Battery cell and electric device

Abstract

The application provides an electric core and an electric device. The electric core comprises a shell, an electrode assembly and an electrolyte. The electrode assembly and the electrolyte are accommodated in the shell. The electric core further comprises a corrosion-resistant layer. The corrosion-resistant layer covers at least part of the inner surface of the shell, can alleviate the corrosion of the shell caused by the contact between the shell and the electrolyte, and can further enhance the strength of the shell, improve the safety performance of the electric core and prolong the service life of the electric core.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell and an electrical device. Background Technology

[0002] Currently, with the rapid development of new energy technologies, battery cells have been widely used in electronic devices, electric vehicles, electric two-wheelers, power tools, and other fields. As the application of battery cells becomes more widespread, higher requirements are being placed on their safety performance. Utility Model Content

[0003] This application provides a battery cell and an electrical device to improve the safety performance of the battery cell.

[0004] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, and an electrolyte; the electrode assembly and the electrolyte are housed within the housing; wherein the battery cell further includes a corrosion-resistant layer that covers at least a portion of the inner surface of the housing.

[0005] In one or more of the above optional embodiments, a corrosion-resistant layer is covered on the inner surface of the casing. The corrosion-resistant layer covers a portion of the inner surface of the casing. The corrosion-resistant layer can prevent the electrolyte from contacting the casing, which can alleviate or solve the problem of casing corrosion caused by contact between the casing and the electrolyte. The corrosion-resistant layer can also enhance the strength of the casing, improve the safety performance of the battery cell, and extend the service life of the battery cell.

[0006] In some embodiments of the first aspect of this application, the area of ​​the inner surface of the housing is S, and the area of ​​the corrosion-resistant layer covering the inner surface of the housing is S1, where 0.8 ≤ S1 / S ≤ 1.

[0007] In one or more of the above optional embodiments, by making S1 / S greater than or equal to 0.8 and less than or equal to 1, the area of ​​the inner surface of the casing covered by the corrosion-resistant layer is large enough to reduce the area of ​​the casing in contact with the electrolyte or to avoid the inner surface of the casing from contacting the electrolyte, thereby reducing the risk of the casing being corroded by the electrolyte or avoiding the casing being corroded by the electrolyte, improving the safety performance of the battery cell and extending the service life of the battery cell.

[0008] In some embodiments of the first aspect of this application, the housing includes a shell and a cover, the shell forming a receiving space with an opening at one end, and the cover sealing the opening; the inner surface of the housing includes a first inner surface located on the shell, the first inner surface being provided with a corrosion-resistant layer, the corrosion-resistant layer covering at least a portion of the first inner surface.

[0009] In one or more of the above optional embodiments, the first inner surface of the casing is the main area in contact with the electrolyte. By covering at least a portion of the first inner surface with a corrosion-resistant layer, the risk of the casing being corroded by the electrolyte can be reduced, thereby improving the safety performance of the battery cell and extending its service life.

[0010] In some embodiments of the first aspect of this application, the housing includes a sidewall and a bottom wall, the first inner surface includes the inner surface of the sidewall and the inner surface of the bottom wall, and the corrosion-resistant layer covers at least a portion of the inner surface of the sidewall and at least a portion of the inner surface of the bottom wall.

[0011] In one or more of the above optional embodiments, the inner surfaces of the sidewalls and the bottom wall are covered with a corrosion-resistant layer, thereby reducing the risk of the casing being corroded by the electrolyte, improving the safety performance of the battery cell, and extending the service life of the battery cell.

[0012] In some embodiments of the first aspect of this application, the corrosion-resistant layer includes a first portion and a second portion. The first portion covers at least a portion of the inner surface of the sidewall, and the second portion covers at least a portion of the inner surface of the bottom wall. The first portion is disposed around the outer periphery of the second portion along the circumferential direction of the opening and is connected to the second portion. One end of the first portion opposite to the second portion forms an open end corresponding to the opening.

[0013] In one or more of the above optional embodiments, the first part surrounds the outer periphery of the second part along the circumferential direction of the opening and is connected to the second part. The end of the first part away from the second part forms an open end corresponding to the opening. This is beneficial because the area of ​​the inner surface of the sidewall covered by the first part is larger, which can reduce the risk of the part of the shell submerged in the electrolyte being corroded by the electrolyte.

[0014] In some embodiments of the first aspect of this application, the area of ​​the inner surface of the sidewall is S', the area of ​​the corrosion-resistant layer covering the inner surface of the sidewall is S2, and 0.8≤S2 / S'≤1.

