Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device, the battery monomer comprises an electrode assembly, a shell and a coating, the electrode assembly is accommodated in the shell, the shell is provided with a welding part, the welding part is electrically connected to a tab of the battery monomer, and the coating is arranged on the outer side of the shell and covers the welding part. The welding part is covered with the coating, so that the welding part is protected, the possibility of corrosion of the welding part is reduced, and the reliability of the single battery is improved.

Description

Technical Field

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

[0002] Batteries have the advantages of high specific energy and high power density. They are widely used in electronic devices and transportation vehicles, such as mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric tools, etc.

[0003] As the application scope of batteries continues to expand, people have higher and higher requirements on the working reliability of batteries. How to improve the reliability of batteries has always been the focus of technical personnel in this field. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, wherein the battery cell has good reliability.

[0005] In a first aspect, some embodiments of the present application provide a battery cell, which includes an electrode assembly, a shell and a coating, wherein the electrode assembly includes a pole ear; the electrode assembly is accommodated in the shell, the shell is provided with a welding portion, and the welding portion is electrically connected to the pole ear; the coating is arranged on the outside of the shell and covers the welding portion.

[0006] In the above structure, the welding part is protected by covering the welding part with the coating, which reduces the possibility of rusting of the welding part, and is beneficial to improving the reliability of the battery cell.

[0007] According to the battery cell provided in some embodiments of the present application, the housing includes a wall portion, a recess is provided on the outer side of the wall portion, and a welding portion is provided on the bottom wall of the recess; at least part of the coating is accommodated in the recess. Through the above structure, the melting zone formed by welding the tab and the welding portion is located on the bottom wall of the recess, which reduces the possibility of the melting zone protruding from the wall portion, which is conducive to reducing the possibility of the melting zone being bumped.

[0008] According to the battery cells provided in some embodiments of the present application, the coating is entirely contained in the recess, so that the melting zones of the coating and the welding portion are both located in the recess, which helps to reduce the possibility of the melting zones and the coating being bumped, which not only helps to extend the life of the coating, but also helps to improve the reliability of the connection between the tab and the welding portion.

[0009] According to the battery cell provided in some embodiments of the present application, the outer surface of the coating is flush with the outer surface of the wall, so that the outer surface of the wall is flat, which is beneficial to improving the flatness of the appearance of the battery cell.

[0010] According to the battery cells provided in some embodiments of the present application, the thickness of the coating is H1, 5μm≤H1≤400μm, which not only makes the coating have a good protective effect, but also avoids waste of coating due to excessive thickness.

[0011] According to the battery cells provided in some embodiments of the present application, 10 μm ≤ H1 ≤ 200 μm, so that the coating has a good protective effect and is not prone to coating waste.

[0012] According to the battery cell provided in some embodiments of the present application, the shell also includes a plating layer arranged on the outside of the wall portion, and the plating layer surrounds the welding portion; the coating is connected to the plating layer, and the plating layer can protect the wall portion and reduce rust on the wall portion.

[0013] According to the battery cells provided in some embodiments of the present application, the projection of the welding portion is located within the range of the coating along the thickness direction of the wall portion, so that the welding portion can be more comprehensively covered and protected by the coating, which is beneficial to reducing the possibility of rust on the welding portion.

[0014] According to the battery cell provided in some embodiments of the present application, the wall portion is a carbon steel structure, and the coating is a nickel coating, so that the coating can protect the wall portion and reduce rust on the wall portion.

[0015] According to the battery cells provided in some embodiments of the present application, the thickness of the coating is H2, 0.05 μm≤H2≤10 μm, so that the coating has a good protective effect without causing waste or increasing costs due to excessive thickness.

[0016] According to the battery cells provided in some embodiments of the present application, 0.1 μm≤H2≤5 μm, so that the coating has a good protective effect and is not likely to cause waste or increase costs.

[0017] According to the battery cell provided in some embodiments of the present application, the coating layer includes a coating material, and the coating material is polyacrylate, polyurethane or epoxy resin, so that the coating material can be formed on the outer surface of the welding portion.

[0018] According to the battery cells provided in some embodiments of the present application, the viscosity of the coating material ranges from 0.5cps to 2000cps, so that the viscosity of the coating material can meet the requirements of coating processes such as spraying, printing, and dispensing, and it is convenient to apply the coating material to the welding part.

