Battery, battery module and electric equipment

Abstract

The invention discloses a battery, a battery module and electric equipment. The battery comprises a shell, an electrode assembly, an end cover, an anti-explosion sheet and a protective layer, the housing has a housing opening. The electrode assembly is housed within the case. The end cover is connected to the shell and covers the opening of the shell. The anti-explosion piece is arranged on the end cover. The protection layer is connected to the surface of the explosion-proof sheet, and at least part of the protection layer is arranged on the side, back to the electrode assembly, of the explosion-proof sheet. And the protective layer can prevent external liquid or other impurities from directly contacting at least part of the explosion-proof sheet, so that the possibility that the explosion-proof sheet is corroded and damaged is reduced, the sealing performance of the battery is improved, the electrolyte leakage risk is reduced, and the reliability and safety performance of the battery are improved.

Description

Technical Field

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

[0002] Rechargeable batteries are batteries that can be recharged to activate the active materials after being discharged and continue to be used. Rechargeable batteries are widely used in electronic devices such as mobile phones, laptops, drones, etc.

[0003] Since batteries need to be used in multiple scenarios and multiple working conditions, how to improve the safety performance of batteries has always been a research direction in the industry. Summary of the invention

[0004] The present application provides a battery, a battery module and an electrical device, which can improve the performance of the battery.

[0005] In a first aspect, the present application provides a battery, comprising a shell, an electrode assembly, an end cap, an explosion-proof disc and a protective layer. The shell has a shell opening. The electrode assembly is accommodated in the shell. The end cap is connected to the shell and covers the shell opening. The explosion-proof disc is arranged on the end cap. The protective layer is connected to the surface of the explosion-proof disc, and at least part of the protective layer is arranged on the side of the explosion-proof disc facing away from the electrode assembly. The protective layer can prevent external liquid or other impurities from directly contacting at least part of the explosion-proof disc, reduce the possibility of corrosion damage to the explosion-proof disc, and help improve the sealing performance of the battery, reduce the risk of electrolyte leakage, and improve the reliability and safety performance of the battery.

[0006] In one or more optional embodiments above, the protective layer includes a first protective layer and a second protective layer, and the second protective layer is arranged between the explosion-proof disk and the first protective layer. The first protective layer and the second protective layer form a stacked structure, which can play a role of double-layer protection, which is beneficial to improving corrosion resistance and protection effect. In addition, the first protective layer and the second protective layer can be made of materials with different corrosion resistance, different structural strength and / or different density, which is beneficial to reducing the influence of the protective layer on the performance of the explosion-proof disk on the basis of improving the protection effect.

[0007] In one or more optional embodiments above, the thickness of the first protective layer is greater than the thickness of the second protective layer. The first protective layer is equivalent to the external protective layer, and the second protective layer is equivalent to the internal protective layer. The first protective layer as the external protective layer has a thicker thickness, which is beneficial to improving the protection effects such as corrosion resistance and anti-damage.

[0008] In one or more of the above optional embodiments, the first protective layer has better salt water corrosion resistance than the second protective layer. The first protective layer has better salt water corrosion resistance, which can slow down the corrosion rate of the first protective layer, reduce the risk of corrosion of the second protective layer, and help improve the protective effect of the protective layer.

[0009] In one or more optional embodiments above, the first protective layer includes a cobalt-tungsten alloy coating, and the second protective layer includes a silver coating. The cobalt-tungsten alloy material has extremely strong corrosion resistance, and its corrosion resistance grade is a very corrosion-resistant material, and the corrosion rate is low, which is conducive to reducing the risk of corrosion of the second protective layer and improving the protective effect of the protective layer. The silver material has relatively good corrosion resistance and good ductility, and can be used as the second layer of protection of the explosion-proof disk, which is conducive to improving the protective effect and the connection stability of the second protective layer.

[0010] In one or more of the above optional embodiments, the protective layer further includes a first connecting layer, the first connecting layer is located between the first protective layer and the second protective layer, and the first connecting layer connects the first protective layer and the second protective layer; and / or, the protective layer further includes a second connecting layer, the second connecting layer is located between the second protective layer and the explosion-proof disk, and the second connecting layer connects the second protective layer and the explosion-proof disk. The first connecting layer can increase the bonding force between the first protective layer and the second protective layer, improve the connection strength and stability, reduce the risk of the first protective layer falling off from the second protective layer, and help the protective layer to stably perform the best protective function. The second connecting layer can play a transition role, and the second connecting layer can be made of a material that is compatible with both the second protective layer and the explosion-proof disk, which is not only conducive to improving the connection strength between the second protective layer and the explosion-proof disk, but also conducive to reducing the stress generated on the explosion-proof disk during the electroplating process, and reducing the influence of the setting of the protective layer on the structural strength of the explosion-proof disk.

[0011] In one or more optional embodiments above, the protective layer includes a first protective layer, a first connecting layer, a second protective layer and a second connecting layer which are stacked, and the second connecting layer is connected to the explosion-proof disk; the first protective layer includes a cobalt-tungsten alloy plating layer, the second protective layer includes a silver plating layer, the first connecting layer includes a gold plating layer, and the second connecting layer includes a copper plating layer. The protective layer with the above four-layer structure is generally detected to be a very corrosion-resistant material with better corrosion resistance.

[0012] In one or more optional embodiments above, the thickness of the protective layer is 50 μm-500 μm. The protective layer has strong corrosion resistance and good protection effect, and will not affect the overturning and explosion of the explosion-proof disk due to excessive structural strength, which is conducive to improving the reliability of the battery.

[0013] In one or more optional embodiments above, the explosion-proof disc includes a weak portion, and at least a portion of the protective layer is disposed on a side of the weak portion facing away from the electrode assembly and covers the weak portion. The protective layer covers the weak portion, which can prevent external liquid or other impurities from directly contacting the weak portion, reduce the possibility of the weak portion being corroded and damaged, and is conducive to improving the sealing performance of the battery, reducing the risk of electrolyte leakage, and improving the reliability and safety performance of the battery.

[0014] In one or more of the above optional embodiments, the end cap is provided with a first opening; at least part of the explosion-proof disc is located on the side of the end cap facing the electrode assembly, and the explosion-proof disc closes the first opening; the end cap and the electrode assembly are arranged along a first direction; along the first direction, at least part of the protective layer is located between the weak portion and the first opening. The protective layer can separate the weak portion from the first opening, thereby shielding the liquid or other impurities entering the inner side of the end cap through the first opening, reducing the possibility of the liquid or other impurities corroding or damaging the weak portion, and helping to reduce the risk of electrolyte leakage.