[0015] In one or more of the above optional embodiments, by making S2 / S' greater than or equal to 0.8 and less than or equal to 1, the area of ​​the inner surface of the sidewall covered by the corrosion-resistant layer is large enough to reduce the contact area between the sidewall and the electrolyte or to avoid contact between the inner surface of the sidewall and the electrolyte, thereby reducing the risk of corrosion of the sidewall by the electrolyte or avoiding corrosion of the sidewall by the electrolyte, improving the safety performance of the battery cell and extending the service life of the battery cell.

[0016] In some embodiments of the first aspect of this application, the corrosion-resistant layer completely covers the first inner surface.

[0017] In one or more of the above optional embodiments, by completely covering the first inner surface of the housing with a corrosion-resistant layer, contact between the electrolyte and the housing can be avoided, thereby reducing the risk of the housing being corroded by the electrolyte.

[0018] In some embodiments of the first aspect of this application, the inner surface of the housing further includes a second inner surface located on the cover, the second inner surface being provided with a corrosion-resistant layer.

[0019] In one or more of the above optional embodiments, the corrosion-resistant layer covering at least a portion of the second inner surface of the end cap can reduce the risk of the end cap being corroded by the electrolyte, improve the safety performance of the battery cell, and extend the service life of the battery cell.

[0020] In some embodiments of the first aspect of this application, the thickness of the corrosion-resistant layer is 1 nm to 5 μm.

[0021] In one or more of the above optional embodiments, the thickness of the corrosion-resistant layer is greater than or equal to 1 nm, resulting in a larger thickness and better strength and corrosion resistance. This improves the strength of the casing and reduces the risk of casing corrosion, thereby enhancing the safety performance of the battery cell. Conversely, a corrosion-resistant layer thickness of less than or equal to 5 μm reduces the space occupied by the corrosion-resistant layer within the casing, mitigating the problem of reduced energy density in the battery cell caused by the corrosion-resistant layer. This results in a higher energy density for the battery cell. Therefore, a corrosion-resistant layer thickness of 1 nm to 5 μm provides both high energy density and safety performance for the battery cell.

[0022] In some embodiments of the first aspect of this application, the corrosion-resistant layer is configured as a structure including an insulating material.

[0023] In one or more of the above optional embodiments, the corrosion-resistant layer is constructed as a structure including insulating material, thereby reducing the risk of internal short circuits in the battery cell and improving the safety performance of the battery cell.

[0024] In some embodiments of the first aspect of this application, the corrosion-resistant layer is configured to include one or more materials selected from ceramics, molecular sieves, aluminum fluoride, iron fluoride, polymers, and graphene.

[0025] In one or more of the above optional embodiments, ceramics have good wear and corrosion resistance, and the corrosion-resistant layer is made of ceramics, reducing the risk of casing corrosion, improving the safety performance, reliability, and lifespan of the battery cell. Molecular sieves have good barrier properties, and the corrosion-resistant layer is made of molecular sieves, which can reduce the risk of electrolyte contact with the casing or prevent electrolyte contact with the casing, thereby reducing the risk of casing corrosion or mitigating the degree of casing corrosion, improving the safety performance and lifespan of the battery cell. Aluminum fluoride and iron fluoride have good chemical stability and corrosion resistance, and the corrosion-resistant layer is made of aluminum fluoride, which helps reduce the risk of casing corrosion, improves the safety performance, and extends the lifespan of the battery cell. Polymers have good corrosion resistance, and the corrosion-resistant layer is made of polymers, which can reduce the risk of electrolyte contact with the casing or prevent electrolyte contact with the casing, thereby reducing the risk of casing corrosion or mitigating the degree of casing corrosion, improving the safety performance and extending the lifespan of the battery cell. The chemical structure of graphene gives it a good barrier effect. The corrosion-resistant layer is made of graphene, which can reduce the risk of electrolyte contact or reduce the amount of electrolyte in contact, thereby improving the safety performance of the battery cell and extending its service life.

[0026] In some embodiments of the first aspect of this application, the corrosion-resistant layer is configured to include a molecular sieve structure, wherein the pore size of the molecular sieve layer is less than or equal to 0.3 nm.

[0027] In one or more of the above optional embodiments, the material of the corrosion-resistant layer includes a molecular sieve with a pore size of less than or equal to 0.3 nm, which makes the corrosion-resistant layer have good barrier properties, reducing the risk of electrolyte contact with the outer casing or preventing electrolyte from contacting the outer casing, thereby reducing the risk of the outer casing being corroded or mitigating the degree of corrosion of the outer casing, improving the safety performance of the battery cell and extending the service life of the battery cell.

[0028] In some embodiments of the first aspect of this application, the battery cell is a hard-cased battery cell.

[0029] In one or more of the above optional embodiments, the outer casing of the hard-shell battery cell is generally made of hard metal. By providing a corrosion-resistant layer on the inner surface of the casing, the strength of the casing can be improved and the risk of the casing being corroded by the electrolyte can be reduced, thereby improving the safety of the hard-shell battery cell and extending its service life.