[0019] According to the battery cell provided in some embodiments of the present application, the viscosity of the coating material ranges from 1 cps to 1000 cps, so that the coating material can be conveniently applied to the welding portion.

[0020] According to the battery cells provided in some embodiments of the present application, the adhesion between the coating and the welding part ranges from level 0 to level 1, so that the adhesion between the coating and the welding part is relatively large, the coating can be firmly attached to the welding part and is not easy to fall off, which is beneficial to extending the life of the coating.

[0021] According to the battery cells provided in some embodiments of the present application, the hardness of the coating is less than the hardness of the welding portion, so that when the battery cell is bumped, the coating is more easily damaged than the welding portion to buffer the bump, thereby helping to reduce the possibility of damage to the welding portion.

[0022] According to the battery cells provided in some embodiments of the present application, the distance that the edge of the coating exceeds the edge of the welding portion is L, L>0.1mm, so that the coating covers the welding portion more completely, which is beneficial for the coating to better protect the welding portion and reduce the possibility of rust on the welding portion.

[0023] In a second aspect, some embodiments of the present application further provide a battery, which includes a battery cell provided by any of the above technical solutions.

[0024] In a second aspect, some embodiments of the present application further provide an electrical device, which includes a battery provided by the aforementioned technical solution, and the battery is used to provide electrical energy.

[0025] The technical solution provided by the embodiments of the present disclosure brings at least the following beneficial effects:

[0026] Some embodiments of the present application provide a battery cell, which includes an electrode assembly, a shell and a coating, wherein the electrode assembly is contained in the shell, the shell is provided with a welding portion, the welding portion is electrically connected to a tab of the battery cell, and the coating is provided on the outer side of the shell and covers the welding portion. By covering the welding portion with the coating, the welding portion is protected, the possibility of rusting of the welding portion is reduced, and the reliability of the battery cell is improved.

[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0029] Figure 1A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0030] Figure 2 An exploded view of a battery provided in some embodiments of the present application;

[0031] Figure 3 A cross-sectional view of a battery cell provided in some embodiments of the present application;

[0032] Figure 4 for Figure 3 The enlarged view of point A in the middle;

[0033] Figure 5 A cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0034] Figure 6 for Figure 5 The enlarged view of point B in the middle;

[0035] Figure 7 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0036] Figure 8 A cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0037] Fig. 9 for Figure 8 Enlarged view of point C in the middle.

[0038] The reference numerals in the specific implementation manner are as follows:

[0039] 10. casing; 101. first casing; 102. second casing; 20. battery cell; 201. electrode assembly; 2011. pole ear; 202. casing; 2021. welding portion; 2022. wall portion; 2023. recessed portion; 2024. coating; 2025. shell; 2026. end cover; 203. coating; 204. current collecting member; 1000. vehicle; 100. battery; 200. controller; 300. motor. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0042] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0043] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0045] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0046] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "perpendicular" also includes not only the absolutely perpendicular situation, but also the roughly perpendicular situation conventionally recognized in engineering. For example, if the angle between two directions is 85°-90°, the two directions can be considered perpendicular; if the angle between two directions is 0°-5°, the two directions can be considered parallel.

[0047] The term "plurality" used in the present application refers to two or more (including two).

[0048] At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields.

[0049] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0050] The battery cell may be a secondary battery cell, which refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0051] The battery cells may be lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0052] A battery cell may include an electrode assembly, an electrolyte and a shell. The electrode assembly and the electrolyte are contained in the shell, and the shell is used to encapsulate the electrode assembly and the electrolyte and other components. The electrode assembly includes a positive electrode, a negative electrode and a separator for isolating the positive electrode and the negative electrode. The electrolyte plays a role in conducting ions between the positive electrode and the negative electrode.

[0053] The outer shell may include a shell and an end cover, wherein the end cover covers the opening of the shell, and the two together form a cavity for accommodating components such as the electrode assembly and the electrolyte.

[0054] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0055] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0056] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0057] In the related art, the tabs of the electrode assembly in the battery cell usually need to be welded to the shell. However, welding will destroy the anti-rust layer on the shell, so that the shell cannot be effectively protected, and the welding area is prone to rust, which is not conducive to improving the reliability of the battery cell.

