Battery cell, battery device, power consuming device, and energy storage device

Abstract

This application provides a battery cell, a battery device, an electrical device, and an energy storage device. The battery cell includes an electrode. The electrode includes a current collector and a first film layer. The current collector includes a main body and a tab. The main body includes a first edge and a second edge. The tab is connected to the first edge. The first film layer is disposed on at least one side of the main body in the thickness direction. The first film layer includes a main film layer and an edge film layer. The edge film layer is disposed in a region of the main body near the second edge and extends along the second edge. Both the main film layer and the edge film layer are in contact with the main body. In the same projection plane perpendicular to the thickness direction of the main body, the orthographic projections of the main film layer and the edge film layer do not overlap. The volume distribution particle size DV99' of the particles in the edge film layer is smaller than the volume distribution particle size DV99 of the particles in the main film layer, and / or, the volume distribution particle size DV50' of the particles in the edge film layer is smaller than the volume distribution particle size DV50 of the particles in the main film layer.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, power supply device, and energy storage device. Background Technology

[0002] The application of new energy batteries in daily life and industry is becoming increasingly widespread. For example, battery-powered electrical devices are already widely used. In addition, batteries are increasingly being used in energy storage and other fields.

[0003] In battery-powered electrical devices, batteries can provide all or part of the power. In the field of energy storage, batteries can be installed in energy storage enclosures or directly on the user side. With continuous technological advancements, higher demands are being placed on the reliability of battery devices. Improving the reliability and stability of battery devices is one of the industry's research topics. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a battery cell, battery device, power supply device, and energy storage device with high reliability and stability.

[0005] This application is achieved through the following technical solution.

[0006] The first aspect of this application provides a battery cell, the battery cell including an electrode, the electrode including: a current collector including a main body and a tab, the main body including a first edge and a second edge, the tab being connected to the first edge; a first film layer disposed on at least one side in the thickness direction of the main body, the first film layer including a main film layer and an edge film layer, the main film layer including a first active material, the edge film layer being disposed in a region of the main body near the second edge and extending along the second edge, both the main film layer and the edge film layer being in contact with the main body, and the orthographic projection of the main film layer and the orthographic projection of the edge film layer not overlapping in the same projection plane perpendicular to the thickness direction of the main body; wherein, the volume distribution particle size DV99' of the particles in the edge film layer is smaller than the volume distribution particle size DV99 of the particles in the main film layer, and / or, the volume distribution particle size DV50' of the particles in the edge film layer is smaller than the volume distribution particle size DV50 of the particles in the main film layer.

[0007] An edge film layer with relatively small particle size distribution is set in the area near the second edge of the main body. When the edge of the electrode is slit or cut, the large particles in the film layer can reduce the compression of the current collector, reduce the possibility of stress concentration, thereby improving the phenomenon of burrs on the electrode. This reduces the possibility of burrs piercing the separator during subsequent battery cell assembly (such as during winding or stacking) or when the battery cell is subjected to vibration or compression, thus improving the reliability, stability and service life of the battery cell.

[0008] Furthermore, since the edge film layer is only applied to the area near the second edge of the main body, while the remaining areas of the main body are still coated with the main film layer with a particle size within the normal range, the possibility of burrs on the electrode sheets can be reduced while ensuring the energy density of the battery cells, thus improving the yield of the battery cells and meeting both performance and efficiency requirements. The largely parallel arrangement of the main film layer and the edge film layer also simplifies the coating process and reduces manufacturing costs. Additionally, it helps ensure uniform electrochemical performance of the battery cells, improving their reliability and stability, and also improves assembly accuracy and yield in subsequent battery cell assembly processes.

[0009] In some embodiments, along the width direction of the edge film layer, one side of the edge film layer is adjacent to the main film layer, and the other side extends to the second edge.

[0010] Therefore, the edge film layer is adjacent to the main film layer and extends to the second edge, which can reduce the possibility of burrs appearing on the second edge of the electrode, while ensuring the energy density of the battery cell as much as possible, improving the reliability of the battery cell, and meeting the performance and efficiency requirements of the battery cell.

[0011] In some embodiments, the ratio of the volume distribution particle size DV99 of the particles in the main membrane layer to the volume distribution particle size DV99' of the particles in the edge membrane layer is (2-10):1, and / or the ratio of the volume distribution particle size DV50 of the particles in the main membrane layer to the volume distribution particle size DV50' of the particles in the edge membrane layer is (2-10):1.

[0012] Therefore, the volumetric particle sizes DV99 and DV50 in the main film layer are 2 to 10 times larger than those DV99' and DV50' in the edge film layer. Because the volumetric particle sizes DV99' and DV50' in the edge film layer are smaller, they can buffer the compression of the current collector by large particles in the film layer during slitting or cutting, thereby reducing the probability of large burrs and improving the reliability and safety performance of the battery cells.

[0013] In some embodiments, the volumetric particle size distribution DV99' of the particles in the edge membrane layer is 0.5 μm-15 μm, and / or the volumetric particle size distribution DV50' of the particles in the edge membrane layer is 0.1 μm-7 μm.

[0014] Therefore, the particle size distribution of particles in the edge film layer, with DV99' and DV50', is within a suitable range, which can further buffer the compression of the current collector by large particles in the film layer during slitting or cutting, thereby reducing the probability of large burrs and improving the reliability and safety performance of the battery cell.

[0015] In some embodiments, the compaction density of the edge membrane layer is less than that of the main membrane layer.

[0016] Because the edge film layer has a lower compaction density, the contact between particles is relatively loose, resulting in lower internal residual stress. Therefore, when the electrode is slitting or cutting, it is less prone to severe edge deformation due to stress release, thus reducing the likelihood of burrs. Furthermore, due to the lower compaction density, the edge film layer may contain more pores. These pores can act as a buffer under external forces, absorbing some fracture energy and further reducing the compression of the current collector by the particles, resulting in a relatively smooth cut and less burr formation.

[0017] In some embodiments, the compaction density of the edge membrane layer is 30%-80% of the compaction density of the main membrane layer.

[0018] Therefore, a compaction density of the edge film layer within a suitable range is beneficial to maintaining the energy density of the battery cell while improving the yield rate during the electrode cutting process, thus meeting the requirements of performance and efficiency.

[0019] In some embodiments, the edge film layer includes an adhesive, and the adhesive of the edge film layer accounts for 1.5%-2.5% of the total mass.

[0020] Therefore, the binder content in the edge film layer is relatively high, which helps to improve the bonding force between the particles in the edge film layer. When slitting or cutting the electrode, the edge film layer is more easily "cut" rather than "pulled out," thus reducing the compression of the current collector by the particles and reducing the possibility of burrs. In addition, an appropriate increase in the binder content helps to improve the flexibility and fracture toughness of the edge film layer, thus providing a certain buffering and lubricating effect when slitting or cutting the electrode, which also helps to reduce the possibility of burrs.

[0021] In some embodiments, the width of the edge membrane layer is 1mm-5mm.

[0022] Therefore, with the width of the edge film layer within a suitable range, it can maintain the high energy density of the battery cell without encroaching too much on the area where the main film layer is located, while leaving a suitable space for the electrode sheet during slitting and cutting. This improves the reliability of slitting and cutting while ensuring the energy density of the battery cell.

[0023] In some embodiments, the edge film layer comprises a second active material; or, the edge film layer comprises an insulating material.

[0024] The first and second active materials can be the same or different. When the edge film layer includes the second active material, the smaller particle size of the second active material reduces the compression of the current collector by the particles, thereby improving burrs. Moreover, since the edge film layer also includes active material, the energy density of the battery cell can be maintained while improving burrs, thus simultaneously meeting the requirements of performance and efficiency, and improving the reliability and stability of the battery cell.

