Battery monomer, pole piece, battery device and power utilization device

Abstract

The utility model discloses a battery monomer, a pole piece, a battery device and a power utilization device. The battery monomer comprises a shell and an electrode assembly, the electrode assembly is arranged in the shell, the electrode assembly comprises a pole piece, the pole piece comprises a current collector and an active substance layer arranged on at least one side of the current collector in the thickness direction, and the active substance layer comprises a main body region and an edge region arranged on at least one end of the main body region in the first direction; wherein in the direction deviating from the main body area, the edge area comprises a first section and a second section which are sequentially arranged, the compaction density of the main body area is larger than that of the first section, the compaction density of the first section is larger than that of the second section, and the thickness difference between the first section and the second section is reduced; therefore, the problem of lithium precipitation caused by a large gap between the edge areas of the adjacent pole pieces is solved, and the electrical performance of the battery monomer is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, electrode, battery device, and power-consuming device. Background Technology

[0002] With the development of new energy technologies, battery cells are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] As batteries are used in a wider range of applications, the requirements for the performance of individual battery cells are becoming increasingly stringent. However, the performance of current individual battery cells is relatively poor and still needs further improvement. Utility Model Content

[0004] This application provides a battery cell, electrode, battery device, and power supply device, which can improve the electrical performance of the battery cell.

[0005] In a first aspect, this application provides a battery cell, including: a housing and an electrode assembly; the electrode assembly is disposed within the housing, the electrode assembly includes an electrode sheet, the electrode sheet includes a current collector and an active material layer disposed on at least one side in the thickness direction of the current collector, the active material layer includes a main region and an edge region disposed at at least one end of the main region along a first direction; wherein, along the direction away from the main region, the edge region includes a first segment and a second segment disposed sequentially, the compaction density of the main region is greater than the compaction density of the first segment, and the compaction density of the first segment is greater than the compaction density of the second segment.

[0006] In this embodiment, the active material layer includes a main region and an edge region disposed at at least one end of the main region along a first direction. The compaction density of the main region is greater than the compaction density of the first segment of the edge region, thereby reducing the thickness difference between the first segment and the main region. The compaction density of the first segment is greater than the compaction density of the second segment, thereby reducing the thickness difference between the first segment and the second segment. This improves the problem of lithium plating caused by the large gap between the edge regions of adjacent electrodes and enhances the electrical performance of the battery cell.

[0007] According to the embodiments of this application, the thickness of the first segment is equal to the thickness of the main body region. By reducing the thickness difference between the first segment and the main body region, the risk of lithium plating caused by large gaps in the edge regions between adjacent electrodes is reduced, thereby improving the electrical performance of the battery cell.

[0008] According to the embodiments of this application, the compaction density of the first segment is 90% to 99% of the compaction density of the main body region, so as to reduce the thickness difference between the first segment and the main body region and reduce the risk of lithium plating caused by large edge gaps between adjacent electrodes.

[0009] According to an embodiment of this application, the thickness of the second segment is less than the thickness of the main body region, thereby improving the structural strength of the second segment.

[0010] According to the embodiments of this application, the compaction density of the second segment is 70% to 80% of the compaction density of the main body region, which reduces the thickness difference between the second segment and the first segment and the main body region, improves the lithium plating problem, and ensures the structural strength of the second segment.

[0011] According to an embodiment of this application, the first segment includes two or more sub-segments arranged sequentially along the direction away from the main body area, and the compaction density of each sub-segment gradually decreases along the direction away from the main body area. This improves the uniformity of the thickness of the first segment and enhances the surface smoothness of the side of the first sub-segment away from the current collector.

[0012] According to the embodiments of this application, the first segment includes a first sub-segment, a second sub-segment, and a third sub-segment arranged sequentially along the direction away from the main body area;

[0013] The compaction density of the first sub-segment is 97% to 99% of the compaction density of the main area;

[0014] And / or, the compaction density of the second sub-segment is 95% to 97% of the compaction density of the main zone;

[0015] And / or, the compaction density of the third segment is 90% to 95% of the compaction density of the main area; improving the consistency of the thickness of the first, second, and third segments with that of the main area.

