Battery case, battery, battery pack, and electric system

Abstract

A battery case (100), a battery, a battery pack, and an electric system. The battery pack is configured to supply power to the electric system, the battery pack comprising a battery. The battery comprises a battery cell and the battery case (100). The battery case (100) of the battery comprises a housing (20) and a cover plate (10). The housing (20) comprises an inner cavity (21), wherein the inner cavity (21) is provided with an opening, the cover plate (10) being fixed on the housing (20), and the cover plate (10) covering the opening of the inner cavity (21). At least one of the surface of the cover plate (10) facing the housing (20) and the surface of the housing (20) facing the cover plate (10) is provided with a first recess (12); a brazing seam (30) is provided between the cover plate (10) and the housing (20), the brazing seam (30) being used for fixedly connecting the housing (20) and the cover plate (10) and sealing the inner cavity (21); and the first recess (12) is adapted to accommodate a solder (30a) for forming the brazing seam (30). The battery case (100) uses brazing, so that the welding difficulty is reduced, thereby saving on manufacturing costs, and reducing the residual stress and failure risk after welding.

Description

Battery casing, battery, battery pack and power system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 12, 2023, with application number 202323414807.3 and invention name “Battery casing, battery, battery pack and power system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery casings, and in particular to a battery casing, a battery, a battery pack, and a power system. Background Art

[0003] In the prior art, the battery housing is formed by welding a battery shell and a battery cover to seal the battery cavity. To meet the sealing requirements, a high clearance is required between the cover and the housing during assembly. This increases the precision requirements and manufacturing process of the housing, thereby increasing processing costs.

[0004] During welding to eliminate gaps in the battery casing, the complex structure of the cover and shell makes welding difficult. Furthermore, the thin shell makes it difficult to fill the gap after the shell and cover melt, resulting in weld holes and incomplete fusion between the shell and cover. A poorly welded battery casing cannot meet sealing requirements. Furthermore, the resolidification of the melted shell and cover can easily lead to residual stress and cracks, increasing the risk of casing failure.

[0005] Summary of the Invention

[0006] In view of the above-mentioned technical problems, the present application provides a battery housing, a battery, a battery pack and a power system, which specifically include the following technical solutions:

[0007] In a first aspect, the present application provides a battery housing, comprising: a shell and a cover.

[0008] The housing includes an inner cavity having an opening. The cover plate is fixed to the housing and covers the opening of the inner cavity. A first groove is provided on at least one of a surface of the cover plate facing the housing and a surface of the housing facing the cover plate. A brazing seam is provided between the cover plate and the housing. The brazing seam is used to fix the housing and the cover plate so that the cover plate seals the inner cavity. The first groove is suitable for receiving solder used to form the brazing seam.

[0009] The battery shell of the present application is provided with a first groove for accommodating solder. After the cover plate and the shell are assembled, they are heated to melt the solder, thereby forming a brazing seam structure and filling the gap between the cover plate and the shell, thereby fixing the cover plate and the shell and achieving sealing of the inner cavity.

[0010] The welding operation of the battery shell of the present application is simple, and the melting point of the solder is lower than that of the battery shell. During the welding process, the solder melts but the battery shell does not melt. The residual stress generated after welding is small, which can reduce the risk of failure of the battery shell.

[0011] In one embodiment, the first groove is located on a surface of the cover plate facing the housing.

[0012] In this embodiment, the first groove is located on the cover plate, and the solder is disposed in the first groove. After welding, the solder in the cover plate melts and forms a brazing seam.

[0013] In one embodiment, a protrusion is provided on a side of the cover plate facing the inner cavity, an outer side wall of the protrusion contacts the inner surface of the inner cavity, and the first groove is located on the outer side wall of the protrusion.

[0014] In this embodiment, the cover plate includes a protrusion, the protrusion extends into the inner cavity, and the outer wall of the protrusion contacts the inner surface of the inner cavity. The first groove is located on the outer wall of the protrusion. After welding, the solder in the cover plate melts and forms a brazing seam, so that the protrusion is fixedly connected to the shell.

[0015] In one embodiment, the first groove includes a top surface facing the first surface, and the distance between the top surface and the first surface decreases along a vertical direction from the middle of the cover plate to the inner surface of the inner cavity.

[0016] In this embodiment, the cover plate is located below the shell during welding, and the top surface of the first groove is inclined, so that the molten solder can flow toward the cover plate under the action of gravity, thereby preventing the solder from flowing into the inner cavity.

[0017] In one embodiment, the thickness of the edge portion of the cover plate increases along a vertical direction from the middle portion of the cover plate to the inner surface of the inner cavity.

[0018] In this embodiment, the edge of the cover plate is tilted inward, and the molten solder is retained on the raised edge, so that the soldering seam has a sufficient thickness on the side away from the inner cavity, thereby ensuring the quality of the welding.