[0025] When the edge film layer includes insulating material, the insulating material can improve the bending strength and impact resistance of the current collector. This allows the edge to remain intact as much as possible when the current collector is subjected to external forces, reducing the likelihood of edge chipping or delamination, and thus minimizing burr formation. Furthermore, even if tiny burrs form at the edge of the electrode, the insulating material acts as a good barrier, reducing the possibility of burrs piercing the separator. This suppresses the potential impact of existing burrs on the performance of the battery cell, improving the reliability and stability of the battery cell.

[0026] In some embodiments, the thickness of the edge film layer is greater than or equal to 5 μm along the thickness direction of the main body.

[0027] Therefore, by keeping the thickness of the edge film within a suitable range, the possibility of burrs can be reduced while ensuring the energy density of the battery cell as much as possible, thus meeting the requirements of performance and efficiency and improving the reliability and stability of the battery cell.

[0028] In some embodiments, a first film layer is provided on both sides of the main body along the thickness direction of the main body.

[0029] This helps to increase the energy density of individual battery cells, reduce the likelihood of burrs on the electrodes, and improve the reliability and stability of individual battery cells.

[0030] In some embodiments, the electrode further includes a second film layer, the material of which is the same as that of the main film layer. Along the thickness direction of the main body, the main body includes a first side and a second side, the first film layer is disposed on the first side, and the second film layer is disposed on the second side.

[0031] Therefore, a first film layer is provided on one side of the current collector, that is, a main film layer and an edge film layer are provided simultaneously, and a second film layer with the same material as the main film layer is provided on the other side. This can improve the yield of battery cells while maintaining the energy density of battery cells as much as possible, and at the same time meet the performance and efficiency requirements of battery cells.

[0032] In some embodiments, the second edge of the body portion has burrs that extend from the second edge toward the second side.

[0033] Since the first film layer, including the edge film layer, is only provided on one side, burrs may still appear on the second side of the current collector. By using different cutting tools during the slitting or cutting process, the burrs generated at the second edge are made to extend towards the second side, thereby reducing the risk of burrs protruding outward and puncturing the separator. This maximizes the energy density of the electrode while minimizing the adverse effects of burrs, thus improving the reliability and stability of the battery cell.

[0034] In some embodiments, the electrode further includes an insulating layer disposed in a region of the body portion near the first edge and extending along the first edge, the insulating layer being in contact with the body portion.

[0035] The insulating layer provides excellent insulation, reducing the likelihood of contact between the film layer of the main body and the outer casing, thereby minimizing the risk of short circuits and further improving the reliability of the battery cell. Furthermore, because the insulating layer is located near the first edge of the main body, burrs generated during the die-cutting of the electrode tab at the first edge are encased in the insulating layer. This ensures that even without a second positive electrode film layer, the area near the first edge of the main body is less prone to short circuits caused by burrs piercing the separator.

[0036] The second aspect of this application provides a battery device, which includes: a housing; and a battery cell according to the first aspect of this application, wherein the battery cell is disposed within the housing.

[0037] The electrical device of this application embodiment has better reliability because it uses the battery cells described above, and the risk of battery device failure due to battery cell failure is reduced, thereby helping to reduce the time spent on maintenance and improving the reliability and stability of the battery device.

[0038] A third aspect of this application provides an electrical device, which includes a battery cell of the first aspect of this application or a battery device of the second aspect of this application for providing electrical energy.

[0039] The electrical device in this application embodiment has better reliability because it uses the battery cells or battery devices as described above, and the risk of failure due to battery cell or battery device failure is reduced, thereby helping to reduce the time spent on maintenance and improving the reliability and stability of the electrical device.

[0040] The fourth aspect of this application provides an energy storage device, which includes a battery cell of the first aspect of this application or a battery device of the second aspect of this application for storing or providing electrical energy.

[0041] The energy storage device of this application embodiment has better reliability because it uses the battery cells or battery devices as described above, and the risk of failure due to battery cell or battery device failure is reduced, thereby helping to reduce the time spent on maintenance and improving the reliability and stability of the energy storage device.

[0042] Invention Effects This application provides a battery cell, battery device, power supply device, and energy storage device that are less prone to burrs, have high reliability, and good stability. Attached Figure Description

[0043] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application; Figure 2 This is an exploded perspective view of a battery device provided in some embodiments of this application; Figure 3 These are exploded perspective views of a battery cell provided in some embodiments of this application; Figure 4 A partial planar structural schematic diagram of the positive electrode, negative electrode, and separator provided for some embodiments of this application; Figure 5 This is a schematic diagram of the planar structure of the master roll electrode sheet provided in some embodiments of this application; Figure 6 This is a schematic side view of the mother roll electrode sheet provided in some embodiments of this application; Figure 7 This is a schematic diagram of the planar structure of the electrode provided in some embodiments of this application. Figure 1 ; Figure 8 This is a schematic diagram of the planar structure of the electrode provided in some embodiments of this application. Figure 2 ; Figure 9 This is a schematic diagram of the planar structure of the electrode provided in some embodiments of this application. Figure 3 ; Figure 10 This is a schematic diagram of the planar structure of the electrode provided in some embodiments of this application. Figure 4 ; Figure 11 These are schematic side views of electrode sheets provided in some embodiments of this application; Figure 12 These are schematic side views of electrode sheets provided in other embodiments of this application; Figure 13 yes Figure 12 A schematic cross-sectional view at point AA; Figure 14 This is a schematic side view of an electrode provided in some other embodiments of this application; Figure 15 This is a schematic side view of an electrode provided in some further embodiments of this application.

[0044] Explanation of reference numerals in the attached figures 1. Electrode; 1a. First film layer; 1b. Second film layer; 2. Current collector; 21. Main body; 21a. First edge; 21b. Second edge; 21c. First side; 21d. Second side; 22. Electrode tab; 3. Main film layer; 4. Edge film layer; 5. Outer shell; 5a. Opening; 51. Shell; 52. End cap; 6. Electrode assembly; 61. Electrode body; 61a. Positive electrode; 61b. Negative electrode; 61c, separator; 7, electrode terminal; 8, current collector; 9, insulating layer; 10, slitting area; 20, burr; 100, battery cell; 200, controller; 300, motor; 400, battery assembly; 401, housing; 401a, cover; 401b, base plate; 500, mother-wound electrode sheet; 1000, vehicle; X, thickness direction of the main body; L, width of the edge film layer; U, thickness of the edge film layer. Detailed Implementation

[0045] 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.

[0046] 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 belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having”, and any variations thereof, in the specification and the foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0047] In the description of the embodiments of this application, technical terms such as "first," "second," and "third" 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.

[0048] 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.

[0049] 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 are in an "or" relationship.

[0050] In the description of the embodiments of this application, the technical terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", etc., 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 do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0051] 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.

[0052] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0053] The following is a detailed description of this application.

[0054] Currently, new energy batteries are being used more and more widely in daily life and industry. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as aircraft. With the continuous expansion of the application areas of power batteries, the market demand is also constantly increasing.

[0055] After the coating process, the wide, continuous master roll electrode sheets of a battery cell need to be slit and cut into narrow strips or single sheets that meet the size requirements. During this slitting or cutting process, the current collector undergoes plastic deformation due to compression, forming burrs that either fold outwards or hang downwards. In subsequent battery cell assembly (e.g., during winding or stacking) or when the battery cell is subjected to vibration or compression, these burrs may puncture the separator, causing direct contact between the positive and negative electrodes. This can lead to internal short circuits, affecting the reliability and lifespan of the battery cell, and in severe cases, even causing thermal runaway.