[0030] In some embodiments of the first aspect of this application, the shell is made of aluminum, the electrolyte comprises a fluorinated compound, and the corrosion-resistant layer is configured to include an aluminum fluoride structure.

[0031] In one or more of the above optional embodiments, the shell material includes aluminum, the electrolyte includes a fluorine-containing compound, and the corrosion-resistant layer is constructed to include an aluminum fluoride structure. The corrosion-resistant layer blocks the electrolyte and the shell, and the electrolyte will not react with the corrosion-resistant layer or the shell, thereby reducing the risk of electrolyte corrosion of the shell, improving the safety performance of the battery cell and extending the service life of the battery cell.

[0032] In some embodiments of the first aspect of this application, the shell material includes iron, the electrolyte includes a fluorine-containing compound, and the corrosion-resistant layer is configured to include an iron fluoride structure.

[0033] In one or more of the above optional embodiments, the shell material includes iron, the electrolyte includes a fluorine-containing compound, and the corrosion-resistant layer is constructed to include iron fluoride. The corrosion-resistant layer blocks the electrolyte and the shell, and the electrolyte will not react with the corrosion-resistant layer or the shell, thereby reducing the risk of electrolyte corrosion of the shell, improving the safety performance of the battery cell and extending the service life of the battery cell.

[0034] Secondly, embodiments of this application provide an electrical device, which includes the battery cell provided in any embodiment of the first aspect.

[0035] In one or more of the above optional embodiments, the battery cell provided in any embodiment of the first aspect has high safety performance, which is beneficial to improving the electrical safety of electrical equipment powered by the battery cell. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope.

[0037] Figure 1 Cross-sectional views of the battery cell provided in some embodiments of this application;

[0038] Figure 2 Cross-sectional views of the battery cell provided for other embodiments of this application;

[0039] Figure 3 A cross-sectional view of a battery cell provided in some embodiments of this application.

[0040] Icons: 100-cell; 10-casing; 11-inner surface of casing; 12-shell; 12'-first inner surface; 121-opening; 122-sidewall; 1221-inner surface of sidewall; 123-bottom wall; 1231-inner surface of bottom wall; 13-cover; 131-second inner surface; 20-electrode assembly; 21-positive electrode tab; 22-negative electrode tab; 30-terminal post; 40-current collector; 50-corrosion resistant layer; 51-first part; 52-second part. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] In the description of the embodiments of this application, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing this application and simplifying the description, and is 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, it should not be construed as a limitation on this application. Furthermore, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0045] Currently, judging from market trends, the application of battery cells is becoming increasingly widespread. Battery cells are widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in power tools, drones, energy storage devices, and many other fields. As the application areas of battery cells continue to expand, the market demand is also constantly increasing, and the requirements for battery cell safety are becoming increasingly stringent.

[0046] A battery cell consists of a casing, electrolyte, and electrode components. When the casing comes into contact with the electrolyte, it is easily corroded, which reduces the mechanical strength of the casing, thereby reducing the safety and lifespan of the battery cell.

[0047] Based on the above considerations, in order to improve the safety performance of the battery cell, this application provides a battery cell including a shell, an electrode assembly, and an electrolyte; the electrode assembly and the electrolyte are housed within the shell; the battery cell also includes a corrosion-resistant layer that covers at least a portion of the inner surface of the shell.

[0048] A corrosion-resistant layer is applied to the inner surface of the casing. This layer covers a portion of the inner surface of the casing and prevents the electrolyte from contacting the casing. This can alleviate or solve the problem of casing corrosion caused by contact between the casing and the electrolyte. The corrosion-resistant layer can also enhance the strength of the casing, improve the safety performance of the battery cell, and extend the service life of the battery cell.

[0049] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical equipment such as electric two-wheelers, power tools, drones, and energy storage devices. Battery cells conforming to the operating conditions of this application can also be used as the power supply system for electrical equipment.

[0050] This application provides an electrical device that uses battery cells as a power source. The electrical device can be, but is not limited to, electronic devices, power tools, electric vehicles, drones, and energy storage devices. Electronic devices can include mobile phones, tablets, laptops, etc.; power tools can include electric drills, chainsaws, etc.; and electric vehicles can include electric cars, electric motorcycles, electric bicycles, etc.

[0051] like Figure 1 As shown, this application embodiment provides a battery cell 100, which includes a housing 10 and an electrode assembly 20, with the electrode assembly 20 housed within the housing 10. The housing 10 forms a receiving space. The receiving space can be used to house the electrode assembly 20, electrolyte, etc. The housing 10 can be formed of a relatively soft material, such as an aluminum-plastic film or a steel-plastic film, to form a soft-pack battery cell. The housing 10 can also be a rigid shell, such as a steel shell or an aluminum shell, to form a rigid-shell battery cell.

