Battery cell, battery device, and electric device

Abstract

The application provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises an electrode assembly, a shell and a protective layer. The shell contains the electrode assembly. The material of the shell comprises steel. The shell comprises a shell body, an end cover and a welding mark part. The shell body has an opening at at least one end in a first direction. The end cover corresponds to the opening one by one. The end cover is arranged on the opening. The welding mark part connects the shell body and the end cover. In the first direction, the end cover has a first surface away from the electrode assembly. The outer surface of the welding mark part connects the outer circumferential surface of the shell body and the first surface. The outer surface of the welding mark part comprises a fillet area connected with the first surface. At least a part of the fillet area is covered with the protective layer. The fillet area eliminates the sharp corners of the edge area of the end cover. In the process of coating the rust-proof material on the fillet area to form the protective layer, the rust-proof material can be better attached to the fillet area. The protective layer is beneficial to be formed on the welding mark part. The risk of rusting of the welding mark part is reduced. The service life of the battery monomer is improved.

Description

Technical Field

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

[0002] Currently, energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In battery technology, the lifespan of individual battery cells is a crucial issue. Therefore, improving the lifespan of individual battery cells is a pressing technical problem that needs to be solved. Utility Model Content

[0004] The purpose of this application is to provide a battery cell, a battery device, and an electrical device that can effectively improve the service life of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, the battery cell including an electrode assembly, a housing, and a protective layer. The housing houses the electrode assembly, and the housing is made of steel. The housing includes a shell, an end cap, and a solder joint. The shell has an opening at at least one end along a first direction, and the end cap corresponds to each opening and is disposed on the opening. The solder joint connects the shell and the end cap. Along the first direction, the end cap has a first surface facing away from the electrode assembly. The outer surface of the solder joint connects the outer peripheral surface of the shell and the first surface. The outer surface of the solder joint includes a rounded corner area connected to the first surface, and at least a portion of the rounded corner area is covered by the protective layer.

[0006] In the above technical solution, the solder joint connects the housing and the end cap, achieving a stable connection between the housing and the end cap. The rounded corner area eliminates the sharp corners of the end cap's edge area, and during the process of applying anti-rust material to the rounded corner area to form a protective layer, the anti-rust material can better adhere to the rounded corner area of ​​the solder joint. The anti-rust material is less likely to fall off the outer surface of the solder joint under gravity, which is conducive to the formation of the protective layer on the solder joint, thereby reducing the risk of corrosion of the solder joint and effectively improving the service life of the battery cell.

[0007] As an optional technical solution in this application embodiment, the outer surface of the soldering part includes a connection area, the connection area is connected to the outer peripheral surface of the housing, the connection area transitions to the first surface through the rounded corner area, and at least a portion of the connection area is covered by the protective layer.

[0008] In the above technical solution, the connecting area connects to the outer peripheral surface of the shell, and the connecting area transitions to the first surface through the rounded corner area. In this way, the outer surface of the soldering part is relatively smooth, and the outer peripheral surface of the shell can smoothly transition to the first surface through the outer surface of the soldering part. During the process of coating the anti-rust material on the rounded corner area to form a protective layer, the anti-rust material can better adhere to the outer surface of the soldering part. The anti-rust material is not easy to fall off the outer surface of the soldering part under the action of gravity, which is conducive to the formation of the protective layer on the soldering part, thereby reducing the risk of the soldering part being corroded and effectively improving the service life of the battery cell.

[0009] As an optional technical solution in this application embodiment, the outer surface of the solder stamp is provided with a first groove, and a portion of the protective layer is accommodated in the first groove.

[0010] In the above technical solution, the protective layer covers at least a portion of the outer surface of the solder joint, and a first groove is provided on the outer surface of the solder joint. A portion of the protective layer is accommodated in the first groove, which increases the adhesion of the protective layer, improves the firmness of the protective layer on the solder joint, realizes long-term protection of the solder joint by the protective layer, reduces the risk of protection failure of the solder joint caused by the protective layer falling off the outer surface of the solder joint in a short period of time, thereby reducing the risk of corrosion of the solder joint of the outer casing and effectively improving the service life of the battery cell.

[0011] As an optional technical solution in this application embodiment, the portion of the protective layer contained within the first groove is connected to the groove wall surface of the first groove.

[0012] In the above technical solution, the portion of the protective layer contained in the first groove is connected to the groove wall surface of the first groove, which helps to increase the contact area between the protective layer and the solder joint, thereby increasing the adhesion of the protective layer on the solder joint of the outer shell and further improving the firmness of the protective layer on the solder joint of the outer shell.

[0013] As an optional technical solution in this application embodiment, at least a portion of the first groove is located in the rounded corner area, and a portion of the protective layer is accommodated within the portion of the first groove located in the rounded corner area.

[0014] In the above technical solution, at least a portion of the first groove is disposed in the rounded corner area, and a portion of the protective layer is accommodated in the portion of the first groove located in the rounded corner area, which improves the firmness of the protective layer in the rounded corner area, realizes the long-term protection of the protective layer for the rounded corner area, and reduces the risk of the outer shell being corroded in the rounded corner area.

[0015] As an optional technical solution in this application embodiment, the outer surface of the soldering part includes a connection area, the connection area is connected to the outer peripheral surface of the housing, and the connection area transitions to the first surface through the rounded corner area; at least a portion of the first groove is located in the connection area, at least a portion of the connection area is covered by the protective layer, and a portion of the protective layer is accommodated in the portion of the first groove located in the connection area.

[0016] In the above technical solution, at least a portion of the first groove is disposed in the connection area, and a portion of the protective layer is accommodated in the portion of the first groove located in the connection area, which improves the firmness of the protective layer in the connection area, realizes the long-term protection of the connection area by the protective layer, and reduces the risk of the outer shell being corroded in the connection area.

[0017] As an optional technical solution in this application embodiment, the outer surface of the soldering part is connected to the outer peripheral surface of the housing at a first edge, the outer surface of the soldering part is connected to the first surface at a second edge, the first edge and the second edge are spaced apart along the first direction, and the first groove extends to the first edge and the second edge.

[0018] In the above technical solution, by extending the first groove on the outer surface of the soldering part to the first edge and the second edge, the span of the first groove in the first direction is increased, which is beneficial for more of the protective layer to be accommodated in the first groove, thereby improving the firmness of the protective layer on the soldering part.

[0019] As an optional technical solution in this application embodiment, there are multiple first grooves, and the multiple first grooves are arranged circumferentially along the opening.

[0020] In the above technical solution, by setting multiple first grooves and arranging the multiple first grooves along the circumference of the opening, the multiple first grooves can accommodate more of the protective layer, thereby improving the firmness of the protective layer on the solder joint.

[0021] As an optional technical solution in this application embodiment, the first groove includes multiple groove groups arranged circumferentially along the opening. Each groove group includes a first groove segment, a second groove segment, and a third groove segment connected in sequence. The first groove segment and the third groove segment are respectively connected to opposite ends of the second groove segment and are located on both sides of the second groove segment along its width direction. The first groove also includes multiple fourth groove segments arranged circumferentially along the opening. In two adjacent groove groups, the end of the first groove segment of one groove group away from the second groove segment is connected to the end of the third groove segment of another groove group away from the second groove segment through a fourth groove segment.

[0022] In the above technical solution, the first groove is similar to multiple consecutive figure-eight structures. On the one hand, with a fixed circumferential dimension of the opening of the first groove, it increases both the extension dimension of the first groove (the sum of the extension dimensions of all groove segments) and the span of the first groove in the first direction. This is beneficial for accommodating more of the protective layer in the first groove, thereby increasing the adhesion of the protective layer to the soldering part. On the other hand, it can reduce the number of first grooves arranged in the first direction on the soldering part, reduce the number of processing steps, and improve production efficiency.

[0023] As an optional technical solution in this application embodiment, the first groove extends circumferentially along the opening.

[0024] In the above technical solution, the first groove extends circumferentially along the opening, and the structure of the first groove is simple and the molding difficulty is low.

[0025] As an optional technical solution in this application embodiment, there are multiple first grooves, and the multiple first grooves are spaced apart along the first direction.

[0026] In the above technical solution, by providing a plurality of first grooves spaced apart along the first direction on the outer surface of the soldering part, it is beneficial to increase the contact area between the protective layer and the soldering part and improve the firmness of the protective layer on the soldering part.

[0027] As an optional technical solution in this application embodiment, the outer shell is cylindrical, the first direction is parallel to the axial direction of the outer shell, and there are multiple first grooves, which are arranged at radial intervals along the outer shell.

[0028] In the above technical solution, by providing a plurality of first grooves arranged radially at intervals along the outer surface of the outer shell, it is beneficial to increase the contact area between the protective layer and the soldering part and improve the firmness of the protective layer on the soldering part.

[0029] As an optional technical solution in this application embodiment, in the projection plane perpendicular to the first direction, the orthographic projection of the first groove extends along the planar spiral trajectory.

[0030] In the above technical solution, the orthographic projection of the first groove in the projection plane perpendicular to the first direction extends along the planar spiral trajectory. On the one hand, it increases the extension size of the first groove, which is beneficial to accommodate more of the protective layer in the first groove and to increase the contact area between the protective layer and the soldering part, thereby increasing the adhesion of the protective layer on the soldering part. On the other hand, it can reduce the number of first grooves arranged on the soldering part in the direction perpendicular to the first direction, reduce the number of processing steps, and improve production efficiency.

[0031] As an optional technical solution in this application embodiment, the first groove extends along a spiral trajectory, and the central axis of the spiral extends along the first direction.

[0032] In the above technical solution, extending the first groove along the spiral trajectory increases the extension dimension of the first groove while keeping the axial dimension of the first groove along the outer shell constant. This allows more of the protective layer to be accommodated in the first groove, increasing the contact area between the protective layer and the soldering part, thereby increasing the adhesion of the protective layer on the soldering part. On the other hand, it can reduce the number of first grooves arranged along the axial dimension of the outer shell on the soldering part, reducing the number of processing steps and improving production efficiency.

[0033] As an optional technical solution in this application embodiment, the first groove includes a plurality of grooves arranged along its extension direction, a portion of the protective layer is accommodated in the grooves, and two adjacent grooves are connected to each other and form a communication port at the connection position.

[0034] In the above technical solution, the first groove includes a plurality of grooves arranged along its extension direction. Two adjacent grooves are connected to each other and form a communication port at the connection position. This structure reduces the flatness of the groove wall surface of the first groove, making the groove wall surface of the first groove rougher, increasing the adhesion between the protective layer and the groove wall surface of the first groove, and further reducing the risk of the protective layer falling off the outer surface of the soldering part.

[0035] As an optional technical solution in this application embodiment, the area of ​​the connecting opening is smaller than the area of ​​any cross-section of the groove, and the cross-section is perpendicular to the extending direction of the first groove.

[0036] In the above technical solution, by setting the area of ​​the connecting opening to be smaller than the area of ​​any cross-section of the groove, the first groove forms a necking structure at the connecting opening position, which can further increase the adhesion between the protective layer and the groove wall of the first groove, and achieve strong adhesion of the protective layer on the soldering part.

[0037] As an optional technical solution in this application embodiment, within the cross-section of the groove, the dimension of the groove in the width direction of the first groove gradually decreases along the depth direction of the first groove, and the cross-section is perpendicular to the extension direction of the first groove.

[0038] In the above technical solution, by setting the dimension of the groove in the width direction of the first groove to gradually decrease along the depth direction of the first groove, the rust-preventive material can more easily adhere to the groove wall surface during the process of coating the rust-preventive material on the outer surface of the weldment to form a protective layer. This is beneficial to increase the contact area between the protective layer and the groove wall surface, thereby increasing the adhesion of the protective layer.

[0039] As an optional technical solution in this application embodiment, the maximum size of the connecting opening is smaller than the maximum size of the groove along the depth direction of the first groove.

[0040] In the above technical solution, by setting the maximum dimension of the connecting opening along the depth direction of the first groove to be smaller than the maximum dimension of the groove along the depth direction of the first groove, the area of ​​the groove wall surface of the groove can be increased, which is beneficial to increasing the contact area between the protective layer and the groove wall surface of the groove, thereby increasing the adhesion of the protective layer.

[0041] As an optional technical solution in this application embodiment, the maximum size of the connecting opening is smaller than the maximum size of the groove along the width direction of the first groove.

[0042] In the above technical solution, by setting the maximum dimension of the connecting opening along the width direction of the first groove to be smaller than the maximum dimension of the groove along the width direction of the first groove, the area of ​​the groove wall surface of the groove can be increased, which is beneficial to increasing the contact area between the protective layer and the groove wall surface of the groove, thereby increasing the adhesion of the protective layer.

[0043] As an optional technical solution in this application embodiment, the maximum dimension of the groove is L along the extension direction of the first groove, and the maximum dimension of the groove is W along the width direction of the first groove, where 1.1≤W / L≤10.

[0044] In the above technical solution, the ratio of the maximum dimension W of the groove along the width direction of the first groove to the maximum dimension L of the groove along the extension direction of the first groove is set to 1.1-10, so that the maximum dimension W of the groove along the width direction of the first groove is larger than the maximum dimension L of the groove along the extension direction of the first groove, which reduces the difficulty of the anti-rust material entering the first groove during the process of coating the anti-rust material on the outer surface of the weldment to form a protective layer.

[0045] As an optional technical solution in this application embodiment, 70μm≤W≤90μm, 7μm≤L≤81μm.

[0046] In the above technical solution, the maximum dimension W of the groove along the width direction of the first groove is set to 70μm-90μm, and the maximum dimension L of the groove along the extension direction of the first groove is set to 7μm-81μm, so that the groove is a small groove with a smaller size, so as to accurately control the surface roughness of the soldering part, which is beneficial to improve the firmness of the protective layer on the soldering part.

[0047] As an optional technical solution in this application embodiment, the maximum width of the first groove is W, where 70μm≤W≤90μm.

[0048] In the above technical solution, W≥70μm ensures that the maximum width of the first groove is not too small. This reduces the processing difficulty of the first groove and the difficulty of the anti-rust material entering the first groove during the process of coating the anti-rust material on the outer surface of the soldering part to form a protective layer. This is beneficial to increasing the contact area between the protective layer and the groove wall of the first groove. W≤90μm ensures that the maximum width of the first groove is not too large, resulting in a narrower first groove on the outer surface of the soldering part. This is beneficial to setting more first grooves per unit area and increasing the density of the first grooves on the soldering part, thereby increasing the adhesion of the protective layer to the outer shell.

[0049] As an optional technical solution in this application embodiment, the maximum depth of the first groove is H, where 5μm≤H≤20μm.

[0050] In the above technical solution, H≥5μm ensures that the maximum depth of the first groove is not too small, allowing the first groove to accommodate more of the protective layer, which is beneficial to increasing the contact area between the protective layer and the groove wall of the first groove; H≤20μm ensures that the maximum depth of the first groove is not too large, reducing the impact of the setting of the first groove on the strength of the solder joint.

[0051] As an optional technical solution in this application embodiment, the first groove is a laser cleaning tank.