[0056] In view of this, this application proposes a battery cell. The battery cell includes an electrode. The electrode includes a current collector and a first film layer. The current collector includes a main body and a tab. The main body includes a first edge and a second edge. The tab is connected to the first edge. The first film layer is disposed on at least one side of the main body in the thickness direction, and the first film layer includes a main film layer and an edge film layer. The main film layer includes a first active material. The edge film layer is disposed in the region of the main body near the second edge and extends along the second edge. Both the main film layer and the edge film layer are in contact with the main body. On the same projection plane perpendicular to the thickness direction of the main body, the orthographic projections of the main film layer and the edge film layer do not overlap. The particle size distribution DV99' of the particles in the edge film layer is smaller than the particle size distribution DV99 of the particles in the main film layer, and / or, the particle size distribution DV50' of the particles in the edge film layer is smaller than the particle size distribution DV50 of the particles in the main film layer.

[0057] An edge film layer with relatively small particle size distribution is set in the area near the second edge of the main body. When the edge of the electrode is slit or cut, the large particles in the film layer can reduce the compression of the current collector, reduce the possibility of stress concentration, thereby improving the phenomenon of burrs on the electrode. This reduces the possibility of burrs piercing the separator during subsequent battery cell assembly (such as during winding or stacking) or when the battery cell is subjected to vibration or compression, thus improving the reliability, stability and service life of the battery cell.

[0058] In addition, since the edge film layer is only set in the area near the second edge of the main body, the rest of the main body is still coated with a main film layer with a particle size within the normal range. As a result, the possibility of burrs on the electrode can be reduced while ensuring the energy density of the battery cell, thereby improving the yield of the battery cell and meeting the requirements of performance and efficiency.

[0059] The main film layer and the edge film layers are arranged roughly side by side, which helps to simplify the coating process and reduce manufacturing costs. In addition, it helps to ensure the uniformity of the electrochemical performance of the battery cells, improve the reliability and stability of the battery cells, and also helps to improve the assembly accuracy and yield in the subsequent battery cell assembly process.

[0060] The battery cells provided in this application embodiment can be used, but are not limited to, in energy storage power systems, vehicles, ships or aircraft and other electrical devices, as well as in energy storage containers, energy storage cabinets and other energy storage devices.

[0061] This application provides an electrical device including the aforementioned battery cell for providing electrical energy. The electrical device includes, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, and spacecraft. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0062] In the following embodiments, for ease of explanation, a vehicle 1000 is used as an example of an electrical device according to an embodiment of this application. The description is as follows with reference to the accompanying drawings.

[0063] Figure 1 The diagram illustrates the structure of a vehicle 1000 as provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Figure 1 As shown, a battery cell 100 is disposed inside the vehicle 1000. The battery cell 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery cell 100 can be used to power the vehicle 1000; for example, the battery cell 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery cell 100 to supply power to the motor 300, for example, to meet the power requirements of the vehicle 1000 during starting, navigation, and driving.

[0064] In some embodiments of this application, the battery cell 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0065] Figure 2 This is an exploded perspective view of the battery device 400 provided in an embodiment of this application. Figure 2As shown, the battery device 400 includes a housing 401 and at least one battery cell 100, which is housed within the housing 401. The housing 401 includes a cover 401a and a base plate 401b, with the cover 401a covering the base plate 401b, thereby forming a housing area for the battery cell 100 between the base plate 401b and the cover 401a.

[0066] In the battery device 400, there can be multiple battery cells 100. These multiple battery cells 100 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 100 are connected in both series and parallel. Multiple battery cells 100 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 100 is placed in the receiving space formed by the base plate 401b and the cover 401a. Alternatively, multiple battery cells 100 can first be connected in series, parallel, or in a mixed configuration to form a battery module, and then these battery modules can be connected in series, parallel, or in a mixed configuration to form an entire assembly, which is then housed within the receiving space formed by the base plate 401b and the cover 401a. The battery device 400 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 100.

[0067] The following reference Figures 3 to 15 Some embodiments of this application will be described in detail.

[0068] Figure 3 These are exploded perspective views of a battery cell provided in some embodiments of this application; Figure 4 A partial planar structural schematic diagram of the positive electrode, negative electrode, and separator provided for some embodiments of this application; Figure 5 This is a schematic diagram of the planar structure of the master roll electrode sheet provided in some embodiments of this application; Figure 6 This is a schematic side view of the mother roll electrode sheet provided in some embodiments of this application; Figure 7 This is a schematic diagram of the planar structure of the electrode provided in some embodiments of this application; Figure 11 These are schematic side views of electrode sheets provided in some embodiments of this application; Figure 12 These are schematic side views of electrode sheets provided in other embodiments of this application; Figure 13 yes Figure 11 A schematic cross-sectional view at point AA; Figure 14 This is a schematic side view of an electrode provided in some other embodiments of this application; Figure 15 This is a schematic side view of an electrode provided in some further embodiments of this application.

[0069] In some embodiments of this application, for ease of explanation, the thickness direction of the main body and the width direction of the edge film layer are defined. For example... Figure 3 , Figure 4 , Figure 6 , Figures 11 to 15 As shown, the direction of arrow X is the thickness direction of the main body. The width direction of the edge film layer is perpendicular to both the thickness direction X of the main body and the extension direction of the second edge. In some embodiments, the thickness direction X of the main body is parallel to the thickness direction of the electrode assembly and the thickness direction of the battery cell.

[0070] A first aspect of this application provides a battery cell 100. The battery cell 100 includes an electrode 1. The electrode 1 includes a current collector 2 and a first film layer 1a. The current collector 2 includes a main body portion 21 and a tab portion 22. The main body portion 21 includes a first edge 21a and a second edge 21b. The tab portion 22 is connected to the first edge 21a. The first film layer 1a includes a main film layer 3 and an edge film layer 4. The main film layer 3 includes a first active material. The edge film layer 4 is disposed in the region of the main body portion 21 near the second edge 21b and extends along the second edge 21b. Both the main film layer 3 and the edge film layer 4 are in contact with the main body portion 21. In the same projection plane perpendicular to the thickness direction of the main body portion 21, the orthographic projections of the main film layer 3 and the edge film layer 4 do not overlap. Wherein, the volume distribution particle size DV99' of the particles in the edge membrane layer 4 is smaller than the volume distribution particle size DV99 of the particles in the main membrane layer 3, and / or, the volume distribution particle size DV50' of the particles in the edge membrane layer 4 is smaller than the volume distribution particle size DV50 of the particles in the main membrane layer 3.

[0071] The battery cell 100 can be used to make a battery device 400, which can then be used to supply power to an electrical device or an energy storage device.

[0072] In this embodiment of the application, the battery cell 100 can be a secondary battery cell, which refers to a battery cell 100 that can be used again after being discharged by recharging to activate the active materials.

[0073] The battery cell 100 can be a lithium-ion battery cell, sodium-ion battery cell, sodium-lithium-ion battery cell, lithium metal battery cell, sodium metal battery cell, lithium-sulfur battery cell, magnesium-ion battery cell, nickel-metal hydride battery cell, nickel-cadmium battery cell, lead-acid battery cell, etc., but this application embodiment does not limit it.

[0074] In this embodiment, the battery cell 100 is a prismatic battery cell. In some other embodiments, the battery cell 100 may also be a battery cell of other shapes; this application does not impose any particular limitation.

[0075] like Figure 3 As shown, the battery cell 100 includes a housing 5 and an electrode assembly 6.

[0076] The outer casing 5 is the external protective shell of the battery cell 100, and has an internal cavity for accommodating the electrode assembly 6 and electrolyte, etc. The outer casing 5 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite shell), or aluminum-plastic film, etc.

[0077] In some embodiments, the housing 5 can be a sealed structure or a non-sealed structure. As an example, when the housing 5 is a sealed structure, it serves to protect the electrode assembly 6 housed within it. A sealing bag may also be included between the housing 5 and the electrode assembly 6, the sealing bag being used to encapsulate the electrode assembly 6 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film.

[0078] In some embodiments, the housing 5 includes a housing 51 and end caps 52. The housing 51 has an opening 5a. The end caps 52 close the opening 5a to form a sealed space for accommodating the electrode assembly 6 and substances such as electrolytes. The housing 51 may have one or more openings 5a. The number of end caps 52 may also be one or more.

