Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device, the battery monomer comprises a shell, an electrode assembly and a first filling component, the electrode assembly is arranged in the shell, in the electrode assembly, the polarities of a first pole piece and a second pole piece are opposite, and a separator separates the first pole piece from the second pole piece; the first pole piece comprises a first current collector and a first active substance layer, the second pole piece comprises a second current collector and a second active substance layer, the first active substance layer comprises a first main body part and a first thinned part arranged on one side of the first main body part, and the thickness of the first thinned part is smaller than that of the first main body part; a first gap is formed between the first thinned part and the second active material layer; the first fill member includes an electrolyte disposed in the first gap. The electrolyte of the first filling part transfers active ions between the first thinned part and the second active material layer, so that the risk of lithium precipitation in the electrode assembly can be reduced, and the 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, a battery device, and an electrical device. Background Technology

[0002] With the development of new energy technologies, batteries 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] In the development of battery technology, the performance of individual battery cells directly affects the overall performance of the battery device. However, currently, individual battery cells are prone to lithium plating during use, which seriously affects their performance. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can improve the performance of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, including a casing, an electrode assembly, and a first filling component. The electrode assembly is disposed within the casing and includes a first electrode, a second electrode, and a separator. The first and second electrodes have opposite polarities. The separator separates the first and second electrodes. The first electrode includes a first current collector and a first active material layer disposed in the first current collector. The second electrode includes a second current collector and a second active material layer disposed in the second current collector. The first active material layer includes a first main body portion and a first thinned portion disposed on one side of the first main body portion. The thickness of the first thinned portion is less than the thickness of the first main body portion. A first gap is formed between the first thinned portion and the second active material layer. The first filling component includes an electrolyte disposed in the first gap.

[0006] In the above scheme, the separator separates the first and second electrodes with opposite polarities, preventing short circuits. The first electrode includes a first current collector and a first active material layer, and the second electrode includes a second current collector and a second active material layer. The first active material layer includes a first main body and a first thinned portion. The thickness of the first thinned portion is less than the thickness of the first main body. The thinned portion reduces the risk of edge bursting due to compression in subsequent processes. A first gap is formed between the first thinned portion and the second active material layer. A first filling component includes an electrolyte disposed in the first gap. The electrolyte can transfer active ions between the first thinned portion and the second active material layer, shortening the ion transport path between them, improving ion transport efficiency, reducing the risk of lithium plating in the electrode assembly, and improving the performance of the battery cell.

[0007] In some embodiments, at least a portion of the first filling member fills the spacer and the first thinning portion.

[0008] In the above solution, a first filling component is filled between the separator and the first thinning part. The electrolyte in the first filling component transfers active ions in the gap between the separator and the first thinning part, which can shorten the ion transport path between the separator and the first thinning part and improve the ion transport efficiency between the separator and the first thinning part. This is equivalent to shortening the total active ion transport path between the first active material layer and the second active material layer, improving the transport efficiency between the first active material layer and the second active material layer, and reducing the risk of lithium plating in the electrode assembly.

[0009] In some embodiments, the first filling member is fixed to at least one of the first thinning portion and the spacer.

[0010] In the above solution, the first filling component is fixed to at least one of the first thinned portion and the separator, which can reduce the risk of the first filling component detaching from the first gap during the use of the battery cell, improve the stability and reliability of the first filling component, and thus improve the reliability of the battery cell.

[0011] In some embodiments, the distance from the side surface of the first filling member facing the spacer to the side surface of the first thinned portion facing away from the spacer is less than or equal to the thickness of the first body portion.

[0012] In the above scheme, the distance from the side surface of the first filling component facing the separator to the side surface of the first thinned portion away from the separator is less than or equal to the thickness of the first main body. That is, the total thickness of the first filling component and the first thinned portion is less than or equal to the thickness of the first main body. On the one hand, the first filling component can transfer active ions in the gap between the separator and the first thinned portion, which shortens the ion transport path between the separator and the first thinned portion to a certain extent. On the other hand, it can reduce the risk of the electrode assembly thickness increasing due to the setting of the first filling component and improve the performance of the battery cell.

[0013] In some embodiments, the first main body and the first thinned portion are arranged along a first direction, which is perpendicular to the thickness direction of the first main body; in the first direction, along the direction from the first main body to the first thinned portion, the thickness of the first thinned portion tends to decrease, and the thickness of the first filling member tends to increase.

[0014] In the above scheme, in the first direction, along the direction from the first main body to the first thinned portion, the thickness of the first thinned portion decreases, which makes the stress transition of the first electrode sheet smoother when it is compressed in subsequent processes, reduces the risk of stress concentration in the first electrode sheet, and improves the performance of the first electrode sheet. Based on this, the thickness of the first filling component increases, which improves the ability of the first filling component to transport active ions between the separator and the first thinned portion, improves ion transport efficiency, and reduces the risk of lithium plating in the first thinned portion.

[0015] In some embodiments, the first filling component includes a gel electrolyte or a solid electrolyte.

[0016] In the above scheme, by optimizing the material of the first filling component, the ability of the first filling component to transport active ions is further improved, and the ion transport efficiency of the first filling component is further improved.

[0017] In some embodiments, the first current collector includes a first current collector body and a first electrode tab, the first current collector body and the first electrode tab are arranged along a first direction, and the first thinned portion is located on the side of the first body portion near the first electrode tab.

[0018] In the above solution, the first thinning part is set on the side of the first main body near the first electrode tab, which can reduce the risk of the first active material layer near the first electrode tab being squeezed and bursting in subsequent processes, and reduce the impact of the first active material layer on the performance of the first electrode sheet.

[0019] In some embodiments, the first main body portion and the first thinned portion are arranged along a first direction, which is perpendicular to the thickness direction of the first main body portion; the second active material layer includes a second main body portion and a second thinned portion, the thickness of the second thinned portion being less than the thickness of the second main body portion; in the first direction, the second thinned portion is located on the side of the second main body portion closer to the first thinned portion; at least a portion of the first gap is formed between the first thinned portion and the second thinned portion.

[0020] In the above scheme, the second thinning portion is located on one side of the second main body, and the thickness of the second thinning portion is less than the thickness of the second main body. The setting of the second thinning portion is equivalent to thinning the edge of the second active material layer, which can reduce the risk of edge bursting due to compression in subsequent processes. Furthermore, placing the second thinning portion on the side of the second main body closer to the first thinning portion helps to achieve a balance of active ions between the first and second thinning portions, reducing the risk of lithium plating due to excess active ions at either the first or second thinning portion. Moreover, at least a portion of the first gap is formed between the first and second thinning portions, allowing the electrolyte of the first filling component to transport active ions between the first and second thinning portions, thereby shortening the ion transport path between them, improving the ion transport efficiency, and reducing the risk of lithium plating in the electrode assembly.

[0021] In some embodiments, the first main body and the first thinned portion are arranged along a first direction, which is perpendicular to the thickness direction of the first main body; the second active material layer includes the second main body and the second thinned portion, the thickness of the second thinned portion being less than the thickness of the second main body; in the first direction, the second thinned portion is located on the side of the second main body away from the first thinned portion; a second gap is formed between the second thinned portion and the first main body, and the battery cell also includes a second filling component, the second filling component including an electrolyte filled in the second gap.