[0052] The outer casing 10 can also contain electrolytes, etc.

[0053] The electrode assembly 20 includes a positive electrode, a negative electrode, and a separator. The separator insulatingly separates the positive and negative electrode to reduce the risk of short circuit in the cell 100. The separator may be made of materials such as PP (polypropylene) or PE (polyethylene).

[0054] The electrode assembly 20 can be a wound structure, in which a positive electrode, a separator, a negative electrode, and another separator are stacked in a certain order and then wound to form a wound electrode assembly; or, a separator, a positive electrode, another separator, and a negative electrode are stacked in a certain order and then wound to form a wound electrode assembly. The wound electrode assembly can be a flat wound electrode assembly.

[0055] The electrode assembly 20 can also be a stacked structure, with the positive electrode, separator, and negative electrode stacked in a certain order to form a stacked electrode assembly.

[0056] Please continue to refer to Figure 1 The electrode assembly 20 also includes a positive electrode tab 21 and a negative electrode tab 22, with the positive electrode tab 21 connected to the positive electrode plate and the negative electrode plate connected to the negative electrode tab 22.

[0057] In some embodiments, the battery cell 100 may further include a terminal post 30 disposed on the housing 10 and insulated from the housing 10. The terminal post 30 is used to electrically connect with the tabs of the electrode assembly 20 to input or output electrical energy of the battery cell 100.

[0058] The outer casing 10 can be provided with a terminal post 30. One of the positive electrode tabs 21 and 22 is electrically connected to the terminal post 30, and the other is electrically connected to the outer casing 10. Thus, the terminal post 30 and the outer casing 10 form two output sections of the battery cell 100 with opposite polarities. The terminal post 30 and the tab can be directly connected, for example, by welding. The terminal post 30 and the tab can also be indirectly connected, for example, through a current collector 40. The outer casing 10 and the tab can be directly connected, for example, by welding. The outer casing 10 and the tab can also be indirectly connected, for example, through a current collector 40. The current collector 40 can be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy. Figure 1 The diagram shows a case where the housing 10 is provided with a pole post 30, the positive pole tab 21 is electrically connected to the pole post 30, and the negative pole tab 22 is electrically connected to the housing 10.

[0059] The outer casing 10 can also be provided with two poles 30, then the positive pole tab 21 and the negative pole tab 22 are electrically connected to the two poles 30 respectively, and the two poles 30 and the outer casing 10 respectively form two output parts with opposite polarities of the battery cell 100.

[0060] Different models of battery cells may use different electrolytes. The electrolyte can be a fluorinated compound, such as LiTFS. i LiFSi, etc.

[0061] In this embodiment, the battery cell 100 further includes a corrosion-resistant layer 50, which covers at least a portion of the inner surface 11 of the casing. The corrosion-resistant layer 50, covering a portion of the inner surface 11 of the casing, can prevent the electrolyte from contacting the casing 10, thus mitigating or solving the problem of corrosion caused by contact between the casing 10 and the electrolyte. The corrosion-resistant layer 50 also enhances the strength of the casing 10, improving the safety performance of the battery cell 100 and extending its service life.

[0062] The corrosion-resistant layer 50 has strong corrosion resistance. The corrosion-resistant layer 50 can be a corrosion-resistant coating applied to the inner surface 11 of the outer casing, or it can be a thin film adhered to the inner surface 11 of the outer casing. The materials of the corrosion-resistant layer 50 include, but are not limited to, aluminum fluoride (AlF3), molecular sieves, graphene, and polymers.

[0063] In some embodiments, the corrosion-resistant layer 50 is configured to include an insulating material.

[0064] That is, the material of corrosion-resistant layer 50 is an insulating material.

[0065] The corrosion-resistant layer 50 is constructed to include insulating material, which reduces the risk of internal short circuits in the cell 100 and improves the safety performance of the cell 100.

[0066] Of course, in other embodiments, the corrosion-resistant layer 50 may also be configured to include a conductive material.

[0067] In some embodiments, the corrosion-resistant layer 50 is configured to include one or more materials selected from ceramics, molecular sieves, aluminum fluoride, iron fluoride, polymers, and graphene.

[0068] The material of the corrosion-resistant layer 50 includes one or more of the following: ceramics, molecular sieves, aluminum fluoride, iron fluoride, polymers, and graphene.

[0069] Ceramic has good wear and corrosion resistance. The corrosion-resistant layer 50 is made of ceramic, which reduces the risk of the outer shell 10 being corroded, improves the safety performance and reliability of the battery cell 100, and extends the service life of the battery cell 100.