[0016] According to the embodiments of this application, the length of the first sub-segment is less than or equal to 5 mm; and / or, the length of the second sub-segment is less than or equal to 5 mm; and / or, the length of the third sub-segment is less than or equal to 3 mm, thereby improving the consistency of the thickness of the first sub-segment, the second sub-segment, and the third sub-segment with the main body region.

[0017] According to embodiments of this application, the electrode includes a positive electrode and a negative electrode. The positive electrode includes a positive current collector, and the negative electrode includes a negative current collector. An active material layer is disposed on at least one side of the positive and / or negative current collectors. The compaction density of the main body region of the active material layer is greater than the compaction density of the first segment, and the compaction density of the first segment is greater than the compaction density of the second segment, thereby reducing the thickness difference between the main body region, the first segment, and the second segment, increasing the spacing between the positive and negative electrode, and thus improving the lithium plating problem.

[0018] Secondly, this application provides an electrode sheet, comprising: a current collector and an active material layer; the active material layer is disposed on at least one side in the thickness direction of the current collector, the active material layer comprising a main body region and an edge region disposed at at least one end of the main body region along a first direction; wherein, along the direction away from the main body region, the edge region comprises a first segment and a second segment disposed sequentially, the compaction density of the main body region is greater than the compaction density of the first segment, and the compaction density of the first segment is greater than the compaction density of the second segment.

[0019] In this embodiment, the active material layer includes a main region and an edge region disposed at at least one end of the main region along a first direction. The compaction density of the main region is greater than the compaction density of the first segment of the edge region, thereby reducing the thickness difference between the first segment and the main region. The compaction density of the first segment is greater than the compaction density of the second segment, thereby reducing the thickness difference between the first segment and the second segment. This improves the problem of lithium plating caused by the large gap between the edge regions of adjacent electrodes and enhances the electrical performance of the battery cell.

[0020] Thirdly, this application provides a battery device including a battery cell according to any embodiment of the first aspect, or an electrode sheet according to any embodiment of the second aspect.

[0021] Fourthly, this application provides an electrical device, including the battery device in the third aspect embodiment. Attached Figure Description

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0023] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0024] Figure 2 Exploded view of the battery device according to some embodiments of this application;

[0025] Figure 3 This is a schematic diagram of the structure of a battery module according to some embodiments of this application;

[0026] Figure 4 This is a schematic diagram of the exploded structure of a battery cell according to some embodiments of this application;

[0027] Figure 5 This is a schematic diagram of the structure of the electrode sheet in some embodiments of this application;

[0028] Figure 6 This is a schematic diagram of the structure of an electrode assembly according to some embodiments of this application.

[0029] Figure label:

[0030] 1. Vehicles;

[0031] 10. Battery assembly; 11. Battery cell; 20. Control system; 30. Motor; 40. Housing; 41. First housing section; 42. Second housing section; 43. Receiving section; 50. Battery module;

[0032] 100, Housing; 101, Opening; 110, Top cover assembly; 200, Electrode assembly; 210, Electrode; 211, Positive electrode; 212, Negative electrode; 220, Current collector; 221, Positive current collector; 222, Negative current collector; 230, Active material layer; 231, Main body region; 232, Edge region; 240, First segment; 240a, Sub-segment; 241, First sub-segment; 242, Second sub-segment; 243, Third sub-segment; 250, Second segment; 260, Tab; 300, Separator; X, First direction. Detailed Implementation

[0033] 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.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0035] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0036] 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.

[0037] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0038] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0039] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0040] 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.

[0041] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery device applications, market demand is also constantly increasing.

[0042] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0043] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0044] A single battery cell includes electrode components and an electrolyte. The electrode components include a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer, which is coated on the surface of the positive current collector. The positive current collector includes a positive current collection section and a positive electrode tab connected to it. The positive current collection section is coated with the positive active material layer, while the positive electrode tab is not. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes the positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, the negative active material layer being coated on the surface of the negative current collector. The negative current collector includes a negative current collection section and a negative electrode tab connected to the negative current collection section. The negative current collection section is coated with the negative active material layer, while the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, which can be carbon or silicon, etc.