[0022] In the above scheme, the second thinning portion is located on one side of the second main body, and the thickness of the second thinning portion is less than the thickness of the second main body. The setting of the second thinning portion is equivalent to thinning the edge of the second active material layer, which can reduce the risk of edge bursting due to compression in subsequent processes. By setting the second thinning portion on the side of the second main body away from the first thinning portion, it helps to balance the volume changes of the first and second active material layers during use, improves the stress distribution inside the battery cell, and reduces the risk of short circuits between the first and second electrodes, thereby improving the reliability and lifespan of the battery cell. Furthermore, the electrolyte in the second filling component transfers active ions in the second gap between the second thinning portion and the first main body, which can shorten the ion transport path between the second thinning portion and the first main body, improve the ion transport efficiency between them, and reduce the risk of lithium plating in the electrode assembly.

[0023] In some embodiments, the first filling member includes a first sub-part filling between the first thinned portion and the spacer. The projection of the first sub-part on the first current collector along the thickness direction of the first main body overlaps with the projection of the first thinned portion on the first current collector along the thickness direction of the first main body. The ratio Z1 of the thickness of the first sub-part to the thickness of the first main body satisfies: 0.08≤Z1≤0.15.

[0024] In the above scheme, the first sub-part fills the space between the first thinned part and the spacer, and active ions are transported between the first thinned part and the spacer. By reasonably setting the thickness ratio between the first sub-part and the first main body, the thickness of the first sub-part is optimized, that is, the height of the corresponding area of ​​the gap between the first thinned part and the spacer is optimized. On the one hand, the risk of the first active material layer being squeezed and bursting during subsequent processes can be reduced. On the other hand, the risk of the height of the gap between the first thinned part and the spacer being too high and the thickness of the first sub-part being too large affecting the performance of the first electrode can be reduced.

[0025] In some embodiments, the first filling member further includes a second sub-part filling between the first thinned portion and the spacer, the second sub-part being located on the side of the first sub-part closer to the first main body portion, and the ratio Z2 of the thickness of the second sub-part to the thickness of the first main body portion satisfies: 0.03≤Z2≤0.08.

[0026] In the above scheme, the second sub-part fills the gap between the first thinned part and the separator. It is located on the side of the first sub-part closer to the first main body. By reasonably setting the thickness ratio between the second sub-part and the first main body, the stress transition between the first sub-part and the second sub-part when they are squeezed in subsequent processes can be smoother, reducing the risk of stress concentration between the first sub-part and the second sub-part.

[0027] In some embodiments, the first filling member further includes a third sub-part filling between the first thinned portion and the spacer, the third sub-part being located on the side of the second sub-part closer to the first main body portion, and the ratio Z3 of the thickness of the third sub-part to the thickness of the first main body portion satisfies: 0.01≤Z3≤0.03.

[0028] In the above scheme, the third sub-part fills the gap between the first thinned part and the separator. It is located on the side of the second sub-part closer to the first main body. By reasonably setting the thickness ratio between the third sub-part and the first main body, the stress transition between the second sub-part and the third sub-part when they are squeezed in subsequent processes can be smoother, reducing the risk of stress concentration between the second sub-part and the third sub-part.

[0029] Secondly, embodiments of this application provide a battery device including a plurality of battery cells as described in any of the above.

[0030] Thirdly, embodiments of this application provide an electrical device including the aforementioned battery device, which is used to provide electrical energy.

[0031] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application;

[0034] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0035] Figure 3 These are schematic diagrams of the structure of a single battery cell provided in some embodiments of this application;

[0036] Figure 4 This is a cross-sectional schematic diagram of an electrode assembly provided in some embodiments of this application;

[0037] Figure 5 This is a cross-sectional schematic diagram of the first electrode and the separator in the electrode assembly provided in some embodiments of this application;

[0038] Figure 6 A cross-sectional schematic diagram of the first electrode in an electrode assembly provided in some embodiments of this application;

[0039] Figure 7 This is a top view of the first electrode in an electrode assembly provided in some embodiments of this application;

[0040] Figure 8 This is a cross-sectional schematic diagram of an electrode assembly provided in other embodiments of this application;

[0041] Figure 9 This is a cross-sectional schematic diagram of an electrode assembly provided in some embodiments of this application;

[0042] Figure 10 This is a partial cross-sectional view of an electrode assembly provided in some embodiments of this application.

[0043] Tag name:

[0044] Vehicle 1000; Battery unit 100; Top cover 110; Box 120; Controller 200; Motor 300;

[0045] Battery cell 1; casing 10; housing 11; end cap 12; electrode assembly 20; first electrode 21; first current collector 211; first current collector body 2111; first tab 2112; first active material layer 212; first main body portion 2121; first thinned portion 2122; second electrode 22; second current collector 221; second current collector body 2211; second tab 2212; second active material layer 222; second main body portion 2221; second thinned portion 2222; separator 23; first filling component 30; first sub-part 31; second sub-part 32; third sub-part 33; fourth sub-part 34; second filling component 40; first direction X. Detailed Implementation

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0051] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0052] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0053] 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.

[0054] 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).

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0061] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0062] 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.

[0063] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0064] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0065] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0066] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0067] 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.

[0068] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0069] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the negative and positive electrodes. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0070] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0071] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0072] 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.).

[0073] 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 ), Li Ni 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 NCM6) 22 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNiNi) 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.

[0074] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0075] 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.).

[0076] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0077] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0078] As an example, the negative electrode active material may be a 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.

[0079] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0080] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0081] In some embodiments, the separator 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.

[0082] 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 can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0083] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0084] In some embodiments, the battery cell 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, or solid.

[0085] Liquid electrolytes include electrolyte salts and solvents.

[0086] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0087] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0088] In some implementations, the electrode assembly is a stacked structure.

[0089] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0090] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0091] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0092] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0093] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0094] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0095] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0096] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0097] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0098] In some embodiments, the housing includes an end cap and a housing, the housing having an opening, and the end cap covering the opening. The housing may have one or more openings. The end cap may also have one or more.

[0099] In the electrode manufacturing process, the active material layer of the electrode is usually rolled to compact it. However, during the rolling process, the active material layer in the middle of the electrode may move towards the edge under pressure, causing edge bursting or bulging. To solve this problem, the edges of the electrode can be thinned, reducing the thickness of the edges. This can alleviate or even prevent edge bursting or bulging during rolling.

[0100] However, in the electrode assembly, the positive and negative electrodes are stacked. When the edge of at least one of the positive and negative electrodes is thinned, there will be a gap in the thinned area between them. During the charging and discharging of the battery cell, the transport path of active ions located between the positive and negative electrodes is lengthened, the transport efficiency is reduced, and ions are easily deposited on the surface of the electrode facing the gap, affecting the performance of the battery cell.