[0052] In the above technical solution, the first groove is a laser cleaning groove, which is formed on the outer surface of the solder area by laser cleaning. On the one hand, the surface contaminants (oxide layer or dirt, etc.) of the solder area can be cleaned during the formation of the first groove, reducing the risk that the contaminants will form a weak interface under the protective layer, thus reducing the adhesion of the protective layer. On the other hand, the groove wall surface of the first groove is relatively rough, which increases the adhesion between the protective layer and the groove wall surface of the first groove.

[0053] As an optional technical solution in this application embodiment, the outer surface of the housing further includes a main body surface connected to the outer surface of the soldering portion. The main body surface includes the outer surface of the housing and the outer surface of the end cap. The main body surface is provided with a second groove. At least a portion of the main body surface is covered by the protective layer, and a portion of the protective layer is accommodated in the second groove.

[0054] In the above technical solution, at least a portion of the main body surface is covered with a protective layer, increasing the area of ​​the protective layer covering the outer surface of the shell and mitigating rusting of the portion of the main body surface covered by the protective layer. A second groove is provided on the main body surface, and a portion of the protective layer is accommodated within the second groove. The second groove provides a certain degree of restraint to the protective layer, improving its firmness on the shell and reducing the risk that the portion of the protective layer on the outer surface of the solder joint may easily detach after the portion on the main body surface detaches, thus achieving long-term protection of the outer surfaces of both the main body surface and the solder joint.

[0055] As an optional technical solution in this application embodiment, the portion of the protective layer contained within the second groove is connected to the groove wall surface of the second groove.

[0056] In the above technical solution, the portion of the protective layer contained in the second groove is connected to the groove wall of the second groove, which helps to increase the contact area between the protective layer and the outer shell, thereby increasing the adhesion of the protective layer on the outer shell and further improving the firmness of the protective layer on the outer shell.

[0057] As an optional technical solution in this application embodiment, the outer surface of the soldering part is provided with a first groove, at least a portion of the outer surface of the soldering part is covered by the protective layer, a portion of the protective layer is accommodated in the first groove, and at least one second groove communicates with at least one first groove.

[0058] In the above technical solution, by communicating at least one second groove with at least one first groove, the portion of the protective layer contained in the second groove and the portion of the protective layer contained in the first groove can be continuous, so that more of the protective layer can be contained in the first groove and / or the second groove, thereby further improving the robustness of the protective layer on the shell.

[0059] As an optional technical solution in this application embodiment, the outer surface of the housing is provided with a second groove, at least a portion of the outer surface of the housing is covered with a protective layer, and a portion of the protective layer is accommodated in the second groove.

[0060] In the above technical solution, at least a portion of the outer surface of the shell is covered with a protective layer, increasing the area of ​​the protective layer covering the outer surface of the shell. This allows the protective layer to provide a certain degree of protection for the shell and alleviate rusting on the portion of the outer surface covered by the protective layer. A second groove is provided on the outer surface of the shell, and a portion of the protective layer is accommodated within the second groove. This improves the firmness of the protective layer on the shell, ensuring long-term protection of the area near the solder joint, and reducing the risk of the protective layer detaching from the solder joint due to the partial detachment of the protective layer from the outer surface of the shell.

[0061] As an optional technical solution in this application embodiment, the outer peripheral surface of the housing is provided with the second groove, at least a portion of the outer peripheral surface of the housing is covered with a protective layer, and a portion of the protective layer is accommodated in the second groove.

[0062] In the above technical solution, at least a portion of the outer peripheral surface of the shell is covered with a protective layer, increasing the area of ​​the protective layer covering the outer surface of the shell. This allows the protective layer to provide a certain degree of protection for the shell and alleviate the rusting phenomenon on the portion of the outer peripheral surface covered by the protective layer. A second groove is provided on the outer peripheral surface of the shell, and a portion of the protective layer is accommodated within the second groove. This improves the firmness of the protective layer on the shell, ensuring long-term protection of the area near the solder joint, and reducing the risk of the portion of the protective layer on the solder joint easily detaching due to the partial detachment of the protective layer on the outer peripheral surface of the shell.

[0063] As an optional technical solution in this application embodiment, the outer surface of the end cap is provided with a second groove, at least a portion of the outer surface of the end cap is covered with a protective layer, and a portion of the protective layer is accommodated in the second groove.

[0064] In the above technical solution, at least a portion of the outer surface of the end cap is covered with a protective layer, increasing the area of ​​the protective layer covering the outer surface of the casing. This allows the protective layer to provide a certain degree of protection for the end cap and alleviate rusting of the portion of the end cap's outer surface covered by the protective layer. A second groove is provided on the outer surface of the end cap, and a portion of the protective layer is accommodated within this groove. This improves the firmness of the protective layer on the end cap, ensuring long-term protection of at least the area near the solder joint of the end cap, and reducing the risk of the protective layer detaching from the solder joint due to the partial detachment of the protective layer from the outer surface of the end cap.

[0065] As an optional technical solution in this application embodiment, the first surface is provided with the second groove, at least a portion of the first surface is covered by the protective layer, and a portion of the protective layer is accommodated in the second groove.

[0066] In the above technical solution, at least a portion of the first surface is covered with a protective layer, increasing the area of ​​the protective layer covering the outer surface of the casing. This allows the protective layer to provide a certain degree of protection for the end cap, mitigating rusting of the portion of the first surface covered by the protective layer. A second groove is provided on the first surface, and a portion of the protective layer is accommodated within the second groove. This improves the firmness of the protective layer on the end cap, ensuring long-term protection of at least the area near the solder joint of the end cap. Furthermore, it reduces the risk of the protective layer detaching from the solder joint due to the partial detachment of the protective layer on the first surface.

[0067] As an optional technical solution in this application embodiment, the shell includes a shell body and a first anti-corrosion layer. The shell body is made of steel. The first anti-corrosion layer is disposed on the surface of the shell body. The outer surface of the first anti-corrosion layer is at least a part of the outer peripheral surface of the shell. Both the shell body and the first anti-corrosion layer are connected to the solder joint.

[0068] In the above technical solution, the outer surface of the first anti-corrosion layer is part of the outer surface of the shell, making the first anti-corrosion layer the surface layer of the shell. The first anti-corrosion layer has better corrosion resistance than the shell body, giving the shell excellent rust prevention capabilities.

[0069] As an optional technical solution in this application embodiment, the first anti-corrosion layer includes a nickel layer.

[0070] In the above technical solution, the nickel layer has good corrosion resistance and high hardness. The first anti-corrosion layer includes the nickel layer, which improves the corrosion resistance and wear resistance of the shell.

[0071] As an optional technical solution in this application embodiment, the outer surface of the first anti-corrosion layer is provided with a second groove, at least a portion of the outer surface of the first anti-corrosion layer is covered by the protective layer, and a portion of the protective layer is accommodated in the second groove.

[0072] In the above technical solution, at least a portion of the outer surface of the first anti-corrosion layer is covered by a protective layer, so that the area where the protective layer overlaps with the first anti-corrosion layer can provide double protection for the shell body, further reducing the risk of the shell body being corroded. At least a portion of the outer surface of the first anti-corrosion layer is covered by a protective layer, and a portion of the protective layer is accommodated within the second groove, improving the firmness of the protective layer on the shell. This ensures long-term protection of the shell, at least in the area near the weldment, and reduces the risk that the portion of the protective layer on the weldment may easily detach after the portion on the outer surface of the first anti-corrosion layer peels off.

[0073] As an optional technical solution in this application embodiment, the depth of the second groove provided on the outer surface of the first anti-corrosion layer is less than the thickness of the first anti-corrosion layer.

[0074] In the above technical solution, the depth of the second groove on the outer surface of the first anti-corrosion layer is set to be less than the thickness of the first anti-corrosion layer, so that the second groove does not penetrate the first anti-corrosion layer along the thickness direction of the first anti-corrosion layer, so that the area of ​​the first anti-corrosion layer with the second groove still has anti-rust capability for the shell body.

[0075] As an optional technical solution in this application embodiment, the end cap includes a cap body and a second anti-corrosion layer. The material of the cap body includes steel. The second anti-corrosion layer is disposed on the surface of the cap body. The outer surface of the second anti-corrosion layer is a part of the outer surface of the end cap. Both the cap body and the second anti-corrosion layer are connected to the solder joint.

[0076] In the above technical solution, the outer surface of the second anti-corrosion layer is part of the outer surface of the outer shell, making the second anti-corrosion layer the surface layer of the end cap. The second anti-corrosion layer has better corrosion resistance than the cap body, giving the end cap excellent rust prevention capabilities.

[0077] As an optional technical solution in this application embodiment, the second anti-corrosion layer includes a nickel layer.

[0078] In the above technical solution, the nickel layer has good corrosion resistance and high hardness, and the second anti-corrosion layer includes the nickel layer, which improves the corrosion resistance and wear resistance of the end cap.

[0079] As an optional technical solution in this application embodiment, the outer surface of the second anti-corrosion layer is provided with a second groove, at least a portion of the outer surface of the second anti-corrosion layer is covered by the protective layer, and a portion of the protective layer is accommodated in the second groove.

[0080] In the above technical solution, at least a portion of the outer surface of the second anti-corrosion layer is covered by a protective layer, so that the area where the protective layer and the second anti-corrosion layer overlap can provide double protection for the cap body, further reducing the risk of the cap body being corroded. A second groove is provided on the outer surface of the second anti-corrosion layer, and a portion of the protective layer is accommodated within the second groove, improving the firmness of the protective layer on the end cap. On the one hand, this ensures long-term protection of the area of ​​the end cap near the weldment, and on the other hand, reduces the risk that the portion of the protective layer on the weldment may easily detach due to the partial detachment of the protective layer on the outer surface of the second anti-corrosion layer.

[0081] As an optional technical solution in this application embodiment, the depth of the second groove provided on the outer surface of the second anti-corrosion layer is less than the thickness of the second anti-corrosion layer.

[0082] In the above technical solution, the depth of the second groove on the outer surface of the second anti-corrosion layer is set to be less than the thickness of the second anti-corrosion layer, so that the second groove does not penetrate the second anti-corrosion layer along the thickness direction of the second anti-corrosion layer, so that the area of ​​the second anti-corrosion layer with the second groove still has anti-rust capability for the cover body. As an optional technical solution of this application embodiment, the welding stamp is an annular structure and the welding stamp extends circumferentially along the opening.

[0083] In the above technical solution, by setting the solder stamp part as an annular structure extending circumferentially along the opening, on the one hand, the contact area between the shell and the end cap and the solder stamp part is increased, and the connection strength between the shell and the end cap and the solder stamp part is increased, thereby improving the welding firmness of the shell and the end cap. On the other hand, the solder stamp part can realize the sealed connection between the shell and the end cap.

[0084] As an optional technical solution in this application embodiment, the protective layer completely covers the outer surface of the solder mark.

[0085] In the above technical solution, by completely covering the outer surface of the solder joint with a protective layer, the protective layer can completely protect the outer surface of the solder joint and further alleviate the rusting phenomenon of the solder joint.

[0086] As an optional technical solution in this application embodiment, the minimum distance of the protective layer extending beyond the edge of the outer surface of the solder mark is greater than or equal to 200 μm.

[0087] In the above technical solution, during the process of welding to form the weld mark, the area of ​​the outer shell near the weld mark will form a heat-affected zone. The minimum distance of the protective layer extending beyond the edge of the outer surface of the weld mark is greater than or equal to 200μm, which can cover the heat-affected zone formed by welding and alleviate the rusting phenomenon in the heat-affected zone.

[0088] As an optional technical solution in this application embodiment, the protective layer is a coating.

[0089] In the above technical solution, the protective layer is a coating, which can be formed by coating the outer surface of the shell with anti-rust material, so that the protective layer has good anti-corrosion performance and stability.

[0090] As an optional technical solution in this application embodiment, the coating comprises, by weight percentage: 15-20% polyurethane acrylate, 10-15% epoxy acrylate, 45-70% reactive diluent and 5-10% photoinitiator.

[0091] In the above technical solution, the coating is a UV-cured coating. This UV-cured coating has the advantage of a short curing time, which helps to improve the forming efficiency of the protective layer, thereby improving the forming efficiency of the battery cell. In addition, the thickness of the UV-cured coating can be controlled by precisely controlling the spraying amount, improving the uniformity of the protective layer thickness and reducing material waste caused by excessive thickness or unevenness.

[0092] As an optional technical solution in this application embodiment, the battery cell is a cylindrical battery cell.

[0093] Secondly, embodiments of this application provide a battery device, including a single battery cell provided in any one of the embodiments of the first aspect.

[0094] Thirdly, embodiments of this application provide an electrical device, including a battery cell provided in any one of the embodiments of the first aspect or a battery device provided in any one of the embodiments of the second aspect. Attached Figure Description

[0095] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0096] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0097] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0098] Figure 3 Exploded views of a single battery cell provided in some embodiments of this application;

[0099] Figure 4 for Figure 3 A cross-sectional view of the battery cell shown;

[0100] Figure 5 for Figure 4 A magnified view of position A in the middle;

[0101] Figure 6 A partially enlarged view of a battery cell provided for other embodiments of this application;

[0102] Figure 7 A partial enlarged view of a battery cell provided for some embodiments of this application;

[0103] Figure 8 Partial schematic diagram of the casing provided for some embodiments of this application;

[0104] Figure 9 for Figure 8 A magnified view of position B in the middle;

[0105] Figure 10 Partial enlarged views of the housing provided for other embodiments of this application;

[0106] Figure 11 A top view of the solder joint provided for some embodiments of the application;

[0107] Figure 12 A partial enlarged view of the housing provided in some embodiments of this application;

[0108] Figure 13 A top view of the solder joint provided for other embodiments of the application;

[0109] Figure 14 A partial enlarged view of the casing provided for some embodiments of this application;

[0110] Figure 15 A partial enlarged view of a first groove provided for some embodiments of this application (showing multiple slots of the first groove);

[0111] Figure 16 for Figure 15 A cross-sectional view at position CC;

[0112] Figure 17 A partial enlarged view of a battery cell provided in some embodiments of this application;

[0113] Figure 18 This application also provides partial enlarged views of individual battery cells in some embodiments;

[0114] Figure 19 A partial enlarged view of a battery cell provided for some other embodiments of this application;

[0115] Figure 20 A partial enlarged view of a battery cell provided in some other embodiments of this application;

[0116] Figure 21 Partial enlarged views of a single battery cell provided for some other embodiments of this application;

[0117] Figure 22 for Figure 17 A magnified view of position D in the middle;

[0118] Figure 23 for Figure 19 A magnified view of position E in the middle.