[0015] In one or more optional embodiments above, along the first direction, the projection of the first opening is located within the projection of the protective layer. Along the first direction, the protective layer can completely cover the first opening. The protective layer has a large protective area, which can block as much liquid or other impurities as possible from entering the inner side of the end cover through the first opening, reduce the possibility of liquid or other impurities contacting the explosion-proof disk, and help further improve the protective effect of the protective layer.

[0016] In one or more of the above optional embodiments, a concave portion is provided on the side of the explosion-proof disc facing away from the electrode assembly, and the protective layer covers the wall surface of the concave portion formed by the explosion-proof disc; the concave portion is provided corresponding to the weak portion. The protective layer covers the concave portion, which can prevent liquid or other impurities from accumulating in the concave portion, and reduce the possibility of the weak portion being corroded and damaged.

[0017] In one or more of the above optional embodiments, the explosion-proof disk includes a connecting portion, the connecting portion is connected to the end cover, and no protective layer is provided between the connecting portion and the end cover. The current can be directly transmitted between the connecting portion and the end cover without passing through the protective layer, which is conducive to reducing the current resistance and improving the current carrying capacity. Moreover, the total thickness of the connecting portion and the end cover after being connected can also be reduced, saving space.

[0018] In one or more of the above optional embodiments, the battery is a cylindrical battery.

[0019] In one or more optional embodiments above, the battery is a cylindrical battery; the shell includes a bottom wall and a side wall, the side wall includes a side wall body and a bending portion, the side wall body is connected to the bottom wall, and the bending portion extends from one end of the side wall body away from the bottom wall and bends toward the axis of the battery; the end cover and the bottom wall are arranged along a first direction, the side wall is insulated and connected to the end cover, and in the first direction, part of the bending portion is located on the side of the end cover facing away from the bottom wall; the shell and the end cover have different polarities. The battery also includes an insulating film and an insulating member, the insulating film is sleeved on the shell, and a part of the insulating film covers the bending portion in the first direction; in the first direction, at least part of the insulating member is arranged between the bending portion and the insulating film. The insulating member and the insulating film can play a dual insulating isolation effect. After the insulating film is damaged due to corrosion, scratches or other reasons, the insulating isolation between the bending portion and the external structure can still be achieved through the insulating member, which is conducive to further reducing the short circuit risk of the battery.

[0020] In one or more optional embodiments above, the electrode assembly includes a first electrode terminal and a second electrode terminal with opposite polarities, the first electrode terminal is connected to the shell, and the second electrode terminal is connected to the end cap.

[0021] In a second aspect, the present application provides a battery module, which includes a plurality of batteries provided according to any embodiment of the first aspect.

[0022] In a third aspect, the present application provides an electrical device, which includes a battery module provided in any embodiment of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram of the structure of a battery provided in some embodiments of the present application;

[0025] Figure 2 for Figure 1 A schematic cross-sectional view of the battery shown;

[0026] Figure 3 for Figure 1 A schematic cross-sectional view of the end cap, explosion-proof plate and related structures of the battery shown;

[0027] Figure 4 for Figure 2 A schematic diagram of the enlarged structure of the middle area A;

[0028] Figure 5 for Figure 4 A schematic diagram of the enlarged structure of the middle area B;

[0029] Figure 6 for Figure 1 A schematic cross-sectional view of a partial structure of an explosion-proof plate and a protective layer of the battery shown;

[0030] Figure 7 A schematic diagram of the structure of a battery module provided in some embodiments of the present application;

[0031] Figure 8 for Figure 7 A schematic cross-sectional view of a battery module shown;

[0032] Fig. 9 for Figure 8 Schematic diagram of the enlarged structure of the middle area C;

[0033] Fig.10 A schematic diagram of the structure of electrical equipment provided in some embodiments of the present application.

[0034] The reference numerals of the specific embodiments are as follows:

[0035] Battery 1, shell 10, shell opening 11, bottom wall 12, side wall 13, side wall body 131, bending portion 132, electrode assembly 20, first electrode end 21, second electrode end 22, end cap 30, first opening 31, explosion-proof disk 40, weak portion 41, connecting portion 42, pressure relief portion 43, recess 44, wall surface 45, protective layer 50, first protective layer 51, second protective layer 52, first connecting layer 53, second connecting layer 54, insulating film 60, insulating member 70, insulating body 71, limiting portion 72, first limiting portion 721, second limiting portion 722, insulating gasket 80, axis a, first direction X;

[0036] Busbar 2, main body 201, first recess 2011, first connection part 202, second connection part 203;

[0037] Bracket 3, second opening 301;

[0038] Battery module 100;

[0039] 1000 electrical equipment. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions 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 only part of the embodiments of the present application, not all of the embodiments.

[0041] The terms "first", "second", "third", 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. In the embodiments of this 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.

[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 "installation", "connection", etc. 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 components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] 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, "vertical" also includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering. For example, if the angle between two directions is 85°-95°, the two directions can be considered to be perpendicular; if the angle between two directions is 0°-10°, the two directions can be considered to be parallel.

[0045] The battery, battery module and electrical equipment of the present application are described below with reference to the accompanying drawings.

[0046] Reference Figures 1 to 9 An embodiment of the present application provides a battery 1, which may be a lithium-ion battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, or other types of batteries.

[0047] The battery 1 can be a square battery, a cylindrical battery or other special-shaped batteries. Optionally, the battery 1 can be a cylindrical battery, for example, the battery 1 can be a 21700 battery, a 18650 battery, a 46800 battery, a 49480 battery or other types of cylindrical batteries.

[0048] In some embodiments, the battery 1 is a secondary battery. After being discharged, the secondary battery can be charged to activate the active material and continue to be used.

[0049] The battery 1 provided in the embodiment of the present application includes a housing 10. The housing 10 has a housing opening 11. When the battery 1 is a cylindrical battery, the housing opening 11 may be provided at one end of the battery 1 along its own axis.

[0050] In some embodiments, the battery 1 further includes an electrode assembly 20 , which is accommodated in the housing 10 .

[0051] In some embodiments, the electrode assembly 20 includes a first electrode sheet and a second electrode sheet with opposite polarities. During the charge and discharge process of the battery 1, active ions (such as lithium ions) are inserted and removed back and forth between the first electrode sheet and the second electrode sheet. One of the first electrode sheet and the second electrode sheet is a positive electrode sheet, and the other is a negative electrode sheet.

[0052] In some embodiments, the electrode assembly 20 includes a diaphragm disposed between the first electrode sheet and the second electrode sheet, and the diaphragm insulates the first electrode sheet from the second electrode sheet. The diaphragm is provided to reduce the risk of short circuit between the positive and negative electrode sheets, and allows active ions to pass through.