[0079] Electrode assembly 6 is the component in the battery cell 100 where the electrochemical reaction occurs, and electrode assembly 6 includes electrode body 61. For example... Figure 4 As shown, the electrode body 61 includes a positive electrode 61a, a negative electrode 61b, and a separator 61c. The positive electrode 61a, negative electrode 61b, and separator 61c are typically stacked along the thickness direction of the battery cell 100. During the charging and discharging process of the battery cell 100, active ions (e.g., lithium ions) repeatedly insert and extract between the positive electrode 61a and the negative electrode 61b. The separator 61c, disposed between the positive electrode 61a and the negative electrode 61b, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0080] In some embodiments, the negative electrode 61b may include a negative current collector and a negative electrode film layer disposed on at least one side of the negative current collector.

[0081] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0082] The negative electrode film layer includes a negative electrode active material. The negative electrode active material can be any negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0083] In some embodiments, the negative electrode 61b can be made of foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. When foamed metal is used as the negative electrode 61b, the surface of the foamed metal may or may not have a negative electrode active material.

[0084] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0085] In some embodiments, the positive electrode 61a may include a positive current collector and a positive electrode film layer disposed on at least one side of the positive current collector.

[0086] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0087] The positive electrode film layer includes a positive electrode active material. As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0088] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0089] In some embodiments, the separator 61c is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0090] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator 61c can be a separate component located between the positive and negative electrode plates, or it can be attached to the surface of the positive and negative electrode plates. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0091] In some embodiments, the battery cell 100 also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel-like, or solid.

[0092] Liquid electrolytes include electrolyte salts and solvents.

[0093] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0094] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0095] The electrode body 61 of the electrode assembly 6 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0096] In some embodiments, the electrode body 61 has a wound structure. The positive electrode 61a and the negative electrode 61b are wound into a wound structure.

[0097] In some embodiments, the electrode body 61 has a stacked structure.

[0098] As an example, multiple positive electrode plates 61a and multiple negative electrode plates 61b can be set, and multiple positive electrode plates 61a and multiple negative electrode plates 61b can be stacked alternately.

[0099] As an example, multiple separators 61c can be provided, respectively disposed between any adjacent positive electrode 61a or negative electrode 61b.

[0100] As an example, the separator 61c can be continuously arranged between any adjacent positive electrode 61a or negative electrode 61b by means of folding or rolling.

[0101] like Figure 5 and Figure 6 As shown, in the battery cell production process, the mixed slurry is evenly coated onto the current collector, and after drying and rolling processes, a roll of electrode sheet with a relatively large width and long length is formed, which is the master roll electrode sheet 500. The master roll electrode sheet 500 is conveyed to the slitting device, where, according to the design requirements of the battery cell 100, the wide master roll electrode sheet 500 is cut into several narrow electrode sheet rolls (also called slitting rolls). After the slitting process, the electrode sheet rolls enter the cutting process, processing the continuous roll electrode sheets into single electrode sheets of a specific shape. The master roll electrode sheet 500 or the electrode sheet roll is die-cut to create the electrode tabs. The single electrode sheets of a specific shape here may include, for example, Figure 7 , Figure 9 The monolithic electrode plates shown for stacking may also include, for example, Figure 8 , Figure 10 The single electrode sheet shown is used for winding.

[0102] During the slitting or cutting process, due to the high hardness and material properties of the active material, laser slitting is not applicable. Therefore, the industry primarily uses mechanical slitting and cutting. During this process, the current collector is deformed by the pressure of particles in the film layer. Large particles in the film layer can easily damage the current collector, forming burrs 20. Specifically, a "burr" refers to a metal protrusion or protrusion extending outward from the current collector, according to the IEEE 1725 standard for cell safety performance review and testing. The direction of extension can be arbitrary, such as the thickness direction or the electrode plane direction. The formation of burrs 20 can adversely affect the performance of the battery cell 100, such as causing a short circuit if the burr punctures the separator.

[0103] In the embodiments of this application, such as Figures 5 to 10As shown, the first film layer 1a includes a main film layer 3 and an edge film layer 4 that are adjacent to each other. The main film layer 3 includes a first active material. The edge film layer 4 may include a second active material or an insulating material. When the edge film layer 4 includes a second active material, the first active material and the second active material may be the same or different. This application embodiment does not specifically limit the types of the first active material and the second active material. Of course, when the edge film layer 4 includes an insulating material, this application embodiment also does not specifically limit the type of the insulating material. The edge film layer 4 is coated on the slitting area 10 of the master roll electrode sheet 500, that is, the area where subsequent slitting or cutting is performed. Thus, after the master roll electrode sheet 500 is slitted or cut, an electrode sheet 1 is formed, and the edge film layer 4 will be located at the edge of the electrode sheet 1.

[0104] Specifically, such as Figure 3 and Figure 10 As shown, the electrode 1 includes a current collector 2 and a first film layer 1a. The first film layer 1a includes a main film layer 3 and an edge film layer 4 adjacent to each other. Portions of both the main film layer 3 and the edge film layer 4 are in contact with the current collector 2. The current collector 2 includes a main body portion 21 and an electrode tab portion 22. Those skilled in the art should understand that... Figure 5 and Figure 6 The tab 22 in the middle is the tab 22 before die cutting. Figures 7 to 10 The tab 22 in the figure is a die-cut tab 22. The film layer can be disposed on at least one side of the main body 21, that is, along the thickness direction X of the main body, the film layer can be coated on only one side or both sides. The tab 22 can conduct current from the main body 21. In some embodiments, at least one electrode terminal 7 is provided on the housing 5. The electrode terminal 7 is electrically connected to the tab 22. The electrode terminal 7 can be directly connected to the tab 22 or indirectly connected to the tab 22 through a current collector 8 (e.g., an adapter). The electrode terminal 7 can be disposed on the end cap 52 or on the housing 51.

[0105] Because an edge film layer 4 is provided, and the volume distribution particle size DV99' of the particles in the edge film layer 4 is smaller than the volume distribution particle size DV99 of the particles in the main film layer 3, and / or, the volume distribution particle size DV50' of the particles in the edge film layer 4 is smaller than the volume distribution particle size DV50 of the particles in the main film layer 3, the compression of the current collector 2 by large particles in the film layer can be reduced when the edge of the electrode sheet is slit or cut, reducing the possibility of stress concentration. This improves the phenomenon of burrs 20 on the electrode sheet and reduces the possibility of burrs 20 piercing the separator during subsequent battery cell 100 assembly (e.g., during winding or stacking) or when the battery cell 100 is subjected to vibration or compression, thereby improving the reliability, stability and service life of the battery cell 100.

[0106] Here, the edge membrane layer 4 may have only particles whose volume distribution particle size DV99' is smaller than that of the particles in the main membrane layer 3, or only particles whose volume distribution particle size DV50' is smaller than that of the particles in the main membrane layer 3, or both particles whose volume distribution particle size DV99' and DV50' are smaller than those of the particles in the main membrane layer 3.

[0107] The volume distribution particle sizes "DV99" and "DV50" refer to the particle sizes corresponding to a cumulative volume distribution percentage of 99% and 50%, respectively. These values ​​can be determined using conventional instruments and methods in this field, such as referring to GB / T19077. In 2016, particle size distribution was measured using an instrument employing laser diffraction (such as the Mastersizer 2000E laser particle size analyzer from Malvern Instruments Ltd., UK). In this application, particles with different volume distribution sizes in the main film layer 3 and the edge film layer 4 can be obtained commercially available or through any known, conventional preparation method.

[0108] Furthermore, the edge film layer 4 is only disposed in the area of ​​the main body 21 near the second edge 21b. The remaining positions of the main body 21 are still coated with the main film layer 3 with a particle size within the normal range. Thus, while ensuring the energy density of the battery cell 100, the possibility of burrs 20 appearing on the electrode is reduced, the yield of the battery cell 100 is improved, and the requirements for performance and efficiency are met.