[0045] The housing may contain one or more electrode assemblies, which are mainly formed by winding or stacking electrode sheets. During the charging and discharging process of the battery, the positive and negative active material layers react with the electrolyte, and the tabs connect the electrode terminals to form a current loop. The housing is a component used to cooperate with the top cover assembly to form the internal environment of the battery cell. The formed internal environment can accommodate the electrode assemblies, electrolyte, and other components. The housing and top cover assembly can be independent components. An opening can be provided on the housing, and the top cover assembly closes the opening to form the internal environment of the battery cell. Optionally, the top cover assembly and housing can be integrated. Optionally, the top cover assembly and housing can form a common connection surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing, the top cover assembly closes the housing. The housing can be made of various materials, including copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0046] In related technologies, the material mass of the edge region of the active material layer in a single battery cell is less than that of the main region. When the active material layer is rolled, the thickness of the edge region is less than that of the main region. When forming the electrode assembly, the large distance between the edge regions of two adjacent electrodes can cause lithium plating on the electrodes, resulting in a decrease in the electrical performance of the battery cell.

[0047] Based on the above-mentioned technical problems, this application provides a technical solution in which the active material layer includes a main region and an edge region disposed at at least one end of the main region along a first direction; wherein, along the direction away from the main region, the edge region includes a first segment and a second segment disposed sequentially, the compaction density of the main region is greater than the compaction density of the first segment, and the compaction density of the first segment is greater than the compaction density of the second segment to reduce the thickness difference between the main region, the first segment and the second segment, thereby improving the problem of lithium plating caused by the large gap between the edge regions of adjacent electrodes and improving the electrical performance of the battery cell.

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

[0049] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

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

[0051] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

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

[0053] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0054] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0055] The technical solutions described in this application are applicable to battery devices and electrical devices using battery devices. Electrical devices include, for example, mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, and power tools. Spacecraft include, for example, airplanes, rockets, space shuttles, and spacecraft. Electric toys include, for example, stationary or mobile electric toys, specifically, game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include, for example, metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, specifically, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0056] The battery cells described in this application are not limited to the electrical devices described above, but for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0057] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0058] Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 10 can be installed inside vehicle 1, specifically, for example, at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1; for example, it can serve as the operating power source for vehicle 1. Vehicle 1 may also include a control system 20 and a motor 30. The control system 20, for example, controls the battery device to supply power to the motor 30. The battery device can be used for starting and navigation of vehicle 1. Of course, the battery device 10 can also be used to drive vehicle 1, replacing or partially replacing gasoline or natural gas as the driving force for vehicle 1.

[0059] Figure 2 This is an exploded structural diagram of a battery device provided in an embodiment of this application. Figure 2 As shown, the battery device 10 includes a housing 40 and battery cells (not shown in the figure), with the battery cells housed within the housing 40.

[0060] The housing 40 is used to house individual battery cells, and the housing 40 can have various structures. In some embodiments, the housing 40 may include a first housing portion 41 and a second housing portion 42, which overlap each other, and together define a receiving portion 43 for housing the individual battery cells. The second housing portion 42 may be a hollow structure with one end open, and the first housing portion 41 may be a plate-like structure, with the first housing portion 41 covering the open side of the second housing portion 42 to form a housing with the receiving portion 43; alternatively, both the first housing portion 41 and the second housing portion 42 may be hollow structures with one side open, with the open side of the first housing portion 41 covering the open side of the second housing portion 42 to form a housing 40 with the receiving portion 43. Of course, the first housing portion 41 and the second housing portion 42 can have various shapes, such as cylinders, cuboids, etc.

[0061] In the battery device 10, there can be multiple battery cells. These multiple battery cells can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells are connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, parallel, or in a mixed configuration and then housed within the housing 40. Alternatively, multiple battery cells can first be connected in series, parallel, or in a mixed configuration to form a battery module 50, and then multiple battery modules 50 can be connected in series, parallel, or in a mixed configuration to form a whole and housed within the housing 40.

[0062] Figure 3 This is a schematic diagram of the structure of a battery module provided in an embodiment of this application.