[0058] In order to improve the reliability of a battery cell, some embodiments of the present application provide a battery cell, which includes an electrode assembly, a shell and a coating, wherein the electrode assembly is accommodated in the shell, the shell is provided with a welding portion, the welding portion is electrically connected to the tab of the battery cell, and the coating is provided on the outer side of the shell and covers the welding portion. By covering the welding portion with the coating, the welding portion is protected, the possibility of rusting of the welding portion is reduced, and the reliability of the battery cell is improved.

[0059] The battery cell described in the embodiments of the present application is suitable for use in batteries and electrical devices using batteries. The battery cell can be used for, but is not limited to, batteries, and can also be used for vehicles, aircraft, ships, electronic equipment, power tools and other products, and can improve the reliability of these products.

[0060] Electrical devices may be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, electric tools, etc. Vehicles may be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc. Spacecraft include aircraft, rockets, space shuttles and spacecrafts, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc.

[0061] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0062] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0063] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0064] Please refer to Figure 2 , Figure 2 An exploded diagram of a battery 100 provided for some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, and the battery cell 20 is accommodated in the housing 10. Among them, the housing 10 is used to provide a storage space for the battery cell 20. There may be multiple battery cells 20 in the battery 100, and the multiple battery cells 20 may be connected in series, in parallel, or in mixed connection. Mixed connection means that multiple battery cells 20 are both connected in series and in parallel. Multiple battery cells 20 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the housing 10; of course, the battery 100 can also be a battery module formed by first connecting multiple battery cells 20 in series, in parallel, or in mixed connection, and then the multiple battery modules are connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the housing 10.

[0065] The box 10 may include a first box 101 and a second box 102, and the first box 101 and the second box 102 cover each other to define a placement space for accommodating the battery cells 20. The first box 101 and the second box 102 may be in various shapes, such as a cuboid, a cylinder, etc. The first box 101 may be a hollow structure with one side open, and the second box 102 may also be a hollow structure with one side open, and the open side of the second box 102 covers the open side of the first box 101, thereby forming a box 10 with a placement space.

[0066] The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component for achieving electrical connection between the plurality of battery cells 20 .

[0067] Each battery cell 20 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0068] In some embodiments of the present application, Figure 3 and Figure 4 As shown, the battery cell 20 includes an electrode assembly 201, a shell 202 and a coating 203. The electrode assembly 201 includes a pole ear 2011. The electrode assembly 201 is accommodated in the shell 202. The shell 202 is provided with a welding portion 2021, and the welding portion 2021 is electrically connected to the pole ear 2011; the coating 203 is arranged on the outside of the shell 202 and covers the welding portion 2021.

[0069] The electrode assembly 201 may be a component in which an electrochemical reaction occurs in the housing 202. The housing 202 may contain one or more electrode assemblies 201. The electrode assembly 201 may be a winding structure or a laminated structure.

[0070] The electrode assembly 201 is in contact with the electrolyte, and active ions (such as lithium ions) can be conducted between the electrode assembly 201201 and the electrolyte. The electrode assembly 201 includes a positive electrode sheet, a negative electrode sheet, and a separator, which are stacked, and the separator is arranged between the positive electrode sheet and the negative electrode sheet to prevent short circuit. Both the positive electrode sheet and the negative electrode sheet are provided with a pole ear 2011, which is used to extract or charge electric energy.

[0071] The housing 202 is a component for packaging the electrode assembly 201 and the electrolyte. A cavity is formed in the housing 202, and the electrode assembly 201 and the electrolyte are arranged in the cavity and surrounded by the housing 202.

[0072] The shell 202 can be in various shapes and sizes, such as a rectangular parallelepiped, a hexagonal prism, etc. Specifically, the shape of the shell 202 can be determined according to the specific shape and size of the electrode assembly 201. The shell 202 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, and aluminum alloy.

[0073] The welding portion 2021 may be a partial structure on the outer shell 202 , which is used to electrically connect to the tab 2011 of the electrode assembly 201 , so that the electrode assembly 201 is electrically connected to the outer shell 202 , and an external device can be electrically connected to the electrode assembly 201 through the outer shell 202 .

[0074] The coating 203 may be a layered structure disposed on the surface of the housing 202. The coating 203 is disposed on the outer surface of the housing 202 and covers the welding portion 2021, thereby protecting the welding portion 2021, reducing the possibility of the welding portion 2021 contacting the external air, and helping to reduce the possibility of the welding portion 2021 rusting.