[0119] Icons: 1-Outer shell; 11-Shell; 111-Outer peripheral surface of the shell; 113-Shell body; 114-First anti-corrosion layer; 12-End cap; 121-Cap body; 122-Second anti-corrosion layer; 13-First groove; 131-Groove group; 1311-First groove segment; 1311a-First end; 1311b-Second end; 1312-Second groove segment; 1313-Third groove segment; 1313a-Third end; 1313b-Fourth end; 1314-Fourth groove segment; 1315-First edge; 1316-Second edge; 133-Groove portion; 134-Connecting port; 14-Second groove; 141-First surface; 2-Electrode assembly; 21-Main body; 22 - Tab; 22a- First tab; 22b- Second tab; 3- Electrode terminal; 4- Current collector; 4a- First current collector; 4b- Second current collector; 5- First insulating component; 6- Protective layer; 7- Solder stamp; 711- Outer surface of solder stamp; 7111- Connection area; 7112- Rounded corner area; 712- First interface; 713- Second interface; 10- Battery cell; 20- Housing; 201- First housing; 202- Second housing; 100- Battery device; 200- Controller; 300- Motor; 1000- Vehicle; O- Extension direction of the first groove; X- Width direction of the first groove; Y- Depth direction of the first groove; Z- First direction. Detailed Implementation

[0120] 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 described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0121] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0122] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0123] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0124] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0125] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0126] In this application, "multiple" means two or more (including two).

[0127] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0128] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0129] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0130] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0131] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0132] As an example, the positive electrode current collector can be a foil or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0133] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM)622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 )), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0134] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0135] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0136] As an example, the negative electrode current collector can be a foil, a foamed metal, or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, or titanium, etc. The foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0137] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0138] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0139] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0140] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0141] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0142] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0143] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0144] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0145] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0146] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0147] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0148] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0149] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0150] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0151] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0152] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0153] In some implementations, the electrode assembly is a stacked structure.

[0154] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0155] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0156] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0157] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0158] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0159] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0160] In some implementations, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0161] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0162] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0163] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0164] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0165] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0166] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cell assemblies housed within the housing.

[0167] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0168] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0169] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0170] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0171] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0172] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0173] In typical battery cells, the outer casing is usually made of aluminum. This casing has advantages such as low hardness and good plasticity, resulting in better formability. To meet strength requirements, the aluminum casing needs to be thicker. However, with a fixed battery cell volume, a thicker aluminum casing results in a lower volumetric energy density, thus affecting the battery cell's volumetric energy density. Therefore, a steel casing can be used. While meeting strength requirements, the outer casing can be made thinner, thereby increasing the battery cell's volumetric energy density.

[0174] For battery cells with steel casings, the welded areas of the casing and end caps, as well as the areas near the welded areas, are easily affected by the high temperatures of welding. Exposure to air leads to oxidation, resulting in rust in these areas and affecting the battery cell's lifespan. Even if the steel casing has an anti-corrosion layer, the high temperatures during welding can cause this layer to oxidize, forming a loose and easily peeling oxide layer. In some cases, the anti-corrosion layer may even evaporate, exposing the steel substrate in the welded areas and surrounding areas, leading to rust.

[0175] To mitigate rusting in and around the welded areas of the casing and end caps, a protective layer can be applied to the outer surface of the steel casing. This layer protects the welded areas and surrounding regions, reducing the risk of oxidation from contact with air and water. However, due to the manufacturing process of the end caps, sharp corners are often formed at their edges. These sharp corners are located near the welded areas, and the protective layer is difficult to adhere to. Consequently, the protective layer easily detaches from these corners, leading to corrosion of the steel casing at these points and impacting the lifespan of the battery cells.

[0176] In view of this, the present application provides a technical solution in which, when welding the shell and the end cap, the sharp corners of the edge area of ​​the end cap are melted to form a weld mark, so that the outer surface of the weld mark connects the first surface and the outer peripheral surface of the shell. Furthermore, the weld mark includes a rounded corner area connected to the first surface. The rounded corner area is relatively smooth. During the process of applying anti-rust material to the rounded corner area to form a protective layer, the anti-rust material can better adhere to the rounded corner area of ​​the weld mark. The anti-rust material is not easy to fall off the outer surface of the weld mark under the action of gravity, which is conducive to the formation of the protective layer on the weld mark, thereby reducing the risk of corrosion of the weld mark and effectively improving the service life of the battery cell.

[0177] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices. The electrical devices can be of various types, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0178] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0179] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0180] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0181] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0182] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery includes a housing 20 and battery cells 10, with the battery cells 10 housed within the housing 20.

[0183] The housing 20 is a component that houses the battery cell 10, providing a space for the battery cell 10. The housing 20 can adopt various structures. In some embodiments, the housing 20 may include a first housing 201 and a second housing 202, which overlap each other to define a space for accommodating the battery cell 10. The first housing 201 and the second housing 202 can have various shapes, such as cuboid or cylindrical. The first housing 201 can be a hollow structure open on one side, and the second housing 202 can also be a hollow structure open on one side, with the open side of the second housing 202 overlapping the open side of the first housing 201, thus forming a housing 20 with a accommodating space. Alternatively, the first housing 201 can be a hollow structure open on one side, and the second housing 202 can be a plate-like structure, with the second housing 202 overlapping the open side of the first housing 201, thus forming a housing 20 with a accommodating space. The first housing 201 and the second housing 202 can be sealed by a sealing element, such as a sealing ring or sealant.

[0184] In a battery, there can be one or more battery cells 10. If there are multiple battery cells 10, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 10 are connected in both series and parallel. Alternatively, multiple battery cells 10 can be first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 20. Another option is that all battery cells 10 can be directly connected in series, parallel, or in a mixed configuration, and then the whole assembly of all battery cells 10 is housed within the housing 20.

[0185] Please refer to Figure 3 and Figure 4 , Figure 3 Exploded views of a battery cell 10 provided in some embodiments of this application; Figure 4 for Figure 3 The diagram shows a cross-sectional view of the battery cell 10. The battery cell 10 may include a housing 1 and an electrode assembly 2, which is housed within the housing 1.

[0186] In some embodiments, the housing 1 may include a housing 11 and an end cap 12, the housing 11 having an opening and the end cap 12 covering the opening of the housing 11.

[0187] The housing 11 is a component used to house the electrode assembly 2. The housing 11 can be a hollow structure with an opening at one end, or a hollow structure with openings at both opposite ends. The housing 11 can be in various shapes, such as cylindrical, cuboid, etc.

[0188] End cap 12 is a component that closes the opening of housing 11 to isolate the internal environment of battery cell 10 from the external environment. End cap 12 and housing 11 together define a receiving space for accommodating electrode assembly 2 and other components. End cap 12 can be connected to housing 11 by welding or roll sealing to close the opening of housing 11. The shape of end cap 12 can be adapted to the shape of housing 1. For example, if housing 11 is cuboid, end cap 12 is a rectangular plate structure adapted to housing 1; or if housing 11 is cylindrical, end cap 12 is a circular plate structure adapted to housing 11.

[0189] In an embodiment where an opening is formed at one end of the housing 11, one end cap 12 may be provided accordingly. In an embodiment where openings are formed at opposite ends of the housing 11, two end caps 12 may be provided accordingly, with the two end caps 12 respectively closing the two openings of the housing 11, and the two end caps 12 and the housing 11 together defining the receiving space.

[0190] Electrode assembly 2 is the component in the battery cell 10 where electrochemical reactions occur. The casing 11 may contain one or more electrode assemblies 2. Electrode assembly 2 is mainly formed by winding positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body 21 of the electrode assembly 2, while the portions of the positive and negative electrode sheets without active material each constitute a tab 22. The positive and negative tabs may be located together at one end of the main body 21 or separately at both ends of the main body 21. During the charging and discharging process of the battery cell 10, the positive and negative active materials react with the electrolyte.

[0191] In some embodiments, the battery cell 10 may further include an electrode terminal 3 disposed on the housing 1. The electrode terminal 3 is used for electrical connection with the tab 22 of the electrode assembly 2 to input or output electrical energy of the battery cell 10. The electrode terminal 3 may be disposed on the housing 11 of the housing 1 or on the end cap 12 of the housing 1. The electrode terminal 3 and the tab 22 may be directly connected, for example, by welding the electrode terminal 3 to the tab 22. The electrode terminal 3 and the tab 22 may also be indirectly connected, for example, by connecting the electrode terminal 3 to the tab 22 through a current collector 4. The current collector 4 may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc. The battery cell 10 may have one or more electrode terminals 3. For example, if the battery cell 10 is a cylindrical battery cell, there can be one electrode terminal 3. One tab 22 of the electrode assembly 2 (one of the positive tab 22 and the negative tab 22) can be electrically connected to the electrode terminal 3, and the other tab 22 of the electrode assembly 2 (the other of the positive tab 22 and the negative tab 22) can be electrically connected to the outer casing 1. As another example, if the battery cell 10 is a prismatic battery cell 10, there can be two electrode terminals 3. The two tabs 22 of the electrode assembly 2 (the positive tab 22 and the negative tab 22) are electrically connected to the two electrode terminals 3 respectively.

[0192] As an example, such as Figure 3 and Figure 4 As shown, the battery cell 10 is a cylindrical battery cell. The housing 11 has an opening at only one end, and there is one end cap 12 covering the opening of the housing 11. Electrode terminals 3 are provided on the wall of the housing 11 opposite to the end cap 12. The electrode assembly 2 has tabs 22 at both ends. The tabs 22 at both ends of the electrode assembly 2 are a first tab 22a and a second tab 22b, respectively. One of the first tabs 22a and the second tab 22b is a positive tab 22, and the other is a negative tab 22. The end cap 12 is electrically connected to the first tab 22a through a first current collector 4a, and the electrode terminal 3 is electrically connected to the second tab 22b through a second current collector 4b. The battery cell 10 also includes a first insulating member 5. At least a portion of the first insulating member 5 is disposed between the second current collector 4b and the wall of the housing 11 to insulate and isolate the second current collector 4b and the wall of the housing 11. This wall is disposed opposite to the end cap 12.

[0193] Please refer to Figure 4 and Figure 5 , Figure 4 for Figure 3 The cross-sectional view of the battery cell 10 shown. Figure 5 for Figure 4Enlarged view of position A. This application provides a battery cell 10, which includes an electrode assembly 2, a housing 1, and a protective layer 6. The housing 1 houses the electrode assembly 2. The housing 1 is made of steel and includes a shell 11, an end cap 12, and a solder joint 7. The shell 1 has an opening at at least one end along a first direction Z, and the end cap 12 corresponds to each opening, covering the opening. The solder joint 7 connects the shell 11 and the end cap 12. Along the first direction Z, the end cap 12 has a first surface 141 facing away from the electrode assembly 2. The outer surface 711 of the solder joint connects the outer peripheral surface 111 of the shell and the first surface 141. The outer surface 711 of the solder joint includes a rounded corner area 7112 connected to the first surface 141, and at least a portion of the rounded corner area 7112 is covered by the protective layer 6.

[0194] The outer casing 1 is made of steel, which may include carbon steel or stainless steel. Carbon steel may be Q195 carbon steel, SPCC carbon steel, etc.; stainless steel may be SUS430 stainless steel, SUS304 stainless steel, SUS316 stainless steel, or modified stainless steel, etc. Both the outer casing 11 and the end cap 12 may be made of steel. The entire outer casing 11 may be made of steel; alternatively, a portion of the outer casing 11 may be made of steel, for example, the outer casing 11 may include the casing body 113 (…). Figure 4 and Figure 5 (not shown in the image) and a first anti-corrosion layer 114 disposed on the surface of the shell body 113. Figure 4 and Figure 5 (Not shown in the image), the shell body 113 is made of steel, and the first anti-corrosion layer 114 is made of non-steel material. The end cap 12 can be entirely made of steel; or a portion of the end cap 12 can be made of steel. For example, the end cap 12 includes the cap body 121 (…). Figure 4 and Figure 5 (not shown in the image) and a second anti-corrosion layer 122 disposed on the surface of the cover body 121. Figure 4 and Figure 5 (Not shown in the image), the cover body 121 is made of steel, and the second anti-corrosion layer 122 is made of non-steel material.

[0195] The solder mark 7 is a solder area formed for welding the housing 11 and the end cap 12. There can be one or more solder marks 7. The outer surface 711 of the solder mark is the surface of the solder mark 7 exposed to the outside of the housing 1. The protective layer 6 can cover a part of the outer surface 711 of the solder mark, or it can cover the entire outer surface 711 of the solder mark (the protective layer 6 completely covers the outer surface 711 of the solder mark).

[0196] Along the first direction Z, the first surface 141 of the end cap 12 faces the outside of the outer casing 1. Along the first direction Z, the first surface 141 can be the surface of the end cap 12 furthest from the electrode assembly 2; the surface of the end cap 12 furthest from the electrode assembly 2 is the surface of the end cap 12 that is farthest from the electrode assembly 2. For example, the end cap 12 has a flat plate structure, and the first surface 141 is the end face of the end cap 12 facing away from the electrode assembly 2. The first surface 141 is a plane, and the first surface 141 is the surface of the end cap 12 furthest from the electrode assembly 2. Along the first direction Z, the first surface 141 may not be the surface of the end cap 12 furthest from the electrode assembly 2. For example, the first surface 141 may be located in the edge region of the end cap 12, and the surface of the end cap 12 furthest from the electrode assembly 2 may be located in the central region of the end cap 12. In this case, the first surface 141 is closer to the electrode assembly 2 than the surface of the end cap 12 furthest from the electrode assembly 2.

[0197] The outer peripheral surface 111 of the housing is a surface that surrounds the opening of the housing 11 circumferentially and extends along the first direction Z. Please refer to... Figure 4 and Figure 5 The battery cell 10 is a cylindrical battery cell, and the outer peripheral surface 111 of the casing is a cylindrical surface.

[0198] "The outer surface 711 of the soldering portion includes a rounded corner area 7112 connected to the first surface 141" can mean that the outer surface 711 of the soldering portion is the rounded corner area 7112, or that a portion of the outer surface 711 of the soldering portion adjacent to the first surface 141 is the rounded corner area 7112. The cross-section of the rounded corner area 7112 parallel to the first direction Z is approximately arc-shaped, and the arc shape can be a circular arc or an elliptical arc.

[0199] The protective layer 6 can cover a portion or the entire rounded corner area 7112. The protective layer 6 is attached to the outer surface of the rounded corner area 7112. It serves to prevent contact between the external environment and the rounded corner area 7112, thus achieving a rust-proof effect; therefore, the protective layer 6 can also be called a rust-proof layer. The protective layer 6 can be an insulating material, such as an adhesive layer, coating, tape, or insulating film.

[0200] The soldering section 7 connects the housing 11 and the end cap 12, achieving a stable connection between the housing 11 and the end cap 12. The rounded corner area 7112 eliminates the sharp corners of the edge area of ​​the end cap 12. During the process of applying anti-rust material to the rounded corner area 7112 to form the protective layer 6, the anti-rust material can better adhere to the rounded corner area 7112 of the soldering section 7. The anti-rust material is less likely to fall off from the outer surface 711 of the soldering section under gravity, which is conducive to the formation of the protective layer 6 on the soldering section 7, thereby reducing the risk of corrosion of the soldering section 7 and effectively improving the service life of the battery cell 10.