[0063] In some embodiments, such as Figure 3 As shown, there are multiple battery cells 11, which are first connected in series, parallel, or in a mixed manner to form a battery module 50. The multiple battery modules 50 are then connected in series, parallel, or in a mixed manner to form a whole, which is housed in the casing.

[0064] like Figure 4 and Figure 5 As shown, in a first aspect, this application proposes a battery cell 11, including: a housing 100 and an electrode assembly 200; the electrode assembly 200 is disposed within the housing 100, the electrode assembly 200 includes an electrode sheet 210, the electrode sheet 210 includes a current collector 220 and an active material layer 230 disposed on at least one side in the thickness direction of the current collector 220, the active material layer 230 includes a main region 231 and an edge region 232 disposed at at least one end of the main region 231 along a first direction X; wherein, along the direction away from the main region 231, the edge region 232 includes a first segment 240 and a second segment 250 disposed sequentially, the compaction density of the main region 231 is greater than the compaction density of the first segment 240, and the compaction density of the first segment 240 is greater than the compaction density of the second segment 250.

[0065] For example, the electrode 210 may include a positive electrode 211 and a negative electrode 212. The active material layer 230 may be disposed on the current collector 220 of the positive electrode 211, and the active material layer 230 may also be disposed on the current collector 220 of the negative electrode 212.

[0066] For example, the active material layer 230 may be disposed on one or both sides of the current collector 220 in the thickness direction.

[0067] In this embodiment, the battery cell 11 includes a housing 100 and an electrode assembly 200, with the electrode assembly 200 located inside the housing 100 for electrochemical reactions. The electrode assembly 200 includes an electrode 210, which includes a current collector 220 and an active material layer 230 disposed on at least one side of the current collector 220 in the thickness direction. The active material layer 230 includes a main region 231 and an edge region 232 disposed at at least one end of the main region 231 along a first direction X. The compaction density of the main region 231 is greater than the compaction density of the first segment 240 of the edge region 232, thereby reducing the thickness difference between the first segment 240 and the main region 231. The compaction density of the first segment 240 is greater than the compaction density of the second segment 250, thereby reducing the thickness difference between the first segment 240 and the second segment 250. When the electrode 210 is stacked or wound to form the electrode assembly 200, it can improve the problem of lithium plating caused by the large gap between the edge regions 232 between adjacent electrode 210, and improve the electrical performance of the battery cell 11.

[0068] Optional, such as Figure 5 As shown, the electrode 210 also includes a tab 260, which is connected to at least one side of the current collector 220 along the first direction X. The tab 260 is used to connect to an external electrical source to enable the charging and discharging of the electrode assembly 200.

[0069] Optional, such as Figure 4 As shown, the housing 100 also includes an opening 101 disposed on at least one side in the first direction X, and the battery cell 11 also includes a top cover assembly 110, which covers the opening 101.

[0070] like Figure 5 As shown, in some optional embodiments, the thickness b of the first segment 240 is equal to the thickness a of the main body region 231.

[0071] For example, the thickness b of the first segment 240 is equal to the thickness a of the main body region 231 within the error range.

[0072] For example, the difference between the thickness b of the first segment 240 and the thickness a of the main body region 231 is less than 2% of the thickness a of the main body region 231.

[0073] In these optional embodiments, the coating weight of the active material layer 230 in the same area of ​​the edge region 232 is less than the coating weight in the same area of ​​the main region 231. The compaction density of the first segment 240 of the edge region 232 is set to be less than the compaction density of the main region 231, so that the thickness of the first segment 240 of the edge region 232 is equal to the thickness of the main region 231. This reduces the thickness difference between the first segment 240 and the main region 231, reduces the risk of lithium plating caused by a large gap in the edge region 232 between adjacent electrodes 210, and improves the electrical performance of the battery cell 11.

[0074] like Figure 5 As shown, in some optional embodiments, the compaction density of the first segment 240 is 90% to 99% of the compaction density of the main region 231.