[0070] Molecular sieves have good barrier properties. The corrosion-resistant layer 50 is made of molecular sieves, which can reduce the risk of electrolyte contact with the outer casing 10 or prevent electrolyte from contacting the outer casing 10, thereby reducing the risk of corrosion of the outer casing 10 or mitigating the degree of corrosion of the outer casing 10, improving the safety performance of the battery cell 100 and extending the service life of the battery cell 100.

[0071] Aluminum fluoride and iron fluoride have good chemical stability and corrosion resistance. The corrosion-resistant layer 50 is made of aluminum fluoride, which helps to reduce the risk of the outer casing 10 being corroded, improve the safety performance of the battery cell 100 and extend the service life of the battery cell 100.

[0072] The polymer has good corrosion resistance. The corrosion-resistant layer 50 is made of polymer, which can reduce the risk of electrolyte contact with the outer casing 10 or prevent electrolyte from contacting the outer casing 10, thereby reducing the risk of corrosion of the outer casing 10 or mitigating the degree of corrosion of the outer casing 10, improving the safety performance of the battery cell 100 and extending the service life of the battery cell 100.

[0073] The chemical structure of graphene gives it a good barrier effect. The corrosion-resistant layer 50 is made of graphene, which can reduce the risk of electrolyte contact or reduce the amount of electrolyte in contact, thereby improving the safety performance of the battery cell 100 and extending its service life.

[0074] The corrosion-resistant layer 50 is made to have better corrosion resistance by being constructed with one or more materials including ceramics, molecular sieves, aluminum fluoride, iron fluoride, polymers, and graphene.

[0075] For example, the outer casing 10 is made of aluminum, and the electrolyte includes a fluorinated compound. The electrolyte reacts with the outer casing 10 to form aluminum fluoride, causing the aluminum outer casing 10 to be corroded by the electrolyte. Therefore, the corrosion-resistant layer 50 can be constructed to include an aluminum fluoride structure. That is, in the embodiment where the outer casing 10 is made of aluminum and the electrolyte includes a fluorinated compound, the corrosion-resistant layer 50 can be made of aluminum fluoride. In this case, the corrosion-resistant layer 50 blocks the electrolyte from the outer casing 10, and the electrolyte will not react with the corrosion-resistant layer 50 or the outer casing 10, thereby preventing the electrolyte from corroding the outer casing 10, improving the safety performance of the battery cell 100, and extending the service life of the battery cell 100.

[0076] For example, if the outer casing 10 is made of iron and the electrolyte contains a fluorine-containing compound, the electrolyte reacts with the outer casing 10 to form iron fluoride, causing the iron outer casing 10 to corrode. Therefore, the corrosion-resistant layer 50 is constructed to include iron fluoride. That is, in embodiments where the outer casing 10 is made of iron and the electrolyte contains a fluorine-containing compound, the corrosion-resistant layer 50 can be made of iron fluoride. In this case, the corrosion-resistant layer 50 isolates the electrolyte from the outer casing 10, preventing the electrolyte from reacting with either the corrosion-resistant layer 50 or the outer casing 10. This avoids electrolyte corrosion of the outer casing 10, improves the safety performance of the battery cell 100, and extends the service life of the battery cell 100.

[0077] In embodiments where the corrosion-resistant layer 50 is configured to include a molecular sieve structure, the pore size of the molecular sieve layer is less than or equal to 0.3 nm.

[0078] The pore size of a molecular sieve refers to the diameter of its pore system. Molecular sieves have a pore size of 0.3 nm or less, and can block molecules with a diameter of less than 0.3 nm, such as water molecules.

[0079] For example, the pore size of the molecular sieve can be 0.02nm, 0.04nm, 0.06nm, 0.08nm, 0.1nm, 0.12nm, 0.14nm, 0.16nm, 0.18nm, 0.2nm, 0.22nm, 0.24nm, 0.26nm, 0.28nm, or 0.3nm.

[0080] The corrosion-resistant layer 50 is made of molecular sieves with a pore size of less than or equal to 0.3 nm, which gives the corrosion-resistant layer 50 good barrier properties. This reduces the risk of electrolyte contact with the outer casing 10 or prevents the electrolyte from contacting the outer casing 10, thereby reducing the risk of corrosion of the outer casing 10 or mitigating the degree of corrosion of the outer casing 10, improving the safety performance of the battery cell 100 and extending the service life of the battery cell 100.

[0081] The corrosion-resistant layer 50 can completely cover the inner surface 11 of the housing, or it can cover a portion of the inner surface 11 of the housing.

[0082] In some embodiments, the area of ​​the inner surface 11 of the housing is S, and the area of ​​the corrosion-resistant layer 50 covering the inner surface 11 of the housing is S1, where 0.8 ≤ S1 / S ≤ 1.

[0083] If the corrosion-resistant layer 50 can completely cover the inner surface 11 of the shell, then S1 / S = 1. In this way, the inner surface 11 of the shell is completely covered by the corrosion-resistant layer 50, and the risk of the shell 10 being corroded by the electrolyte is lower.