[0201] Please refer to Figure 4 and Figure 5 In some embodiments, the outer surface 711 of the soldering portion includes a connection area 7111, which connects to the outer peripheral surface 111 of the housing. The connection area 7111 transitions to the first surface 141 via a rounded corner area 7112. At least a portion of the connection area 7111 is covered with a protective layer 6.

[0202] The connection area 7111 is the area connecting the fillet area 7112 of the outer surface 711 of the soldering part and the outer peripheral surface 111 of the housing. The connection area 7111 smoothly transitions to the outer peripheral surface 111 of the housing, and the fillet area 7112 smoothly transitions to the first surface 141, so that the outer peripheral surface 111 of the housing can smoothly transition to the first surface 141 through the outer surface 711 of the soldering part. The cross-section of the connection area 7111 parallel to the first direction Z can be arc-shaped or straight.

[0203] The protective layer 6 can cover a part of the connection area 7111, or it can cover the entire connection area 7111 (that is, the protective layer 6 completely covers the connection area 7111).

[0204] The connecting area 7111 connects to the outer peripheral surface 111 of the housing. The connecting area 7111 transitions to the first surface 141 through the rounded corner area 7112. In this way, the outer surface 711 of the soldering part is relatively smooth, and the outer peripheral surface 111 of the housing can smoothly transition to the first surface 141 through the outer surface 711 of the soldering part. During the process of coating the anti-rust material on the rounded corner area 7112 to form the protective layer 6, the anti-rust material can better adhere to the outer surface 711 of the soldering part. The anti-rust material is not easy to fall off from the outer surface 711 of the soldering part under the action of gravity, which is conducive to the formation of the protective layer 6 on the soldering part 7, thereby reducing the risk of the soldering part 7 being corroded and effectively improving the service life of the battery cell 10.

[0205] Please refer to Figure 6 , Figure 6 This is a partial enlarged view of a battery cell 10 provided in other embodiments of this application. In some embodiments, the outer surface 711 of the solder mark is provided with a first groove 13, and a portion of the protective layer 6 is accommodated within the first groove 13.

[0206] The outer surface of the soldering part 7 is the surface of the soldering part 7 exposed to the outside of the outer casing 1. The outer surface 711 of the soldering part is a surface that can come into contact with a medium in the external environment, such as air, water, and other corrosive substances. The outer surface 711 of the soldering part is provided with a first groove 13, such that the first groove 13 is recessed inward from the outer surface 711 of the soldering part, and the groove opening of the first groove 13 is formed on the outer surface 711 of the soldering part.

[0207] The first groove 13 can be formed on the outer surface 711 of the solder area by laser cleaning, stamping, milling, or other methods. The cross-section of the first groove 13 can be rectangular, V-shaped, semi-circular, etc., and the cross-section of the first groove 13 is perpendicular to the extension direction O of the groove (not shown in 6). The extension trajectory line of the first groove 13 can be a straight line, an arc, a circular line, a planar spiral, a helix, etc.

[0208] The portion of the protective layer 6 contained within the first groove 13 may or may not completely fill the first groove 13. Alternatively, the portion of the protective layer 6 contained within the first groove 13 may be connected to the groove wall of the first groove 13; or the portion may not be connected to the groove wall of the first groove 13, for example, the portion of the protective layer 6 contained within the first groove 13 may be inserted into the first groove 13, such that the portion of the protective layer 6 contained within the first groove 13 only maintains contact with the groove wall of the first groove 13.

[0209] The protective layer 6 covers at least a portion of the outer surface 711 of the soldering portion, and the outer surface 711 of the soldering portion is provided with a first groove 13. A portion of the protective layer 6 is accommodated in the first groove 13, which increases the adhesion of the protective layer 6 and improves the firmness of the protective layer 6 on the soldering portion 7. This achieves long-term protection of the soldering portion 7 by the protective layer 6, reduces the risk of the protective layer 6 falling off the outer surface 711 of the soldering portion in a short period of time, and further reduces the risk of the soldering portion 7 of the outer casing 1 being corroded, effectively improving the service life of the battery cell 10.

[0210] Even in embodiments where both the housing 11 and end cap 12 in the outer casing 1 have anti-corrosion layers, the high welding temperature during welding of the housing 11 and / or end cap 12 can cause the surface anti-corrosion layer to oxidize, forming a loose and easily peeling oxide layer. This can even lead to partial evaporation of the anti-corrosion layer, exposing the steel substrate in the welding area and making the welded portion 7 prone to rusting. In other words, in related technologies, even if both the housing 11 and end cap 12 in the outer casing 1 have anti-corrosion layers, the outer casing 1 is still prone to rusting at the welded portion 7. Therefore, in this embodiment, by covering at least a portion of the outer surface of the welded portion 7 with the protective layer 6, the rusting of the welded portion 7 can be effectively mitigated.

[0211] Please refer to Figure 6 In some embodiments, the portion of the protective layer 6 contained within the first groove 13 is connected to the groove wall of the first groove 13.

[0212] The portion of the protective layer 6 contained within the first groove 13 is connected to the groove wall of the first groove 13, resulting in a certain degree of adhesion between the portion of the protective layer 6 contained within the first groove 13 and the groove wall of the first groove 13. The portion of the protective layer 6 contained within the first groove 13 may cover a portion of the groove wall of the first groove 13, or it may cover the entire groove wall of the first groove 13. It is understood that if the portion of the protective layer 6 contained within the first groove 13 completely fills the first groove 13, then the portion of the protective layer 6 contained within the first groove 13 covers the entire groove wall of the first groove 13.

[0213] The groove wall of the first groove 13 defines the internal space of the first groove 13. Taking the cross-section of the first groove 13 as rectangular as an example, the groove wall of the first groove 13 may include the groove side and the groove bottom. The groove bottom is disposed opposite to the groove opening of the first groove 13. The portion of the protective layer 6 accommodated in the first groove 13 may be connected to the groove side and / or the groove bottom of the first groove 13.

[0214] Connecting the portion of the protective layer 6 contained within the first groove 13 to the groove wall of the first groove 13 helps to increase the contact area between the protective layer 6 and the solder mark 7, thereby increasing the adhesion of the protective layer 6 to the solder mark 7 of the outer shell 1 and further improving the firmness of the protective layer 6 to the solder mark 7 of the outer shell 1.

[0215] Please refer to Figure 6 In some embodiments, at least a portion of the first groove 13 is located in the rounded corner area 7112, and a portion of the protective layer 6 is accommodated within the portion of the first groove 13 located in the rounded corner area 7112.

[0216] It is possible that a portion of a first groove 13 is disposed in the rounded corner area 7112, or that all of a first groove 13 is disposed in the rounded corner area 7112, or that only a portion of each of multiple first grooves 13 is disposed in the rounded corner area 7112, or that all of each of multiple first grooves 13 is disposed in the rounded corner area 7112.

[0217] The portion of the first groove 13 located in the rounded corner area 7112 is the portion of the first groove 13 that is recessed from the rounded corner area 7112 toward the solder pad 7.

[0218] At least a portion of the first groove 13 is disposed in the rounded corner area 7112, and a portion of the protective layer 6 is accommodated in the portion of the first groove 13 located in the rounded corner area 7112, which improves the firmness of the protective layer 6 in the rounded corner area 7112, realizes the long-term protection of the rounded corner area 7112 by the protective layer 6, and reduces the risk of the outer shell 1 being corroded in the rounded corner area 7112.

[0219] Please refer to Figure 7 , Figure 7This is a partially enlarged view of a battery cell 10 provided in some embodiments of this application. In some embodiments, the outer surface 711 of the soldered portion includes a connection area 7111, which connects to the outer peripheral surface 111 of the housing. The connection area 7111 transitions to the first surface 141 via a rounded corner area 7112. At least a portion of the first groove 13 is located in the connection area 7111, and at least a portion of the connection area 7111 is covered by a protective layer 6. A portion of the protective layer 6 is accommodated within the portion of the first groove 13 located in the connection area 7111.

[0220] It is possible that a portion of a first groove 13 is disposed in the connecting area 7111, or all of a first groove 13 is disposed in the connecting area 7111, or only a portion of multiple first grooves 13 are disposed in the connecting area 7111, or all of multiple first grooves 13 are disposed in the connecting area 7111.

[0221] The portion of the first groove 13 located in the connection area 7111 is the portion of the first groove 13 that is recessed from the connection area 7111 toward the solder pad 7.

[0222] The first groove 13 may have portions located in the rounded corner area 7112 and the connecting area 7111. Alternatively, a portion of the first groove 13 may be disposed in the connecting area 7111, and a portion of the protective layer 6 may be accommodated within the portion of the first groove 13 located in the connecting area 7111, while another portion of the first groove 13 may be disposed in the rounded corner area 7112, and a portion of the protective layer 6 may be accommodated within the portion of the first groove 13 located in the rounded corner area 7112.

[0223] There may be multiple first grooves 13, with both the rounded corner area 7112 and the connecting area 7111 having first grooves 13. A portion of the first grooves 13 may be located in the connecting area 7111, with a portion of the protective layer 6 contained within the first groove 13 in the connecting area 7111; another portion of the first grooves 13 may be located in the rounded corner area 7112, with a portion of the protective layer 6 contained within the first groove 13 in the rounded corner area 7112.

[0224] At least a portion of the first groove 13 is disposed in the connection area 7111, and a portion of the protective layer 6 is accommodated in the portion of the first groove 13 located in the connection area 7111, which improves the firmness of the protective layer 6 in the connection area 7111, realizes the long-term protection of the connection area 7111 by the protective layer 6, and reduces the risk of the outer shell 1 being corroded in the connection area 7111.

[0225] Please refer to Figure 8 and Figure 9 , Figure 8 This is a partial schematic diagram of the housing 1 provided in some embodiments of this application. Figure 9 for Figure 8Enlarged view of position B. In some embodiments, the outer surface 711 of the soldering portion is connected to the outer peripheral surface 111 of the housing at the first edge 1315, the outer surface 711 of the soldering portion is connected to the first surface 141 at the second edge 1316, the first edge 1315 and the second edge 1316 are spaced apart along the first direction Z, and the first groove 13 extends to the first edge 1315 and the second edge 1316.

[0226] The first edge 1315 is the intersection line formed at the connection position of the outer surface 711 of the soldering portion and the outer peripheral surface 111 of the housing, and the second edge 1316 is the intersection line formed at the connection position of the outer surface 711 of the soldering portion and the first surface 141. The first edge 1315 and the second edge 1316 can extend circumferentially along the opening of the housing 11. The first groove 13 extends to the first edge 1315 and the second edge 1316, with one end of the first groove 13 located at the first edge 1315 and the other end located at the second edge 1316.

[0227] The first groove 13 can be a groove extending along a straight trajectory, such as the first groove 13 extending along the first direction Z; the first groove 13 can also be a groove extending along a curved trajectory, and the plane where the curved trajectory is located can be set at a non-zero angle with the first direction Z.

[0228] By extending the first groove 13 provided on the outer surface 711 of the soldering portion to the first edge 1315 and the second edge 1316, the span of the first groove 13 in the first direction Z is increased, which is beneficial for more of the protective layer 6 to be accommodated in the first groove 13, thereby improving the firmness of the protective layer 6 on the soldering portion 7.

[0229] Please refer to Figure 8 and Figure 9 In some embodiments, there are multiple first grooves 13, and the multiple first grooves 13 are arranged circumferentially along the opening.

[0230] The number of first grooves 13 can be two, three, four, five, six, or more. Along the circumference of the opening, two adjacent first grooves can be spaced apart or connected to each other.

[0231] In the plurality of first grooves 13, two adjacent first grooves 13 can be arranged in parallel or at a non-zero included angle.

[0232] As an example, the outer peripheral surface 111 of the shell is provided with a second groove 14, and the outer peripheral surface 111 of the shell is covered with a protective layer 6, a portion of which is accommodated within the second groove 14. Two adjacent first grooves 13 are arranged at a non-zero included angle. Among three adjacent first grooves 13, the first first groove 13, a second groove 14 provided on the outer peripheral surface 111 of the shell, the second first groove 13, and the third second groove 14 are sequentially connected to form an N-shaped structure.

[0233] By setting multiple first grooves 13 and arranging the multiple first grooves 13 circumferentially along the opening, the multiple first grooves 13 can accommodate more of the protective layer 6, thereby improving the firmness of the protective layer 6 on the solder area 7.

[0234] Please refer to Figure 10 , Figure 10 This is a partial enlarged view of the housing 1 provided for other embodiments of this application. In some embodiments, the first groove 13 includes a plurality of groove groups 131 arranged circumferentially along the opening. Each groove group 131 includes a first groove segment 1311, a second groove segment 1312, and a third groove segment 1313 connected in sequence. The first groove segment 1311 and the third groove segment 1313 are respectively connected to opposite ends of the second groove segment 1312 and are respectively located on both sides of the second groove segment 1312 along its width direction. The first groove 13 also includes a plurality of fourth groove segments 1314 arranged circumferentially along the opening. In two adjacent groove groups 131, the end of the first groove segment 1311 of one groove group 131 away from the second groove segment 1312 is connected to the end of the third groove segment 1313 of another groove group 131 away from the second groove segment 1312 via a fourth groove segment 1314.

[0235] The first groove 13 may include two groove groups 131, three groove groups 131, four groove groups 131 or more groove groups 131, with the multiple groove groups 131 spaced apart circumferentially along the opening.

[0236] Each slot group 131 includes a first slot segment 1311, a second slot segment 1312, and a third slot segment 1313, wherein the second slot segment 1312 connects the first slot segment 1311 and the third slot segment 1313. Specifically, the first slot segment 1311 and the third slot segment 1313 are arranged opposite to each other along a first direction Z. The first slot segment 1311 has a first end 1311a and a second end 1311b at its two ends in its extension direction, and the third slot segment 1313 has a third end 1313a and a fourth end 1313b at its two ends in its extension direction. Along the first direction Z, the first end 1311a and the third end 1313a are arranged opposite to each other, the second end 1311b and the fourth end 1313b are arranged opposite to each other, and the second slot segment 1312 connects the first end 1311a and the fourth end 1313b.

[0237] The first groove 13 also includes a plurality of fourth groove segments 1314, which are spaced apart circumferentially along the opening. In two adjacent groove groups 131, the second end 1311b of the first groove segment 1311 of one groove group 131 is connected to the third end 1313a of the third groove segment 1313 of the other groove group 131 through a fourth groove segment 1314, so that the first groove segment 1311, the second groove segment 1312, the third groove segment 1313 and the fourth groove segment 1314 roughly form an “8” shape.

[0238] The first groove segment 1311, the second groove segment 1312, the third groove segment 1313, and the fourth groove segment 1314 can be grooves extending along a straight trajectory or grooves extending along a curved trajectory, etc. In the embodiment where the outer shell 1 is cuboid, the first groove segment 1311, the second groove segment 1312, the third groove segment 1313, and the fourth groove segment 1314 can be grooves extending along a straight trajectory; in the embodiment where the outer shell 1 is cylindrical, the first groove segment 1311, the second groove segment 1312, the third groove segment 1313, and the fourth groove segment 1314 can be grooves extending along an elliptical trajectory.