[0075] For example, the first segment 240 may include one sub-segment 240a or two or more sub-segments 240a, wherein the compaction density of one sub-segment 240a is 90% to 99% of the compaction density of the main body region 231. The first segment 240 may also include two or more sub-segments 240a, wherein the compaction density of each sub-segment 240a is 90% to 99% of the compaction density of the main body region 231, and the compaction density of each sub-segment 240a may be the same or different.

[0076] In these alternative embodiments, the compaction density of the first segment 240 is 90% to 99% of the compaction density of the main body region 231, specifically 90%, 92%, 94%, 96%, 98%, 99%, etc.

[0077] like Figure 5 As shown, in some optional embodiments, the thickness c of the second segment 250 is less than the thickness a of the main body region 231.

[0078] In these optional embodiments, in order to ensure that the second segment 250 is within a certain compaction density range, the thickness of the second segment 250 is compressed to be less than the thickness of the main body region 231, thereby improving the structural strength of the second segment 250.

[0079] like Figure 5 As shown, in some optional embodiments, the compaction density of the second segment 250 is 70% to 80% of the compaction density of the main region 231.

[0080] In these optional embodiments, the compaction density of the second segment 250 is 70% to 80% of the compaction density of the main body region 231, specifically 70%, 72%, 74%, 76%, 78%, 80%, etc., which can reduce the thickness difference between the second segment 250 and the first segment 240 and the main body region 231, improve the lithium plating problem, and at the same time, improve the structural strength of the second segment 250.

[0081] like Figure 5 As shown, in some optional embodiments, the first segment 240 includes two or more sub-segments 240a arranged sequentially in a direction away from the main body region 231, and the compaction density of each sub-segment 240a gradually decreases in a direction away from the main body region 231.

[0082] In these alternative embodiments, along the direction away from the main body region 231, the coating weight of the active material layer 230 of each sub-segment 240a gradually decreases, and the compaction density of each sub-segment 240a gradually decreases, thereby improving the uniformity of the thickness of each sub-segment 240a in the first segment 240 and improving the surface flatness of the side of the first sub-segment 241 away from the current collector 220.

[0083] like Figure 5 As shown, in some optional embodiments, the first segment 240 includes a first sub-segment 241, a second sub-segment 242 and a third sub-segment 243 arranged sequentially along a direction away from the main body region 231.

[0084] For example, the first sub-segment 241 is connected to the main body area 231, the third sub-segment 243 is connected to the second sub-segment 250, and the second sub-segment 242 is connected between the first sub-segment 241 and the second sub-segment 242.

[0085] For example, the compaction densities of the first sub-segment 241, the second sub-segment 242, and the third sub-segment 243 decrease sequentially and are located between 90% and 99% of the compaction density of the main region 231.

[0086] Optional, such as Figure 5 As shown, the compaction density of the first segment 241 is 97% to 99% of the compaction density of the main body region 231. The coating weight of the active material layer 230 in the same area of ​​the first segment 241 is 97% to 99% of the coating weight in the same area of ​​the main body region 231. Setting the compaction density of the first segment 241 to 97% to 99% of the compaction density of the main body region 231 improves the consistency of the thickness between the first segment 241 and the main body region 231.

[0087] Optional, such as Figure 5 As shown, the compaction density of the second segment 242 is 95% to 97% of the compaction density of the main body region 231; the coating weight of the active material layer 230 in the same area of ​​the second segment 242 is 95% to 97% of the coating weight in the same area of ​​the main body region 231. Setting the compaction density of the second segment 242 to 95% to 97% of the compaction density of the main body region 231 improves the consistency of the thickness between the second segment 242 and the main body region 231.

[0088] Optional, such as Figure 5As shown, the compaction density of the third segment 243 is 90% to 95% of the compaction density of the main body region 231. The coating weight of the active material layer 230 in the same area of ​​the third segment 243 is 90% to 95% of the coating weight in the same area of ​​the main body region 231. Setting the compaction density of the third segment 243 to 90% to 95% of the compaction density of the main body region 231 improves the consistency of the thickness between the third segment 243 and the main body region 231.

[0089] Optional, such as Figure 5 As shown, the length of the first segment 241 is less than or equal to 5 mm, and the length of the first segment 241 can be 1 mm, 2 mm, 3 mm or 5 mm, etc.