[0075] In the above structure, the welding portion 2021 is covered with the coating 203 , so that the welding portion 2021 is protected, and the possibility of rusting of the welding portion 2021 is reduced, which is beneficial to improving the reliability of the battery cell 20 .

[0076] Illustratively, the pole tab 2011 can be connected to the inner side of the welding portion 2021 by welding, and the material of the pole tab 2011 and the material of the welding portion 2021 are melted together to achieve electrical connection between the pole tab 2011 and the welding portion 2021, which is beneficial to reduce the resistance between the pole tab 2011 and the welding portion 2021.

[0077] For example, Figure 5 and Figure 6 As shown, the tab 2011 can also be connected to the inner side of the welding portion 2021 through the current collector 204. The current collector 204 includes a welding structure, the tab 2011 is welded to the current collector, the welding structure of the current collector is welded to the welding portion 2021, the material of the current collector 204 and the material of the welding portion 2021 are melted together, and the tab 2011 is electrically connected to the welding portion 2021 through the current collector 204. This is conducive to reducing the difficulty of electrical connection between the tab 2011 and the housing 202.

[0078] In some embodiments, the housing 202 includes a wall portion 2022 , a recess 2023 is disposed on the outer side of the wall portion 2022 , and a welding portion 2021 is disposed on the bottom wall of the recess 2023 ; at least a portion of the coating 203 is accommodated in the recess 2023 .

[0079] like Figure 7 As shown, the housing 202 may include a shell 2025 and an end cover 2026 . The shell 2025 is formed with an opening, and the end cover 2026 covers the opening. The wall portion 2022 may be either the end cover 2026 or a wall structure in the shell 2025 .

[0080] The wall portion 2022 may be a wall structure in the housing 202. Figure 8 and Fig. 9 As shown, the recess 2023 may be a recessed structure formed by removing material from the wall 2022, and is used to accommodate the molten zone formed by welding in the welding portion 2021. By arranging the recess 2023 on the outside of the wall 2022 and arranging the welding portion 2021 on the bottom wall of the recess 2023, the molten zone formed by welding the tab 2011 and the welding portion 2021 is located on the bottom wall of the recess 2023, which reduces the possibility of the molten zone protruding from the wall 2022, and helps to reduce the possibility of the molten zone being bumped.

[0081] At least part of the coating 203 is contained in the recess 2023. The entire coating 203 may be contained in the recess 2023, and the molten zone of the coating 203 and the welding portion 2021 does not protrude from the wall 2022. Alternatively, part of the coating 203 is contained in the recess 2023, and another part of the coating 203 protrudes from the recess 2023. Those skilled in the art may set whether the coating 203 protrudes from the recess 2023 according to actual conditions.

[0082] By accommodating at least part of the coating 203 in the recess 2023, the coating 203 is filled in the recess 2023 to protect the welding part 2021, and the recess 2023 is used to limit the coating 203, so that the recess 2023 can position the coating 203, which is conducive to improving the convenience of the coating 203 covering the surface of the welding part 2021. In some embodiments, the coating 203 can be formed by curing the coating. The coating 203 can be formed by curing the coating after self-leveling in the recess 2023; the coating 203 can also be formed by spraying the coating on the bottom wall of the recess 2023 and curing it. Under the limiting effect of the recess 2023, the coating 203 is convenient to form on the bottom wall of the recess 2023.

[0083] In some embodiments, the coating 203 is entirely contained within the recess 2023 .

[0084] By accommodating the coating 203 as a whole in the recess 2023, the melting zones of the coating 203 and the welding portion 2021 are both located in the recess 2023, which helps to reduce the possibility of the melting zone and the coating 203 being bumped, which not only helps to extend the life of the coating 203, but also helps to improve the reliability of the connection between the tab 2011 and the welding portion 2021.

[0085] In some embodiments, the outer surface of the coating 203 is flush with the outer surface of the wall 2022 .

[0086] By making the outer surface of the coating 203 flush with the outer surface of the wall 2022 , the outer surface of the wall 2022 is made flat, which helps to improve the flatness of the appearance of the battery cell 20 .

[0087] In some embodiments, the coating 203 has a thickness H1, 5 μm≤H1≤400 μm.