[0053] In some embodiments, the first electrode sheet includes a first electrode sheet body and a first electrode terminal 21, and the second electrode sheet includes a second electrode sheet body and a second electrode terminal 22. The first electrode sheet body includes a first current collector and a first active material layer coated on the surface of the first current collector, and the first electrode terminal 21 is connected to the first current collector. The second electrode sheet body includes a second current collector and a second active material layer coated on the surface of the second current collector, and the second electrode terminal 22 is connected to the second current collector. The polarities of the first electrode terminal 21 and the second electrode terminal 22 are opposite, and one of the first electrode terminal 21 and the second electrode terminal 22 is a positive electrode ear, and the other is a negative electrode ear.

[0054] In some embodiments, the battery 1 further includes an end cover 30 , which is connected to the housing 10 and covers the housing opening 11 .

[0055] The end cap 30 can close the housing opening 11, thereby forming a relatively closed accommodation space between the housing 10 and the end cap 30. The housing 10 and the end cap 30 can encapsulate components such as the electrode assembly 20 and the electrolyte.

[0056] In some embodiments, the material of the housing 10 and the end cap 30 can be steel, aluminum, composite metal or other conductive materials. The material of the housing 10 and the end cap 30 can be the same or different.

[0057] In some embodiments, the battery 1 further includes an explosion-proof piece 40 , which is disposed on the end cover 30 .

[0058] When the gas pressure inside the battery 1 exceeds the upper limit that the explosion-proof plate 40 can withstand, the gas pressure inside the battery 1 can cause the explosion-proof plate 40 to flip and explode away from the electrode assembly 20, thereby achieving the purpose of power off and pressure relief, which is beneficial to reduce the risk of explosion of the battery 1 due to excessive internal gas pressure and improve the safety performance of the battery 1.

[0059] In some embodiments, at least a portion of the explosion-proof disc 40 may be located between the end cap 30 and the electrode assembly 20. For example, the explosion-proof disc 40 may be located entirely between the end cap 30 and the electrode assembly 20, or only a portion of the explosion-proof disc 40 may be located between the end cap 30 and the electrode assembly 20, and another portion of the explosion-proof disc 40 may be bent toward the end cap 30 away from the outer side of the electrode assembly 20 to cover the edge of the end cap 30, which is beneficial to improve the connection strength and reliability between the explosion-proof disc 40 and the end cap 30.

[0060] In other embodiments, the explosion-proof disc 40 may also be located on the side of the end cap 30 away from the electrode assembly 20. For example, the end cap 30 may be provided with an opening, and the explosion-proof disc 40 is connected to the end cap 30 on the side of the end cap 30 away from the electrode assembly 20 and covers the opening.

[0061] In some embodiments, the burst disk 40 may be connected to the end cap 30 by welding, riveting, bonding or other suitable means.

[0062] In other embodiments, the end cap 30 and the bursting disk 40 may be integrally formed.

[0063] In some embodiments, the battery 1 further includes a protective layer 50 , which is connected to the surface of the explosion-proof disc 40 , and at least a portion of the protective layer 50 is disposed on a side of the explosion-proof disc 40 that faces away from the electrode assembly 20 .

[0064] In some embodiments, the protective layer 50 may be a single-layer structure; the protective layer 50 may also be a multi-layer stacked structure, and the materials of the layers of the protective layer 50 may be the same or different.

[0065] In some embodiments, the protective layer 50 may include corrosion-resistant materials to enhance its protective effect.

[0066] In some embodiments, the protective layer 50 may be connected to the surface of the explosion-proof disk 40 by electroplating, chemical plating, bonding or other suitable methods.

[0067] In some embodiments, the protective layer 50 may be disposed on a side of the explosion-proof disk 40 that is away from the electrode assembly 20 , or may be disposed on both sides of the explosion-proof disk 40 at the same time.

[0068] In some examples, the protective layer 50 may only cover a portion of the bursting disk 40. For example, the bursting disk 40 may include a weak structure, and the protective layer 50 covers the weak structure. In other examples, the protective layer 50 may also cover the entire bursting disk 40.

[0069] The protective layer 50 can prevent external liquid or other impurities from directly contacting at least part of the explosion-proof plate 40, reducing the possibility of corrosion and damage to the explosion-proof plate 40, which is beneficial to improving the sealing performance of the battery 1, reducing the risk of electrolyte leakage, and improving the reliability and safety performance of the battery 1.

[0070] In some embodiments, the bursting disc 40 includes a weak portion 41. The weak portion 41 is a portion of the bursting disc 40 that is easily broken, and the bursting disc 40 can release pressure through the breaking of the weak portion 41.

[0071] Optionally, compared with other parts of the bursting disk 40 , the thickness of the weak portion 41 is thinner, so that the weak portion 41 is easier to rupture than other parts.

[0072] In some embodiments, the explosion-proof disc 40 further includes a connecting portion 42 and a pressure relief portion 43. The connecting portion 42 is connected to the end cover 30. The connecting portion 42 is arranged along the outer periphery of the weak portion 41, and the weak portion 41 connects the pressure relief portion 43 and the connecting portion 42. At least part of the connecting portion 42 is located outside the weak portion 41 away from the pressure relief portion 43, so as to facilitate connection with the end cover 30.

[0073] Exemplarily, the weak portion 41 may be an arc-shaped structure arranged on the periphery of the pressure relief portion 43, and the two ends of the weak portion 41 are not connected to form a non-enclosed structure. The connecting line between the two ends of the weak portion 41 and the weak portion 41 together enclose the pressure relief portion 43. The weak portion 41 is located radially outside of part of the pressure relief portion 43, a part of the connecting portion 42 is located radially outside of the weak portion 41, and another part of the connecting portion 42 is directly connected to the pressure relief portion 43. Optionally, the central angle corresponding to the weak portion 41 may be 270° to 360°.

[0074] As another example, the weak portion 41 may also be in a closed ring shape, the connecting portion 42 surrounds the weak portion 41, and the weak portion 41 surrounds the pressure relief portion 43. The weak portion 41 is located between the connecting portion 42 and the pressure relief portion 43.

[0075] In some embodiments, at least a portion of the protection layer 50 is disposed on a side of the weak portion 41 facing away from the electrode assembly 20 and covers the weak portion 41 .

[0076] The protective layer 50 may be entirely disposed on the side of the weak portion 41 facing away from the electrode assembly 20, or only a portion of the protective layer 50 may be disposed on the side of the weak portion 41 facing away from the electrode assembly 20, and another portion of the protective layer 50 may, for example, be disposed on the side of the weak portion 41 facing the electrode assembly 20, and another portion of the protective layer 50 may, for example, also be disposed on the pressure relief portion 43 and / or the connecting portion 42.