[0109] The second edge 21b is the edge of the main body 21 where the tab portion 22 is not connected. For example... Figures 7 to 10 As shown, a rectangular electrode sheet 1 is used as an example. The master roll electrode sheet 500 is slitting and cutting to form a rectangular electrode sheet 1. Along the width direction of the edge film layer 4, the main body 21 of the electrode sheet 1 has four edges (i.e., the four sides of the rectangle). The edge connected to the tab 22 is the first edge 21a, and the remaining edges not connected to the tab 22 are the second edges 21b. In some embodiments, such as... Figure 7 and Figure 8 As shown, since the tab 22 is connected to the same side of the main body 21, the remaining three edges can all be referred to as the second edge 21b. In some other embodiments, such as Figure 9 and Figure 10As shown, the tab 22 can be located on different sides of the main body 21, and the remaining two edges can be referred to as second edges 21b. When there are multiple second edges 21b, an edge film layer 4 can be provided in the region near each second edge 21b, or an edge film layer 4 can be provided only in the region near one or several second edges 21b. For example, an edge film layer 4 can be provided only in the second edges 21b opposite to the first edge 21a.

[0110] In some embodiments, electrode 1 includes a positive electrode. In some embodiments, electrode 1 may also include a negative electrode.

[0111] In some embodiments, along the width direction of the edge film layer 4, one side of the edge film layer 4 is adjacent to the main film layer 3, and the other side extends to the second edge 21b.

[0112] Therefore, the edge film layer 4 is adjacent to the main film layer 3, and the edge film layer 4 extends to the second edge 21b. This can reduce the possibility of burrs appearing on the second edge 21b of the electrode 1, while ensuring the energy density of the battery cell 100 as much as possible, improving the reliability of the battery cell 100, and meeting the performance and efficiency requirements of the battery cell 100.

[0113] In some embodiments, such as Figures 7 to 15 As shown, the electrode 1 also includes an insulating layer 9. The insulating layer 9 is disposed in the region of the main body 21 near the first edge 21a and extends along the first edge 21a. The insulating layer 9 is in contact with the main body 21.

[0114] Specifically, the main body 21 is not completely coated with a film layer (either the first film layer 1a or the second film layer 1b). The insulating layer 9 is located on the side of the main body 21 facing the tab portion 22, and the area of ​​the main body 21 where the insulating layer is provided is not coated with a film layer. In other words, the area of ​​the main body 21 near the first edge 21a is not coated with a film layer. The insulating layer 9 is provided in the area of ​​the main body 21 near the first edge 21a and extends along the first edge 21a.

[0115] The insulating layer 9 provides excellent insulation, reducing the likelihood of the film layer of the main body 21 contacting the outer casing, thereby reducing the risk of short circuits and further improving the reliability of the battery cell 100. Furthermore, since the insulating layer 9 is provided in the area of ​​the main body near the first edge 21a, even if burrs are generated at the first edge 21a during electrode die-cutting, the burrs can be covered by the insulating layer 9. This means that even without the edge film layer 4, the first edge 21a is less prone to short circuits due to burrs piercing the separator.

[0116] For example, the insulating layer 9 includes, but is not limited to, tab adhesive.

[0117] As an example, the insulating layer 9 may be included only in the positive electrode, or only in the negative electrode, or both the positive and negative electrodes may include the insulating layer 9.

[0118] In some embodiments of this application, the ratio of the volume distribution particle size DV99 of the particles in the main membrane layer 3 to the volume distribution particle size DV99' of the particles in the edge membrane layer 4 is (2-10):1, and / or, the ratio of the volume distribution particle size DV50 of the particles in the main membrane layer 3 to the volume distribution particle size DV50' of the particles in the edge membrane layer 4 is (2-10):1.

[0119] For example, the ratio of the volume distribution particle size DV99 of the particles in the main membrane layer 3 to the volume distribution particle size DV99' of the particles in the edge membrane layer 4 can be a value between 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, or any combination of both. The ratio of the volume distribution particle size DV50 of the particles in the main membrane layer 3 to the volume distribution particle size DV50' of the particles in the edge membrane layer 4 can be 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, or a value within a range of any two of these ratios.

[0120] As a specific example, if the volumetric particle size distribution (DV99) of the particles in the main membrane layer 3 is 25 μm, then the volumetric particle size distribution (DV99') of the particles in the edge membrane layer 4 can be 5 μm. If the volumetric particle size distribution (DV50) of the particles in the main membrane layer 3 is 11 μm, then the volumetric particle size distribution (DV50') of the particles in the edge membrane layer 4 can be 2 μm.

[0121] Therefore, the volumetric particle sizes DV99 and DV50 of the particles in the main film layer 3 are 2 to 10 times larger than those DV99' and DV50' of the particles in the edge film layer 4. Because the volumetric particle sizes DV99' and DV50' of the particles in the edge film layer 4 are smaller, they can buffer the compression of the current collector 2 by large particles in the film layer during slitting or cutting, thereby reducing the probability of large burrs 20 and improving the reliability and safety performance of the battery cell 100.

[0122] In some embodiments of this application, the volume distribution particle size DV99' of the particles in the edge film layer 4 is 0.5 μm-15 μm, and / or the volume distribution particle size DV50' of the particles in the edge film layer 4 is 0.1 μm-7 μm.

[0123] Optionally, the volume distribution particle size DV99' of the particles in the edge film layer 4 is greater than or equal to 0.5 μm and less than 5 μm, and the volume distribution particle size DV50' of the particles in the edge film layer 4 is greater than or equal to 0.1 μm and less than 0.4 μm.

[0124] For example, the volume distribution particle size DV99' of the particles in the edge membrane layer 4 can be a value between 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, or any combination thereof. The volumetric particle size DV50' of the particles in the edge membrane layer 4 can be a value between 0.1 μm, 0.15 μm, 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, or any combination thereof.

[0125] Therefore, the volume distribution particle sizes DV99' and DV50' of the particles in the edge film layer 4 are within a suitable range, which can further buffer the compression of the current collector 2 by large particles in the film layer during the slitting or cutting process, thereby reducing the probability of large-sized burrs 20 and improving the reliability and safety performance of the battery cell 100.

[0126] In some embodiments, the volume distribution particle size DV99 of the particles in the main film layer 3 is 0.6-35 μm, and the volume distribution particle size DV50 of the particles in the main film layer 3 is 0.2-15 μm.

[0127] For example, the volume distribution particle size DV99 of the particles in the main film layer 3 can be a value between 0.6μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, or any combination thereof. The volumetric particle size distribution (DV50) of the particles in the main film layer 3 can be a value between 0.2 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm, 15 μm, or any combination of two of these values.

[0128] In this embodiment, the DV99 and DV50 of the main film layer 3 are not specifically limited, as long as the DV99' of the edge film layer 4 is smaller than the DV99 of the main film layer 3, and the DV50' of the edge film layer 4 is smaller than the DV50 of the main film layer 3.

[0129] In some embodiments of this application, the compaction density of the edge membrane layer 4 is less than that of the main membrane layer 3.

[0130] In this embodiment, the compaction density of the film layer = the areal density of the film layer / the thickness of the film layer, and can be measured using instruments and methods known in the art. The thickness of the film layer can be measured using instruments and methods known in the art. For example, a micrometer (e.g., Mitutoyo 293-100, with an accuracy of 0.1 μm) can be used to measure the thickness of the electrode at at least 12 different locations along the thickness direction of the main body, and the average value is taken as the thickness of the electrode. Then, the thickness of the current collector is subtracted to obtain the thickness of the film layer. The areal density of the film layer can be measured using instruments and methods known in the art. For example, a cold-pressed electrode or an electrode obtained after disassembling a battery (if it is a double-sided coated electrode, first wipe off the film layer on one side), punched into a small circular piece with an area of ​​S1, and its weight recorded as M1. Then, the film layer of the weighed electrode is wiped off, and the weight of the current collector is recorded as M0. The areal density of the film layer = (M1 - M0) / S1. Then the compaction density of the electrode is calculated by compaction density = surface density of the film / thickness of the film.