[0084] If the corrosion-resistant layer 50 covers part of the inner surface 11 of the housing, then S1 / S < 1. For example, if the corrosion-resistant layer 50 is made of an insulating material, the area where the housing 10 is directly connected to the tab or the current collector 40 may not be covered by the corrosion-resistant layer 50, which facilitates the electrical connection between the housing 10 and the tab.

[0085] For example, S1 / S can be 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1, etc.

[0086] By ensuring that S1 / S is greater than or equal to 0.8 and less than or equal to 1, the area covered by the corrosion-resistant layer 50 on the inner surface 11 of the casing is sufficiently large, thereby reducing the contact area between the casing 10 and the electrolyte or preventing the inner surface 11 of the casing from contacting the electrolyte. This reduces the risk of the casing 10 being corroded by the electrolyte or prevents the casing 10 from being corroded by the electrolyte, improves the safety performance of the battery cell 100, and extends the service life of the battery cell 100.

[0087] like Figure 1 As shown, in some embodiments, the outer casing 10 includes a housing 12 and a cover 13, the housing 12 forming a receiving space with an opening 121 at one end, and the cover 13 sealing the opening 121.

[0088] The housing 12 is a component used to house the electrode assembly 20 and the electrolyte. The housing 12 can be a hollow structure with an opening 121 at one end, or it can be a hollow structure with openings 121 at both opposite ends. The housing 12 can have various shapes, such as a cylinder or a cuboid. The electrode assembly 20 can be partially or completely located within the housing 12.

[0089] The cover 13 seals the opening 121 of the housing 12. Here, "sealing" refers to covering or closing, and can be either sealed or unsealed.

[0090] The cover 13 and the housing 12 together define a receiving space for accommodating the electrode assembly 20 and other components. The cover 13 can be connected to the housing 12 by welding, sealant bonding, or other methods to close the opening 121 of the housing 12. The shape of the cover 13 can be adapted to the shape of the housing 12. For example, if the housing 12 is a cuboid structure, the cover 13 can be a rectangular plate structure adapted to the housing 12; or if the housing 12 is a cylindrical structure, the cover 13 can be a circular plate structure adapted to the housing 12.

[0091] In an embodiment where the housing 12 has an opening 121 at one end, one cover 13 may be provided accordingly. In an embodiment where the housing 12 has openings 121 at opposite ends, two covers 13 may be provided accordingly, with the two covers 13 respectively closing the two openings 121 of the housing 12, and the two covers 13 and the housing 12 together defining the receiving space.

[0092] The pole post 30 can be disposed on the housing 12 of the outer casing 10, or on the cover 13 of the outer casing 10. For example... Figure 1 As shown, the pole post 30 is disposed on the cover 13.

[0093] In some embodiments, the inner surface 11 of the housing includes a first inner surface located on the housing 12, the first inner surface being provided with a corrosion-resistant layer 50, the corrosion-resistant layer 50 covering at least a portion of the first inner surface.

[0094] The corrosion-resistant layer 50 can completely cover the first inner surface, which can prevent the electrolyte from contacting the housing 12, thereby reducing the risk of the housing 12 being corroded by the electrolyte.

[0095] The corrosion-resistant layer 50 may also cover a portion of the first inner surface, such as the area where the housing 12 is directly connected to the tab or the area where the housing 12 is directly connected to the current collector 40. This allows the housing 12 to be connected to the tab or the current collector 40.

[0096] The first inner surface of the housing 12 is the main area in contact with the electrolyte. By covering at least a portion of the first inner surface with the corrosion-resistant layer 50, the risk of the housing 12 being corroded by the electrolyte can be reduced, thereby improving the safety performance of the cell 100 and extending the service life of the cell 100.

[0097] In some embodiments, the housing 12 includes a side wall 122 and a bottom wall 123. The side wall 122 surrounds the outer periphery of the bottom wall 123. One end of the side wall 122 is connected to the bottom wall 123, and the other end of the side wall 122 forms an opening 121.

[0098] The first inner surface includes an inner surface 1221 of the sidewall and an inner surface 1231 of the bottom wall, and the corrosion-resistant layer 50 covers at least a portion of the inner surface 1221 of the sidewall and at least a portion of the inner surface 1231 of the bottom wall.

[0099] The corrosion-resistant layer 50 may completely cover the inner surface 1221 of the sidewall, or it may cover a portion of the inner surface 1221 of the sidewall. The corrosion-resistant layer 50 may completely cover the inner surface 1231 of the bottom wall, or it may cover a portion of the inner surface 1231 of the bottom wall.