[0077] In some embodiments, a portion of the protective layer 50 may be disposed on the side of the pressure relief portion 43 facing away from the electrode assembly 20 and cover at least a portion of the pressure relief portion 43. Optionally, the protective layer 50 may cover the entirety of the weak portion 41 and the pressure relief portion 43 to improve the protective effect.

[0078] In some embodiments, a portion of the protective layer 50 may be disposed on a side of the connection portion 42 facing away from the electrode assembly 20 and cover at least a portion of the connection portion 42. For example, the protective layer 50 may cover a portion of the connection portion 42 that is directly connected to the weak portion 41 or the pressure relief portion 43 and is not connected to the end cap 30.

[0079] In some embodiments, at least a portion of the protective layer 50 may be connected to the surface of the weak portion 41 facing away from the electrode assembly 20, or may be spaced apart from the surface of the weak portion 41 facing away from the electrode assembly 20, as long as the protective layer 50 can cover the weak portion 41 along the arrangement direction of the end cover 30 and the electrode assembly 20.

[0080] The weak portion 41 is the weakest structure of the explosion-proof disc 40 and is most susceptible to corrosion and damage by external liquid or impurities. The protective layer 50 covers the weak portion 41, which can prevent external liquid or other impurities from directly contacting the weak portion 41, reduce the possibility of corrosion and damage to the weak portion 41, and is conducive to improving the sealing performance of the battery 1, reducing the risk of electrolyte leakage, and improving the reliability and safety performance of the battery 1.

[0081] In some embodiments, the end cap 30 is provided with a first opening 31 . At least a portion of the explosion-proof disk 40 is located on a side of the end cap 30 facing the electrode assembly 20 , and the explosion-proof disk 40 closes the first opening 31 .

[0082] The first opening 31 can penetrate the end cover 30 along the thickness direction of the end cover 30. A portion of the explosion-proof disc 40 is exposed on the side of the end cover 30 facing away from the electrode assembly 20 through the first opening 31. The first opening 31 can reduce the blocking effect of the end cover 30 on the explosion-proof disc 40, which is conducive to the flipping of the explosion-proof disc 40.

[0083] A thickness direction of the end cap 30 may be parallel to an arrangement direction of the electrode assembly 20 and the end cap 30 .

[0084] In some embodiments, the end cap 30 and the electrode assembly 20 are disposed along the first direction X, and along the first direction X, at least a portion of the protective layer 50 is located between the weak portion 41 and the first opening 31 .

[0085] Along the first direction X, the first opening 31 and the weak portion 41 are arranged opposite to each other, and the weak portion 41 can be exposed on the side of the end cover 30 facing away from the electrode assembly 20 through the first opening 31. In the first direction X, the end cover 30 does not cover the weak portion 41. When the gas pressure inside the battery 1 exceeds the upper limit that the explosion-proof plate 40 can withstand, the gas pressure inside the battery 1 can directly act on the weak portion 41, which is conducive to the high-pressure gas breaking through the weak portion 41, thereby achieving the purpose of rapid power off and pressure relief.

[0086] Optionally, along the first direction X, the pressure relief portion 43 and the first opening 31 are arranged opposite to each other, and the pressure relief portion 43 can be exposed on the side of the end cover 30 facing away from the electrode assembly 20 through the first opening 31. In the first direction X, the end cover 30 also does not block the pressure relief portion 43. When the gas pressure inside the battery 1 exceeds the upper limit that the explosion-proof disc 40 can withstand, the gas inside the battery 1 can directly act on the pressure relief portion 43, which is conducive to the pressure relief portion 43 turning away from the electrode assembly 20.

[0087] The protective layer 50 may be entirely located between the weak portion 41 and the first opening 31 , or only a portion of the protective layer 50 may be located between the weak portion 41 and the first opening 31 , and another portion of the protective layer 50 may be located, for example, between the pressure relief portion 43 and the first opening 31 or at other suitable locations.

[0088] The protective layer 50 can separate the weak portion 41 from the first opening 31, thereby blocking the liquid or other impurities that enter the inner side of the end cover 30 through the first opening 31, reducing the possibility of the liquid or other impurities corroding or damaging the weak portion 41, and helping to reduce the risk of electrolyte leakage.

[0089] In some embodiments, along the first direction X, a projection of the first opening 31 is located within a projection of the protective layer 50 .

[0090] The projection of the first opening 31 along the first direction X refers to a region surrounded by the projection of the periphery of the first opening 31 along the first direction X.

[0091] Along the first direction X, the protective layer 50 can completely cover the first opening 31. The protective layer 50 has a large protective area, and can block as much liquid or other impurities as possible from entering the inner side of the end cover 30 through the first opening 31, thereby reducing the possibility of liquid or other impurities contacting the explosion-proof disk 40, which is conducive to further improving the protective effect of the protective layer 50.

[0092] In some embodiments, a concave portion 44 is provided on the side of the explosion-proof disc 40 facing away from the electrode assembly 20, and the protective layer 50 covers the wall surface 45 of the explosion-proof disc 40 that forms the concave portion 44. The concave portion 44 is provided corresponding to the weak portion 41. That is, the portion of the explosion-proof disc 40 corresponding to the concave portion 44 forms the weak portion 41.

[0093] The recess 44 may be recessed in the direction close to the electrode assembly 20 on the surface of the pressure relief portion 43 and the connection portion 42 facing away from the electrode assembly 20. Optionally, the recess 44 may be in the form of a notch, a pit, a groove, or the like.

[0094] The provision of the recess 44 makes the thickness of the weak portion 41 thinner than the thickness of other portions of the explosion-proof plate 40 , which is conducive to the weak portion 41 being ruptured first under the action of the gas pressure in the battery 1 .

[0095] The protective layer 50 may be connected to the wall surface 45 of the explosion-proof disk 40 that forms the recess 44. In some examples, the wall surface 45 may include a bottom surface and two side surfaces, and the bottom surface is connected between the two side surfaces. The bottom surface may be a curved surface, and the side surfaces may be flat or curved surfaces. In other examples, the wall surface 45 may also include only two side surfaces, one end of the two side surfaces is directly connected, and the side surfaces may be flat or curved surfaces.

[0096] The recess 44 is located on the side of the explosion-proof disc 40 facing away from the electrode assembly 20. Compared with other parts of the explosion-proof disc 40, liquid and other impurities are more likely to accumulate in the recess 44, causing the weak portion 41 corresponding to the recess 44 to be corroded at a faster rate. The protective layer 50 covers the recess 44, which can prevent liquid or other impurities from accumulating in the recess 44 and reduce the possibility of the weak portion 41 being corroded and damaged.