[0088] By setting the thickness range of the coating 203 to 5 μm to 400 μm, the coating 203 has a good protective effect, and does not cause paint waste due to excessive thickness. For example, 10 μm ≤ H1 ≤ 200 μm, by setting the thickness range of the coating 203 to 10 μm to 200 μm, the coating 203 can not only provide a good protective effect on the welding portion 2021, but also does not easily waste paint.

[0089] In some embodiments, the thickness of the coating 203 may be set to 15 μm, 30 μm, 50 μm or 200 μm. Those skilled in the art may select the thickness of the coating 203 according to the assembly conditions of the battery cell 20 and external devices.

[0090] Whether the thickness of the coating 203 meets the requirements can be judged by the gray value of the coating 203. For example, the gray value corresponding to the thickness of the coating 203 of 5 μm is set to the first preset value, and the gray value corresponding to the thickness of the coating 203 of 400 μm is set to the second preset value. The first preset value is greater than the second preset value. If the gray value of the coating 203 is greater than the first preset value, it can be determined that the thickness of the coating 203 is less than 5 μm and cannot meet the minimum requirement for the thickness of the coating 203; if the gray value of the coating 203 is less than the first preset value and greater than the second preset value, it can be determined that the thickness of the coating 203 is greater than 5 μm and less than 400 μm, which meets the thickness requirement of the coating 203. If the gray value of the coating 203 is less than the second preset value, it can be determined that the thickness of the coating 203 exceeds 400 μm and cannot meet the requirements.

[0091] The coating 203 may also be a transparent coating 203 provided with a fluorescent agent, and whether the thickness of the coating 203 meets the requirements may be judged by the fluorescence intensity of the coating 203 .

[0092] In some embodiments, the housing further includes a plating layer 2024 disposed on the outer side of the wall portion 2022 , the plating layer 2024 surrounds the welding portion 2021 ; and the coating layer 203 is connected to the plating layer 2024 .

[0093] The coating 2024 may be a layered structure provided on the wall 2022. The coating 2024 may be a plastic layer or a metal layer, and those skilled in the art may set it according to actual conditions. In some embodiments, the wall 2022 may be made of carbon steel, and the coating 2024 provided on the outer side thereof may be formed by nickel plating, and the coating 2024 may protect the wall 2022 and reduce the rust of the wall 2022.

[0094] The plating layer 2024 is arranged around the welding portion 2021, and the plating layer 2024 arranged outside the wall portion 2022 may be vacant at the welding portion 2021. When the welding portion 2021 is connected to the tab 2011 by welding, the plating layer 2024 outside the welding portion 2021 will be damaged, forming a vacancy there.

[0095] The coating 203 covering the welding portion 2021 is connected to the plating 2024. The projection of the coating 203 in the thickness direction of the wall 2022 may coincide with the projection of the vacancy of the plating 2024 in the thickness direction of the wall 2022, and the edge of the coating 203 is connected to the edge of the plating 2024. Alternatively, the projection of the coating 203 in the thickness direction of the wall 2022 may coincide with the projection of at least part of the plating 2024 in the thickness direction of the wall 2022, and in the overlapping part, the coating 203 adheres to the outer surface of the plating 2024.

[0096] In some embodiments, along the thickness direction of the wall portion 2022 , the projection of the welding portion 2021 is located within the range of the coating 203 .

[0097] By making the projection of the welding portion 2021 in the thickness direction of the shell 202 be within the range of the coating 203, the welding portion 2021 and the gaps in the plating layer 2024 are completely covered by the coating 203, which is beneficial for obtaining more comprehensive protection, reducing the possibility of the welding portion 2021 contacting the air, and helping to reduce the possibility of rust on the welding portion 2021.

[0098] In some embodiments, the thickness of the coating layer 2024 is H2, 0.05 μm≤H2≤10 μm.

[0099] By setting the thickness range of the coating 2024 to 0.05 μm to 10 μm, the coating 2024 has a good protective effect, and does not cause waste or increase costs due to excessive thickness. For example, 0.1 μm ≤ H2 ≤ 5 μm, by setting the thickness range of the coating 2024 to 0.1 μm to 5 μm, the coating 2024 can not only provide good protection for the wall 2022, but also reduce material waste.

[0100] In some embodiments, the thickness of the coating layer 2024 may be set to 0.5 μm, 1 μm, 2 μm, or 3 μm. Those skilled in the art may set the thickness of the coating layer 2024 according to actual conditions.