[0239] The shapes of the first groove segment 1311 and the third groove segment 1313 can be the same or different.

[0240] The first groove 13 is similar to multiple consecutive figure-eight structures. On the one hand, with a fixed circumferential dimension along the opening of the first groove 13, it increases both the extension dimension of the first groove 13 (the sum of the extension dimensions of all groove segments) and the span of the first groove 13 in the first direction Z. This is beneficial for accommodating more of the protective layer 6 within the first groove 13, thereby increasing the adhesion of the protective layer 6 to the soldering part 7. On the other hand, it can reduce the number of first grooves 13 arranged along the first direction Z on the soldering part 7, reducing the number of processing steps and improving production efficiency.

[0241] Please refer to Figure 11 , Figure 11 This is a top view of the solder joint 7 provided in some embodiments of the application. The first groove 13 extends circumferentially along the opening.

[0242] The first groove 13 can be an annular groove, or the first groove 13 can be spaced apart at both ends along the circumference of the opening of the housing 11. The number of first grooves 13 can be one or more.

[0243] The first groove 13 extends circumferentially along the opening. The structure of the first groove 13 is simple and easy to form.

[0244] Please refer to Figure 12 , Figure 12This is a partial enlarged view of the housing 1 provided in some embodiments of this application. In some embodiments, there are multiple first grooves 13, which are spaced apart along a first direction Z.

[0245] The multiple first grooves 13 can be set with varying spacing along the first direction Z, or they can be set with equal spacing along the first direction Z.

[0246] The number of first grooves 13 can be two, three, four, five, six, or more. As an example, the number of first grooves 13 is four or more (including four).

[0247] By providing a plurality of first grooves 13 spaced apart along the first direction Z on the outer surface 711 of the soldering part, it is beneficial to increase the contact area between the protective layer 6 and the soldering part 7 and improve the firmness of the protective layer 6 on the soldering part 7.

[0248] In some embodiments, the outer casing 1 is cylindrical, and the first direction Z is parallel to the axial direction of the outer casing 1. There are multiple first grooves 13, which are arranged at radial intervals along the outer casing 1.

[0249] The number of first grooves 13 can be two, three, four, five, six, or more. As an example, the number of first grooves 13 is four or more (including four). Multiple first grooves 13 are spaced apart along the radial direction of the housing 1.

[0250] By providing a plurality of first grooves 13 arranged radially at intervals along the outer surface 711 of the soldering portion, it is beneficial to increase the contact area between the protective layer 6 and the soldering portion 7, thereby improving the firmness of the protective layer 6 on the soldering portion 7.

[0251] Please refer to Figure 13 , Figure 13 This is a top view of the solder joint 7 provided for other embodiments of the application. In some embodiments, the orthographic projection of the first groove 13 extends along a planar spiral trajectory in a projection plane perpendicular to the first direction Z.

[0252] A planar spiral can be an Archimedean spiral, a logarithmic spiral, etc.

[0253] It should be noted that the orthographic projection of the groove refers to the orthographic projection of the groove wall. It can be understood that, in the projection plane perpendicular to the first direction Z, the orthographic projection of the first groove 13 is the orthographic projection of the groove wall of the first groove 13.

[0254] The orthographic projection of the first groove 13 in the projection plane perpendicular to the first direction Z extends along a planar spiral trajectory. On the one hand, this increases the extension size of the first groove 13, which is beneficial for accommodating more of the protective layer 6 within the first groove 13 and for increasing the contact area between the protective layer 6 and the soldering part 7, thereby increasing the adhesion of the protective layer 6 to the soldering part 7. On the other hand, it can reduce the number of first grooves 13 arranged on the soldering part 7 in the direction perpendicular to the first direction Z, thereby reducing the number of processing steps and improving production efficiency.

[0255] Please refer to Figure 14 , Figure 14 This is a partial enlarged view of the housing 1 provided for some embodiments of this application. In some embodiments, the first groove 13 extends along a spiral trajectory, and the central axis of the spiral extends along a first direction Z.

[0256] A moving point rotates around a central axis and simultaneously moves along the extension direction of that central axis. The trajectory of this combined motion of the moving point is a spiral, and the central axis is the central axis of the spiral.

[0257] As an example, the outer casing 1 is cylindrical, and the first groove 13 extends along a cylindrical helical trajectory. The outer surface 711 of the soldering portion is connected to the outer peripheral surface 111 of the casing at the first edge 1315. The outer peripheral surface 111 of the casing is provided with a second groove 14, which extends along a cylindrical helical trajectory. The second groove 14 and the first groove 13 on the outer peripheral surface 111 of the casing can be continuously provided, such that the first groove 13 communicates with the second groove 14 on the outer peripheral surface 111 of the casing.

[0258] Extending the first groove 13 along the spiral trajectory increases the extension dimension of the first groove 13 while keeping the axial dimension of the first groove 13 along the outer shell 1 constant. This allows more of the protective layer 6 to be accommodated within the first groove 13, increasing the contact area between the protective layer 6 and the soldering part 7, thereby increasing the adhesion of the protective layer 6 to the soldering part 7. On the other hand, it reduces the number of first grooves 13 arranged along the axial dimension of the outer shell 1 on the soldering part 7, reducing the number of processing steps and improving production efficiency.

[0259] Please refer to Figure 15 and Figure 16 , Figure 15 A partial enlarged view of a first groove 13 provided for some embodiments of this application (showing a plurality of grooves 133 of the first groove 13). Figure 16 for Figure 15 A cross-sectional view at the CC position. In some embodiments, the first groove 13 includes a plurality of slots 133 arranged along its extending direction, and a portion of the protective layer 6 is accommodated within the slots 133. Two adjacent slots 133 are connected to each other, forming a communication opening 134 at the connection position.

[0260] Multiple grooves 133 in the first groove 13 are continuously arranged, and two adjacent grooves 133 form a connecting port 134 at the connection position, and the two adjacent grooves 133 are connected at the connecting port 134.

[0261] As an example, the connecting port 134 is recessed from the outer surface 711 of the soldering portion into the soldering portion 7. The groove walls of two adjacent groove portions 133 intersect to form an intersecting line, which defines the connecting port 134. The connecting port 134 is semi-circular.

[0262] The area of ​​the connecting opening 134 can be smaller than the area of ​​any cross-section of the groove 133; alternatively, the area of ​​the connecting opening 134 can be larger than the area of ​​any cross-section of the groove 133. For a groove 133 with connecting openings 134 formed at both ends, any cross-section of the groove 133 is located between the two connecting openings 134 at both ends of the groove 133. Within the cross-section of the groove 133, the groove 133 can be a constant-width structure with a width that remains constant along the depth direction, or a variable-width structure with a width that varies along the depth direction. Here, the cross-section refers to the section perpendicular to the extension direction O of the first groove.

[0263] The first groove 13 includes a plurality of grooves 133 arranged along its extension direction. Two adjacent grooves 133 are connected to each other and form a communication opening 134 at the connection position. This structure reduces the flatness of the groove wall surface of the first groove 13, making the groove wall surface of the first groove 13 rougher, increasing the adhesion between the protective layer 6 and the groove wall surface of the first groove 13, and further reducing the risk of the protective layer 6 falling off from the outer surface 711 of the soldering part.

[0264] Please refer to Figure 15 and Figure 16 In some embodiments, the area of ​​the connecting port 134 is smaller than the area of ​​any cross-section of the groove 133, and the cross-section is perpendicular to the extension direction O of the first groove.

[0265] As an example, the cross-sectional area of ​​the groove 133 gradually decreases from the middle to both ends, such that the area of ​​the connecting opening 134 is smaller than the area of ​​any cross-section of the groove 133. The area of ​​the connecting opening 134 is less than or equal to 0.8 times the maximum cross-sectional area of ​​the groove 133.

[0266] By setting the area of ​​the connecting opening 134 to be smaller than the area of ​​any cross-section of the groove 133, the first groove 13 forms a necking structure at the position of the connecting opening 134, which can further increase the adhesion between the protective layer 6 and the groove wall, and achieve strong adhesion of the protective layer 6 to the soldering part 7.

[0267] Please refer to Figure 15 and Figure 16In some embodiments, within the cross-section of the groove 133, the dimension of the groove 133 in the width direction X of the first groove gradually decreases along the depth direction Y of the first groove, and the cross-section is perpendicular to the extension direction O of the first groove.

[0268] It is understood that in this embodiment, within the cross-section of the groove 133, the groove 133 is a widened structure whose width varies along the depth direction.

[0269] The dimension of the groove 133 in the width direction X of the first groove is the width of the groove 133. The depth direction of the groove 133 is consistent with the depth direction Y of the first groove. The direction from the groove opening of the groove 133 to the bottom of the groove 133 is the depth direction of the groove 133.

[0270] As an example, along the width direction X of the first groove, the groove 133 has two opposite groove sides, which intersect with the cross section of the groove 133 and form two intersecting lines, both of which are arcs.

[0271] By setting the dimension of the groove 133 in the width direction X of the first groove to gradually decrease along the depth direction Y of the first groove, the rust-preventive material can more easily adhere to the groove wall surface of the groove 133 during the process of coating the rust-preventive material on the outer surface 711 of the soldering part to form the protective layer 6. This is beneficial to increasing the contact area between the protective layer 6 and the groove wall surface of the groove 133, thereby increasing the adhesion of the protective layer 6.

[0272] Please refer to Figure 15 and Figure 16 In some embodiments, the maximum size of the communication opening 134 is smaller than the maximum size of the groove 133 along the depth direction of the groove 133.

[0273] The maximum dimension of the connecting opening 134 along the depth direction Y of the first groove is the maximum depth of the connecting opening 134, and the maximum dimension of the groove 133 along the depth direction Y of the first groove is the maximum depth of the groove 133.

[0274] By setting the maximum dimension of the connecting port 134 along the depth direction Y of the first groove to be smaller than the maximum dimension of the groove 133 along the depth direction Y of the first groove, the area of ​​the groove wall of the groove 133 can be increased, which is beneficial to increasing the contact area between the protective layer 6 and the groove wall of the groove 133, thereby increasing the adhesion of the protective layer 6.

[0275] Please refer to Figure 15 and Figure 16 In some embodiments, the maximum size of the communication opening 134 is smaller than the maximum size of the groove 133 along the width direction X of the first groove.

[0276] The maximum dimension of the connecting opening 134 along the width direction X of the first groove is the maximum width of the connecting opening 134, and the maximum dimension of the groove 133 along the width direction X of the first groove is the maximum width of the groove 133.

[0277] By setting the maximum dimension of the connecting opening 134 along the width direction X of the first groove to be smaller than the maximum dimension of the groove 133 along the width direction X of the first groove, the area of ​​the groove wall of the groove 133 can be increased, which is beneficial to increasing the contact area between the protective layer 6 and the groove wall of the groove 133, thereby increasing the adhesion of the protective layer 6.

[0278] Please refer to Figure 15 and Figure 16 In some embodiments, the maximum dimension of the groove 133 is L along the extension direction O of the first groove, and the maximum dimension of the groove 133 is W along the width direction X of the first groove, where 1.1 ≤ W / L ≤ 10.

[0279] The maximum dimension L of the groove 133 along the extension direction O of the first groove is the extension length of the groove 133 in the extension direction O of the first groove. For example, if the first groove 13 extends along a straight line, L is the straight line length of the groove 133 in the extension direction O of the first groove; or if the first groove 13 extends along an arc, L is the arc length of the groove 133 in the extension direction O of the first groove.

[0280] W / L can take any one of the following point values ​​or a range between any two: 1.1, 1.3, 1.7, 2, 2.3, 2.7, 3, 3.3, 3.7, 4, 4.3, 4.7, 5, 5.3, 5.7, 6, 6.3, 6.7, 7, 7.3, 7.7, 8, 8.3, 8.7, 9, 9.3, 9.7, 10.

[0281] The ratio of the maximum dimension W of the groove 133 along the width direction X of the first groove to the maximum dimension L of the groove 133 along the extension direction O of the first groove is set to 1.1-10, so that the maximum dimension W of the groove 133 along the width direction X of the first groove is larger than the maximum dimension L of the groove 133 along the extension direction O of the first groove, which reduces the difficulty of the anti-rust material entering the first groove 13 during the process of coating the anti-rust material on the outer surface 711 of the soldering part to form the protective layer 6.

[0282] In some embodiments, 70μm≤W≤90μm, 7μm≤L≤81μm.

[0283] W can take any one of the following values ​​or a range between any two: 70μm, 71μm, 72μm, 73μm, 74μm, 75μm, 76μm, 77μm, 78μm, 79μm, 80μm, 81μm, 82μm, 83μm, 84μm, 85μm, 86μm, 87μm, 88μm, 89μm, and 90μm.

[0284] L can be any point value or a range between any two of the following: 7μm, 10μm, 15μm, 18μm, 20μm, 22μm, 26μm, 30μm, 33μm, 37μm, 40μm, 45μm, 48μm, 50μm, 53μm, 57μm, 60μm, 62μm, 66μm, 70μm, 72μm, 74μm, 79μm, 80μm, 81μm.

[0285] The maximum dimension W of the groove 133 along the width direction X of the first groove is set to 70μm-90μm, and the maximum dimension L of the groove 133 along the extension direction O of the first groove is set to 7μm-81μm, so that the groove 133 is a small groove with a small size, so as to accurately control the surface roughness of the soldering part 7, which is beneficial to improve the firmness of the protective layer 6 on the soldering part 7.

[0286] Please refer to Figure 15 and Figure 16 In some embodiments, the maximum width of the first groove 13 is W, where 70μm≤W≤90μm.

[0287] Among them, such as Figure 16 As shown, in an embodiment where the first groove 13 includes a plurality of groove portions 133, and the maximum dimension of the connecting opening 134 along the width direction X of the first groove is smaller than the maximum dimension of the groove portion 133 along the width direction X of the first groove, the maximum dimension of the groove portion 133 along the width direction X of the first groove can be the maximum width of the first groove 13 being W.

[0288] W can take any one of the following values ​​or a range between any two: 70μm, 71μm, 72μm, 73μm, 74μm, 75μm, 76μm, 77μm, 78μm, 79μm, 80μm, 81μm, 82μm, 83μm, 84μm, 85μm, 86μm, 87μm, 88μm, 89μm, and 90μm.

[0289] W≥70μm ensures that the maximum width of the first groove 13 is not too small. This reduces the processing difficulty of the first groove 13 and the difficulty of the anti-rust material entering the first groove 13 during the process of coating the anti-rust material on the outer surface 711 of the soldering part to form the protective layer 6. This is beneficial to increasing the contact area between the protective layer 6 and the groove wall of the first groove 13. W≤90μm ensures that the maximum width of the first groove 13 is not too large. This allows for the formation of a narrower groove on the outer surface 711 of the soldering part. This is beneficial to setting more first grooves 13 per unit area and to increasing the density of the first grooves 13 on the soldering part 7, thereby increasing the adhesion of the protective layer 6 on the soldering part 7.

[0290] Please refer to Figure 15 and Figure 16 In some embodiments, the maximum depth of the first groove 13 is H, where 5μm≤H≤20μm.