[0097] In some embodiments, the connection portion 42 is connected to the end cover 30 , and no protective layer 50 is disposed between the connection portion 42 and the end cover 30 .

[0098] Optionally, the projection of the connecting portion 42 and the projection of the protective layer 50 are separated along the first direction X. The protective layer 50 may only cover the weak portion 41 , or the protective layer 50 may only cover the weak portion 41 and at least part of the pressure relief portion 43 .

[0099] In some examples, the connection portion 42 can be connected to the end cap 30 by welding, riveting, bonding or other suitable methods. No protective layer 50 is provided between the connection portion 42 and the end cap 30, which can reduce the total thickness of the connection portion 42 and the end cap 30 after connection, saving space.

[0100] In some examples, the connection portion 42 may be electrically connected to the end cap 30, the explosion-proof disc 40 may be electrically connected to the second electrode terminal 22 of the electrode assembly 20, and the end cap 30 may serve as one of the electrode terminals of the battery 1. No protective layer 50 is provided between the connection portion 42 and the end cap 30, and the current may be directly transmitted between the connection portion 42 and the end cap 30 without passing through the protective layer 50, which is conducive to reducing the current resistance and improving the current carrying capacity.

[0101] In some embodiments, the protective layer 50 includes a first protective layer 51 and a second protective layer 52 , and the second protective layer 52 is disposed between the bursting disk 40 and the first protective layer 51 .

[0102] The second protective layer 52 may be directly connected to the explosion-proof disk 40 , and other layer structures may be disposed between the second protective layer 52 and the explosion-proof disk 40 .

[0103] The first protective layer 51 and the second protective layer 52 may be directly in contact with and connected to each other, and other layer structures may be disposed between the first protective layer 51 and the second protective layer 52 .

[0104] The first protective layer 51 may be a surface layer of the protective layer 50 on the side away from the explosion-proof disk 40 , or may be an intermediate layer of the protective layer 50 . Other layer structures may be provided on the side of the first protective layer 51 away from the explosion-proof disk 40 .

[0105] The materials of the first protective layer 51 and the second protective layer 52 may be the same or different.

[0106] The thicknesses of the first protective layer 51 and the second protective layer 52 may be the same or different.

[0107] The second protective layer 52 is disposed between the explosion-proof disk 40 and the first protective layer 51. The first protective layer 51 and the second protective layer 52 form a stacked structure, which can play a double-layer protection role, which is beneficial to improving the corrosion resistance and protection effect. In addition, the first protective layer 51 and the second protective layer 52 can be made of materials with different corrosion resistance, different structural strength and / or different density, which is beneficial to reduce the impact of the protective layer 50 on the performance of the explosion-proof disk 40 on the basis of improving the protection effect.

[0108] In some embodiments, the thickness of the first protective layer 51 is greater than the thickness of the second protective layer 52 .

[0109] In some examples, the thickness of the first protective layer 51 may be 20 μm-400 μm. Optionally, the thickness of the first protective layer 51 may be 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm or 400 μm.

[0110] In some examples, the thickness of the second protective layer 52 may be 5 μm-50 μm. Optionally, the thickness of the second protective layer 52 may be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm.

[0111] The first protective layer 51 is further away from the explosion-proof plate 40 than the second protective layer 52. The first protective layer 51 is equivalent to an external protective layer, and the second protective layer 52 is equivalent to an internal protective layer. The first protective layer 51 as an external protective layer is thicker, which is beneficial to improving the corrosion resistance, anti-destruction and other protective effects.

[0112] In some embodiments, the first protective layer 51 has better salt water corrosion resistance than the second protective layer 52 .

[0113] The salt water corrosion resistance of the protective layer can be obtained in the following manner: undergo a damp heat test for a preset time (e.g., 72 hours) under damp heat test conditions (e.g., relative humidity of 100% and temperature of 40°C), and then test the loss rate of the protective layer according to certain testing standards (e.g., GB / T10125-2023) after undergoing a salt spray test for a preset time (e.g., 480 hours).

[0114] Under the damp heat test conditions of 100% relative humidity and 40°C, after 72 hours of damp heat test, there was no rust on the first protective layer 51 and the second protective layer 52. After 480 hours of salt spray test and according to the test standard GB / T10125-2023, the loss rate of the first protective layer 51 was less than the loss rate of the second protective layer 52.

[0115] The first protective layer 51 is closer to the outside of the explosion-proof disk 40 than the second protective layer 52, and the first protective layer 51 contacts the corrosive liquid before the second protective layer 52. In the embodiment of the present application, the salt water corrosion resistance of the first protective layer 51 is set to be better, which can slow down the corrosion rate of the first protective layer 51, reduce the risk of the second protective layer 52 being corroded, and help improve the protective effect of the protective layer 50.

[0116] In some embodiments, the first protective layer 51 includes a cobalt-tungsten alloy plating layer, and the second protective layer 52 includes a silver plating layer.

[0117] Optionally, the first protective layer 51 may be formed on the surface of the second protective layer 52 or the surface of other structural layers by electroplating.

[0118] Optionally, the second protective layer 52 may be formed on the surface of the explosion-proof disk 40 or the surface of other structural layers by electroplating.

[0119] The corrosion level of metal materials can be defined by the size of the corrosion rate, which can be expressed by the corrosion depth per year. A corrosion rate of less than 0.001mm / year is a completely corrosion-resistant material; a corrosion rate greater than 0.001mm / year and less than 0.01mm / year is a very corrosion-resistant material; a corrosion rate greater than 0.01mm / year and less than 0.1mm / year is a corrosion-resistant material; a corrosion rate greater than 0.1mm / year and less than 1mm / year is a general corrosion-resistant material; a corrosion rate greater than 1mm / year and less than 10mm / year is a poorly corrosion-resistant material.

[0120] The cobalt-tungsten alloy coating includes a cobalt-tungsten alloy material, which has extremely strong corrosion resistance. Its corrosion resistance level is very corrosion-resistant material, and its corrosion rate is low, which is beneficial to reducing the risk of corrosion of the second protective layer 52 and improving the protective effect of the protective layer 50.

[0121] The silver plating layer includes silver material, which has relatively good corrosion resistance and good ductility, and can be used as the second layer of protection of the explosion-proof plate 40, which is beneficial to improving the protection effect and the connection stability of the second protection layer 52.

[0122] In some embodiments, the protective layer 50 further includes a first connecting layer 53 . The first connecting layer 53 is located between the first protective layer 51 and the second protective layer 52 . The first connecting layer 53 connects the first protective layer 51 and the second protective layer 52 .