[0101] In some embodiments, the coating 203 includes a coating material, and the coating material is polyacrylate, polyurethane, or epoxy resin.

[0102] The coating material may refer to a material adhered to the outer side of the housing 202 for forming the coating 203. In some embodiments, the coating material may be applied to the welding portion 2021 by spraying, so that the coating material adheres to the outer side of the welding portion 2021 to form the coating 203 covering the welding portion 2021; the coating material may be applied to the welding portion 2021 by printing, so that the coating material adheres to the outer side of the welding portion 2021 to form the coating 203 covering the welding portion 2021; the coating material may also be applied to the welding portion 2021 by dispensing, so that the coating material adheres to the outer side of the welding portion 2021 to form the coating 203 covering the welding portion 2021.

[0103] The coating material is polyacrylate, polyurethane or epoxy resin, which may refer to the core material of the coating material being polyacrylate, polyurethane or epoxy resin, and may also include materials such as organic silane, alkyl phosphate ester, etc. that can increase the adhesion of the material.

[0104] In some embodiments, the viscosity of the coating material ranges from 0.5 cps to 2000 cps.

[0105] By setting the viscosity range of the coating material to 0.5 cps to 2000 cps, the viscosity of the coating material can meet the requirements of coating processes such as spraying, printing, and dispensing, so that the coating material can be easily applied to the welding part 2021. Exemplarily, the viscosity range of the coating material can be set to 1 cps to 1000 cps, so that the coating material can be easily applied to the welding part 2021.

[0106] In some embodiments, the viscosity of the coating material can be set to 0.5 cps, 1 cps, 500 cps or 800 cps. Those skilled in the art can set the viscosity of the coating material according to actual conditions so that the coating material can adapt to the coating process used.

[0107] For example, the viscosity of the coating material can be measured using a rotational viscometer according to the national standard GB / T 24148.4-2009. The specific measurement method can be carried out with reference to the national standard GB / T 24148.4-2009, which will not be described in detail here.

[0108] In some embodiments, the adhesion between the coating 203 and the welding portion 2021 ranges from level 0 to level 1.

[0109] By setting the adhesion between the coating 203 and the welding part 2021 to be in the range of level 0 to level 1, the adhesion between the coating 203 and the welding part 2021 is large, the coating 203 can be firmly attached to the welding part 2021 and is not easy to fall off, which is conducive to extending the life of the coating 203. By configuring the adhesion between the coating 203 and the welding part 2021 to be level 0 or level 1, the coating 203 is firmly attached to the welding part 2021 and is not easy to fall off.

[0110] Exemplarily, the adhesion of the coating 203 on the welding portion 2021 can be measured by a cross-cut method according to the national standard GB / T 9286-1998. The specific measurement method can be referred to the national standard GB / T 9286-1998 and will not be repeated here.

[0111] In some embodiments, the hardness of the coating 203 is less than the hardness of the weld 2021 .

[0112] By setting the hardness of the coating 203 to be less than the hardness of the welding portion 2021, when the battery cell 20 is bumped, the coating 203 is not easy to damage the welding portion 2021, thereby reducing the possibility of damage to the welding portion 2021. The hardness of the coating 203 and the hardness of the welding portion 2021 can both be Brinell hardness, which can be measured according to the national standard GB / T 231.1-2019. The specific measurement method can refer to the national standard GB / T 231.1-2019 and will not be repeated here.

[0113] In some embodiments, the surface of the coating 203 has a certain surface tension, so that an adhesive can be provided on the coating 203 , and the adhesive can bond the outer surface of the battery cell 20 to other components.

[0114] In some embodiments, the distance L that the edge of the coating 203 extends beyond the edge of the welding portion 2021 is greater than 0.1 mm.

[0115] The distance that the edge of the coating 203 exceeds the edge of the welding portion 2021 is greater than 0.1 mm, which may mean that in any direction perpendicular to the thickness direction of the shell 202, the distance that the edge of the coating 203 exceeds the edge of the welding portion 2021 is greater than 0.1 mm. Along the thickness direction of the shell 202, the projection of the welding portion 2021 is located within the projection range of the coating 203, and the distance that the projection edge of the coating 203 exceeds the projection edge of the welding portion 2021 is greater than 0.1 mm, which makes the coating 203 cover the welding portion 2021 more completely, which is conducive to enabling the coating 203 to better protect the welding portion 2021 and reduce the possibility of rusting of the welding portion 2021.