[0019] In one embodiment, the first groove includes a bottom surface away from the first surface, and the brazing seam is higher than or flush with the bottom surface in a vertical direction.

[0020] In this embodiment, the cover plate is located below the shell during welding, and the molten solder flows from the first groove into the gap and flows toward the cover plate under the action of gravity. After cooling and solidification, the brazing seam is higher than or flush with the bottom surface of the first groove.

[0021] In one embodiment, the housing includes an isolation ring, which is disposed on the inner surface of the inner cavity and extends toward the center of the inner cavity. The extension length of the isolation ring is greater than the spacing distance between the protrusion and the inner surface of the inner cavity.

[0022] In this embodiment, the cover plate is located above the shell during the welding process, and an isolation ring is provided on the inner surface of the inner cavity to prevent the molten solder from flowing further toward the inner cavity.

[0023] In one embodiment, the inner edge of the isolation ring is located vertically above the outer edge of the isolation ring; or

[0024] The isolation ring extends in a horizontal direction and is provided with a second groove. The second groove is located on a surface of the isolation ring facing the cover plate.

[0025] In this embodiment, the isolation plate is tilted or a third groove is provided on the surface of the isolation ring facing the cover plate, both of which can retain the solder and prevent the molten solder from overflowing the isolation ring.

[0026] In one embodiment, the cover plate includes a third groove, the third groove is located on the first surface, and the third groove is circumferentially arranged on the outer side of the protrusion.

[0027] In this embodiment, the cover plate is provided with a third groove, which is circumferentially arranged on the outer side of the protrusion. The third groove accommodates solder, and after welding, the cover plate can also form a fixed connection with the shell.

[0028] In one embodiment, a gap is present between the contacting surfaces of the cover plate and the shell, and the brazing seam is located in the gap to seal the cover plate and the shell.

[0029] In this embodiment, the cover plate and the shell are in contact with each other, and a gap exists between the contact surfaces. After the solder melts, the gap is filled to form a brazing seam, and the brazing seam seals and connects the cover plate and the shell.

[0030] In one embodiment, a brazing seam is provided in the first groove.

[0031] In this embodiment, after the solder in the first groove is melted, at least a portion of the solder remains in the first groove, and a soldering seam is formed after the solder is cooled.

[0032] In one embodiment, the thickness of the side wall of the housing is in the range of 0.05 mm to 0.2 mm.

[0033] In one embodiment, the distance between the side of the first groove of the cover plate away from the outer side wall of the protrusion and the outer side wall of the protrusion is D, and the range of D is 0.2 mm-1.0 mm;

[0034] And / or, the distance from the top surface to the bottom surface of the first groove is W, and the range of W is 0.2 mm-1.0 mm;

[0035] And / or, the distance between the protrusion and the inner surface of the inner cavity in the horizontal direction ranges from 0.01 mm to 0.20 mm.

[0036] In one embodiment, the distance between the top surface of the first groove and the first surface of the cover plate is L1, and the range of L1 is 0.2 mm-1.0 mm;

[0037] And / or, the distance from the bottom surface to the surface of the protrusion facing the inner cavity is L2, and the range of L2 is 0.2mm-1.0mm.

[0038] In one embodiment, the cover plate includes a second surface away from the inner cavity, and an angle α1 is formed between the top surface and the second surface, and the range of α1 is 15°-45°;

[0039] And / or, the included angle between the bottom surface and the second surface of the cover plate is α2, and the range of α2 is 15°-45°.

[0040] In one embodiment, the included angle between the first surface and the second surface of the edge portion of the cover plate facing the inner cavity is β1, and the range of β1 is 3°-15°;

[0041] And / or, the angle between the surface of the isolation ring away from the inner cavity and the second surface of the cover plate is β2, and the range of β2 is 3°-15°.

[0042] In one embodiment, the material of the battery housing is aluminum or steel.

[0043] In this embodiment, a battery casing made of aluminum or steel is used to ensure the strength of the battery casing, and the melting point of the battery casing is higher than the melting point of the solder, thereby ensuring that the battery casing will not melt during the welding process.

[0044] In a second aspect, the present application also relates to a battery, comprising a battery cell and a battery casing provided in any embodiment, wherein the battery cell is fixed in an inner cavity of the battery casing.

[0045] The battery provided in the second aspect of the present application adopts the battery casing provided in the first aspect of the present application, so the assembly process is simpler, the reliability of the battery casing can be improved, and the sealing protection effect of the battery casing on the battery cell can be ensured.

[0046] In a third aspect, the present application also relates to a battery pack, which includes a battery pack housing and the above-mentioned battery, wherein the battery is arranged in the battery pack housing.