[0291] Among them, such as Figure 16 As shown, in an embodiment where the first groove 13 includes a plurality of groove portions 133, and the maximum dimension of the connecting opening 134 along the depth direction Y of the first groove is smaller than the maximum dimension of the groove portion 133 along the depth direction Y of the first groove, the maximum dimension of the groove portion 133 along the depth direction Y of the first groove can be the maximum depth H of the first groove 13.

[0292] H can be any one of the following values: 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, or any value between two of them.

[0293] H≥5μm ensures that the maximum depth of the first groove 13 is not too small, allowing the first groove 13 to accommodate more of the protective layer 6, which is beneficial to increasing the contact area between the protective layer 6 and the groove wall of the first groove 13; H≤20μm ensures that the maximum depth of the first groove 13 is not too large, reducing the impact of the setting of the first groove 13 on the strength of the soldering part 7.

[0294] In some embodiments, the first groove 13 is a laser cleaning tank.

[0295] The first groove 13 is formed on the outer surface 711 of the solder area by laser cleaning. To process the outer surface 711 of the solder area as follows... Figure 15 The first groove 13 shown can form a groove 133 on the outer surface 711 of the soldering part when the laser spot moves to each set position during laser cleaning. By controlling the overlap rate of the laser spots at two adjacent set positions, the two adjacent grooves 133 can be connected and a connecting port 134 is formed at the connection position.

[0296] The first groove 13 is a laser cleaning tank, which is formed on the outer surface 711 of the solder area by laser cleaning. On the one hand, during the process of forming the first groove 13, surface contaminants (oxide layer or dirt, etc.) of the solder area 7 can be cleaned away, reducing the risk that contaminants will form a weak interface under the protective layer 6, resulting in a decrease in the adhesion of the protective layer 6. On the other hand, the groove wall of the first groove 13 is relatively rough, which increases the adhesion between the protective layer 6 and the groove wall of the first groove 13.

[0297] Please refer to Figure 17 and Figure 18 , Figure 17 This is a partial enlarged view of the battery cell 10 provided in some embodiments of this application. Figure 18 This application also provides a partial enlarged view of the battery cell 10 provided in some embodiments. In some embodiments, the outer surface of the housing 1 further includes a main body surface connected to the outer surface 711 of the soldering portion. The main body surface includes the outer surface of the housing 11 and the outer surface of the end cap 12. The main body surface is provided with a second groove 14. At least a portion of the main body surface is covered with a protective layer 6, and a portion of the protective layer 6 is accommodated in the second groove 14.

[0298] The main body surface is the part of the outer surface of the outer shell 1 other than the outer surface 711 of the soldering part. The outer surface of the shell 11 and the outer surface of the end cap 12 are both part of the main body surface.

[0299] The second groove 14 can be formed on the main body surface by laser cleaning, stamping, milling, or other methods. The cross-section of the second groove 14 can be rectangular, V-shaped, semi-circular, etc., and the cross-section of the second groove 14 is perpendicular to the extension direction of the second groove 14. The extension trajectory line of the second groove 14 can be a straight line, an arc, a circular line, a planar spiral, a helix, etc.

[0300] At least a portion of the main surface is covered by a protective layer 6, meaning the protective layer 6 covers at least a portion of the main surface. The protective layer 6 can cover a part or the entire main surface. The protective layer 6 is connected to the main surface and serves to prevent media from the external environment from contacting the portion of the main surface covered by the protective layer 6, thereby achieving a rust-proof effect. The protective layer 6 has a portion covering the main surface and a portion accommodated within the second groove 14. The portion of the protective layer 6 accommodated within the second groove 14 may fill the second groove 14 completely, or it may not occupy the entire space of the second groove 14. The portion of the protective layer 6 accommodated within the second groove 14 may be connected to the groove wall of the second groove 14; alternatively, the portion of the protective layer 6 accommodated within the second groove 14 may not be connected to the groove wall of the second groove 14, for example, the portion of the protective layer 6 accommodated within the second groove 14 may be inserted into the second groove 14, such that the portion of the protective layer 6 accommodated within the second groove 14 only maintains contact with the groove wall of the second groove 14.

[0301] It should be noted that the structure of the second groove 14 can be the same as that of the first groove 13. The second groove 14 can also include a plurality of grooves 133 arranged along its extension direction. A portion of the protective layer 6 is accommodated in the grooves 133. Two adjacent grooves 133 are connected to each other and form a communication port 134 at the connection position.

[0302] At least a portion of the main body surface is covered with a protective layer 6, increasing the area of ​​the protective layer 6 covering the outer surface of the outer shell 1 and mitigating rusting of the portion of the main body surface covered by the protective layer 6. A second groove 14 is provided on the main body surface, and a portion of the protective layer 6 is accommodated within the second groove 14. The second groove 14 provides a certain degree of restraint to the protective layer 6, improving its firmness on the outer shell 1 and reducing the risk that the portion of the protective layer 6 on the outer surface 711 of the solder joint may easily detach after the portion on the main body surface detaches, thus achieving long-term protection of the main body surface and the outer surface 711 of the solder joint by the protective layer 6.

[0303] In some embodiments, the portion of the protective layer 6 housed within the second groove 14 is connected to the groove wall surface of the second groove 14.

[0304] The portion of the protective layer 6 contained within the second groove 14 is connected to the groove wall of the second groove 14, resulting in a certain degree of adhesion between the portion of the protective layer 6 contained within the second groove 14 and the groove wall of the second groove 14. The portion of the protective layer 6 contained within the second groove 14 may cover a portion of the groove wall of the second groove 14, or it may cover the entire groove wall of the second groove 14. It is understood that if the portion of the protective layer 6 contained within the second groove 14 completely fills the second groove 14, then the portion of the protective layer 6 contained within the second groove 14 covers the entire groove wall of the second groove 14.

[0305] The groove wall of the second groove 14 defines the internal space of the second groove 14. Taking the cross-section of the second groove 14 as rectangular as an example, the groove wall of the second groove 14 may include the groove side and the groove bottom. The groove bottom is disposed opposite to the groove opening of the second groove 14. The portion of the protective layer 6 accommodated in the second groove 14 may be connected to the groove side and / or the groove bottom of the second groove 14.

[0306] Connecting the portion of the protective layer 6 contained within the second groove 14 to the groove wall of the second groove 14 helps to increase the contact area between the protective layer 6 and the outer shell 1, thereby increasing the adhesion of the protective layer 6 to the outer shell 1 and further improving the firmness of the protective layer 6 on the outer shell 1.

[0307] In some embodiments, the outer surface 711 of the soldering portion is provided with a first groove 13, at least a portion of the outer surface 711 of the soldering portion is covered with a protective layer 6, a portion of the protective layer 6 is accommodated in the first groove 13, and at least one second groove 14 communicates with at least one first groove 13.

[0308] It can be that one second groove 14 is connected to one first groove 13, or multiple second grooves 14 are connected to one first groove 13, or one second groove 14 is connected to multiple first grooves 13, or multiple second grooves 14 are connected to multiple first grooves 13.

[0309] exist Figure 17 In the illustrated embodiment, the outer surface 711 of the solder joint is provided with at least two first grooves 13. In a projection plane perpendicular to the first direction Z, the orthographic projection of one first groove 13 extends along a planar spiral trajectory, and this first groove 13 is located in the rounded corner area 7112; the other first groove 13 extends along a spiral trajectory, and this first groove 13 is located in the connecting area 7111. The outer peripheral surface 111 of the housing is provided with a second groove 14, which extends along a spiral trajectory and communicates with the first groove 13 located in the connecting area 7111, such that one first groove 13 communicates with one second groove 14 located on the outer peripheral surface 111 of the housing.

[0310] exist Figure 18 In the illustrated embodiment, the first groove 13 and the second groove 14 disposed on the outer peripheral surface 111 of the housing are arranged in accordance with... Figure 9 The connection is as shown, with the second groove 14 on the outer peripheral surface 111 of the housing connecting to two adjacent first grooves 13, such that each second groove 14 on the outer peripheral surface 111 of the housing is connected to two adjacent first grooves 13.

[0311] By communicating at least one second groove 14 with at least one first groove 13, the portion of the protective layer 6 contained in the second groove 14 and the portion of the protective layer 6 contained in the first groove 13 can be continuous, allowing more portions of the protective layer 6 to be contained in the first groove 13 and / or the second groove 14, further improving the robustness of the protective layer 6 on the outer casing 1.

[0312] Please refer to Figure 17 and Figure 18 In some embodiments, the outer surface of the housing 11 is provided with a second groove 14, and at least a portion of the outer surface of the housing 11 is covered with a protective layer 6, a portion of which is accommodated within the second groove 14.

[0313] At least a portion of the outer surface of the housing 11 is covered by the protective layer 6, that is, the protective layer 6 covers at least a portion of the outer surface of the housing 11. It may be that the protective layer 6 covers a part of the outer surface of the housing 11 or the entire outer surface of the housing 11.

[0314] exist Figure 18 In the illustrated embodiment, the outer peripheral surface 111 of the housing is part of the main body surface, the outer peripheral surface 111 of the housing is provided with a second groove 14, and the protective layer 6 covers a part of the outer peripheral surface 111 of the housing.

[0315] At least a portion of the outer surface of the housing 11 is covered with a protective layer 6, increasing the area covered by the protective layer 6 on the outer surface of the housing 11. This provides a certain degree of protection for the housing 11 and alleviates rusting of the portion of the outer surface of the housing 11 covered by the protective layer 6. A second groove 14 is provided on the outer surface of the housing 11, and a portion of the protective layer 6 is accommodated within the second groove 14. This improves the firmness of the protective layer 6 on the housing 11, ensuring long-term protection of the area of ​​the housing 11 near the solder joint 7, and reducing the risk of the portion of the protective layer 6 on the solder joint 7 detaching due to the partial detachment of the protective layer 6 from the outer surface of the housing 11.

[0316] Please refer to Figure 17 and Figure 18 In some embodiments, the outer peripheral surface 111 of the housing is provided with a second groove 14, and at least a portion of the outer peripheral surface 111 of the housing is covered with a protective layer 6, a portion of the protective layer 6 being accommodated within the second groove 14.

[0317] The outer peripheral surface 111 of the housing is at least a portion of the outer surface of the housing 11, and the outer peripheral surface 111 surrounds the opening of the housing 11 circumferentially. At least a portion of the outer peripheral surface 111 is covered by a protective layer 6, meaning the protective layer 6 covers at least a portion of the outer peripheral surface 111. The protective layer 6 may cover a portion of the outer peripheral surface 111 or it may cover the entire outer peripheral surface 111 (the protective layer 6 completely covers the outer peripheral surface 111). The outer peripheral surface 111 of the housing is provided with a second groove 14, such that the second groove 14 is recessed from the outer peripheral surface 111 into the wall of the housing 11, and the opening of the second groove 14 is formed on the outer peripheral surface 111 of the housing.

[0318] The second groove 14 provided on the outer peripheral surface 111 of the housing can be a groove extending circumferentially along the opening of the housing 11, or it can be a groove extending along a spiral trajectory.

[0319] At least a portion of the outer peripheral surface 111 of the housing is covered with a protective layer 6, increasing the area of ​​the protective layer 6 covering the outer surface of the housing 1. This allows the protective layer 6 to provide a certain degree of protection for the housing 11 and alleviate rusting of the portion of the outer peripheral surface 111 covered by the protective layer 6. A second groove 14 is provided on the outer peripheral surface 111 of the housing, and a portion of the protective layer 6 is accommodated within the second groove 14. This improves the firmness of the protective layer 6 on the housing 11, ensuring long-term protection of the area of ​​the housing 11 near the solder joint 7, and reducing the risk of the portion of the protective layer 6 on the solder joint 7 easily detaching after the portion on the outer peripheral surface 111 of the housing detaches.

[0320] Please refer to Figure 19 , Figure 20 and Figure 21 , Figure 19 This is a partial enlarged view of a battery cell 10 provided in some other embodiments of this application. Figure 20 This is a partial enlarged view of a battery cell 10 provided in some other embodiments of this application. Figure 21 The following is a partial enlarged view of the battery cell 10 provided in some other embodiments of this application. In some embodiments, a second groove 14 is provided on the outer surface of the end cap 12, and at least a portion of the outer surface of the end cap 12 is covered with a protective layer 6, a portion of which is accommodated within the second groove 14.

[0321] At least a portion of the outer surface of the end cap 12 is covered with a protective layer 6, that is, the protective layer 6 covers at least a portion of the outer surface of the end cap 12. It may be that the protective layer 6 covers a part of the outer surface of the end cap 12, or the end cap 12 covers the entire outer surface of the housing 11.

[0322] exist Figure 19 , Figure 20 and Figure 21 In the illustrated embodiment, the first surface 141 of the end cap 12 is part of the main body surface, the first surface 141 is provided with a second groove 14, and the protective layer 6 covers the entire first surface 141.

[0323] At least a portion of the outer surface of the end cap 12 is covered with a protective layer 6, increasing the area of ​​the protective layer 6 covering the outer surface of the outer shell 1. This allows the protective layer 6 to provide a certain degree of protection for the end cap 12, mitigating rusting of the portion of the outer surface of the end cap 12 covered by the protective layer 6. A second groove 14 is provided on the outer surface of the end cap 12, and a portion of the protective layer 6 is accommodated within the second groove 14. This improves the firmness of the protective layer 6 on the end cap 12, ensuring long-term protection of the area of ​​the end cap 12 near the solder mark 7, and reducing the risk of the portion of the protective layer 6 on the solder mark 7 detaching due to the partial detachment of the protective layer 6 from the outer surface of the end cap 12.

[0324] Please refer to Figure 19 , Figure 20 and Figure 21 In some embodiments, the first surface 141 is provided with a second groove 14, and at least a portion of the first surface 141 is covered with a protective layer 6, a portion of the protective layer 6 being accommodated within the second groove 14.

[0325] At least a portion of the first surface 141 is covered by a protective layer 6, meaning the protective layer 6 covers at least a portion of the first surface 141. The protective layer 6 may cover a portion of the first surface 141 or it may cover the entire first surface 141 (the protective layer 6 completely covers the first surface 141). The first surface 141 is provided with a second groove 14, such that the second groove 14 is recessed from the first surface 141 into the end cap 12, and the opening of the second groove 14 is formed on the first surface 141.

[0326] The second groove 14 provided on the first surface 141 can be a groove extending circumferentially along the opening of the housing 11, or it can be a groove extending along a planar spiral trajectory.

[0327] As an example, in Figure 19 In the projection plane perpendicular to the first direction Z, the orthographic projection of the first groove 13 and the orthographic projection of the second groove 14 disposed on the first surface 141 both extend along a planar spiral trajectory. The first groove 13 is disposed in the rounded corner area 7112, and the first groove 13 and the second groove 14 disposed on the first surface 141 are connected. The protective layer 6 completely covers the outer surface 711 of the solder stamp, and covers a portion of the first surface 141 and a portion of the outer peripheral surface 111 of the housing.