[0116] Exemplarily, the distance that the edge of the coating 203 exceeds the edge of the welding portion 2021 may be 0.5 mm, 0.8 mm or 1 mm, so that the coating 203 has a better covering effect on the welding portion 2021.

[0117] Some embodiments of the present application further provide a battery 100 , which includes a battery cell 20 provided by the above technical solution.

[0118] Some embodiments of the present application further provide an electrical device, which includes the battery 100 provided by the above technical solution, and the battery 100 is used to provide electrical energy.

[0119] Some embodiments of the present application provide a battery cell 20, such as Figure 8 and Fig. 9As shown, the battery cell 20 includes an electrode assembly 201, a shell 202, a current collector 204 and a coating 203. The electrode assembly 201 is accommodated in the shell 202. A recess 2023 is provided on the outer side of a wall portion 2022 of the shell 202. A welding portion 2021 is provided on the bottom wall of the recess 2023. The pole ear 2011 of the electrode assembly 201 is welded to the current collector 204. The current collector 204 is welded to the welding portion 2021. The coating 203 is accommodated in the recess 2023 as a whole and covers the welding portion 2021. The coating 203 fills the recess 2023 and the outer surface of the coating 203 is flush with the outer surface of the wall portion 2022. In the above structure, by setting the coating 203 as a whole in the recess 2023 and filling the recess 2023, the welding portion 2021 can be better covered by the coating 203, which is beneficial to improve the protection of the welding portion 2021, and can better reduce the possibility of rust on the welding portion 2021, which is beneficial to improve the reliability of the battery cell 20.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: Electrode assembly, including tabs; A shell, wherein the electrode assembly is accommodated in the shell, and the shell is provided with a welding portion, and the welding portion is electrically connected to the electrode lug; as well as A coating is disposed on the outer side of the shell and covers the welding portion.

2. The battery cell according to claim 1, characterized in that: The housing comprises a wall portion, a recess is provided on the outer side of the wall portion, and the bottom wall of the recess is provided with the welding portion; At least a portion of the coating is received in the recess.

3. The battery cell according to claim 2, characterized in that: The coating layer is entirely accommodated in the recess.

4. The battery cell according to claim 3, characterized in that: The outer surface of the coating is flush with the outer surface of the wall.

5. The battery cell according to claim 1, characterized in that: The thickness of the coating is H1, 5 μm≤H1≤400 μm.

6. The battery cell according to claim 5, characterized in that: 10μm≤H1≤200μm.

7. The battery cell according to claim 2, characterized in that: The shell further comprises a plating layer arranged on the outer side of the wall portion, the plating layer surrounds the welding portion; and the coating layer is connected to the plating layer.

8. The battery cell according to claim 7, characterized in that: Along the thickness direction of the wall portion, a projection of the welding portion is located within the range of the coating layer.

9. The battery cell according to claim 7, characterized in that: The wall portion is a carbon steel structure, and the plating layer is a nickel plating layer.

10. The battery cell according to claim 7, characterized in that: The thickness of the coating is H2, 0.05 μm≤H2≤10 μm.

11. The battery cell according to claim 7, characterized in that: 0.1μm≤H2≤5μm.

12. The battery cell according to claim 1, characterized in that: The coating layer comprises a coating material, and the coating material is polyacrylate, polyurethane or epoxy resin.

13. The battery cell according to claim 12, characterized in that: The viscosity of the coating material ranges from 0.5 cps to 2000 cps.

14. The battery cell according to claim 13, characterized in that: The viscosity of the coating material ranges from 1 cps to 1000 cps.

15. The battery cell according to claim 1, characterized in that: The adhesion between the coating and the welding portion ranges from level 0 to level 1.

16. The battery cell according to claim 1, characterized in that: The hardness of the coating layer is lower than the hardness of the welding portion.

17. The battery cell according to claim 1, characterized in that: The distance that the edge of the coating exceeds the edge of the welding portion is L, and L>0.1 mm.

18. A battery, characterized in that: Comprising the battery cell according to any one of claims 1 to 17.

19. An electrical device, characterized in that: Comprising a battery as claimed in claim 18, the battery is used to provide electrical energy.

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