[0047] In a fourth aspect, the present application also relates to an electric power system, comprising the above-mentioned battery pack or the above-mentioned battery, wherein the battery pack or the battery is arranged inside the electric power system and is used to supply power to the electric power system.

[0048] The battery pack and power system of the present application can achieve higher safety and reliability and have a longer service life because they use the above-mentioned batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG1 is a schematic diagram of the structure of a battery housing provided in one embodiment of the present application;

[0050] FIG2 is a schematic diagram of the internal cross-sectional structure of a battery housing provided in one embodiment of the present application;

[0051] FIG3 is a partial schematic diagram of the internal cross-sectional structure of a battery housing provided in one embodiment of the present application;

[0052] FIG4 is a partial schematic diagram of the internal cross-sectional structure of a battery housing before welding provided in one embodiment of the present application;

[0053] FIG5 is a partial schematic diagram of the internal cross-sectional structure of a battery housing provided in another embodiment of the present application;

[0054] FIG6 is a partial schematic diagram of the internal cross-sectional structure of a battery housing provided in another embodiment of the present application;

[0055] FIG7 is a partial schematic diagram of the internal cross-sectional structure of a battery housing provided in another embodiment of the present application. Specific embodiments

[0056] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0057] The following descriptions of the embodiments are with reference to the attached diagrams to illustrate specific embodiments that the present application can be used to implement. The serial numbers of the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present application include direct and indirect connections (couplings) unless otherwise specified. The directional terms mentioned in the present application, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0058] The present application relates to an electrical system, which includes a battery pack or battery for powering electricity. The battery pack includes a battery and a battery pack housing. The battery includes a cell and a battery housing. The cell is fixed in the inner cavity of the battery housing, and the battery housing is used to seal and protect the cell therein. The battery of the present application can be set in the electrical system, the cell is used to power the electrical system, and the battery housing is used to seal the cell to prevent external liquids and gases from entering the inner cavity to maintain a stable working environment for the cell.

[0059] In order to meet the sealing requirements of the battery, the manufacturing assembly and welding precision required for the battery shell are high, and because the thickness of the battery shell is too thin, the welding of the battery shell is difficult and it is difficult to ensure the welding quality. The battery shell of this application is welded by built-in solder to form a brazing seam to achieve the sealing protection of the battery shell. The welding difficulty is relatively low, the required welding steps are simple, and the manufacturing efficiency of the battery shell can be improved. At the same time, compared with ordinary welding, the residual stress of the battery shell after brazing is small, which can reduce the failure risk of the battery shell and improve its reliability.

[0060] Please refer to Figures 1 and 2. Figure 1 shows a schematic structural diagram of a battery housing 100 provided in an embodiment of the present application, and Figure 2 shows a schematic internal cross-sectional structure diagram of the battery housing 100.

[0061] The battery housing 100 provided in this application includes a cover plate 10 and a shell 20. The shell 20 includes an inner cavity 21 having an opening, and the cover plate 10 is fixed to the open side of the shell 20 and shields the opening of the inner cavity 21. The cover plate 10 is sealed to the shell 20, and the inner cavity 21 is used to accommodate the battery cell. The battery housing 100 is also provided with two electrodes 40 spaced apart from each other. The two electrodes 40 are electrically conductive with the battery cell respectively and pass through the housing 100 respectively, so that the battery cell in the housing 100 can be connected to the external circuit and provide or receive electrical energy.

[0062] 1 and 2 , two electrodes 40 are spaced apart and disposed on the cover plate 10. In other embodiments, at least one of the two electrodes 40 may also be disposed on the housing 20, and the specific position of the electrode 40 may be arbitrarily set based on the operating scenario of the battery of the present application.

[0063] Please refer to FIG3 , which is a partial schematic diagram of the internal cross-sectional structure of the battery housing 100 .

[0064] The cover plate 10 is generally plate-shaped. Specifically, in one embodiment, the cover plate 10 has a first surface 101 facing the inner cavity 21. A protrusion 11 is provided on the side of the cover plate 10 facing the inner cavity 21. The protrusion 11 extends from the cover plate 10 toward the inner cavity 21. Along a direction perpendicular to the extension of the protrusion 11, the protrusion 11 is spaced apart from the housing 20. That is, a gap is left between the outer wall of the protrusion 11 and the inner surface of the inner cavity 21.