[0100] The inner surface 1221 of the side wall and the inner surface 1231 of the bottom wall are both covered by a corrosion-resistant layer 50, thereby reducing the risk of the casing 12 being corroded by the electrolyte, improving the safety performance of the battery cell 100 and extending the service life of the battery cell 100.

[0101] In some embodiments, the area of ​​the inner surface 1221 of the sidewall is S', and the area of ​​the corrosion-resistant layer 50 covering the inner surface 1221 of the sidewall is S2, where 0.8 ≤ S2 / S' ≤ 1.

[0102] If the corrosion-resistant layer 50 can completely cover the inner surface 1221 of the sidewall, then S2 / S' = 1. In this way, the inner surface 1221 of the sidewall is completely covered by the corrosion-resistant layer 50, and the risk of the outer shell 10 being corroded by the electrolyte is lower.

[0103] If the corrosion-resistant layer 50 covers part of the inner surface 1221 of the sidewall, then S2 / S' < 1.

[0104] For example, S2 / S' can be 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1, etc.

[0105] By ensuring that S2 / S' is greater than or equal to 0.8 and less than or equal to 1, the area covered by the corrosion-resistant layer 50 on the inner surface 1221 of the sidewall is sufficiently large, reducing the contact area between the sidewall 122 and the electrolyte or preventing the inner surface 1221 of the sidewall from contacting the electrolyte. This reduces the risk of corrosion of the sidewall 122 by the electrolyte or prevents the sidewall 122 from being corroded by the electrolyte, thereby improving the safety performance of the cell 100 and extending the service life of the cell 100.

[0106] like Figure 1 As shown, in some embodiments, the corrosion-resistant layer 50 includes a first portion 51 and a second portion 52, the first portion 51 covering at least a portion of the inner surface 1221 of the sidewall, and the second portion 52 covering at least a portion of the inner surface 1231 of the bottom wall.

[0107] The first part 51 may completely cover the inner surface 1221 of the sidewall, or it may cover a portion of the inner surface 1221 of the sidewall.

[0108] The second part 52 may completely cover the inner surface 1231 of the bottom wall, or it may cover a portion of the inner surface 1231 of the bottom wall.

[0109] The end of the first part 51 closest to the second part 52 can be connected to the second part 52, thus reducing the risk of electrolyte contacting the casing 12 through a gap between the first part 51 and the second part 52. Alternatively, the end of the first part 51 closest to the second part 52 can contact the second part 52 but is not connected to it.

[0110] The first part 51 is arranged circumferentially around the opening 121 around the outer periphery of the second part 52, and the end of the first part 51 facing away from the second part 52 forms an open end corresponding to the opening 121. The open end of the first part 51 can extend to be flush with the opening 121 end of the sidewall 122, which helps the first part 51 to completely cover the inner surface 1221 of the sidewall. Of course, the open end of the first part 51 can also be closer to the bottom wall 123 than the opening 121 end of the sidewall 122.

[0111] like Figure 2 , Figure 3 As shown, in some embodiments, the inner surface 11 of the outer casing also includes a second inner surface 131 located on the cover 13, and the second inner surface 131 is provided with a corrosion-resistant layer 50.

[0112] like Figure 2 As shown, the corrosion-resistant layer 50 can completely cover the second inner surface 131, which can prevent the electrolyte from contacting the housing 12, thereby reducing the probability of the housing 12 being corroded by the electrolyte.

[0113] like Figure 3 As shown, the corrosion-resistant layer 50 can also cover a portion of the second inner surface 131. For example, the area where the end cap is directly connected to the housing 12 may not be covered by the corrosion-resistant layer 50 to facilitate the connection between the end cap and the housing 12. Of course, the second inner surface 131 can also be an area that will directly contact the electrolyte and be covered by the corrosion-resistant layer 50.

[0114] The corrosion-resistant layer 50 covers at least a portion of the second inner surface 131 of the end cap, which can reduce the risk of the end cap being corroded by the electrolyte, improve the safety performance of the cell 100 and extend the service life of the cell 100.

[0115] In some embodiments, the thickness of the corrosion-resistant layer 50 is 1 nm to 5 μm.

[0116] The corrosion-resistant layer 50 can be of uniform thickness, meaning that the thickness of the corrosion-resistant layer 50 is the same at any location.

[0117] The corrosion-resistant layer 50 can also be a non-uniform thickness structure. The thickness of the corrosion-resistant layer 50 at any position is 1nm to 5μm. The minimum thickness of the corrosion-resistant layer 50 is not less than 1nm and the maximum thickness is not more than 5μm. Figures 1-3 The thickness of the corrosion-resistant layer 50 at one location is shown to be H1, where 1 nm ≤ H1 ≤ 5 μm.

[0118] For example, the thickness of the corrosion-resistant layer 50 can be 1 μm, 100 μm, 500 μm, 700 μm, 900 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc.