[0101] Therefore, this application provides a battery cell including a casing, an electrode assembly, and a first filling component. The electrode assembly is disposed within the casing and includes a first electrode, a second electrode, and a separator. The first and second electrodes have opposite polarities, and the separator separates the first and second electrodes. The first electrode includes a first current collector and a first active material layer disposed on the first current collector. The second electrode includes a second current collector and a second active material layer disposed on the second current collector. The first active material layer includes a first main body portion and a first thinned portion disposed on one side of the first main body portion. The thickness of the first thinned portion is less than the thickness of the first main body portion, and a first gap is formed between the first thinned portion and the second active material layer. The first filling component includes an electrolyte disposed in the first gap. The electrolyte disposed in the first gap allows active ions to be transferred between the first thinned portion and the second active material layer, shortening the ion transport path between the first thinned portion and the second active material layer, improving the ion transport efficiency between the first thinned portion and the second active material layer, reducing the risk of lithium plating in the electrode assembly, and improving the performance of the battery cell.

[0102] The technical solutions described in the embodiments of this application are applicable to various power devices that use battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0103] The battery devices 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.

[0104] Please see Figure 1 , Figure 1This is a simplified schematic diagram of a vehicle 1000 provided in an embodiment of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 can be installed inside the vehicle 1000; specifically, for example, the battery device 100 can be installed at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 100 may also include a controller 200 and a motor 300. The controller 200, for example, is used to control the battery to supply power to the motor 300. The battery device 100 can be used for starting, navigation, etc., of the vehicle 1000. Of course, the battery device 100 can also be used to drive the vehicle 1000, replacing or partially replacing gasoline or natural gas to provide propulsion for the vehicle 1000.

[0105] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0106] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device provided in some embodiments of this application. The battery device 100 includes a battery housing and a battery cell 1. In some embodiments, the battery housing may include a top cover 110 and a housing 120, with the top cover 110 and the housing 120 covering each other, and the top cover 110 and the housing 120 together defining a receiving cavity for accommodating the battery cell 1. The housing 120 may be a hollow structure with one end open, and the top cover 110 may be a plate-like structure, with the top cover 110 covering the open side of the housing 120 so that the top cover 110 and the housing 120 together define the receiving cavity; the top cover 110 and the housing 120 may also be hollow structures with one side open, with the open side of the top cover 110 covering the open side of the housing 120. Of course, the battery housing formed by the top cover 110 and the housing 120 may be of various shapes, such as a cylinder, a cuboid, etc.

[0107] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application. In the battery device 100, there can be multiple battery cells 1, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 1 are connected in both series and parallel. Multiple battery cells 1 can be directly connected in series, parallel, or in a mixed manner, and then the whole formed by the multiple battery cells 1 is housed in a box. Of course, the battery device 100 can also be formed by first connecting multiple battery cells 1 in series, parallel, or in a mixed manner to form a battery module, and then connecting multiple battery modules in series, parallel, or in a mixed manner to form a whole, which is then housed in a box.

[0108] Each battery cell can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited to these. The battery cell can be cylindrical, flat, cuboid, or other shapes.

[0109] In some embodiments, the housing 10 includes a housing 11 and an end cap 12. The housing 11 has an opening, and the end cap 12 is connected to the housing 11 and closes the opening. The housing 11 is a component used to mate with the end cap 12 to form an internal cavity of the battery cell 1. The formed internal cavity can be used to accommodate the electrode assembly 20, the electrolyte, and other components. The housing 11 and the end cap 12 can be separate components. For example, an opening can be provided on the housing 11, and the internal cavity of the battery cell 1 is formed by closing the opening with the end cap 12. The housing 11 can be of various shapes and sizes, such as a cuboid. Specifically, the shape of the housing 11 can be determined according to the specific shape and size of the electrode assembly 20. The material of the housing 11 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc. The shape of the end cap 12 can be adapted to the shape of the housing 11 to mate with the housing 11. The material of the end cap 12 can be the same as or different from the material of the housing 11. Optionally, the end cap 12 can be made of a material with certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.). This makes the end cap 12 less prone to deformation under pressure and impact, allowing the battery cell 1 to have higher structural strength and improved reliability. The end cap 12 is connected to the housing 11 by welding, bonding, snap-fitting, or other methods. The housing 11 can be open at one end or at both ends. In some examples, the housing 11 may have an opening on one side, with one end cap 12 covering the housing 11. In other examples, the housing 11 may have openings on both sides, with two end caps 12 covering the two openings of the housing 11 respectively. The electrode assembly 20 is the component in the battery cell 1 where the electrochemical reaction occurs. The housing 11 may contain one or more electrode assemblies 20.

[0110] The structure of the battery cell 1 will be described in detail below with reference to the accompanying drawings.

[0111] Please see Figure 3 and Figure 4In a first aspect, embodiments of this application provide a battery cell 1, including a housing 10, an electrode assembly 20, and a first filling component 30. The electrode assembly 20 is disposed within the housing 10 and includes a first electrode 21, a second electrode 22, and a separator 23. The first electrode 21 and the second electrode 22 have opposite polarities. The separator 23 separates the first electrode 21 and the second electrode 22. The first electrode 21 includes a first current collector 211 and a first active material layer 212 disposed on the first current collector 211. The second electrode 22 includes a second current collector 221 and a second active material layer 222 disposed on the second current collector 221. The first active material layer 212 includes a first main body portion 2121 and a first thinned portion 2122 disposed on one side of the first main body portion 2121. The thickness of the first thinned portion 2122 is less than the thickness of the first main body portion 2121. A first gap is formed between the first thinned portion 2122 and the second active material layer 222. The first filling component 30 includes an electrolyte disposed in the first gap.

[0112] The housing 10 is a component used to protect the electrode assembly 20. The housing 10 can enclose and form a receiving cavity for accommodating the electrode assembly 20, and the electrode assembly 20 and the electrolyte are disposed in the receiving cavity.

[0113] The electrode assembly 20 includes a first electrode 21, a second electrode 22, and a separator 23. The first electrode 21 and the second electrode 22 have opposite polarities. One of the first electrode 21 and the second electrode 22 can be a positive electrode and the other can be a negative electrode. This application will use the example of the first electrode 21 being a negative electrode and the second electrode 22 being a positive electrode for illustration.

[0114] The first electrode 21 includes a first current collector 211 and a first active material layer 212. The first active material layer 212 can be disposed on one or both surfaces of the first current collector 211 along its own thickness direction. The first current collector 211 can be used as a carrier of the first active material layer 212 and can also be used as a collector and conductor of corresponding electrons.

[0115] The first active material layer 212 includes a first main body portion 2121 and a first thinned portion 2122. Both the first main body portion 2121 and the first thinned portion 2122 can embed or extract active ions during the charging and discharging process of the battery cell 1. In a direction parallel to the plane of the first main body portion 2121, the first thinned portion 2122 can be connected to at least one side of the first main body portion 2121. The first thinned portion 2122 is disposed at the edge of the first main body portion 2121, and its thickness is less than the thickness of the first main body portion 2121. The provision of the first thinned portion 2122 is equivalent to thinning the edge of the first active material layer, thereby reducing the risk of the first active material layer 212 bursting under pressure.