[0065] A first groove 12 is provided on at least one of the surface of the cover plate 10 facing the housing 20 and the surface of the housing 20 facing the cover plate 10. A brazing seam 30 is provided between the cover plate 10 and the housing 20. The brazing seam 30 securely connects the cover plate 10 and the housing 20 and seals the inner cavity 21. The first groove 12 is adapted to accommodate solder used to form the brazing seam 30. Specifically, in one embodiment, the cover plate 10 has a protrusion 11 facing the inner cavity 21. The outer wall of the protrusion 11 is provided with the first groove 12. The first groove 12 extends perpendicularly to the extension direction of the protrusion 11 toward the geometric center of the cover plate 10. A brazing seam 30 is provided between the outer wall of the protrusion 11 and the inner surface of the inner cavity 21. The brazing seam 30 securely connects the cover plate 10 and the housing 20, thereby sealing the inner cavity 21.

[0066] Furthermore, in one embodiment, since the first groove 12 contains solder 30a for forming the brazing seam 30, and the brazing seam 30 is present between the cover plate 10 and the housing 20, the surface of the cover plate 10 facing the housing 20 is the surface in contact between the cover plate 10 and the housing 20, and the surface of the housing 20 facing the cover plate 10 is the surface in contact between the housing 20 and the cover plate 10. As a result, the solder 30a contained in the first groove 12, after being melted at high temperature, fills the space between the cover plate 10 and the housing 20 to form the brazing seam 30, thereby achieving a sealed connection between the cover plate 10 and the housing 20. In this embodiment, the contact between the cover plate 10 and the housing 20 can be direct contact, i.e., the cover plate 10 and the housing 20 are in contact with each other without any other substance in between. Alternatively, the contact can be indirect contact, i.e., the cover plate 10 and the housing 20 are in contact with each other through other substances, such as the brazing seam 30, an insulating member, etc.

[0067] Furthermore, in other embodiments, the purpose of providing the first groove 12 is to ensure that, after the solder 30a is provided in the first groove 12, it melts at high temperature and fills the space between the cover plate 10 and the housing 20 to form the brazing seam 30, thereby achieving a sealed connection between the cover plate 10 and the housing 20. Therefore, the surface of the cover plate 10 facing the housing 20 may also be the surface between the cover plate 10 and the inner cavity 21, and the surface of the housing 20 facing the cover plate 10 may also be the surface of the inner cavity 21 of the housing 20. That is, after the first groove 12 is provided on this surface, the solder 30a can flow through this surface between the cover plate 10 and the housing 20, thereby forming the brazing seam 30.

[0068] Specifically, please refer to FIG4 , which is a partial schematic diagram of the internal cross-sectional structure of the battery housing 100 before welding.

[0069] In some embodiments, as shown in FIG4 , solder 30 a is filled in the first groove 12 , and the brazing seam 30 is formed by welding the solder 30 a. In this embodiment, the solder 30 a completely fills the first groove 12 . In other embodiments, the solder 30 a may not completely fill the first groove 12 , and the volume of the solder 30 a disposed in the first groove 12 may be adjusted based on the size of the gap between the cover plate 10 and the housing 20 .

[0070] Specifically, in the manufacturing process of the battery casing 100 of the present application, taking the first groove 12 located on the cover plate 10 as an example, first, the solder 30a is placed in the first groove 12 of the cover plate 10. Then, the cover plate 10 and the shell 20 are assembled, and the protrusion 11 of the cover plate 10 is first extended into the inner cavity 21 to guide the assembly of the cover plate 10 and the shell 20. There is a gap in the horizontal direction between the assembled cover plate 10 and the shell 20. Finally, the solder 30a set in the first groove 12 in advance is heated. Under the action of gravity, the molten solder 30a flows into the first groove 12 and fills the gap between the cover plate 10 and the shell 20. After the solder 30a cools and solidifies, a brazing seam 30 is formed. The brazing seam 30 fixes the cover plate 10 and the shell 20 and can isolate the inner cavity 21 from the outside to ensure the sealing of the battery casing 100.

[0071] It can be understood that in the welding process of the battery shell 100 of the present application, the solder 30a is set in the first groove 12 in advance. It is only necessary to heat and melt the solder 30a so that the molten solder 30a flows into the gap between the cover plate 10 and the shell 20 under the action of gravity. After the solder 30a cools and solidifies, a brazing seam 30 is formed to achieve a fixed connection between the cover plate 10 and the shell 20 and seal the inner cavity 21. In the welding process of the battery shell 100 of the present application, the steps required for welding can be reduced, the difficulty of welding can be reduced, and the welding operation can be simplified. At the same time, the solder 30a is set in the first groove 12 in advance, which reduces the operating steps of the processing technology, reduces the process difficulty, and can improve the manufacturing efficiency of the battery shell 100.

[0072] At the same time, the battery housing 100 of the present application is brazed. The melting point of the solder 30a is lower than that of the cover plate 10 and the shell 20. During the welding process, only the solder 30a melts, while the cover plate 10 and the shell 20 do not melt, thereby ensuring the integrity of the appearance of the cover plate 10 and the shell 20. At the same time, during the welding process of the battery housing 100, only the solder 30a melts and then solidifies, which can reduce the residual stress generated after welding, reduce the deformation of the battery housing 100 caused by welding, and thus reduce the risk of failure of the battery housing 100.