[0090] Optional, such as Figure 5 As shown, the length of the second sub-segment 242 is less than or equal to 5 mm, and the length of the second sub-segment 242 can be 1 mm, 2 mm, 3 mm or 5 mm, etc.

[0091] Optional, such as Figure 5 As shown, the length of the third sub-segment 243 is less than or equal to 3 mm, and the length of the third sub-segment 243 can be 1 mm, 2 mm or 3 mm, etc.

[0092] Optional, such as Figure 5 As shown, the length of the second segment 250 can be less than or equal to 5 mm, and the length of the second segment 250 can be 1 mm, 2 mm, 3 mm or 5 mm, etc.

[0093] For example, the lengths of the first sub-segment 241, the second sub-segment 242, the third sub-segment 243, and the second segment 250 are parallel to the first direction X.

[0094] like Figure 5 and Figure 6 As shown, in some optional embodiments, the electrode 210 includes a positive electrode 211 and a negative electrode 212. The positive electrode 211 includes a positive current collector 221, and the negative electrode 212 includes a negative current collector 222. The active material layer 230 is disposed on at least one side of the positive current collector 221 and / or the negative current collector 222.

[0095] In these optional embodiments, the positive current collector 221 and the negative current collector 222 are disposed opposite to each other, and the active material layer 230 is disposed on at least one side of the positive current collector 221 and / or the negative current collector 222. The compaction density of the main body region 231 of the active material layer 230 is greater than the compaction density of the first segment 240, and the compaction density of the first segment 240 is greater than the compaction density of the second segment 250, thereby reducing the thickness difference between the main body region 231, the first segment 240 and the second segment 250, increasing the spacing between the positive electrode 211 and the negative electrode 212, thereby improving the lithium plating problem.

[0096] Optionally, a separator 300 is provided between the positive electrode 211 and the negative electrode 212. The battery cell 11 mainly relies on the movement of metal ions between the positive electrode 210 and the negative electrode 210 to work.

[0097] Secondly, such as Figure 5 As shown, this application proposes an electrode 210, including: a current collector 220 and an active material layer 230; the active material layer 230 is disposed on at least one side in the thickness direction of the current collector 220, and the active material layer 230 includes a main region 231 and an edge region 232 disposed at at least one end of the main region 231 along a first direction X; wherein, along the direction away from the main region 231, the edge region 232 includes a first segment 240 and a second segment 250 disposed sequentially, the compaction density of the main region 231 is greater than the compaction density of the first segment 240, and the compaction density of the first segment 240 is greater than the compaction density of the second segment 250.

[0098] In this embodiment, the active material layer 230 includes a main region 231 and an edge region 232 disposed at at least one end of the main region 231 along the first direction X. The compaction density of the main region 231 is greater than the compaction density of the first segment 240 of the edge region 232, thereby reducing the thickness difference between the first segment 240 and the main region 231. The compaction density of the first segment 240 is greater than the compaction density of the second segment 250, thereby reducing the thickness difference between the first segment 240 and the second segment 250. When the electrode 210 forms the electrode assembly 200, it improves the problem of lithium plating caused by the large gap between the edge regions 232 between adjacent electrode 210, and improves the electrical performance of the battery cell 11.

[0099] Thirdly, this application provides a battery device 10, including a battery cell 11 in any of the embodiments of the first aspect above or an electrode 210 in any of the embodiments of the second aspect above.

[0100] The battery device 10 provided in the embodiments of this application has all the beneficial effects of the battery cell 11 in any of the embodiments of the first aspect due to the use of the battery cell 11 provided in the first aspect. For details, please refer to the specific description of the battery cell 11 in the above embodiments. This embodiment will not repeat the description here.

[0101] Fourthly, this application also provides an electrical device, including the battery device 10 in any of the embodiments of the third aspect above, the battery device 10 being used to store or provide electrical energy.