[0131] Because the compaction density of the edge film layer 4 is relatively low, the contact between particles is relatively loose, and the internal residual stress is small. Therefore, when the electrode sheet 1 is slitting or cutting, it is less likely to undergo severe edge deformation due to stress release, thereby reducing the possibility of burrs 20 appearing.

[0132] In addition, due to the low compaction density, there may be more pores inside the edge membrane layer 4. These pores can play a certain buffering role when subjected to external forces, absorb a certain amount of fracture energy, and further reduce the compression of particles on the current collector 2, so that the cut is relatively smooth and less prone to burrs 20.

[0133] In some embodiments of this application, the compaction density of the edge membrane layer 4 is 30%-80% of the compaction density of the main membrane layer 3.

[0134] For example, the compaction density of the edge membrane layer 4 can be a value within a range of 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or any combination thereof of the compaction density of the main membrane layer 3.

[0135] Therefore, the compaction density of the edge film layer 4 is within a suitable range, which is beneficial to maintain the energy density of the battery cell 100 while improving the yield rate during the electrode cutting process, and at the same time meeting the requirements of performance and efficiency.

[0136] In some embodiments of this application, the edge film layer 4 includes an adhesive. The adhesive in the edge film layer 4 accounts for 1.5%-2.5% of the total mass.

[0137] The adhesive may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0138] In this embodiment, the mass percentage of the binder can be determined using instruments and methods known in the art. For example, the mass percentage of the binder can be determined by detecting specific elements (such as fluorine F, which is unique to binders) using an energy dispersive spectroscopy (EDS) or electron probe microanalysis (EPMA).

[0139] For example, the mass percentage of the adhesive in the edge membrane layer 4 can be 1.5%, 2%, 2.5%, or any combination thereof.

[0140] Therefore, the adhesive content of the edge film layer 4 is relatively high, which helps to improve the bonding force between the particles of the edge film layer 4. When the electrode 1 is slitting or cutting, the edge film layer 4 is easier to "cut" rather than "pull out", which can reduce the compression of the particles on the current collector 2 and reduce the possibility of burrs 20.

[0141] In addition, appropriately increasing the content of binder is beneficial to improving the flexibility and fracture toughness of the edge film layer 4, thus providing a certain buffering and lubricating effect when slitting or cutting the electrode 1, and also helping to reduce the possibility of burrs 20 appearing.

[0142] In some embodiments of this application, such as Figure 7 and Figure 11 As shown, the width L of the edge membrane layer is 1mm-5mm.

[0143] Specifically, the edge film layer 4 has a certain width along the extension direction perpendicular to the second edge and perpendicular to the thickness direction of the main body.

[0144] For example, the width L of the edge membrane layer can be a value between 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or any combination thereof.

[0145] The width L of the edge film can be measured using instruments and methods known in the field, such as optical image measurement and machine vision inspection.

[0146] Therefore, the width L of the edge film layer is within a suitable range, which can maintain the high energy density of the battery cell 100 without encroaching too much on the area where the main film layer 3 is located, while leaving a suitable space for the electrode sheet to be cut and diced. This improves the reliability of cutting and dicing while ensuring the energy density of the battery cell 100.

[0147] In some embodiments of this application, the edge film layer 4 includes a second active material, or the edge film layer 4 includes an insulating material.

[0148] When the edge film layer 4 includes a second active material, the smaller particle size of the second active material in the edge film layer 4 reduces the compression of the current collector 2 by large particles, thereby improving the burr 20. Moreover, since the edge film layer 4 also includes an active material, the energy density of the battery cell 100 can be maintained while improving the burr 20, thus simultaneously meeting the requirements of performance and efficiency, and improving the reliability and stability of the battery cell 100.

[0149] For example, the second active material of the edge membrane layer 4 can be the same as the first active material of the main membrane layer 3.

[0150] For example, the second active material of the edge membrane layer 4 is different from the first active material of the main membrane layer 3.

[0151] When the edge membrane layer 4 includes insulating material, the insulating material can improve the bending strength and impact resistance of the current collector 2, so that when the current collector 2 is subjected to external force, the edge can be kept intact as much as possible, and it is not easy to break or delaminate, which helps to reduce the formation of burrs 20.

[0152] In addition, even if tiny burrs 20 are formed on the edge of the electrode after slitting or cutting, the insulating material can still play a good barrier role, reducing the possibility of the burrs 20 piercing the separator, thereby suppressing the possibility of the existing burrs 20 affecting the performance of the battery cell 100, and improving the reliability and stability of the battery cell 100.

[0153] For example, insulating materials include, but are not limited to, aluminum oxide.

[0154] In some embodiments of this application, such as Figure 11 and Figure 12 As shown, on the same projection plane perpendicular to the thickness direction of the main body, the orthographic projection of the main body film layer 3 and the orthographic projection of the edge film layer 4 do not overlap.

[0155] Therefore, the main film layer 3 and the edge film layer 4 are arranged substantially side by side, which helps to simplify the coating process and reduce manufacturing costs. Furthermore, in this embodiment, the thickness of the main film layer 3 is substantially the same as the thickness of the edge film layer 4, which helps to ensure the uniformity of the electrochemical performance of the battery cell 100, improve the reliability and stability of the battery cell 100, and also helps to improve the assembly accuracy and yield in the subsequent battery cell 100 assembly process.

[0156] In some embodiments of this application, such as Figure 14 and Figure 15 As shown, along the thickness direction X of the main body, at least a portion of the edge film layer 4 is located between the main body 21 and the main film layer 3.

[0157] Along the thickness direction X of the main body, the edge film layer 4 with a smaller particle size is present on the side near the current collector 2. This reduces the compression of the current collector 2 by larger particles during the slitting or cutting of the electrode, thereby reducing the probability of burrs 20 appearing. A main film layer 3 is also coated on the upper surface of the edge film layer 4. This improves burr 20 while minimizing the energy density loss of the battery cell 100, thus improving yield while ensuring the performance of the battery cell 100 and meeting the efficiency and performance requirements of the battery cell 100.

[0158] In some embodiments of this application, the thickness U of the edge film layer is greater than or equal to 5 μm along the thickness direction X of the main body.

[0159] The thickness U of the edge film layer can be measured using instruments and methods known in the art, such as micrometers.

[0160] Therefore, by keeping the thickness U of the edge film layer within a suitable range, the possibility of burrs 20 can be reduced while ensuring the energy density of the battery cell 100 as much as possible, while meeting the requirements of performance and efficiency, and improving the reliability and stability of the battery cell 100.

[0161] In some embodiments of this application, such as Figure 11 and Figure 14 As shown, a first film layer 1a is provided on both sides of the main body 21 along the thickness direction X of the main body.

[0162] Therefore, the current collector 2 is provided with a main film layer 3 and an edge film layer 4 on both sides, which helps to improve the energy density of the battery cell 100 and reduce the possibility of burrs 20 appearing on the electrode 1, thereby improving the reliability and stability of the battery cell 100.

[0163] For example, such as Figure 11 As shown, the main film layer 3 and the edge film layer 4 of the first film layer 1a on both sides of the thickness direction of the main body 21 can be arranged side by side.

[0164] For example, such as Figure 14 As shown, the edge film layers 4 of the first film layer 1a on both sides of the thickness direction of the main body 21 can be located between the main film layer 3 and the main body 21.