[0073] Therefore, the battery housing 100 in the battery of the present application can simplify the welding process and improve the production efficiency of the battery housing 100. The battery housing 100 can also reduce the residual stress after welding, reduce the risk of failure, and thus improve the reliability of the battery housing 100, thereby ensuring a longer-term sealing and protective effect of the battery cell.

[0074] In one embodiment, the cover plate 10 is provided with a protrusion 11, the outer wall of the protrusion 11 contacts the inner surface of the inner cavity 21, the first groove 12 is located on the outer wall of the protrusion 11, and the solder 30a is disposed in the first groove 12. After welding, the solder 30a forms a brazing seam 30, which also securely connects the cover plate 10 and the housing 20 and seals the inner cavity 21.

[0075] In another embodiment, the cover plate 10 includes a third groove located on the first surface 101 of the cover plate 10 and circumferentially disposed outside the protrusion 11. Solder 30a is disposed within the third groove. After welding, the solder 30a forms a brazing seam 30, which also securely connects the cover plate 10 to the housing 20 and seals the inner cavity 21.

[0076] In one embodiment, the side wall of the cover plate 10 contacts the shell 20, the first groove can be set on the side wall of the cover plate 10, the solder 30a is set in the first groove 12, and after welding, the solder 30a forms a brazing seam 30. The brazing seam 30 can also fixedly connect the cover plate 10 and the shell 20 and seal the inner cavity 21.

[0077] In another embodiment, the first groove 12 can also be set on the shell 20, the first groove 12 is located on the inner wall of the inner cavity 21, and the solder 30a is set in the first groove 12. After welding, the solder 30a forms a brazing seam 30, and the brazing seam 30 can also fix the cover plate 10 and the shell 20 and seal the inner cavity 21.

[0078] There are two methods for welding the cover plate 10 to the housing 20. In one method, the cover plate 10 can be vertically positioned below the housing 20 during welding; in the other method, the cover plate 10 can be vertically positioned above the housing 20 during welding. Because the molten solder 30a during welding is fluid and flows in different directions under the influence of gravity, the shape and position of the brazed seam 30 formed by the two methods also differ.

[0079] Please refer to Figure 5 for a partial schematic diagram of the internal cross-sectional structure of a battery housing 100 provided in another embodiment of the present application. In this embodiment, the battery housing 100 is welded in the aforementioned manner of "the cover plate 10 is vertically positioned below the housing 20" during the welding process.

[0080] Specifically, as shown in Figure 5, the first groove 12 is located on the sidewall of the protrusion 11. The first groove 12 includes a bottom surface 122 that is away from the first surface 101. The brazing seam 30 is vertically higher than or flush with the bottom surface 122. In this embodiment, when the cover plate 10 is welded to the housing 20, the cover plate 10 is vertically located below the housing 20. Under the action of gravity, the molten solder 30a flows from the first groove 12 into the gap between the cover plate 10 and the housing 20 and flows toward the cover plate 10, thereby forming the brazing seam 30 that is vertically higher than or flush with the bottom surface 122.

[0081] In one embodiment, as shown in Figure 5, the first groove 12 includes a top surface 121 facing the first surface 101. The distance between the top surface 121 and the first surface 101 decreases along a vertical direction from the middle of the cover plate 10 to the inner surface of the inner cavity 21. In this embodiment, when the cover plate 10 and the housing 20 are welded, the cover plate 10 is vertically positioned below the housing 20, and the molten solder 30a flows toward the cover plate 10 under the action of gravity. The inclined top surface 121 of the first groove 12 facilitates the flow of the molten solder 30a into the gap between the cover plate 10 and the housing 20, thereby achieving welding of the cover plate 10 and the housing 20.

[0082] In one embodiment, as shown in Figure 5, the cover plate 10 includes an edge portion along the outer side of the outer wall of the protrusion 11. The thickness of the edge portion of the cover plate 10 increases vertically from the middle of the cover plate 10 to the inner surface of the inner cavity 21. In this embodiment, when the cover plate 10 is welded to the shell 20, the cover plate 10 is vertically positioned below the shell 20, and the molten solder 30a flows toward the cover plate 10 under the action of gravity. The inclined edge portion of the cover plate 10 and the outer side of the protrusion 11 form a receiving area for the solder 30a. When the solder 30a flows to the edge portion of the cover plate 10, the inclined edge portion can retain the solder 30a, so that the brazing seam 30 formed by cooling and solidification has a sufficient thickness on the side away from the inner cavity 21, ensuring a sealing effect after welding.