[0328] As an example, in Figure 20In the design, at least two first grooves 13 are provided on the outer surface 711 of the soldering portion, and second grooves 14 are provided on both the first surface 141 and the outer peripheral surface 111 of the housing. In a projection plane perpendicular to the first direction Z, the orthographic projection of one of the first grooves 13 and the orthographic projection of the second groove 14 on the first surface 141 both extend along a planar spiral trajectory. The first groove 13 is located in the rounded corner area 7112 and communicates with the second groove 14 on the first surface 141. Another first groove 13 and the second groove 14 on the outer peripheral surface 111 of the housing both extend along a spiral trajectory. The first groove 13 is located in the connecting area 7111 and communicates with the second groove 14 on the outer peripheral surface 111 of the housing. The protective layer 6 completely covers the outer surface 711 of the soldering portion and also covers a portion of the first surface 141 and a portion of the outer peripheral surface 111 of the housing.

[0329] As an example, in Figure 21 In the middle, both the first surface 141 and the outer peripheral surface 111 of the shell are provided with second grooves 14. In the projection plane perpendicular to the first direction Z, the orthographic projection of the second groove 14 on the first surface 141 extends along a planar spiral trajectory. The first groove 13 and the second groove 14 on the outer peripheral surface 111 of the shell are arranged in a... Figure 9 The connection is as shown, with the second groove 14 on the outer peripheral surface 111 of the housing connecting to two adjacent first grooves 13, such that each second groove 14 on the outer peripheral surface 111 of the housing is connected to two adjacent first grooves 13.

[0330] At least a portion of the first surface 141 is covered with a protective layer 6, increasing the area of ​​the protective layer 6 covering the outer surface of the outer casing 1. This allows the protective layer 6 to provide some protection for the end cap 12, mitigating rusting of the portion of the first surface 141 covered by the protective layer 6. A second groove 14 is provided on the first surface 141, and a portion of the protective layer 6 is accommodated within the second groove 14. This improves the firmness of the protective layer 6 on the end cap 12, ensuring long-term protection of the area of ​​the end cap 12 near the solder mark 7, and reducing the risk of the protective layer 6 detaching from the solder mark 7 due to the partial detachment of the protective layer 6 from the first surface 141.

[0331] Please refer to Figure 17 and Figure 22 , Figure 22 for Figure 17 Enlarged view of position D. In some embodiments, the housing 11 includes a housing body 113 and a first anti-corrosion layer 114. The housing body 113 is made of steel, and the first anti-corrosion layer 114 is disposed on the surface of the housing body 113. The outer surface of the first anti-corrosion layer 114 is at least a portion of the outer peripheral surface 111 of the housing. Both the housing body 113 and the first anti-corrosion layer 114 are connected to the solder joint 7.

[0332] The shell body 113 is the base material of the shell 11, and the shell body 113 can be made of steel, such as carbon steel. The first anti-corrosion layer 114 is the surface layer of the shell 11, and the thickness of the first anti-corrosion layer 114 is less than the thickness of the shell body 113. The first anti-corrosion layer 114 can be a plating layer disposed on the surface of the shell body 113. The material of the first anti-corrosion layer 114 can include at least one of nickel, aluminum, zinc, etc.

[0333] As an example, in Figure 22 In this context, the outer surface of the first anti-corrosion layer 114 is the outer surface of the shell 11, and the outer surface of the first anti-corrosion layer 114 includes the outer peripheral surface 111 of the shell.

[0334] The outer surface of the first anti-corrosion layer 114 is part of the outer surface of the outer shell 1, making the first anti-corrosion layer 114 the surface layer of the outer shell 1. The first anti-corrosion layer 114 has better corrosion resistance than the shell body 113, giving the shell 11 excellent rust prevention capabilities.

[0335] In some embodiments, the first anti-corrosion layer 114 includes a nickel layer.

[0336] It is possible that a portion of the first anti-corrosion layer 114 is a nickel layer, or the first anti-corrosion layer 114 itself is a nickel layer.

[0337] The nickel layer has good corrosion resistance and high hardness. The first anti-corrosion layer 114 includes a nickel layer, which improves the corrosion resistance and wear resistance of the shell 11.

[0338] Please refer to Figure 22 In some embodiments, the outer surface of the first anti-corrosion layer 114 is provided with a second groove 14, at least a portion of the outer surface of the first anti-corrosion layer 114 is covered with a protective layer 6, and a portion of the protective layer 6 is accommodated in the second groove 14.

[0339] At least a portion of the outer surface of the first anti-corrosion layer 114 is covered by the protective layer 6, that is, the protective layer 6 covers at least a portion of the outer surface of the first anti-corrosion layer 114. The protective layer 6 may cover a portion or the entire outer surface of the first anti-corrosion layer 114. A second groove 14 is provided on the outer surface of the first anti-corrosion layer 114, such that the second groove 14 is recessed from the outer surface of the first anti-corrosion layer 114 into the wall of the housing 11, and the opening of the second groove 14 is formed on the outer surface of the first anti-corrosion layer 114.

[0340] The depth of the second groove 14 on the outer surface of the first anti-corrosion layer 114 may be less than or equal to the thickness of the first anti-corrosion layer 114; or the depth of the second groove 14 on the outer surface of the first anti-corrosion layer 114 may be greater than the thickness of the first anti-corrosion layer 114, such that the second groove 14 penetrates the first anti-corrosion layer 114 along the depth direction and extends partly into the shell body 113.

[0341] At least a portion of the outer surface of the first anti-corrosion layer 114 is covered with the protective layer 6, so that the area where the protective layer 6 overlaps with the first anti-corrosion layer 114 can provide double protection for the shell body 113, further reducing the risk of the shell body 113 being corroded. At least a portion of the outer surface of the first anti-corrosion layer 114 is covered with the protective layer 6, and a portion of the protective layer 6 is accommodated in the second groove 14, which improves the firmness of the protective layer 6 on the shell 11. On the one hand, it enables the protective layer 6 to provide long-term protection for at least the area of ​​the shell 11 near the solder mark 7, and on the other hand, it reduces the risk that the portion of the protective layer 6 on the solder mark 7 may easily fall off due to the partial peeling off of the protective layer 6 on the outer surface of the first anti-corrosion layer 114.

[0342] Please refer to Figure 22 In some embodiments, the depth of the second groove 14 disposed on the outer surface of the first anti-corrosion layer 114 is less than the thickness of the first anti-corrosion layer 114.

[0343] Understandably, the second groove 14, which is provided on the outer surface of the first anti-corrosion layer 114, does not penetrate the first anti-corrosion layer 114 in the depth direction.

[0344] As an example, the depth of the second groove 14 provided on the outer surface of the first anti-corrosion layer 114 is less than or equal to 0.7 times the thickness of the first anti-corrosion layer 114.

[0345] The depth of the second groove 14 on the outer surface of the first anti-corrosion layer 114 is set to be less than the thickness of the first anti-corrosion layer 114, so that the second groove 14 does not penetrate the first anti-corrosion layer 114 along the thickness direction of the first anti-corrosion layer 114, so that the area of ​​the first anti-corrosion layer 114 where the second groove 14 is provided still has anti-rust capability for the shell body 113.

[0346] Please refer to Figure 19 and Figure 23 , Figure 23 for Figure 19 Enlarged view of position E. In some embodiments, the end cap 12 includes a cap body 121 and a second anti-corrosion layer 122. The cap body 121 is made of steel, and the second anti-corrosion layer 122 is disposed on the surface of the cap body 121. The outer surface of the second anti-corrosion layer 122 is a part of the outer surface of the end cap 12. Both the cap body 121 and the second anti-corrosion layer 122 are connected to the solder joint 7.

[0347] The cover body 121 is the base material of the end cap 12, and the cover body 121 can be made of steel, such as carbon steel. The second anti-corrosion layer 122 is the surface layer of the end cap 12, and the thickness of the second anti-corrosion layer 122 is less than the thickness of the cover body 121. The second anti-corrosion layer 122 can be a plating layer disposed on the surface of the cover body 121. The material of the second anti-corrosion layer 122 can include at least one of nickel, aluminum, zinc, etc.

[0348] As an example, in Figure 23 In this context, the outer surface of the second anti-corrosion layer 122 is the outer surface of the end cap 12, and the outer surface of the second anti-corrosion layer 122 includes the first surface 141 of the end cap 12.

[0349] The outer surface of the second anti-corrosion layer 122 is part of the outer surface of the outer shell 1, making the second anti-corrosion layer 122 the surface layer of the end cap 12. The second anti-corrosion layer 122 has better corrosion resistance than the cap body 121, giving the end cap 12 excellent rust prevention capabilities.

[0350] In some embodiments, the second anti-corrosion layer 122 includes a nickel layer.

[0351] It is possible that a portion of the second anti-corrosion layer 122 is a nickel layer, or that the second anti-corrosion layer 122 itself is a nickel layer.

[0352] The nickel layer has good corrosion resistance and high hardness. The second anti-corrosion layer 122 includes a nickel layer, which improves the corrosion resistance and wear resistance of the end cap 12.

[0353] Please refer to Figure 19 and Figure 23 In some embodiments, the outer surface of the second anti-corrosion layer 122 is provided with a second groove 14, and at least a portion of the outer surface of the second anti-corrosion layer 122 is covered with a protective layer 6, a portion of the protective layer 6 being accommodated within the second groove 14.

[0354] At least a portion of the outer surface of the second anti-corrosion layer 122 is covered by the protective layer 6, that is, the protective layer 6 covers at least a portion of the outer surface of the second anti-corrosion layer 122. The protective layer 6 may cover a portion or the entire outer surface of the second anti-corrosion layer 122. A second groove 14 is provided on the outer surface of the second anti-corrosion layer 122, such that the second groove 14 is recessed from the outer surface of the second anti-corrosion layer 122 into the end cap 12, and the opening of the second groove 14 is formed on the outer surface of the second anti-corrosion layer 122.

[0355] The depth of the second groove 14 on the outer surface of the second anti-corrosion layer 122 may be less than or equal to the thickness of the second anti-corrosion layer 122; or the depth of the second groove 14 on the outer surface of the second anti-corrosion layer 122 may be greater than the thickness of the second anti-corrosion layer 122, so that the second groove 14 penetrates the second anti-corrosion layer 122 along the depth direction and extends partly into the cover body 121.

[0356] At least a portion of the outer surface of the second anti-corrosion layer 122 is covered by the protective layer 6, so that the overlapping area of ​​the protective layer 6 and the second anti-corrosion layer 122 can provide double protection for the cover body 121, further reducing the risk of the cover body 121 being corroded. The outer surface of the second anti-corrosion layer 122 is provided with a second groove 14, and a portion of the protective layer 6 is accommodated in the second groove 14, which improves the firmness of the protective layer 6 on the end cap 12. On the one hand, it enables the protective layer 6 to provide long-term protection for at least the area of ​​the end cap 12 near the solder mark 7, and on the other hand, it reduces the risk that the portion of the protective layer 6 on the solder mark 7 may easily fall off due to the partial peeling off of the protective layer 6 on the outer surface of the second anti-corrosion layer 122.

[0357] Please refer to Figure 19 and Figure 23 In some embodiments, the depth of the second groove 14 disposed on the outer surface of the second anti-corrosion layer 122 is less than the thickness of the second anti-corrosion layer 122.

[0358] It is understandable that the second groove 14, which is provided on the outer surface of the second anti-corrosion layer 122, does not penetrate the second anti-corrosion layer 122 in the depth direction.

[0359] As an example, the depth of the second groove 14 provided on the outer surface of the second anti-corrosion layer 122 is less than or equal to 0.7 times the thickness of the second anti-corrosion layer 122.

[0360] The depth of the second groove 14 on the outer surface of the second anti-corrosion layer 122 is set to be less than the thickness of the second anti-corrosion layer 122, so that the second groove 14 does not penetrate the second anti-corrosion layer 122 along the thickness direction of the second anti-corrosion layer 122, so that the area of ​​the second anti-corrosion layer 122 with the second groove 14 still has the ability to prevent rust on the cover body 121. In some embodiments, the solder stamp 7 is an annular structure and the solder stamp 7 extends circumferentially along the opening.

[0361] When welding the housing 11 and the end cap 12, welding can be performed continuously along the circumference of the opening of the housing 11 to form a weld mark 7 with an annular structure.

[0362] The surface of the soldering portion 7 includes a first interface 712, a second interface 713, and an outer surface 711 of the soldering portion. The first interface 712, the second interface 713, and the outer surface 711 of the soldering portion all extend circumferentially along the opening of the housing 11. The first interface 712 is connected to and covered by the housing 11. The second interface 713 is connected to and covered by the end cap 12. The outer surface 711 of the soldering portion is exposed to the outside of the housing 1 and is not covered by the housing 11 or the end cap 12. Within the cross-section of the soldering portion 7 (parallel to the first direction Z), the first interface 712, the second interface 713, and the outer surface 711 of the soldering portion are connected end-to-end.

[0363] By setting the solder mark 7 as an annular structure extending circumferentially along the opening, the contact area between the housing 11 and the end cap 12 and the solder mark 7 is increased, the connection strength between the housing 11 and the end cap 12 and the solder mark 7 is increased, thereby improving the welding firmness of the housing 11 and the end cap 12. On the other hand, the solder mark 7 can achieve a sealed connection between the housing 11 and the end cap 12.

[0364] In some embodiments, the protective layer 6 completely covers the outer surface 711 of the solder mark.

[0365] Understandably, the protective layer 6 covers the entire outer surface of the solder joint 7.

[0366] By completely covering the outer surface 711 of the solder mark with the protective layer 6, the protective layer 6 can provide complete protection for the outer surface 711 of the solder mark, further alleviating the rusting phenomenon of the solder mark 7.

[0367] In some embodiments, the minimum distance of the protective layer 6 extending beyond the edge of the outer surface 711 of the solder mark is greater than or equal to 200 μm.

[0368] The minimum distance of the protective layer 6 extending beyond the edge of the outer surface of the solder mark 7 can be any one of the following values ​​or a range between any two: 200μm, 220μm, 250μm, 280μm, 300μm, 320μm, 350μm, 380μm, 400μm, 420μm, 450μm, 480μm, and 500μm.

[0369] During the welding process to form the weld mark 7, a heat-affected zone will be formed in the area of ​​the outer shell 1 near the weld mark 7. The minimum distance of the protective layer 6 beyond the edge of the outer surface 711 of the weld mark is greater than or equal to 200 μm, which can cover the heat-affected zone formed by welding and alleviate the rusting phenomenon in the heat-affected zone.

[0370] In some embodiments, the protective layer 6 is a coating.

[0371] The coating may include at least one of UV-cured coatings, epoxy resin coatings, polyurethane coatings, and water-based anti-rust paint coatings.

[0372] The protective layer 6 is a coating that can be formed by applying anti-rust material to the outer surface of the outer shell 1, giving the protective layer 6 good anti-corrosion performance and stability.

[0373] Optionally, the coating comprises, by weight percentage: 15-20% polyurethane acrylate, 10-15% epoxy acrylate, 45-70% reactive diluent and 5-10% photoinitiator.