[0165] As another example, the main film layer 3 and the edge film layer 4 of the first film layer 1a on one side of the thickness direction of the main body 21 can be arranged side by side, and the edge film layer 4 of the first film layer 1a on the other side of the thickness direction of the main body 21 can be located between the main film layer 3 and the main body 21.

[0166] In some embodiments of this application, such as Figure 12 and Figure 15 As shown, the electrode 1 also includes a second film layer 1b. The material of the second film layer 1b is the same as that of the main film layer 3. Along the thickness direction X of the main body portion, the main body portion 21 includes a first side 21c and a second side 21d, with the first film layer 1a disposed on the first side 21c and the second film layer 1b disposed on the second side 21d.

[0167] Therefore, a first film layer 1a is provided on one side of the current collector 2, that is, a main film layer 3 and an edge film layer 4 are provided at the same time, while only a second film layer 1b with the same material as the main film layer 3 is provided on the other side. This can improve the yield of the battery cell 100 while maintaining the energy density of the battery cell 100 as much as possible, and at the same time meet the performance and efficiency requirements of the battery cell 100.

[0168] In some embodiments of this application, such as Figure 13 As shown, the second edge 21b of the main body 21 has burrs 20, which extend from the second edge 21b toward the second side 21d.

[0169] Since the first film layer 1a, including the edge film layer 4, is only provided on one side, burrs 20 may still appear on the second side 21d of the current collector 2. By selecting different cutting tools during the slitting or cutting process (for example, using a beveled blade on the first side 21c and a straight blade on the second side 21d), the burrs 20 generated at the second edge 21b extend towards the second side 21d, thereby reducing the risk of the burrs 20 protruding outward and puncturing the separator. This maximizes the energy density of the electrode 1 while minimizing the adverse effects of the burrs 20, thus improving the reliability and stability of the battery cell 100.

[0170] A second aspect of this application provides a battery device 400. The battery device 400 includes a housing 401 and a battery cell 100 according to the first aspect of this application. The battery cell 100 is disposed within the housing 401.

[0171] The electrical device of this application embodiment has better reliability because it uses the battery cell 100 as described above, and the risk of failure of the battery device 400 due to the failure of the battery cell 100 is reduced, thereby helping to reduce the time spent on maintenance and improving the reliability and stability of the battery device 400.

[0172] A third aspect of this application provides an electrical device. The electrical device includes a battery cell 100 of the first aspect of this application or a battery device 400 of the second aspect of this application for providing electrical energy.

[0173] The electrical device in this application embodiment has better reliability because it uses the battery cell 100 or battery device 400 as described above, and the risk of failure due to failure of the battery cell 100 or battery device 400 is reduced, thereby helping to reduce the time spent on maintenance and improving the reliability and stability of the electrical device.

[0174] A fourth aspect of this application provides an energy storage device. The energy storage device includes a battery cell 100 of the first aspect of this application or a battery device 400 of the second aspect of this application for storing or providing electrical energy.

[0175] The energy storage device of this application embodiment has better reliability because it uses the battery cell 100 or battery device 400 as described above, and the risk of failure due to failure of the battery cell 100 or battery device 400 is reduced, thereby helping to reduce the time spent on maintenance and improving the reliability and stability of the energy storage device.

[0176] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the application will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0177] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0178] Example 1 (1) Preparation of positive electrode sheet The first positive electrode active material, lithium iron phosphate (LFP), conductive agent (Super P), and binder (polyvinylidene fluoride) are mixed at a mass ratio of 98:1:1. A solvent (N-methylpyrrolidone) is added, and the mixture is stirred under vacuum until homogeneous, obtaining the main film slurry. The second positive electrode active material, lithium iron phosphate (LFP), conductive agent (Super P), and binder (polyvinylidene fluoride) are mixed at a mass ratio of 97:1:2. A solvent (N-methylpyrrolidone) is added, and the mixture is stirred under vacuum until homogeneous, obtaining the edge film slurry. The main film slurry is uniformly coated onto a portion of the positive electrode current collector (aluminum foil). The edge film slurry is uniformly coated onto the remaining areas of the positive electrode current collector (aluminum foil) (areas requiring slitting or cutting). After drying, cold pressing, slitting, cutting, and die-cutting, the positive electrode sheet is obtained. In this design, the main film layer and the edge film layer are arranged side by side along the width direction of the edge film layer, and the thickness of both the main film layer and the edge film layer on one side is 75 μm. The volumetric particle size distribution of the particles in the main film layer is DV99 = 25 μm and DV50 = 10 μm. The volumetric particle size distribution of the particles in the edge film layer is DV99' = 0.5 μm and DV50' = 0.1 μm.

[0179] (2) Preparation of negative electrode sheet The negative electrode natural graphite, binder and conductive agent are fully mixed and ball-milled in a deionized water solvent system at a mass ratio of 90:5:5 to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on the surface of the negative electrode current collector (copper foil), and then dried, cold-pressed, slit, cut and die-cut to obtain the negative electrode sheet.

[0180] (3) Preparation of the separating membrane A 7mm thick polyethylene film was used as the separator.

[0181] (4) Preparation of electrolyte Lithium hexafluorophosphate (LiPF6) was dissolved in ethylene carbonate (EC), diethyl carbonate (DEC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1 to form a homogeneous solution, resulting in an electrolyte with a LiPF6 concentration of 1 mol / L.

[0182] (5) Preparation of battery cells The positive electrode, separator, and negative electrode are stacked in sequence, with the separator positioned between the positive and negative electrodes to provide isolation. The electrode assembly is then formed by bending and winding. The electrode assembly is placed in a housing, dried, and then injected with the prepared electrolyte. After vacuum sealing, settling, formation, and shaping, a single battery cell is obtained.

[0183] Examples 2-9 Example 2 The preparation method of the battery cell of Example 9 is similar to that of the battery cell in Example 1. The difference is that the volume distribution particle sizes DV99' and DV50' of the particles in the edge film layer of the positive electrode are adjusted. The specific preparation parameters are shown in Table 1.

[0184] Example 10 The battery cell of Example 10 is prepared in a similar way to the battery cell of Example 1. The difference is that the particle size DV50' of the particles in the edge film layer of the positive electrode in Example 10 is not in the range of 0.1μm-7μm.

[0185] Example 11 The battery cell in Example 11 is prepared in a similar manner to the battery cell in Example 1. The difference is that the particle size DV99' of the particles in the edge film layer of the positive electrode in Example 11 is not in the range of 0.5μm-15μm.

[0186] Example 12 The battery cell in Example 12 is prepared in a similar manner to the battery cell in Example 1. The difference is that the volume distribution particle size DV99 of the particles in the main film layer in Example 12 is 35 μm and DV50 is 11 μm.

[0187] Comparative Example 1 The battery cell of Comparative Example 1 is prepared in a similar manner to the battery cell in Example 1. The difference is that the positive electrode does not include the edge film layer, and the entire area is coated with a second film layer of the same material as the main film layer. The specific preparation parameters are shown in Table 1.

[0188] Comparative Example 2 The battery cell of Comparative Example 2 is prepared in a similar manner to the battery cell of Example 1. The difference is that the particle size distribution DV99' of the particles in the edge film layer of the positive electrode in Comparative Example 2 is not in the range of 0.5μm-15μm, and DV50' is not in the range of 0.1μm-7μm.

[0189] Performance testing (1) Test method for particle size of material in positive electrode sheet The battery cells were disassembled, and the powder to be tested was scraped out from the main film layer and the edge film layer respectively. The powder to be tested was poured into an air dispersion tank containing ethanol and ultrasonically dispersed for 5 minutes. Sodium dodecyl sulfate (SDS) was added as a dispersant. Then it was loaded into a laser particle size analyzer (Malvin 2000E) for testing to obtain the volume distribution particle size of the particles in the main film layer and the edge film layer.