[0083] In other embodiments, the first groove 12 may also be located on the side wall of the cover plate 10. Setting the surface of the first groove 12 away from the first surface 101 to be inclined can also facilitate the molten solder 30a to flow into the gap between the cover plate 10 and the shell 20, thereby achieving welding of the cover plate 10 and the shell 20.

[0084] Please refer to Figure 6 for a partial schematic diagram of the internal cross-sectional structure of a battery housing provided in another embodiment of the present application. In this embodiment, the battery housing 100 is formed by welding in the manner described above where the cover plate 10 is vertically positioned above the housing 20.

[0085] Specifically, as shown in Figure 6, the brazing seam 30 is vertically lower than or flush with the top surface 121 of the first groove 12. In this embodiment, when the cover plate 10 is welded to the housing 20, the cover plate 10 is vertically positioned above the housing 20. Under the influence of gravity, the molten solder 30a flows from the first groove 12 into the gap between the cover plate 10 and the housing 20 and toward the inner cavity 21, thereby forming the brazing seam 30 that is vertically lower than or flush with the top surface 121.

[0086] In one embodiment, as shown in FIG6 , the shell 20 includes an isolation ring 50, which is disposed on the inner surface of the inner cavity 21 and extends toward the center of the inner cavity 21. The extension length of the isolation ring 50 is greater than the distance between the protrusion 11 and the inner surface of the inner cavity 21. In this embodiment, when the cover plate 10 is welded to the shell 20, the cover plate 10 is located above the shell 20 in the vertical direction, and the molten solder 30a flows from the first groove 12 toward the inner cavity 21 under the action of gravity. After the solder 30a flows out of the gap between the cover plate 10 and the shell 20, the isolation ring 50 can block the solder 30a, preventing the solder 30a from further flowing toward the inner cavity 21, and preventing the higher temperature solder 30a from approaching or contacting the battery cell in the inner cavity 21, thereby damaging the battery cell or affecting its working environment, affecting the normal operation of the battery cell.

[0087] Please refer to FIG. 7 , which is a partial schematic diagram of the internal cross-sectional structure of a battery housing 100 provided in another embodiment of the present application.

[0088] Specifically, as shown in Figure 7, the inner edge of the isolation ring 50 is vertically positioned above the outer edge of the isolation ring 50. In this embodiment, when the cover plate 10 is welded to the housing 20, the cover plate 10 is vertically positioned above the housing 20, and the molten solder 30a flows toward the inner cavity 21 under the action of gravity. The inclined isolation ring 50 and the inner surface of the inner cavity 21 form a receiving area for the solder 30a, which facilitates the retention of the solder 30a within the isolation ring 50. The retained solder 30a ensures that the brazed seam 30, formed by cooling and solidification, has sufficient thickness on the side facing the inner cavity 21, thereby ensuring a sealing effect after welding.

[0089] In another embodiment, the isolation ring 50 extends horizontally and is provided with a second groove located on the surface of the isolation ring 50 facing the cover plate 10. In this embodiment, when the cover plate 10 is welded to the housing 20, the cover plate 10 is vertically positioned above the housing 20, and the solder 30a flows toward the inner cavity 21 under the action of gravity. The second groove, provided on the surface of the isolation ring 50 facing the cover plate 10, also retains the molten solder 30a, ensuring a sufficient thickness of the brazing seam 30 on the side facing the inner cavity 21, thereby ensuring a sealing effect after welding.

[0090] In one embodiment, as shown in Figure 7, the distance between the bottom surface 122 and the first surface 101 increases along the vertical direction from the middle of the cover plate 10 to the inner surface of the inner cavity 21. In this embodiment, when the cover plate 10 and the housing 20 are welded, the cover plate 10 is vertically positioned above the housing 20, and the molten solder 30a flows toward the inner cavity 21 under the action of gravity. The inclined bottom surface 122 of the first groove 12 facilitates the molten solder 30a to flow into the gap between the cover plate 10 and the housing 20 under the action of gravity.

[0091] In other embodiments, the first groove 12 may also be located on the side wall of the cover plate 10. Setting the surface of the first groove 12 inclined toward the first surface 101 can also facilitate the molten solder 30a to flow into the gap between the cover plate 10 and the shell 20, thereby achieving welding of the cover plate 10 and the shell 20.

[0092] In some embodiments, the thickness of the sidewalls of the housing 20 ranges from 0.05 mm to 0.20 mm. As will be appreciated, the battery housing 100 of this application is relatively thin. During conventional welding, the thin-walled housing melts to fill the gaps, which can easily create weld holes and render the battery housing 100 less airtight. Therefore, this application utilizes brazing, which prevents the battery housing 100 from melting during the welding process, thus avoiding weld holes and other poor welding issues and ensuring the integrity of the battery housing 100's appearance.

