioning properties, which helps balance the expansion force of the electrode assembly 22 during charging and discharging.

[0142] Optionally, by manufacturing steel plates, aluminum plates, nickel plates or hard plastics into the required rigid body 2231, manufacturing polyethylene foam material or polypropylene foam material into the required elastomer 2232, and then combining and connecting the rigid body 2231 and the elastomer 2232 together through a fixed processing technology to form a winding needle 223, the winding needle 223 can be prevented from bending during use, thereby balancing the expansion force of the electrode assembly 22 during charging and discharging.

[0143] Please refer to Figures 8 to 10 In some embodiments, both sides of the winding needle 223 perpendicular to the thickness direction D are convex arc-shaped.

[0144] By making arc-shaped transitions on the two side surfaces perpendicular to the thickness direction, scratches on the diaphragm 221 can be avoided to a certain extent.

[0145] Optionally, the two side surfaces of the winding needle 223 along the length direction L may be convex arc surfaces, that is, the third side surface 2235 and the fourth side surface 2236 are both convex arc surfaces (such as Figure 8 and Figure 9 By setting the third side surface 2235 and the fourth side surface 2236 as convex arc-shaped surfaces, the diaphragm 221 can be prevented from being scratched to a certain extent during the winding process along the A direction, thereby ensuring the integrity of the diaphragm 221 to a certain extent.

[0146] According to some embodiments of the present application, the present application further provides a battery cell 20 , which includes a housing 23 and an electrode assembly 22 according to any of the above embodiments, wherein the electrode assembly 22 is accommodated in the housing 23 .

[0147] According to some embodiments of the present application, the present application further provides a battery 100 , which includes a housing 10 and the battery cells 20 of the above embodiment, and the battery cells 20 are accommodated in the housing 10 .

[0148] According to some embodiments of the present application, the present application further provides an electrical device, which includes the battery 100 of any of the above solutions, and the battery 100 is used to provide electrical energy to the electrical device.

[0149] The power-consuming device may be any of the aforementioned devices or systems using the battery 100 .

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises an end cap, a housing, and an electrode assembly. The housing has an opening, the end cap is fitted over the opening, the housing and the end cap cooperate to form an internal environment of the battery cell, and the electrode assembly is accommodated in the internal environment. The electrode assembly comprises: diaphragm; Pole piece; A winding needle is fixedly connected to one end of the diaphragm, the diaphragm separates the pole piece and the winding needle, and the diaphragm and the pole piece are wound on the winding needle.

2. The battery cell according to claim 1, wherein: The diaphragm includes a first diaphragm and a second diaphragm, and the electrode includes a first electrode and a second electrode with opposite polarities. The first diaphragm separates the first electrode and the second electrode, and the second diaphragm separates the first electrode and the second electrode. The connecting end of the first diaphragm and the connecting end of the second diaphragm are fixed on the same side of the winding needle along the thickness direction.

3. The battery cell according to claim 2, characterized in that: The connecting end of the first diaphragm and the connecting end of the second diaphragm are stacked and fixed on the same side of the winding needle along the thickness direction, and the second diaphragm is located between the first diaphragm and the winding needle, or the connecting end of the second diaphragm and the connecting end of the first diaphragm are both fixed on the same side of the winding needle along the thickness direction, and the connecting end of the second diaphragm is spaced apart from the connecting end of the first diaphragm.

4. The battery cell according to claim 1, wherein: The diaphragm includes a first diaphragm and a second diaphragm, and the electrode includes a first electrode and a second electrode with opposite polarities. The first diaphragm separates the first electrode and the second electrode, and the second diaphragm separates the first electrode and the second electrode. The connecting end of the first diaphragm and the connecting end of the second diaphragm are respectively fixed on two opposite sides of the winding needle along the thickness direction, and the winding needle is located between the connecting end of the first diaphragm and the connecting end of the second diaphragm.

5. The battery cell according to claim 4, characterized in that The winding needle includes a first side surface and a second side surface opposite to each other in the thickness direction, the connecting end of the first diaphragm is fixed to the first side surface, and the connecting end of the second diaphragm is fixed to the second side surface; A projection of the connecting end of the first diaphragm along the thickness direction of the winding needle at least partially overlaps with a projection of the connecting end of the second diaphragm along the thickness direction of the winding needle, or; A projection of the connecting end of the first diaphragm along the thickness direction of the winding needle is staggered from a projection of the connecting end of the second diaphragm along the thickness direction of the winding needle.

6. The battery cell according to claim 1, characterized in that The electrode assembly includes a fastening mechanism that fixes the connecting end of the diaphragm to the winding needle.

7. The battery cell according to claim 6, characterized in that The fastening mechanism includes adhesive tape.

8. The battery cell according to claim 6, characterized in that The fastening mechanism includes a fastener and a groove. The groove is provided on the winding needle, and an elastic member is provided on the side wall of the groove. The fastener is at least partially accommodated in the groove. The elastic member connects the fastener so that the fastener presses the connecting end of the diaphragm into the groove.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The winding needle includes a rigid body and an elastic body, and the elastic body is arranged on at least one side of the rigid body along the thickness direction of the winding needle.

10. The battery cell according to claim 9, characterized in that The rigid body includes a steel plate, an aluminum plate, a nickel plate or a hard plastic, and the elastic member includes a polyethylene foam material or a polypropylene foam material.

11. The battery cell according to claim 1, characterized in that The two side surfaces of the winding needle perpendicular to the thickness direction are both in an outwardly convex arc shape.

12. The battery cell according to any one of claims 1 to 11, characterized in that: The bending strength of the winding needle is greater than or equal to 50 Newtons.

13. A battery, characterized in that: The utility model comprises a box body and the battery cell according to any one of claims 1 to 12, wherein the battery cell is accommodated in the box body.

14. An electrical device, characterized in that: The battery according to claim 13 is used to provide electrical energy.

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