[0190] (2) Characterization method of cross-sectional burrs on positive electrode sheet The slit positive electrode sheets were characterized using a super depth-of-field microscope (Keyence 600). The test temperature was 25℃, the size of the positive electrode sheet was 80mm × 60mm, the magnification was 300x, and the light-gathering aperture was 30%. Burrs were observed and their dimensions were calibrated from the slit cross-section of the electrode sheet. Burrs with a size greater than or equal to 40% of the thickness of the positive electrode sheet were included in the statistical range and calibrated as positive electrode sheets with burrs. The percentage of positive electrode sheets with burrs was calculated by observing 1000 slit positive electrode sheets with a CCD and counting the frequency K1 of the burr-bearing electrodes. The percentage of burrs was calculated as K1 / 1000 × 100%.

[0191] Analysis of test results for each embodiment and comparative example Battery cells for each embodiment and comparative example were prepared according to the above method, and various performance parameters were measured. The results are shown in the table below.

[0192] Table 1

[0193] As can be seen from the comparison of the results of the embodiments and comparative examples, when the main body is provided with an edge film layer whose volume distribution particle size DV99' is smaller than that of the main film layer, and / or an edge film layer whose volume distribution particle size DV50' is smaller than that of the main film layer, the probability of burrs generated during the cutting process of the positive electrode sheet can be effectively reduced, and the reliability and safety performance of the battery cell can be improved.

[0194] Specifically, a comparison of the results of Examples 10 and 11 with those of Comparative Examples 1 and 2 shows that when the volume distribution particle size DV99' of the edge film layer is smaller than that of the main film layer, or when the volume distribution particle size DV50' of the edge film layer is smaller than that of the main film layer, the probability of burr generation is significantly lower than that when there is no edge film layer. Furthermore, the probability of burr generation is also significantly lower than that when the volume distribution particle size DV99' and DV50' of the edge film layer are larger than that of the main film layer.

[0195] Furthermore, a structural comparison between Examples 1-8 and Examples 10 and 11 shows that when the volume distribution particle sizes DV99' and DV50' of the edge film layer are both smaller than those of the main film layer, the probability of burr generation is further reduced compared to the case where one of the volume distribution particle sizes DV99' and DV50' of the edge film layer is smaller than that of the main film layer, thereby further improving the probability of burr generation.

[0196] In other words, as can be seen from Table 1, when the volume distribution particle size DV99' of the particles in the edge film layer is 0.5μm-15μm and the volume distribution particle size DV50' of the particles in the edge film layer is 0.1μm-7μm, the proportion of positive electrode sheets with burrs is lower, which can further improve the reliability and stability of the battery cell.

[0197] The following describes specific examples of some embodiments of this application with reference to the accompanying drawings.

[0198] As a specific example, the electrode (positive electrode) includes a positive electrode substrate aluminum foil (positive current collector 2). A tab adhesive (insulating layer 9) is coated on both sides of the aluminum foil on the tab side. An active material region is formed in the area immediately adjacent to the tab adhesive. Active material (main film layer 3) is coated on one or both sides of the active material region. A slit region is formed immediately adjacent to the active material region. The width L of the slit region is 1-5 mm (width L of the edge film layer). Small particulate material (edge ​​film layer 4) is coated on one or both sides of this slit region. The small particulate material can be either active material or insulating material. The particle sizes DV99' and DV50' of the small particulate material are half the particle size of the active material in the active material region, or the particle sizes DV99' are less than or equal to 15 μm and DV50' are less than or equal to 7 μm.

[0199] For example, a double-layer coating can be applied to the slitting area, with small particles coated in the lower layer and a normal active material coated in the upper layer. Due to the protection provided by the lower layer of small particles, damage to the substrate is reduced during cold pressing, and large particles are less likely to be squeezed onto the aluminum foil during slitting, thereby reducing the probability of burrs 20 occurring. The thickness of this lower layer of small particles (the thickness U of the edge film layer) is typically greater than or equal to 5 μm, which reduces both the probability of burrs 20 and energy density loss.

[0200] For example, the damage to the substrate caused by cold pressing can also be reduced by decreasing the cold pressing density in the slit region. The lower the density, the less damage to the substrate, thereby reducing the probability of burrs 20 occurring. The density of small particles in the slit region can be reduced to 30%-80% of that in the normal active material region.

[0201] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. A battery cell, characterized in that, The battery cell includes an electrode, and the electrode includes: A current collector includes a main body and an electrode tab, the main body including a first edge and a second edge, and the electrode tab being connected to the first edge; A first film layer is disposed on at least one side of the main body in the thickness direction. The first film layer includes a main film layer and an edge film layer. The main film layer includes a first active material. The edge film layer is disposed in the region of the main body near the second edge and extends along the second edge. Both the main film layer and the edge film layer are in contact with the main body. On the same projection plane perpendicular to the thickness direction of the main body, the orthographic projection of the main film layer and the orthographic projection of the edge film layer do not overlap. Wherein, the volume distribution particle size DV99' of the particles in the edge membrane layer is smaller than the volume distribution particle size DV99 of the particles in the main membrane layer, and / or, the volume distribution particle size DV50' of the particles in the edge membrane layer is smaller than the volume distribution particle size DV50 of the particles in the main membrane layer.

2. The battery cell according to claim 1, characterized in that, Along the width direction of the edge film layer, one side of the edge film layer is adjacent to the main film layer, and the other side extends to the second edge.

3. The battery cell according to claim 1, characterized in that, The ratio of the volume distribution particle size DV99 of the particles in the main membrane layer to the volume distribution particle size DV99' of the particles in the edge membrane layer is (2-10):1, and / or the ratio of the volume distribution particle size DV50 of the particles in the main membrane layer to the volume distribution particle size DV50' of the particles in the edge membrane layer is (2-10):

1.

4. The battery cell according to claim 1, characterized in that, The particle size distribution DV99' of the particles in the edge membrane layer is 0.5μm-15μm, and / or the particle size distribution DV50' of the particles in the edge membrane layer is 0.1μm-7μm.

5. The battery cell according to claim 1, characterized in that, The compaction density of the edge membrane layer is less than that of the main membrane layer.

6. The battery cell according to claim 5, characterized in that, The compaction density of the edge membrane layer is 30%-80% of the compaction density of the main membrane layer.

7. The battery cell according to claim 1, characterized in that, The edge membrane layer includes an adhesive, and the adhesive in the edge membrane layer accounts for 1.5%-2.5% of the total mass.

8. The battery cell according to claim 1, characterized in that, The width of the edge membrane layer is 1mm-5mm.

9. The battery cell according to claim 1, characterized in that, The edge membrane layer includes a second active material; or... The edge membrane layer includes an insulating material.

10. The battery cell according to claim 1, characterized in that, Along the thickness direction of the main body, the thickness of the edge film layer is greater than or equal to 5 μm.

11. The battery cell according to claim 1, characterized in that, Along the thickness direction of the main body, the first film layer is provided on both sides of the main body.

12. The battery cell according to claim 1, characterized in that, The electrode further includes a second film layer, the material of which is the same as that of the main film layer; Along the thickness direction of the main body, the main body includes a first side and a second side, the first film layer is disposed on the first side, and the second film layer is disposed on the second side.

13. The battery cell according to claim 12, characterized in that, The second edge of the main body has burrs that extend from the second edge toward the second side.

14. The battery cell according to claim 1, characterized in that, The electrode further includes an insulating layer disposed in the area of ​​the main body near the first edge and extending along the first edge, the insulating layer being in contact with the main body.

15. A battery device, characterized in that, The battery device includes: Box; The battery cell according to any one of claims 1 to 14, wherein the battery cell is disposed in the housing.

16. An electrical appliance, characterized in that, The electrical device includes a battery cell as described in any one of claims 1 to 14 or a battery device as described in claim 15 for providing electrical energy.

17. An energy storage device, characterized in that, The energy storage device includes a battery cell as described in any one of claims 1 to 14 or a battery device as described in claim 15, for storing or providing electrical energy.

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