[0102] In some optional embodiments, the battery cell 11 includes a housing 100 and an electrode assembly 200; the electrode assembly 200 is disposed within the housing 100 and includes an electrode sheet 210, which includes a positive electrode sheet 211 and a negative electrode sheet 212. The positive electrode sheet 211 includes a positive current collector 221, and the negative electrode sheet 212 includes a negative current collector 222. An active material layer 230 is disposed on both sides of the positive current collector 221 and the negative current collector 222. The active material layer 230 includes a main region 231 and edge regions 232 disposed at both ends of the main region 231 along a first direction X. In the direction away from the main region 231, the edge regions 232 include a first segment 240 and a second segment 250 disposed sequentially. The compaction density of the main region 231 is greater than the compaction density of the first segment 240, and the compaction density of the first segment 240 is greater than the compaction density of the second segment 250. The thickness b of the first segment 240 is equal to the thickness a of the main body region 231, and the thickness c of the second segment 250 is less than the thickness a of the main body region 231. The first segment 240 includes a first sub-segment 241, a second sub-segment 242, and a third sub-segment 243 arranged sequentially in a direction away from the main body region 231. The compaction density of the first sub-segment 241 is 97% to 99% of the compaction density of the main body region 231, the compaction density of the second sub-segment 242 is 95% to 97% of the compaction density of the main body region 231, and the compaction density of the third sub-segment 243 is 90% to 95% of the compaction density of the main body region 231. The length of the first sub-segment 241 is less than or equal to 5 mm, the length of the second sub-segment 242 is less than or equal to 5 mm, and the length of the third sub-segment 243 is less than or equal to 3 mm.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: case; An electrode assembly is disposed within the housing. The electrode assembly includes an electrode sheet, the electrode sheet includes a current collector and an active material layer disposed on at least one side of the current collector in the thickness direction, the active material layer includes a main region and an edge region disposed at at least one end of the main region along a first direction. Along the direction away from the main body area, the edge area includes a first segment and a second segment arranged sequentially. The compaction density of the main body area is greater than the compaction density of the first segment, and the compaction density of the first segment is greater than the compaction density of the second segment.

2. The battery cell according to claim 1, characterized in that, The thickness of the first segment is equal to the thickness of the main body region.

3. The battery cell according to claim 1, characterized in that, The compaction density of the first segment is 90% to 99% of the compaction density of the main area.

4. The battery cell according to claim 1, characterized in that, The thickness of the second segment is less than the thickness of the main body area.

5. The battery cell according to claim 1, characterized in that, The compaction density of the second segment is 70% to 80% of the compaction density of the main area.

6. The battery cell according to any one of claims 1-5, characterized in that, The first segment includes two or more sub-segments arranged sequentially in a direction away from the main body area, and the compaction density of each sub-segment gradually decreases in a direction away from the main body area.

7. The battery cell according to claim 6, characterized in that, The first segment includes a first sub-segment, a second sub-segment, and a third sub-segment arranged sequentially along a direction away from the main body area; Wherein, the compaction density of the first sub-segment is 97% to 99% of the compaction density of the main area; And / or, the compaction density of the second sub-segment is 95% to 97% of the compaction density of the main region; And / or, the compaction density of the third sub-segment is 90% to 95% of the compaction density of the main region.

8. The battery cell according to claim 7, characterized in that, The length of the first segment is less than or equal to 5 millimeters; And / or, the length of the second sub-segment is less than or equal to 5 millimeters; And / or, the length of the third sub-segment is less than or equal to 3 millimeters.

9. The battery cell according to any one of claims 1-8, characterized in that, The electrode includes a positive electrode and a negative electrode. The positive electrode includes a positive current collector, and the negative electrode includes a negative current collector. The active material layer is disposed on at least one side of the positive current collector and / or the negative current collector.

10. An electrode sheet, characterized in that, include: current collector; An active material layer is disposed on at least one side of the current collector in the thickness direction, the active material layer including a main body region and an edge region disposed at at least one end of the main body region along a first direction; Along the direction away from the main body area, the edge area includes a first segment and a second segment arranged sequentially. The compaction density of the main body area is greater than the compaction density of the first segment, and the compaction density of the first segment is greater than the compaction density of the second segment.

11. A battery device, characterized in that, It includes the battery cell as described in any one of claims 1-9, or the electrode as described in claim 10.

12. An electrical appliance, characterized in that, Includes the battery device as described in claim 11.

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