[0123] The first connection layer 53 can be connected to the surface of the second protection layer 52 away from the bursting disk 40 by electroplating, chemical plating, bonding or other suitable methods. The first protection layer 51 can be connected to the surface of the first connection layer 53 away from the second protection layer 52 by electroplating, chemical plating, bonding or other suitable methods.

[0124] The thickness of the first connection layer 53 may be smaller than the thickness of the first protection layer 51 and the thickness of the second protection layer 52 to reduce the occupied space thereof.

[0125] In some examples, the thickness of the first connection layer 53 may be 1 μm-10 μm. Alternatively, the thickness of the first connection layer 53 may be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm.

[0126] The first connection layer 53 may have a higher ductility than the first protection layer 51 and the second protection layer 52, so as to bond the first protection layer 51 and the second protection layer 52 by utilizing the high ductility of the first connection layer 53. Optionally, the first connection layer 53 may include a gold plating layer.

[0127] The first protective layer 51 and the second protective layer 52 are connected by the first connecting layer 53. The first connecting layer 53 can increase the bonding force between the first protective layer 51 and the second protective layer 52, improve the connection strength and stability, reduce the risk of the first protective layer 51 falling off from the second protective layer 52, and help the protective layer 50 to stably perform the best protective function. In addition, the first protective layer 51 and the second protective layer 52 are connected by the first connecting layer 53, which can also reduce the material restrictions on the first protective layer 51 and the second protective layer 52 and improve the flexibility of material selection.

[0128] In some embodiments, the protective layer 50 further includes a second connecting layer 54 . The second connecting layer 54 is located between the second protective layer 52 and the bursting disk 40 . The second connecting layer 54 connects the second protective layer 52 and the bursting disk 40 .

[0129] The second connection layer 54 can be connected to the surface of the bursting disk 40 by electroplating, chemical plating, bonding or other suitable methods. The second protective layer 52 can be connected to the surface of the second connection layer 54 away from the bursting disk 40 by electroplating, chemical plating, bonding or other suitable methods.

[0130] The thickness of the second connection layer 54 and the thickness of the second protection layer 52 may be the same or different.

[0131] The thickness of the second connection layer 54 may be greater than that of the first connection layer 53 to improve its structural strength, which is beneficial to reducing the stress generated on the explosion-proof disk 40 during the electroplating process of the second protective layer 52 .

[0132] In some examples, the second connection layer 54 may have a thickness of 5 μm-50 μm. Alternatively, the second connection layer 54 may have a thickness of 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm.

[0133] The materials of the second connection layer 54 and the first connection layer 53 may be the same or different.

[0134] The hardness of the second connection layer 54 may be greater than the hardness of the burst disk 40, and the second connection layer 54 may have a higher compressive strength to reduce the possibility of deformation. Optionally, the second connection layer 54 may include a copper plating layer.

[0135] Due to the material characteristics, the interlayer connection strength between the second protective layer 52 and the explosion-proof disk 40 may be insufficient, and the second connecting layer 54 can play a transition role. The second connecting layer 54 can be made of a material that is compatible with the second protective layer 52 and the explosion-proof disk 40. This is not only beneficial to improve the connection strength between the second protective layer 52 and the explosion-proof disk 40, but also beneficial to reduce the stress generated on the explosion-proof disk 40 during the electroplating process, and reduce the influence of the setting of the protective layer 50 on the structural strength of the explosion-proof disk 40.

[0136] In some embodiments, the protective layer 50 includes a first protective layer 51 , a first connecting layer 53 , a second protective layer 52 , and a second connecting layer 54 which are stacked, and the second connecting layer 54 is connected to the explosion-proof disk 40 .

[0137] Each layer of the protective layer 50 may be a plated structure formed by electroplating. During the electroplating process, the quality and thickness of each layer may be controlled by adjusting parameters such as electroplating voltage and current.

[0138] In some embodiments, the first protective layer 51 includes a cobalt-tungsten alloy plating layer, the second protective layer 52 includes a silver plating layer, the first connection layer 53 includes a gold plating layer, and the second connection layer 54 includes a copper plating layer.

[0139] Under the damp heat test conditions of 100% relative humidity and 40°C, after 72 hours of damp heat test, the protective layer 50 with the above four-layer structure showed no rust. After 480 hours of salt spray test, the protective layer 50 with the above four-layer structure was tested according to the test standard GB / T10125-2023, and the overall test showed that it was a very corrosion-resistant material.

[0140] The cobalt-tungsten alloy coating has extremely strong corrosion resistance, and the silver coating has relatively good corrosion resistance and good ductility. The cobalt-tungsten alloy coating and the silver coating form a double-layer protection with different corrosion resistance, which is beneficial to improving the corrosion resistance and protective effect of the protective layer 50.

[0141] The gold plating layer includes gold material. The gold material has good ductility and can increase the bonding force between the first protective layer 51 and the second protective layer 52, thereby improving the connection strength and stability.

[0142] The copper plating layer includes copper material. The copper material has a relatively high compressive strength, which can reduce the stress on the explosion-proof disk 40 during the electroplating process and reduce the impact on the structural strength of the explosion-proof disk 40 .

[0143] In order to improve the bonding strength and connection effect between the protective layer 50 and the explosion-proof disk 40, and between the layers of the protective layer 50, the surfaces of the first protective layer 51, the first connecting layer 53, the second protective layer 52 and the second connecting layer 54 all have a certain roughness. Optionally, the surface roughness of the first protective layer 51, the first connecting layer 53, the second protective layer 52 and the second connecting layer 54 can be 0.3μm-0.7μm.

[0144] In some embodiments, the protective layer 50 may have a thickness of 50 μm-500 μm.

[0145] Optionally, the thickness of the protective layer 50 may be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm, etc.

[0146] If the protective layer 50 is too thin, the corrosion resistance of the protective layer 50 is low and the protective effect is poor; if the protective layer 50 is too thick, the structural strength is too high, which may affect the normal rupture of the weak part 41 and affect the flipping and explosion of the explosion-proof plate 40.

[0147] In the embodiment of the present application, the thickness of the protective layer 50 is set to 50μm-500μm. The protective layer 50 has both strong corrosion resistance and good protection effect, and will not affect the flipping and explosion of the explosion-proof plate 40 due to excessive structural strength, which is beneficial to improving the reliability of the battery 1.

[0148] In some embodiments, the battery 1 may be a cylindrical battery. The first direction X is the axial direction of the cylindrical battery.