[0116] The second electrode 22 includes a second current collector 221 and a second active material layer 222. The second active material layer 222 can be disposed on one or both surfaces of the second current collector 221 along its thickness direction. The second current collector 221 can serve as a carrier for the second active material layer 222 and also as a collector and conductor of electrons. The second active material layer 222 can be used to insert or extract active ions during the charging and discharging process of the battery cell 1.

[0117] It is understood that the first electrode 21 and the second electrode 22 are stacked. In the first electrode 21, the first active material layer 212 is located on the side of the first current collector 211 facing the second electrode 22. In the second electrode 22, the second active material layer 222 is located on the side of the second current collector 221 facing the first electrode 21. Furthermore, in the first active material layer 212, the thickness of the first thinned portion 2122 is less than the thickness of the first main body portion 2121. Therefore, a first gap can be formed between the first thinned portion 2122 and the second active material layer 222. The first gap is located on one side of the first main body portion 2121.

[0118] The first filling component 30 includes an electrolyte disposed in a first gap, the electrolyte being capable of transporting active ions within the first gap, and the first filling component 30 is located on one side of the first main body 2121. The electrolyte of the first filling component 30 can fill at least a portion of the first gap; that is, the electrolyte can fill a part of the first gap or completely fill the first gap. The electrolyte can be a solid electrolyte or a gel electrolyte.

[0119] The separator 23 can be in the form of a thin film, which is disposed between the first active material layer 212 of the first electrode 21 and the second active material layer 222 of the second electrode 22 to separate the first electrode 21 and the second electrode 22, thereby reducing the risk of short circuit between the first electrode 21 and the second electrode 22.

[0120] It should be noted that the first gap may be located between the first thinned portion 2122 and the spacer 23. Alternatively, when the second active material layer 222 includes a second main body portion 2221 and a second thinned portion 2222 disposed on the second main body portion 2221, the thickness of the second thinned portion 2222 is less than the thickness of the second main body portion 2221, and the projections of the second thinned portion 2222 and the first thinned portion 2122 onto the spacer 23 along the thickness direction of the first main body portion 2121 overlap, the first gap may include the gap between the first thinned portion 2122 and the spacer 23 as well as the gap between the second thinned portion 2222 and the spacer 23.

[0121] In the above scheme, the separator 23 separates the first electrode 21 and the second electrode 22 with opposite polarities, which can prevent the first electrode 21 and the second electrode 22 from short-circuiting. The first electrode 21 includes a first current collector 211 and a first active material layer 212, and the second electrode 22 includes a second current collector 221 and a second active material layer 222. The first active material layer 212 includes a first main body portion 2121 and a first thinned portion 2122. The thickness of the first thinned portion 2122 is less than the thickness of the first main body portion 2121. The setting of the first thinned portion 2122 can reduce the risk of the first active material layer 212 bursting due to compression in subsequent processes. A first gap is formed between the first thinned portion 2122 and the second active material layer 222. The first filling component 30 includes an electrolyte disposed in the first gap. The electrolyte can transfer active ions between the first thinned portion 2122 and the second active material layer 222, shortening the ion transport path between the first thinned portion 2122 and the second active material layer 222, improving the ion transport efficiency between the first thinned portion 2122 and the second active material layer 222, reducing the risk of lithium plating in the electrode assembly 20, and improving the performance of the battery cell 1.

[0122] It is understandable that there are multiple ways to prepare the first filling component 30. For example, the first filling component 30 can be prepared after the first electrode 21, the spacer 23 and the second electrode 22 are wound or stacked. Alternatively, the first filling component 30 can be placed in the area corresponding to the first thinned portion 2122 after the first thinned portion 2122 is formed. That is, the preparation of the first filling component 30 is completed before the first electrode 21, the spacer 23 and the second electrode 22 are wound or stacked.

[0123] In some embodiments, at least a portion of the first filling member 30 is filled between the spacer 23 and the first thinning portion 2122.

[0124] In the above solution, a first filling component 30 is filled between the separator 23 and the first thinned portion 2122. The electrolyte in the first filling component 30 transfers active ions in the gap between the separator 23 and the first thinned portion 2122, which can shorten the ion transport path between the separator 23 and the first thinned portion 2122 and improve the ion transport efficiency between the separator 23 and the first thinned portion 2122. This is equivalent to shortening the total active ion transport path between the first active material layer 212 and the second active material layer 222, improving the transport efficiency between the first active material layer 212 and the second active material layer 222, and reducing the risk of lithium plating in the electrode assembly 20.

[0125] In some embodiments, the first filling member 30 is fixed to at least one of the first thinning portion 2122 and the spacer 23.

[0126] The first filling component 30 can be directly fixed to at least one of the first thinned portion 2122 and the separator 23. For example, the electrolyte material of the first filling component 30 can be optimized to give it a certain adhesive ability, and it can be fixed to at least one of the first thinned portion 2122 and the separator 23 by adhesive bonding. Alternatively, the first filling component 30 can also be fixed to at least one of the first thinned portion 2122 and the separator 23 by means of other structures.

[0127] In the above solution, the first filling component 30 is fixed to at least one of the first thinning part 2122 and the separator 23, which can reduce the risk of the first filling component 30 detaching from the first gap during the use of the battery cell 1, improve the stability and reliability of the first filling component 30, and thus improve the reliability of the battery cell 1.

[0128] Please see Figure 5 In some embodiments, the distance H1 from the side surface of the first filling member 30 facing the separator 23 to the side surface of the first thinned portion 2122 away from the separator 23 is less than or equal to the thickness H2 of the first main body portion 2121.

[0129] When the first filling member 30 fills the first gap, the distance H1 from the side surface of the first filling member 30 facing the spacer 23 to the side surface of the first thinned portion 2122 facing away from the spacer 23 can be equal to the sum of the thicknesses of the first filling member 30 and the first thinned portion 2122. This distance H1 is less than or equal to the thickness H2 of the first main body portion 2121, that is, the total thickness of the first filling member 30 and the first thinned portion 2122 is less than or equal to the thickness H2 of the first main body portion 2121, thereby reducing the risk that the thickness of the first electrode 21 will increase due to the placement of the first filling member 30.

[0130] In some alternative embodiments, the distance H1 from the side surface of the first filling member 30 facing the separator 23 to the side surface of the first thinned portion 2122 away from the separator 23 can be equal to the thickness H2 of the first main body portion 2121, so that the first thinned portion 2122, the first filling member 30 and the first main body portion 2121 can together form a film structure with uniform thickness.

[0131] In the above scheme, the distance H1 from the side surface of the first filling component 30 facing the separator 23 to the side surface of the first thinned portion 2122 away from the separator 23 is less than or equal to the thickness H2 of the first main body portion 2121. That is, the total thickness of the first filling component 30 and the first thinned portion 2122 is less than or equal to the thickness H2 of the first main body portion 2121. On the one hand, the first filling component 30 can transfer active ions in the gap between the separator 23 and the first thinned portion 2122, which shortens the ion transport path between the separator 23 and the first thinned portion 2122 to a certain extent. On the other hand, it can reduce the risk of the electrode assembly 20 increasing in thickness due to the setting of the first filling component 30, and improve the performance of the battery cell 1.