[0374] The reactive diluent may include one or more of the following: benzyl acrylate, n-butyl acrylate, isooctyl acrylate, lauryl acrylate, styrene, isobornyl acrylate, 1,6-hexanediol diacrylate, tricyclodecanediethanol diacrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate, etc.

[0375] The coating is a UV-cured coating, which has the advantage of short curing time, which helps to improve the molding efficiency of the protective layer 6, and thus improves the molding efficiency of the battery cell 10. In addition, the thickness of the UV-cured coating can be controlled by precisely controlling the spraying amount, improving the uniformity of the thickness of the protective layer 6 and reducing material waste caused by excessive thickness or unevenness.

[0376] In some embodiments, the battery cell 10 is a cylindrical battery cell.

[0377] In this embodiment, the outer casing 1 of the battery cell 10 is cylindrical, the first direction Z is parallel to the axial direction of the outer casing 1, and the direction perpendicular to the first direction Z is the radial direction of the outer casing 1.

[0378] This application provides a battery device 100, which includes a battery cell 10 provided in any of the above embodiments.

[0379] This application provides an electrical device, including a battery cell 10 or a battery device 100 provided in any of the above embodiments.

[0380] According to some embodiments of this application, please refer to Figures 3 to 23 .

[0381] This application provides a battery cell 10, which includes an electrode assembly 2, a housing 1, and a protective layer 6. The housing 1 houses the electrode assembly 2. The housing 1 is made of steel and includes a shell 11, an end cap 12, and a solder joint 7. The shell 1 has an opening at at least one end along a first direction Z, and the end cap 12 corresponds to each opening and covers the opening. The solder joint 7 connects the shell 11 and the end cap 12. Along the first direction Z, the end cap 12 has a first surface 141 facing away from the electrode assembly 2. The outer surface 711 of the solder joint connects the outer peripheral surface 111 of the shell and the first surface 141. The outer surface 711 of the solder joint includes a rounded corner area 7112 connected to the first surface 141, and at least a portion of the rounded corner area 7112 is covered by the protective layer 6. The solder joint 7 connects the shell 11 and the end cap 12, achieving a stable connection between the shell 11 and the end cap 12. The rounded corner area 7112 eliminates the sharp corners of the edge area of ​​the end cap 12. During the process of applying the anti-rust material to the rounded corner area 7112 to form the protective layer 6, the anti-rust material can better adhere to the rounded corner area 7112 of the soldering part 7. The anti-rust material is not easy to fall off from the outer surface 711 of the soldering part under the action of gravity, which is conducive to the formation of the protective layer 6 on the soldering part 7, thereby reducing the risk of the soldering part 7 being corroded and effectively improving the service life of the battery cell 10.

[0382] The outer surface 711 of the soldering portion includes a connection area 7111, which connects to the outer peripheral surface 111 of the housing. The connection area 7111 transitions to the first surface 141 through a rounded corner area 7112. At least a portion of the connection area 7111 is covered with a protective layer 6. Because the connection area 7111 connects to the outer peripheral surface 111 of the housing and transitions to the first surface 141 through the rounded corner area 7112, the outer surface 711 of the soldering portion is relatively smooth. The outer peripheral surface 111 of the housing can smoothly transition to the first surface 141 through the outer surface 711 of the soldering portion. During the process of applying rust-preventive material to the rounded corner area 7112 to form the protective layer 6, the rust-preventive material can better adhere to the outer surface 711 of the soldering portion. The rust-preventive material is less likely to fall off from the outer surface 711 of the soldering portion under gravity, which is beneficial for the formation of the protective layer 6 on the soldering portion 7, thereby reducing the risk of corrosion of the soldering portion 7 and effectively improving the service life of the battery cell 10.

[0383] The outer surface 711 of the soldering portion is provided with a first groove 13, and a portion of the protective layer 6 is accommodated within the first groove 13. The protective layer 6 covers at least a portion of the outer surface 711 of the soldering portion, and the first groove 13 is provided on the outer surface 711 of the soldering portion, with a portion of the protective layer 6 accommodated within the first groove 13. This increases the adhesion of the protective layer 6, improves the firmness of the protective layer 6 on the soldering portion 7, and achieves long-term protection of the soldering portion 7 by the protective layer 6. This reduces the risk of the protective layer 6 failing to protect the soldering portion 7 due to short-term detachment from the outer surface 711 of the soldering portion, thereby reducing the risk of corrosion of the soldering portion 7 of the outer casing 1 and effectively improving the service life of the battery cell 10.

[0384] The portion of the protective layer 6 housed within the first groove 13 is connected to the groove wall of the first groove 13. Connecting the portion of the protective layer 6 housed within the first groove 13 to the groove wall of the first groove 13 increases the contact area between the protective layer 6 and the solder joint 7, thereby increasing the adhesion of the protective layer 6 to the solder joint 7 of the outer casing 1 and further improving the firmness of the protective layer 6 on the solder joint 7 of the outer casing 1.

[0385] At least a portion of the first groove 13 is located in the rounded corner area 7112, and a portion of the protective layer 6 is accommodated within the portion of the first groove 13 located in the rounded corner area 7112. The fact that at least a portion of the first groove 13 is located in the rounded corner area 7112, and that a portion of the protective layer 6 is accommodated within the portion of the first groove 13 located in the rounded corner area 7112, improves the robustness of the protective layer 6 in the rounded corner area 7112, achieves long-term protection of the rounded corner area 7112 by the protective layer 6, and reduces the risk of corrosion of the outer casing 1 in the rounded corner area 7112.

[0386] At least a portion of the first groove 13 is located in the connection area 7111, and at least a portion of the connection area 7111 is covered by a protective layer 6. A portion of the protective layer 6 is accommodated within the portion of the first groove 13 located in the connection area 7111. The fact that at least a portion of the first groove 13 is located in the connection area 7111, and a portion of the protective layer 6 is accommodated within this portion, improves the robustness of the protective layer 6 in the connection area 7111, achieving long-term protection of the connection area 7111 by the protective layer 6 and reducing the risk of corrosion of the outer casing 1 in the connection area 7111.

[0387] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: Electrode assembly; A housing for accommodating the electrode assembly, the housing being made of steel, the housing including a shell, an end cap, and a solder joint, the shell having an opening at at least one end along a first direction, the end cap corresponding to each opening and covering the opening, the solder joint connecting the shell and the end cap, the end cap having a first surface facing away from the electrode assembly along the first direction, the outer surface of the solder joint connecting the outer peripheral surface of the shell and the first surface, the outer surface of the solder joint including a rounded corner area connected to the first surface, at least a portion of the rounded corner area being covered with a protective layer.

2. The battery cell as described in claim 1, characterized in that, The outer surface of the solder stamp includes a connection area that connects to the outer peripheral surface of the housing. The connection area transitions to the first surface through the rounded corner area, and at least a portion of the connection area is covered by the protective layer.

3. The battery cell as described in claim 1, characterized in that, The outer surface of the solder mark is provided with a first groove, and a portion of the protective layer is accommodated within the first groove.

4. The battery cell as described in claim 3, characterized in that, The portion of the protective layer contained within the first groove is connected to the groove wall surface of the first groove.

5. The battery cell as described in claim 3, characterized in that, At least a portion of the first groove is located in the rounded corner area, and a portion of the protective layer is accommodated within the portion of the first groove located in the rounded corner area.

6. The battery cell as described in claim 3, characterized in that, The outer surface of the solder stamp includes a connection area, which connects to the outer peripheral surface of the housing, and the connection area transitions to the first surface through the rounded corner area; At least a portion of the first groove is located in the connection area, at least a portion of the connection area is covered by the protective layer, and a portion of the protective layer is accommodated within the portion of the first groove located in the connection area.

7. The battery cell as described in claim 3, characterized in that, The outer surface of the soldering part is connected to the outer peripheral surface of the housing at a first edge, and the outer surface of the soldering part is connected to the first surface at a second edge. The first edge and the second edge are spaced apart along the first direction, and the first groove extends to the first edge and the second edge.

8. The battery cell as described in claim 7, characterized in that, There are multiple first grooves, and the multiple first grooves are arranged circumferentially along the opening.

9. The battery cell as described in claim 3, characterized in that, The first groove includes multiple groove groups, which are arranged circumferentially along the opening. Each groove group includes a first groove segment, a second groove segment, and a third groove segment connected in sequence. The first groove segment and the third groove segment are respectively connected to opposite ends of the second groove segment and are respectively located on both sides of the second groove segment along the width direction of the second groove segment. The first groove also includes a plurality of fourth groove segments, which are arranged circumferentially along the opening. In two adjacent groove groups, the end of the first groove segment of one groove group away from the second groove segment is connected to the end of the third groove segment of the other groove group away from the second groove segment through a fourth groove segment.

10. The battery cell as described in claim 3, characterized in that, The first groove extends circumferentially along the opening.

11. The battery cell as described in claim 10, characterized in that, There are multiple first grooves, and the multiple first grooves are spaced apart along the first direction.

12. The battery cell as described in claim 11, characterized in that, The outer shell is cylindrical, the first direction is parallel to the axial direction of the outer shell, and there are multiple first grooves, which are arranged at radial intervals along the outer shell.

13. The battery cell as described in claim 3, characterized in that, In a projection plane perpendicular to the first direction, the orthographic projection of the first groove extends along a planar spiral trajectory.

14. The battery cell as described in claim 3, characterized in that, The first groove extends along a spiral trajectory, and the central axis of the spiral extends along the first direction.

15. The battery cell as described in claim 3, characterized in that, The first groove includes a plurality of slots arranged along its extension direction, a portion of the protective layer is accommodated within the slots, and two adjacent slots are connected to each other to form a communication port at the connection position.

16. The battery cell as described in claim 15, characterized in that, The area of ​​the connecting opening is smaller than the area of ​​any cross-section of the groove, and the cross-section is perpendicular to the extension direction of the first groove.

17. The battery cell as described in claim 15, characterized in that, Within the cross-section of the groove, the dimension of the groove in the width direction of the first groove gradually decreases along the depth direction of the first groove, and the cross-section is perpendicular to the extension direction of the first groove.

18. The battery cell as described in claim 15, characterized in that, Along the depth direction of the first groove, the maximum size of the connecting opening is smaller than the maximum size of the groove portion.

19. The battery cell as described in claim 15, characterized in that, Along the width direction of the first groove, the maximum size of the connecting opening is smaller than the maximum size of the groove portion.

20. The battery cell as described in claim 15, characterized in that, Along the extension direction of the first groove, the maximum dimension of the groove is L, and along the width direction of the first groove, the maximum dimension of the groove is W, where 1.1 ≤ W / L ≤ 10.

21. The battery cell as described in claim 20, characterized in that, 70μm≤W≤90μm, 7μm≤L≤81μm.

22. The battery cell as described in claim 3, characterized in that, The maximum width of the first groove is W, where 70μm≤W≤90μm.

23. The battery cell as described in claim 3, characterized in that, The maximum depth of the first groove is H, where 5μm≤H≤20μm.

24. The battery cell as described in claim 3, characterized in that, The first groove is a laser cleaning tank.

25. The battery cell as described in claim 1, characterized in that, The outer surface of the housing also includes a main body surface connected to the outer surface of the soldering part. The main body surface includes the outer surface of the housing and the outer surface of the end cap. The main body surface is provided with a second groove. At least a portion of the main body surface is covered by the protective layer, and a portion of the protective layer is accommodated in the second groove.

26. The battery cell as described in claim 25, characterized in that, The portion of the protective layer contained within the second groove is connected to the groove wall of the second groove.

27. The battery cell as described in claim 25, characterized in that, The outer surface of the soldering part is provided with a first groove, at least a portion of the outer surface of the soldering part is covered with the protective layer, a portion of the protective layer is accommodated in the first groove, and at least one second groove communicates with at least one first groove.

28. The battery cell as described in claim 25, characterized in that, The outer surface of the housing is provided with a second groove, and at least a portion of the outer surface of the housing is covered with a protective layer, a portion of which is accommodated within the second groove.

29. The battery cell as described in claim 28, characterized in that, The outer peripheral surface of the housing is provided with the second groove, and at least a portion of the outer peripheral surface of the housing is covered with a protective layer, a portion of which is accommodated within the second groove.

30. The battery cell as described in claim 25, characterized in that, The outer surface of the end cap is provided with a second groove, and at least a portion of the outer surface of the end cap is covered with a protective layer, a portion of which is accommodated within the second groove.

31. The battery cell as described in claim 30, characterized in that, The first surface is provided with the second groove, at least a portion of the first surface is covered by the protective layer, and a portion of the protective layer is accommodated within the second groove.

32. The battery cell as described in claim 1, characterized in that, The shell includes a shell body and a first anti-corrosion layer. The shell body is made of steel. The first anti-corrosion layer is disposed on the surface of the shell body. The outer surface of the first anti-corrosion layer is at least a part of the outer peripheral surface of the shell. Both the shell body and the first anti-corrosion layer are connected to the welded part.

33. The battery cell as described in claim 32, characterized in that, The first anti-corrosion layer includes a nickel layer.

34. The battery cell as described in claim 32, characterized in that, The outer surface of the first anti-corrosion layer is provided with a second groove, at least a portion of the outer surface of the first anti-corrosion layer is covered by the protective layer, and a portion of the protective layer is accommodated in the second groove.

35. The battery cell as described in claim 34, characterized in that, The depth of the second groove provided on the outer surface of the first anti-corrosion layer is less than the thickness of the first anti-corrosion layer.

36. The battery cell as described in claim 1, characterized in that, The end cap includes a cap body and a second anti-corrosion layer. The cap body is made of steel. The second anti-corrosion layer is disposed on the surface of the cap body. The outer surface of the second anti-corrosion layer is a part of the outer surface of the end cap. Both the cap body and the second anti-corrosion layer are connected to the welded portion.

37. The battery cell as described in claim 36, characterized in that, The second anti-corrosion layer includes a nickel layer.

38. The battery cell as described in claim 36, characterized in that, The outer surface of the second anti-corrosion layer is provided with a second groove, at least a portion of the outer surface of the second anti-corrosion layer is covered by the protective layer, and a portion of the protective layer is accommodated in the second groove.

39. The battery cell as described in claim 38, characterized in that, The depth of the second groove provided on the outer surface of the second anti-corrosion layer is less than the thickness of the second anti-corrosion layer.

40. The battery cell according to any one of claims 1-39, characterized in that, The solder mark is a ring structure and extends circumferentially along the opening.

41. The battery cell according to any one of claims 1-39, characterized in that, The protective layer completely covers the outer surface of the solder joint.

42. The battery cell as described in claim 41, characterized in that, The minimum distance of the protective layer extending beyond the edge of the outer surface of the solder mark is greater than or equal to 200 μm.

43. The battery cell according to any one of claims 1-39, characterized in that, The protective layer is a coating.

44. The battery cell according to any one of claims 1-39, characterized in that, The battery cell is a cylindrical battery cell.

45. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-44.

46. ​​An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-44 or a battery device as described in claim 45.

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