[0149] In some embodiments, the battery 1 may be a cylindrical battery, and the housing 10 of the battery 1 includes a bottom wall 12 and a side wall 13. The side wall 13 includes a side wall body 131 and a bending portion 132, the side wall body 131 is connected to the bottom wall 12, and the bending portion 132 extends from one end of the side wall body 131 away from the bottom wall 12 and bends toward the axis a of the battery 1. The end cap 30 and the bottom wall 12 are arranged along the first direction X, and the side wall 13 is insulated and connected to the end cap 30. In the first direction X, part of the bending portion 132 is located on the side of the end cap 30 that is away from the bottom wall 12.

[0150] The bending portion 132 can exert a certain restriction on the end cover 30 in the arrangement direction of the end cover 30 and the electrode assembly 20 , which is beneficial for the end cover 30 to press the explosion-proof disk 40 and improve the connection stability between the end cover 30 and the explosion-proof disk 40 .

[0151] In some embodiments, the housing 10 and the end cap 30 have different polarities. For example, one of the housing 10 and the end cap 30 has a positive polarity, and the other has a negative polarity.

[0152] In some embodiments, the electrode assembly 20 includes a first electrode terminal 21 and a second electrode terminal 22 with opposite polarities. The first electrode terminal 21 is connected to the housing 10, and the second electrode terminal 22 is connected to the end cap 30. The housing 10 and the end cap 30 respectively form two electrode terminals of the battery 1, eliminating the traditional electrode terminals, which is conducive to simplifying the structure of the battery 1.

[0153] Optionally, the first electrode terminal 21 may be in direct contact with and connected to the bottom wall 12 .

[0154] The bottom wall 12 is arranged opposite to the shell opening 11 along the axial direction of the battery 1, and the side wall 13 is connected to the bottom wall 12 and encloses the bottom wall 12 to form a cylindrical space, which is opened to the outside through the shell opening 11. The bottom wall 12 and the side wall 13 can be an integrally formed structure.

[0155] In some embodiments, an insulating gasket 80 is also provided on the inner side of the side wall 13 facing the electrode assembly 20. A portion of the insulating gasket 80 is located between the side wall 13 and the end cover 30, and another portion is located between the end cover 30 and the electrode assembly 20, which is used to insulate and isolate the end cover 30 and the side wall 13, thereby reducing the risk of short circuit between the end cover 30 and the side wall 13.

[0156] In some embodiments, the battery 1 further includes an insulating film 60. The insulating film 60 is sleeved on the housing 10, and a portion of the insulating film 60 covers the bent portion 132 in the first direction X.

[0157] A portion of the insulating film 60 may cover the entire side wall body 131 , another portion of the insulating film 60 may cover the bending portion 132 along the first direction X, and another portion of the insulating film 60 may cover a portion of the bottom wall 12 along a direction opposite to the first direction X.

[0158] Optionally, the insulating film 60 may be a heat shrinkable film, which is beneficial to improving the covering effect of the insulating film 60 on the housing 10 .

[0159] The insulating film 60 can insulate and isolate the battery 1 from external structures (such as adjacent batteries, busbar components, etc.), thereby reducing the risk of short circuit of the battery 1 .

[0160] In some embodiments, the battery 1 further includes an insulating member 70 . In the first direction X, at least a portion of the insulating member 70 is disposed between the bending portion 132 and the insulating film 60 .

[0161] The insulating member 70 may be disposed entirely between the bending portion 132 and the insulating film 60 , or only a portion of the insulating member 70 may be disposed between the bending portion 132 and the insulating film 60 , and the other portion of the insulating member 70 may, for example, be disposed on one side of the bending portion 132 close to the axis a.

[0162] The insulating film 60 can cover the insulating member 70 to restrict the insulating member 70 so as to reduce the possibility of displacement or falling of the insulating member 70 .

[0163] The insulating member 70 can be connected to the bending portion 132 by bonding, welding, screw connection, melting, clamping or other suitable methods to improve the connection stability between it and the bending portion 132 and further reduce the possibility of displacement or falling of the insulating member 70.

[0164] Optionally, the insulating member 70 may be an annular insulating gasket.

[0165] The insulating member 70 and the insulating film 60 can play a dual insulating isolation effect. After the insulating film 60 is damaged due to corrosion, scratches or other reasons, the insulating member 70 can still achieve insulation isolation between the bending portion 132 and the external structure, which is conducive to further reducing the short circuit risk of the battery 1.

[0166] In some embodiments, the insulating member 70 may include an insulating body 71 and a limiting portion 72 , at least a portion of the insulating body 71 is disposed between the bending portion 132 and the insulating film 60 , and the limiting portion 72 is configured to limit the radial displacement of the insulating body 71 of the battery 1 .

[0167] It can be understood that the limiting portion 72 limits the radial displacement of the insulating body 71 in the battery 1, which means that the limiting portion 72 can completely limit the radial displacement of the insulating body 71 relative to the bending portion 132 along the battery 1, and can also allow the insulating body 71 to be slightly displaced relative to the bending portion 132 along the battery 1 to allow a certain assembly tolerance and reduce the difficulty of assembly.

[0168] In some examples, the limiting portion 72 fixes the insulating body 71 to the bending portion 132. Optionally, the limiting portion 72 may be an adhesive member, and the insulating body 71 and the bending portion 132 are bonded by the limiting portion 72. Under the limiting effect of the limiting portion 72, the insulating body 71 and the bending portion 132 will hardly generate relative displacement along the radial direction of the battery 1.

[0169] In other examples, the limiting portion 72 may include a first limiting portion 721 and a second limiting portion 722, the first limiting portion 721 is connected to one end of the insulating body 71 close to the axis a, the second limiting portion 722 is connected to one end of the insulating body 71 away from the axis a, and the first limiting portion 721 and the second limiting portion 722 are both bent relative to the insulating body 71.

[0170] The first limiting portion 721 can limit the insulating body 71 from moving radially outward away from the axis a relative to the bending portion 132 , and the second limiting portion 722 can limit the insulating body 71 from moving radially inward close to the axis a relative to the bending portion 132 .

[0171] The first limiting portion 721 and the second limiting portion 722 can allow the insulating body 71 to have a slight radial displacement relative to the bending portion 132 within the range of the assembly tolerance, and can also have a limiting effect on the insulating body 71 .

[0172] The embodiment of the present application further provides a battery module 100, and the battery module 100 includes a plurality of batteries 1 provided according to any embodiment of the present application.

[0173] The battery module 100 provided in the embodiment of the present application has the same technical effect as the battery 1 provided in any embodiment of the present application, and therefore will not be described in detail here.