[0132] Please continue reading. Figure 5 In some embodiments, the first main body portion 2121 and the first thinned portion 2122 are arranged along a first direction X, which is perpendicular to the thickness direction of the first main body portion 2121. In the first direction X, along the direction from the first main body portion 2121 to the first thinned portion 2122, the thickness of the first thinned portion 2122 tends to decrease, and the thickness of the first filling member 30 tends to increase.

[0133] The first direction X can be the length direction or the width direction of the first main body 2121, and the first main body 2121 and the first thinned part 2122 are distributed sequentially along the first direction X.

[0134] If the thickness of the first thinned portion 2122 decreases along the direction X from the first main body portion 2121 toward the first thinned portion 2122, then the thickness of the first thinned portion 2122 can decrease linearly or non-linearly along the direction from the first main body portion 2121 toward the first thinned portion 2122. The surface of the first thinned portion 2122 facing the first gap can be a slope or an arc surface, and the distance between this surface and the spacer 23 can gradually increase along the direction from the first main body portion 2121 toward the first thinned portion 2122.

[0135] The surface of the first filling member 30 facing the first thinned portion 2122 can contact the surface of the first thinned portion 2122 facing the first gap, and the shapes of the two surfaces are compatible. Alternatively, the surface of the first filling member 30 facing the first thinned portion 2122 can be separated from the surface of the first thinned portion 2122 facing the first gap. The thickness of the first filling member 30 can increase linearly or non-linearly along the direction from the first main body portion 2121 to the first thinned portion 2122. The surface of the first filling member 30 facing the first thinned portion 2122 can be a slope or an arc surface.

[0136] In the above scheme, along the first direction X, from the first main body 2121 to the first thinned portion 2122, the thickness of the first thinned portion 2122 is set to decrease. This allows for a smoother stress transition when the first electrode 21 is subjected to compression in subsequent processes, reducing the risk of stress concentration in the first electrode 21 and improving its performance. Furthermore, the thickness of the first filling component 30 is set to increase. This enhances the ability of the first filling component 30 to transport active ions between the separator 23 and the first thinned portion 2122, improving ion transport efficiency and reducing the risk of lithium plating at the first thinned portion 2122.

[0137] In some embodiments, the first filling component 30 includes a gel electrolyte or a solid electrolyte.

[0138] Gel electrolytes may include polymers as a backbone network and can be used in conjunction with ionic liquids—lithium salts.

[0139] Solid electrolytes can include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes. As an example, the polymer in a polymer solid electrolyte can include polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0140] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0141] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0142] In the above scheme, by optimizing the material of the first filling component 30, the ability of the first filling component 30 to transport active ions is further improved, and the ion transport efficiency of the first filling component 30 is further improved.

[0143] Please see Figure 6 and Figure 7 In some embodiments, the first current collector 211 includes a first current collector body 2111 and a first electrode 2112, the first current collector body 2111 and the first electrode 2112 are arranged along a first direction X, and a first thinned portion 2122 is located on the side of the first body portion 2121 near the first electrode 2112.

[0144] The first current collector 2111 is the main component in the first current collector 211 that serves as a carrier for the first active material layer 212 and as a collector and conductor of electrons. The first active material layer 212 may be stacked on at least one surface of the first current collector 2111 in its thickness direction.

[0145] The first tab 2112 is a component in the first current collector 211 used for electrical connection with an external device to transmit current. The first tab 2112 is disposed on one side of the first current collector body 2111 along the first direction X and protrudes relative to the first active material layer 212 along the first direction X to facilitate electrical connection with an external device.

[0146] In the above solution, the first thinning part 2122 is disposed on the side of the first main body 2121 near the first electrode tab 2112, which can reduce the risk of the first active material layer 212 near the first electrode tab 2112 being squeezed and bursting in subsequent processes, and reduce the impact of the first active material layer 212 on the performance of the first electrode sheet 21.

[0147] Please see Figure 8 In some embodiments, the first main body portion 2121 and the first thinned portion 2122 are arranged along a first direction X, which is perpendicular to the thickness direction of the first main body portion 2121; the second active material layer 222 includes the second main body portion 2221 and the second thinned portion 2222, the thickness of the second thinned portion 2222 is less than the thickness of the second main body portion 2221; in the first direction X, the second thinned portion 2222 is located on the side of the second main body portion 2221 close to the first thinned portion 2122; at least a portion of the first gap is formed between the first thinned portion 2122 and the second thinned portion 2222.

[0148] Both the second main body 2221 and the second thinned part 2222 can insert or extract active ions during the charging and discharging process of the battery cell 1.

[0149] The structure of the second thinning portion 2222 can be the same as that of the first thinning portion 2122. For example, the structure of the second thinning portion 2222 is the same as that of the first thinning portion 2122. The second thinning portion 2222 is disposed on one side of the first main body portion 2121 along the first direction X, and the second thinning portion 2222 decreases in size along the direction from the second main body portion 2221 to the first thinning portion 2222 in the first direction X. Of course, the structure of the second thinning portion 2222 can also be different from that of the first thinning portion 2122.

[0150] The second thinned portion 2222 is disposed on the side of the second main body portion 2221 close to the first thinned portion 2122 along the first direction X. The projection of the first thinned portion 2122 onto the spacer 23 along the thickness direction of the first main body portion 2121 and the projection of the second thinned portion 2222 onto the spacer 23 along the thickness direction of the first main body portion 2121 can at least partially overlap, and a first gap can be formed between them. It is understood that the first gap may include the gap between the spacer 23 and the first thinned portion 2122 and the gap between the spacer 23 and the second thinned portion 2222.

[0151] In the above scheme, the second thinning portion 2222 is located on one side of the second main body portion 2221, and the thickness of the second thinning portion 2222 is less than the thickness of the second main body portion 2221. The setting of the second thinning portion 2222 is equivalent to thinning the edge of the second active material layer 222, which can reduce the risk of the second active material layer 222 bursting due to compression in subsequent processes. On this basis, setting the second thinning portion 2222 on the side of the second main body portion 2221 close to the first thinning portion 2122 is beneficial to achieving active ion balance between the first thinning portion 2122 and the second thinning portion 2222, reducing the risk of lithium plating due to excess active ions at the first thinning portion 2122 or the second thinning portion 2222. Furthermore, at least a portion of the first gap is formed between the first thinning portion 2122 and the second thinning portion 2222. The electrolyte of the first filling member 30 can transport active ions between the first thinning portion 2122 and the second thinning portion 2222 to shorten the ion transport path between the first thinning portion 2122 and the second thinning portion 2222, improve the ion transport efficiency between the first thinning portion 2122 and the second thinning portion 2222, and reduce the risk of lithium plating in the electrode assembly 20.