[0119] The corrosion-resistant layer 50 has a thickness greater than or equal to 1 nm, resulting in a relatively large thickness and good strength and corrosion resistance. This improves the strength of the outer casing 10 and reduces the risk of corrosion, thus enhancing the safety performance of the battery cell 100. Conversely, if the corrosion-resistant layer 50 has a thickness less than or equal to 5 μm, it reduces the space occupied by the corrosion-resistant layer 50 within the outer casing 10, mitigating the problem of reduced energy density in the battery cell 100 caused by the corrosion-resistant layer 50. This allows the battery cell 100 to possess a higher energy density. Therefore, the thickness of the corrosion-resistant layer 50 is typically between 1 nm and 5 μm, resulting in both high energy density and good safety performance for the battery cell 100.

[0120] In embodiments where the cell 100 is a hard-shell cell, the outer shell 10 of the hard-shell cell 100 is generally made of hard metal. By providing a corrosion-resistant layer 50 on the inner surface 11 of the outer shell, the strength of the outer shell 10 can be improved and the risk of the outer shell 10 being corroded by the electrolyte can be reduced, thereby improving the safety of the hard-shell cell 100 and extending its service life.

[0121] This application also provides an electrical device, which includes the battery cell 100 provided in any of the above embodiments.

[0122] Cell 100 provides power to electrical equipment.

[0123] The battery cell 100 provided in any of the above embodiments has high safety performance, which is beneficial to improving the electrical safety of electrical equipment powered by the battery cell 100.

[0124] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art.

Claims

1. An electric cell, characterized by, include: shell; The electrode assembly and electrolyte are housed within the housing; The battery cell further includes a corrosion-resistant layer that covers at least a portion of the inner surface of the outer casing.

2. The battery cell according to claim 1, characterized in that, The area of ​​the inner surface of the outer shell is S, and the area of ​​the corrosion-resistant layer covering the inner surface of the outer shell is S1, where 0.8 ≤ S1 / S ≤ 1.

3. The battery cell according to claim 1, characterized in that, The outer casing includes a shell and a cover, the shell forming a receiving space with an opening at one end, and the cover sealing the opening; The inner surface of the housing includes a first inner surface located on the housing, the first inner surface being provided with the corrosion-resistant layer, the corrosion-resistant layer covering at least a portion of the first inner surface.

4. The battery cell according to claim 3, characterized in that, The housing includes a sidewall and a bottom wall, the first inner surface includes the inner surface of the sidewall and the inner surface of the bottom wall, and the corrosion-resistant layer covers at least a portion of the inner surface of the sidewall and at least a portion of the inner surface of the bottom wall.

5. The battery cell according to claim 4, characterized in that, The corrosion-resistant layer includes a first part and a second part. The first part covers at least a portion of the inner surface of the sidewall, and the second part covers at least a portion of the inner surface of the bottom wall. The first part is disposed around the outer periphery of the second part along the circumference of the opening and is connected to the second part. One end of the first part opposite to the second part forms an open end corresponding to the opening.

6. The battery cell according to claim 4, characterized in that, The area of ​​the inner surface of the sidewall is S', and the area of ​​the inner surface of the sidewall covered by the corrosion-resistant layer is S2, where 0.8 ≤ S2 / S' ≤ 1.

7. The battery cell according to claim 3, characterized in that, The corrosion-resistant layer completely covers the first inner surface.

8. The battery cell according to claim 3, characterized in that, The inner surface of the outer shell also includes a second inner surface located on the cover, and the second inner surface is provided with the corrosion-resistant layer.

9. The battery cell according to any one of claims 1-8, characterized in that, The thickness of the corrosion-resistant layer is 1 nm to 5 μm.

10. The battery cell according to any one of claims 1-8, characterized in that, The corrosion-resistant layer is configured to include an insulating material.

11. The battery cell according to any one of claims 1-8, characterized in that, The corrosion-resistant layer is constructed as a structure comprising one or more materials including ceramics, molecular sieves, aluminum fluoride, iron fluoride, polymers, and graphene layers.

12. The battery cell according to claim 11, characterized in that, The corrosion-resistant layer is configured to include a molecular sieve structure, wherein the pore size of the molecular sieve layer is less than or equal to 0.3 nm.

13. The battery cell according to any one of claims 1-8, characterized in that, The battery cell is a hard-shell battery cell.

14. The battery cell according to claim 13, characterized in that, The outer casing is made of aluminum, the electrolyte includes a fluorine-containing compound, and the corrosion-resistant layer is configured to include an aluminum fluoride structure.

15. The battery cell according to claim 13, characterized in that, The outer casing is made of iron, the electrolyte includes a fluorine-containing compound, and the corrosion-resistant layer is configured to include an iron fluoride structure.

16. An electrical appliance, characterized in that, Includes the battery cell according to any one of claims 1-15.

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