[0174] In some embodiments, the battery module 100 further includes a plurality of busbars 2, and the busbars 2 are connected to the batteries 1. The busbars 2 include a main body 201, a first connecting portion 202, and a second connecting portion 203. The first connecting portion 202 is connected to the end cap 30 of one battery 1, and the second connecting portion 203 is connected to the end cap 30 or the bottom wall 12 of another battery 1.

[0175] One battery 1 and another battery 1 may be connected in series or in parallel via the bus bar 2 .

[0176] The insulating film 60 and the insulating member 70 can separate the bent portion 132 of a battery 1 from the busbar 2 , thereby reducing the possibility of the side wall 13 of a battery 1 overlapping the busbar 2 and reducing the risk of short circuit of the battery 1 .

[0177] In some embodiments, in the first direction X, the main body 201 is spaced apart from the bending portion 132 of a battery 1, and a first recess 2011 is provided on the side of the main body 201 facing the bending portion 132, and a projection of the first recess 2011 along the first direction X partially overlaps with a projection of the bending portion 132 along the first direction X.

[0178] The first concave portion 2011 is recessed in the surface of the first connecting portion 202 and the second connecting portion 203 facing the electrode assembly 20 in a direction away from the bending portion 132. The first concave portion 2011 can increase the distance between the main body 201 and the bending portion 132 along the first direction X, extend the creepage distance, and help further reduce the risk of short circuit.

[0179] In some embodiments, the battery module 100 further includes a bracket 3, the bracket 3 having one or more accommodating cavities, and a plurality of batteries 1 are disposed in the accommodating cavities. The accommodating cavities are provided with second openings 301 at both ends along the first direction X, the first connecting portion 202 is provided at one second opening 301 and connected to the end cover 30 of one battery 1, and the second connecting portion 203 is provided at another second opening 301 and connected to the bottom wall 12 of another battery 1.

[0180] The embodiment of the present application further provides an electric device 1000, and the electric device 1000 includes the battery module 100 provided in any embodiment of the present application. The battery module 100 can provide electric energy for the operation of the electric device 1000.

[0181] The electric device 1000 of the embodiment of the present application may be a portable device, a laptop computer, an electric toy, a drone, an electric tool, an energy storage system, etc. The electric tool includes a metal cutting electric tool, a cleaning tool, etc., for example, an electric drill, an electric wrench, a vacuum cleaner, a sweeping robot, etc. The embodiment of the present application does not impose any special restrictions on the above-mentioned electric devices.

[0182] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery, characterized in that: include: a housing having a housing opening; an electrode assembly, contained in the housing; An end cover connected to the shell and covering the shell opening; An explosion-proof disk, arranged on the end cover; The protective layer is connected to the surface of the explosion-proof disk, and at least a part of the protective layer is arranged on a side of the explosion-proof disk facing away from the electrode assembly.

2. The battery according to claim 1, characterized in that The protective layer comprises a first protective layer and a second protective layer, wherein the second protective layer is arranged between the explosion-proof disk and the first protective layer.

3. The battery according to claim 2, characterized in that The thickness of the first protective layer is greater than the thickness of the second protective layer.

4. The battery according to claim 2 or 3, characterized in that: The first protective layer has better salt water corrosion resistance than the second protective layer.

5. The battery according to any one of claims 2 to 4, characterized in that: The first protective layer includes a cobalt-tungsten alloy plating layer, and the second protective layer includes a silver plating layer.

6. The battery according to any one of claims 2 to 5, characterized in that: The protective layer further includes a first connecting layer, the first connecting layer is located between the first protective layer and the second protective layer, and the first connecting layer connects the first protective layer and the second protective layer; and / or The protective layer further includes a second connecting layer, wherein the second connecting layer is located between the second protective layer and the bursting disk, and the second connecting layer connects the second protective layer and the bursting disk.

7. The battery according to claim 1, characterized in that The protective layer comprises a first protective layer, a first connecting layer, a second protective layer and a second connecting layer which are stacked, and the second connecting layer is connected to the explosion-proof disk; The first protective layer includes a cobalt-tungsten alloy plating layer, the second protective layer includes a silver plating layer, the first connecting layer includes a gold plating layer, and the second connecting layer includes a copper plating layer.

8. The battery according to any one of claims 1 to 7, characterized in that: The thickness of the protective layer is 50 μm-500 μm.

9. The battery according to any one of claims 1 to 8, characterized in that: The explosion-proof plate comprises a weak portion, and at least a portion of the protective layer is arranged on a side of the weak portion facing away from the electrode assembly and covers the weak portion.

10. The battery according to claim 9, characterized in that The end cover is provided with a first opening; At least a portion of the explosion-proof disk is located on a side of the end cap facing the electrode assembly, and the explosion-proof disk closes the first opening; The end cap and the electrode assembly are arranged along a first direction; Along the first direction, at least a portion of the protection layer is located between the weak portion and the first opening.

11. The battery according to claim 10, characterized in that Along the first direction, a projection of the first opening is located within a projection of the protective layer.

12. The battery according to any one of claims 9 to 11, characterized in that: A concave portion is provided on a side of the explosion-proof disc facing away from the electrode assembly, and the protective layer covers the wall surface of the concave portion formed by the explosion-proof disc; The recessed portion is arranged corresponding to the weak portion.

13. The battery according to any one of claims 1 to 12, characterized in that: The explosion-proof plate includes a connecting portion, the connecting portion is connected to the end cover, and the protective layer is not arranged between the connecting portion and the end cover.

14. The battery according to any one of claims 1 to 13, characterized in that: The battery is a cylindrical battery.

15. The battery according to any one of claims 1 to 14, characterized in that: The battery is a cylindrical battery; The housing comprises a bottom wall and a side wall, the side wall comprises a side wall body and a bending portion, the side wall body is connected to the bottom wall, and the bending portion extends from one end of the side wall body away from the bottom wall and bends toward the axis of the battery; The end cover and the bottom wall are arranged along a first direction, the side wall is insulated from and connected to the end cover, and in the first direction, part of the bent portion is located on a side of the end cover facing away from the bottom wall; The housing and the end cap have different polarities; The battery further includes an insulating film and an insulating member, wherein the insulating film is sleeved on the shell, and a portion of the insulating film covers the bent portion in the first direction; in the first direction, at least a portion of the insulating member is disposed between the bent portion and the insulating film.

16. The battery according to any one of claims 1 to 15, characterized in that: The electrode assembly includes a first electrode terminal and a second electrode terminal with opposite polarities, wherein the first electrode terminal is connected to the shell, and the second electrode terminal is connected to the end cap.

17. A battery module, characterized in that: Comprising a plurality of batteries according to any one of claims 1-16.

18. An electrical equipment, characterized in that: Comprising the battery module according to claim 17.

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