[0152] Please continue reading. Figure 8 In some optional embodiments, the second current collector 221 may include a second current collector body 2211 and a second tab 2212. The second tab 2212 is disposed on one side of the second current collector body 2211, and the second thinned portion 2222 is located on the side of the second body portion 2221 near the second tab 2212. This can reduce the risk of the second active material layer 222 being squeezed and bursting at the edge in subsequent processes, thereby reducing the impact of the second active material layer 222 on the performance of the second electrode 22.

[0153] It is understandable that when the first thinned portion 2122 is located on the side of the first main body portion 2121 near the first tab 2112, and the second thinned portion 2222 is located on the side of the second main body portion 2221 near the second tab 2212, the second thinned portion 2222 is disposed on the side of the second main body portion 2221 near the first thinned portion 2122 along the first direction X. This is equivalent to the first tab 2112 and the second tab 2212 being disposed on the same side of the isolator 23 along the first direction X, which can reduce the distance between the first tab 2112 and the second tab 2212, and facilitate the electrical connection between the first tab 2112 and the second tab 2212 and external devices.

[0154] Please see Figure 9 In some embodiments, the first main body portion 2121 and the first thinned portion 2122 are arranged along a first direction X, which is perpendicular to the thickness direction of the first main body portion 2121; the second active material layer 222 includes the second main body portion 2221 and the second thinned portion 2222, the thickness of the second thinned portion 2222 is less than the thickness of the second main body portion 2221; in the first direction X, the second thinned portion 2222 is located on the side of the second main body portion 2221 away from the first thinned portion 2122; a second gap is formed between the second thinned portion 2222 and the first main body portion 2121, and the battery cell 1 also includes a second filling component 40, which includes an electrolyte filled in the second gap.

[0155] The second thinning portion 2222 is disposed on the side of the second main body portion 2221 away from the first thinning portion 2122 along the first direction X. At this time, the first thinning portion 2122 and the second thinning portion 2222 are disposed on both sides of the separator 23 along the first direction X. A first gap can be formed between the first thinning portion 2122 and the second main body portion 2221, and a second gap can be formed between the second thinning portion 2222 and the first main body portion 2121.

[0156] The second filling component 40 includes an electrolyte disposed in the second gap and serves as a component for transporting active ions within the second gap. The electrolyte of the second filling component 40 can fill at least a portion of the second gap; that is, the electrolyte can fill a part of the second gap or completely fill the second gap.

[0157] It should be noted that the material of the second filling component 40 can be the same as that of the first filling component 30, and both can be prepared using the same process. Alternatively, the material of the second filling component 40 can be different from that of the first filling component 30, and both can be prepared separately.

[0158] In the above scheme, the second thinning portion 2222 is located on one side of the second main body portion 2221, and the thickness of the second thinning portion 2222 is less than the thickness of the second main body portion 2221. The setting of the second thinning portion 2222 is equivalent to thinning the edge of the second active material layer 222, which can reduce the risk of the second active material layer 222 bursting due to compression in subsequent processes. By setting the second thinning portion 2222 on the side of the second main body portion 2221 away from the first thinning portion 2122, it helps to balance the volume changes of the first active material layer 212 and the second active material layer 222 during use, improve the stress distribution inside the battery cell 1, and reduce the risk of short circuit between the first electrode 21 and the second electrode 22, thereby improving the reliability and service life of the battery cell 1. Furthermore, by transmitting active ions through the electrolyte in the second filling member 40 in the second gap between the second thinned portion 2222 and the first main body portion 2121, the ion transport path between the second thinned portion 2222 and the first main body portion 2121 can be shortened, the ion transport efficiency between the second thinned portion 2222 and the first main body portion 2121 can be improved, and the risk of lithium plating in the electrode assembly 20 can be reduced.

[0159] It is understandable that when the first thinned portion 2122 is located on the side of the first main body portion 2121 close to the first electrode tab 2112, and the second thinned portion 2222 is located on the side of the second main body portion 2221 close to the second electrode tab 2212, the second thinned portion 2222 is disposed on the side of the second main body portion 2221 away from the first thinned portion 2122 along the first direction X. This is equivalent to making the first electrode tab 2112 and the second electrode tab 2212 disposed close to the opposite sides of the separator 23 along the first direction X, which can increase the distance between the first electrode tab 2112 and the second electrode tab 2212 and reduce the risk of mutual interference between the first electrode tab 2112 and the second electrode tab 2212.

[0160] Please see Figure 10 In some embodiments, the first filling member 30 includes a first sub-part 31 filled between the first thinned portion 2122 and the spacer 23. The projection of the first sub-part 31 on the first current collector 211 along the thickness direction of the first main body portion 2121 overlaps with the projection of the first thinned portion 2122 on the first current collector 211 along the thickness direction of the first main body portion 2121. The ratio Z1 of the thickness of the first sub-part 31 to the thickness of the first main body portion 2121 satisfies: 0.08≤Z1≤0.15.

[0161] The first sub-part 31 is part of the first filling member 30, which may include an electrolyte and fills the gap between the first thinned portion 2122 and the spacer 23. When the first gap is located between the first thinned portion 2122 and the spacer 23, the first sub-part 31 is located in the first gap. When the first gap includes both the gap between the first thinned portion 2122 and the spacer 23 and the gap between the second thinned portion 2222 and the spacer 23, the first sub-part 31 fills a portion of the first gap.

[0162] If the projection of the first sub-part 31 along the thickness direction of the first main body 2121 onto the first current collector 211 overlaps with the projection of the first thinned part 2122 along the thickness direction of the first main body 2121 onto the first current collector 211, then the first sub-part 31 can transfer active ions between the first thinned part 2122 and the separator 23.

[0163] It should be noted that the first sub-part 31 is a component with a certain width in the direction from the first main body 2121 to the first thinned part 2122. When the first filling component 30 increases in size along the direction from the first main body 2121 to the first thinned part 2122, the thickness of each part of the first sub-part 31 in the direction from the first main body 2121 to the first thinned part 2122 gradually increases, and the ratio of the thickness of each part to the thickness of the first main body 2121 is within the aforementioned range. The ratio of the thickness of the first sub-part 31 to the thickness of the first main body 2121 can be greater than or equal to 0.08 and less than or equal to 0.15. For example, the ratio can be 0.08, 0.09, 0.1, 0.12, 0.15, etc.

[0164] In the above scheme, the first sub-part 31 is filled between the first thinned part 2122 and the separator 23, and active ions are transported between the first thinned part 2122 and the separator 23. By reasonably setting the thickness ratio between the first sub-part 31 and the first main body 2121, the thickness of the first sub-part 31 is optimized, that is, the height of the corresponding area of ​​the gap between the first thinned part 2122 and the separator 23 is optimized. On the one hand, it can reduce the risk of the first active material layer 212 being squeezed and bursting in subsequent processes. On the other hand, it can reduce the risk of the height of the gap between the first thinned part 2122 and the separator 23 being too high and the thickness of the first sub-part 31 being too large, which would affect the performance of the first electrode 21.

[0165] Please continue reading. Figure 10 In some embodiments, the first filling member 30 further includes a second sub-part 32 filled between the first thinned portion 2122 and the spacer 23. The second sub-part 32 is located on the side of the first sub-part 31 close to the first main body portion 2121. The ratio Z2 of the thickness of the second sub-part 32 to the thickness of the first main body portion 2121 satisfies: 0.03≤Z2≤0.08.