[0093] In some embodiments, the battery housing 100 is made of aluminum or steel. Using aluminum or steel ensures the strength of the battery housing 100. Furthermore, the melting point of aluminum or steel is higher than that of the solder 30a. The temperature during the welding process is higher than the melting point of the solder 30a but lower than the melting point of the battery housing 100. This ensures that only the solder 30a melts, while the battery housing 100 itself does not melt, thereby maintaining the integrity of the appearance of the battery housing 100.

[0094] In one embodiment, the distance from the protrusion 11 to the edge of the cover plate 10 increases in the vertical direction toward the inner cavity 21. During the assembly process of the cover plate 10 and the housing 20, the protrusion 11 of the cover plate 10 first extends into the inner cavity 21 of the housing 20 and moves toward the inner cavity 21, thereby guiding the assembly of the cover plate 10 and the housing 20.

[0095] In this embodiment, the distance between the protrusion 11 and the edge of the cover plate 10 increases along the vertical direction toward the inner cavity 21. During the assembly process, the end of the protrusion 11 is smaller, which is convenient for extending into the inner cavity 21 and guiding the installation of the cover plate 10, thereby reducing the difficulty of assembling the cover plate 10 and the shell 20 and improving the assembly efficiency of the cover plate 10 and the shell 20.

[0096] In one embodiment, the cover plate 10 and the shell 20 are in contact with each other, and there is a gap between the surfaces of the cover plate 10 and the shell 20 that contact each other. After the solder 30a in the first groove 12 melts, the solder 30a flows into and fills the gap, forming a brazing seam 30, so that the cover plate 10 and the shell 20 are sealed.

[0097] In one embodiment, the cover plate 10 and the housing 20 are in contact with each other, and a gap exists between the contacting surfaces of the cover plate 10 and the housing 20. The solder 30a in the first groove 12 melts and flows into the gap between the cover plate 10 and the housing 20, thereby sealing the cover plate 10 and the housing 20. At the same time, some solder 30a remains in the first groove 12. After the solder 30a cools, a brazing seam 30 is formed. A brazing seam 30 is defined in the first groove 12.

[0098] In another embodiment, the cover plate 10 and the shell 20 are in contact with each other, and the solder 30 a in the first groove 12 melts to form a brazing seam 30 , so that the cover plate 10 and the shell 20 are sealed and connected. The formed brazing seam 30 is located in the first groove 12 .

[0099] In some embodiments, as shown in Figure 3, the distance from the side of the first groove 12 of the cover plate 10 away from the outer wall of the protrusion 11 to the outer wall of the protrusion 11 is D, and the distance from the top surface 121 to the bottom surface 122 of the first groove 12 is W, the range of D is 0.2mm-1.0mm, and the range of W is 0.2mm-1.0mm.

[0100] It is understandable that excessively large W and D will result in excessive flow into the gap between the cover plate 10 and the shell 20, and the excess solder 30a will easily overflow the gap; excessively small W and D will result in insufficient solder 30a flowing into the gap between the cover plate 10 and the shell 20, resulting in insufficient thickness of the brazing seam 30 formed by cooling and solidification, and an inability to ensure the sealing and protective effect of the inner cavity 21. Therefore, by limiting the range of W and D, the first groove 12 can accommodate an appropriate amount of solder 30a. This appropriate amount of solder 30a does not affect the battery cells of the present application, and can also ensure the quality of the brazing seam 30, thereby achieving a sealed battery shell 100.

[0101] In some embodiments, as shown in FIG4 , the distance from the top surface 121 to the first surface 101 of the cover plate 10 is L1, and the range of L1 is 0.2 mm to 1.0 mm. In this embodiment, when the cover plate 10 is welded to the shell 20, the cover plate 10 is located below the shell 20 in the vertical direction, and the solder 30a flows toward the cover plate 10 under the action of gravity. When L1 is too small, the thickness of the formed brazing seam 30 in the vertical direction is insufficient and cannot meet the sealing requirements of the battery shell 100; when L1 is too large, the gap between the cover plate 10 and the shell 20 is too large, and more solder 30a is required to fill the gap. The thickness of the formed brazing seam 30 in the vertical direction is insufficient, making it difficult to achieve sealing protection of the battery shell 100. A suitable L1 can form a brazing seam 30 of sufficient thickness to meet the sealing requirements of the battery shell 100.

[0102] In other embodiments, as shown in FIG4 , the distance from the bottom surface 122 to the surface of the protrusion 11 facing the inner cavity 21 is L2, and L2 ranges from 0.2 mm to 1.0 mm. In this embodiment, when the cover plate 10 is welded to the shell 20, the cover plate 10 is vertically positioned above the shell 20, and the solder 30a flows toward the inner cavity 21 under the action of gravity. A suitable L2 can also form a solder seam 30 of sufficient thickness to meet the sealing requirements of the battery housing 100.