[0166] The second sub-part 32 fills the gap between the first thinned portion 2122 and the spacer 23. When the first gap is located between the first thinned portion 2122 and the spacer 23, the second sub-part 32 is located in the first gap. When the first gap includes both the gap between the first thinned portion 2122 and the spacer 23 and the gap between the second thinned portion 2222 and the spacer 23, the second sub-part 32 partially fills the first gap.

[0167] Since the first thinned portion 2122 is located on one side of the first main body portion 2121, and the projection of the first sub-portion 31 along the thickness direction of the first main body portion 2121 onto the first current collector 211 overlaps with the projection of the first thinned portion 2122 along the thickness direction of the first main body portion 2121 onto the first current collector 211, when the second sub-portion 32 is disposed on the side of the first sub-portion 31 close to the first main body portion 2121, the projection of the second sub-portion 32 along the thickness direction of the first main body portion 2121 onto the first current collector 211 overlaps with the projection of the first thinned portion 2122 along the thickness direction of the first main body portion 2121 onto the first current collector 211. The second sub-portion 32 is part of the first filling member 30, which may include an electrolyte and is capable of transferring active ions between the first thinned portion 2122 and the separator 23.

[0168] It should be noted that the second sub-part 32 is a component with a certain width in the direction from the first main body 2121 to the first thinned part 2122. When the first filling component 30 increases in size along the direction from the first main body 2121 to the first thinned part 2122, the thickness of each part of the second sub-part 32 in the direction from the first main body 2121 to the first thinned part 2122 gradually increases, and the ratio of the thickness of each part to the thickness of the first main body 2121 is within the aforementioned range. The ratio of the thickness of the second sub-part 32 to the thickness of the first main body 2121 can be greater than or equal to 0.03 and less than or equal to 0.08. For example, the ratio can be 0.03, 0.04, 0.05, 0.06, 0.08, etc.

[0169] In the above scheme, the second sub-part 32 fills the gap between the first thinned part 2122 and the separator 23. It is located on the side of the first sub-part 31 close to the first main body part 2121. By reasonably setting the thickness ratio between the second sub-part 32 and the first main body part 2121, the stress transition of the first sub-part 31 and the second sub-part 32 when they are squeezed in subsequent processes can be smoother, reducing the risk of stress concentration between the first sub-part 31 and the second sub-part 32.

[0170] Please continue reading. Figure 10In some embodiments, the first filling member 30 further includes a third sub-part 33 filled between the first thinned portion 2122 and the spacer 23. The third sub-part 33 is located on the side of the second sub-part 32 close to the first main body portion 2121. The ratio Z3 of the thickness of the third sub-part 33 to the thickness of the first main body portion 2121 satisfies: 0.01≤Z3≤0.03.

[0171] The third sub-part 33 fills the gap between the first thinned portion 2122 and the spacer 23. When the first gap is located between the first thinned portion 2122 and the spacer 23, the third sub-part 33 is located in the first gap. When the first gap includes the gap between the first thinned portion 2122 and the spacer 23 and the gap between the second thinned portion 2222 and the spacer 23, the third sub-part 33 fills part of the first gap.

[0172] The third sub-part 33 is disposed on the side of the second sub-part 32 near the first main body 2121. It is located between the second sub-part 32 and the first main body 2121. Since the first thinned part 2122 is located on the side of the first main body 2121, and the projection of the second sub-part 32 along the thickness direction of the first main body 2121 onto the first current collector 211 overlaps with the projection of the first thinned part 2122 along the thickness direction of the first main body 2121 onto the first current collector 211, the projection of the third sub-part 33 along the thickness direction of the first main body 2121 onto the first current collector 211 overlaps with the projection of the first thinned part 2122 along the thickness direction of the first main body 2121 onto the first current collector 211.

[0173] The third sub-part 33 is part of the first filling member 30, which may include an electrolyte and be able to transfer active ions between the first thinned portion 2122 and the separator 23.

[0174] It should be noted that the third sub-part 33 is a component with a certain width in the direction from the first main body 2121 to the first thinned part 2122. When the first filling component 30 increases in size along the direction from the first main body 2121 to the first thinned part 2122, the thickness of each part of the third sub-part 33 gradually increases in the direction from the first main body 2121 to the first thinned part 2122, and the ratio of the thickness of each part to the thickness of the first main body 2121 also gradually increases, and the ratio of the thickness of each part to the thickness of the first main body 2121 is within the aforementioned range. The ratio of the thickness of the third sub-part 33 to the thickness of the first main body 2121 can be greater than or equal to 0.01 and less than or equal to 0.03. For example, the ratio can be 0.01, 0.015, 0.02, 0.025, 0.03, etc.

[0175] In the above scheme, the third sub-part 33 fills the gap between the first thinned part 2122 and the separator 23. It is located on the side of the second sub-part 32 close to the first main body part 2121. By reasonably setting the thickness ratio between the third sub-part 33 and the first main body part 2121, the stress transition between the second sub-part 32 and the third sub-part 33 when they are squeezed in subsequent processes can be smoother, reducing the risk of stress concentration between the second sub-part 32 and the third sub-part 33.

[0176] Please continue reading. Figure 10 In some optional embodiments, the first filling member 30 may further include a fourth sub-part 34 filled between the first thinned portion 2122 and the spacer 23. The fourth sub-part 34 is located on the side of the third sub-part 33 near the first main body portion 2121. The thickness of the fourth sub-part 34 may be greater than 0 and less than the thickness of the third sub-part 33. By providing the fourth sub-part 34, the transition between the first filling member 30 and the first main body portion 2121 can be made smoother, reducing the risk of a large step forming between the first filling member 30 and the main body portion.

[0177] It should be noted that the shape of the overall structure formed by the first sub-part 31, the second sub-part 32, the third sub-part 33, and the fourth sub-part 34 can be adapted to the gap between the first thinned part 2122 and the spacer 23. Therefore, the ratio of the thickness of each sub-part to the thickness of the first main body 2121 is the ratio of the height of the corresponding area of ​​the gap between the first thinned part 2122 and the spacer 23 to the thickness of the first main body 2121.

[0178] For example, in the direction from the first thinned portion 2122 to the first main body portion 2121, the width of the first sub-portion 31 can be approximately 3 mm. The first sub-portion 31 can correspond to a first partial gap with a width of approximately 3 mm between the first thinned portion 2122 and the spacer 23. The ratio of the height of the first partial gap to the thickness of the first main body portion 2121 can be greater than or equal to 0.08 and less than or equal to 0.15.

[0179] The width of the second sub-part 32 can be approximately 5 mm. The second sub-part 32 can correspond to a second gap with a width of approximately 5 mm between the first thinned part 2122 and the spacer 23. The second gap is located on the side of the first gap close to the first main body 2121. The ratio of its height to the first main body 2121 can be greater than or equal to 0.03 and less than or equal to 0.08.

[0180] The width of the third sub-part 33 can be approximately 5 mm. The third sub-part 33 can correspond to the third part gap with a width of approximately 5 mm between the first thinned part 2122 and the spacer 23. The third part gap is located on the side of the second part gap close to the first main body part 2121. The ratio of its height to the first main body part 2121 can be greater than or equal to 0.01 and less than or equal to 0.03.

[0181] The width of the fourth sub-part 34 can be approximately 2 mm, which corresponds to the fourth part gap between the first thinned part 2122 and the spacer 23, which is approximately 2 mm wide. This fourth part gap is located on the side of the third part gap near the first main body part 2121, and its height is less than the height of the third part gap and greater than 0.

[0182] It should be noted that, in the embodiments of this application, "thickness" and "height" refer to the dimensions of the corresponding component in the thickness direction of the first main body 2121, and "width" refers to the dimensions of the corresponding component in the first direction X.

[0183] Secondly, embodiments of this application provide a battery device 100, including a plurality of battery cells 1 as described in any of the above claims.

[0184] Thirdly, embodiments of this application provide an electrical device including the aforementioned battery device 100, which is used to provide electrical energy.

[0185] In some embodiments, this application provides a battery cell 1, a battery device 100, and an electrical device. The battery cell 1 includes a housing 10, an electrode assembly 20, and a first filling component 30. The electrode assembly 20 is disposed within the housing 10 and includes a first electrode 21, a second electrode 22, and a separator 23. The first electrode 21 and the second electrode 22 have opposite polarities. The separator 23 separates the first electrode 21 and the second electrode 22. The first electrode 21 includes a first current collector 211 and a first current collector 22 disposed in the first current collector 211. An active material layer 212 is provided. A second electrode 22 includes a second current collector 221 and a second active material layer 222 disposed on the second current collector 221. The first active material layer 212 includes a first main body portion 2121 and a first thinned portion 2122 disposed on one side of the first main body portion 2121. The thickness of the first thinned portion 2122 is less than the thickness of the first main body portion 2121. A first gap is formed between the first thinned portion 2122 and the second active material layer 222. A first filling member 30 includes an electrolyte disposed in the first gap. At least a portion of the first filling member 30 fills the spacer 23 and the first thinned portion 2122. The first filling member 30 is fixed to at least one of the first thinned portion 2122 and the spacer 23. The first main body portion 2121 and the first thinned portion 2122 are arranged along a first direction X, which is perpendicular to the thickness direction of the first main body portion 2121. Along the first direction X, from the first main body portion 2121 to the first thinned portion 2122, the thickness of the first thinned portion 2122 decreases, while the thickness of the first filling member 30 increases. The first main body portion 2121 and the first thinned portion 2122 are arranged along the first direction X, which is perpendicular to the thickness direction of the first main body portion 2121. The second active material layer 222 includes a second main body portion 2221 and a second thinned portion 2222, the thickness of which is less than the thickness of the second main body portion 2221. Along the first direction X, the second thinned portion 2222 is located on the side of the second main body portion 2221 closest to the first thinned portion 2122. At least a portion of the first gap is formed between the first thinned portion 2122 and the second thinned portion 2222.

[0186] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: shell; An electrode assembly is disposed within the housing. The electrode assembly includes a first electrode, a second electrode, and a separator. The first electrode and the second electrode have opposite polarities. The separator separates the first electrode and the second electrode. The first electrode includes a first current collector and a first active material layer disposed on the first current collector. The second electrode includes a second current collector and a second active material layer disposed on the second current collector. The first active material layer includes a first main body portion and a first thinned portion disposed on one side of the first main body portion. The thickness of the first thinned portion is less than the thickness of the first main body portion. A first gap is formed between the first thinned portion and the second active material layer. The first filling component includes an electrolyte disposed in the first gap.

2. The battery cell according to claim 1, characterized in that, At least a portion of the first filling component fills the spacer and the first thinned portion.

3. The battery cell according to claim 2, characterized in that, The first filling component is fixed to at least one of the first thinned portion and the separator.

4. The battery cell according to claim 2, characterized in that, The distance from the side surface of the first filling member facing the separator to the side surface of the first thinned portion facing away from the separator is less than or equal to the thickness of the first main body portion.

5. The battery cell according to claim 1, characterized in that, The first main body and the first thinned portion are arranged along a first direction, which is perpendicular to the thickness direction of the first main body. In the first direction, along the direction from the first main body to the first thinned portion, the thickness of the first thinned portion tends to decrease, while the thickness of the first filling member tends to increase.

6. The battery cell according to claim 1, characterized in that, The first filling component includes a gel electrolyte or a solid electrolyte.

7. The battery cell according to claim 1, characterized in that, The first current collector includes a first current collector body and a first electrode tab, the first current collector body and the first electrode tab are arranged along a first direction, and the first thinned portion is located on the side of the first body portion close to the first electrode tab.

8. The battery cell according to any one of claims 1-7, characterized in that, The first main body and the first thinned portion are arranged along a first direction, which is perpendicular to the thickness direction of the first main body. The second active material layer includes a second main body portion and a second thinned portion, wherein the thickness of the second thinned portion is less than the thickness of the second main body portion; in the first direction, the second thinned portion is located on the side of the second main body portion closer to the first thinned portion; At least a portion of the first gap is formed between the first thinned portion and the second thinned portion.

9. The battery cell according to any one of claims 1-7, characterized in that, The first main body and the first thinned portion are arranged along a first direction, which is perpendicular to the thickness direction of the first main body. The second active material layer includes a second main body portion and a second thinned portion, wherein the thickness of the second thinned portion is less than the thickness of the second main body portion; in the first direction, the second thinned portion is located on the side of the second main body portion away from the first thinned portion; A second gap is formed between the second thinned portion and the first main body portion, and the battery cell further includes a second filling component, the second filling component including an electrolyte filled in the second gap.

10. The battery cell according to any one of claims 1-7, characterized in that, The first filling component includes a first sub-part filling between the first thinned portion and the spacer. The projection of the first sub-part along the thickness direction of the first main body overlaps with the projection of the first thinned portion along the thickness direction of the first main body. The ratio Z1 of the thickness of the first sub-part to the thickness of the first main body satisfies: 0.08≤Z1≤0.

15.

11. The battery cell according to claim 10, characterized in that, The first filling component further includes a second sub-part filling between the first thinned portion and the separator. The second sub-part is located on the side of the first sub-part closer to the first main body portion. The ratio Z2 of the thickness of the second sub-part to the thickness of the first main body portion satisfies: 0.03≤Z2≤0.

08.

12. The battery cell according to claim 11, characterized in that, The first filling component further includes a third sub-part filling between the first thinned portion and the spacer, the third sub-part being located on the side of the second sub-part closer to the first main body portion, and the ratio Z3 of the thickness of the third sub-part to the thickness of the first main body portion satisfies: 0.01≤Z3≤0.

03.

13. A battery device, characterized in that, It includes multiple battery cells as described in any one of claims 1-12.

14. An electrical appliance, characterized in that, Includes the battery device of claim 13, the battery device being used to provide electrical energy.

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