[0103] In some embodiments, as shown in FIG. 5 , the cover plate 10 includes a second surface 102 away from the inner cavity 21 , and an angle α1 is formed between the top surface 121 and the second surface 102 , and the range of α1 is 15°-45°.

[0104] In this embodiment, when the cover plate 10 and the housing 20 are welded, the cover plate 10 is vertically positioned below the housing 20, and the solder 30a flows toward the cover plate 10 under the influence of gravity. If α1 is too large, the molten solder 30a flows into the gap between the cover plate 10 and the housing 20 too quickly, easily causing the solder 30a to overflow from the side of the gap away from the inner cavity 21. If α1 is too small, the molten solder 30a flows into the gap between the cover plate 10 and the housing 20 too slowly, resulting in increased welding time and reduced manufacturing efficiency. Therefore, a suitable α1 facilitates the molten solder 30a to flow from the first groove 12 into the gap between the cover plate 10 and the housing 20 at an appropriate rate.

[0105] In other embodiments, as shown in FIG7 , the angle α2 between the bottom surface 122 and the second surface 102 of the cover plate 10 is α2, and the range of α2 is 15°-45°. In this embodiment, when the cover plate 10 and the housing 20 are welded, the cover plate 10 is vertically positioned above the housing 20, and the solder 30a flows toward the inner cavity 21 under the action of gravity. Setting an appropriate α2 also allows the solder 30a to flow from the first groove 12 into the gap between the cover plate 10 and the housing 20 at a suitable rate.

[0106] In some embodiments, as shown in FIG. 5 , the angle between the first surface 101 and the second surface 102 of the edge portion of the cover plate 10 facing the inner cavity 21 is β1, and the range of β1 is 3°-15°.

[0107] In this embodiment, when the cover plate 10 is welded to the housing 20, the cover plate 10 is vertically positioned below the housing 20, and the solder 30a flows toward the cover plate 10 under the influence of gravity. When β1 is too large, the gap at the edge of the cover plate 10 becomes larger, requiring more solder 30a to fill the gap and seal the cover plate 10 and the housing 20. When β1 is too small, too little solder 30a is allowed to remain at the edge of the cover plate 10, which can easily lead to insufficient thickness of the brazing seam 30 on the side away from the inner cavity 21, making it difficult to ensure the sealing of the battery housing 100. Therefore, an appropriate β1 is conducive to the retention of molten solder 30a at the edge of the cover plate 10.

[0108] In other embodiments, the angle β2 between the surface of the isolation ring 50 facing away from the inner cavity 21 and the second surface 102 of the cover plate 10 is 3°-15°. In this embodiment, when the cover plate 10 is welded to the housing 20, the cover plate 10 is vertically positioned above the housing 20, and the solder 30a flows toward the inner cavity 21 under the influence of gravity. Setting an appropriate β2 also helps the molten solder 30a remain in the isolation ring 50, thereby preventing the solder 30a from flowing further toward the inner cavity 21.

[0109] In some embodiments, the horizontal distance between the protrusion 11 and the inner surface of the inner cavity 21 ranges from 0.01 mm to 0.20 mm. Setting the gap between the cover plate 10 and the housing 20 within an appropriate range can limit the size of the gap. Excessively large gaps require more solder 30a to seal the battery housing 100, while excessively small gaps increase the difficulty of assembling the cover plate 10 and the housing 20.

[0110] The various embodiments described above can each control the volume of the molten solder 30a flowing into the inner cavity 21, as well as the volume occupied by the formed solder seam 30 within the inner cavity 21. This prevents the hot solder 30a from coming into contact with the battery cells, potentially damaging them. Furthermore, it helps control the internal space size of the inner cavity 21 while ensuring a secure, sealed connection between the cover plate 10 and the housing 20.

[0111] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0112] It should be understood that the application of this application is not limited to the above examples. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the scope of protection of the claims appended to this application. Those skilled in the art will understand that implementing all or part of the processes of the above embodiments and making equivalent changes in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A battery housing (100), wherein: It comprises a housing (20) and a cover plate (10); The shell (20) comprises an inner cavity (21), the inner cavity (21) has an opening, and the cover plate (10) is fixed to the shell (20) and covers the opening; At least one of a surface of the cover plate (10) facing the shell (20) and a surface of the shell (20) facing the cover plate (10) is provided with a first groove (12); a brazing seam (30) is provided between the cover plate (10) and the shell (20); the brazing seam (30) is used to seal the shell (20) and the cover plate (10) so that the cover plate (10) seals the inner cavity (21); and the first groove (12) is suitable for accommodating solder (30a) used to form the brazing seam (30).

2. The battery housing (100) according to claim 1, wherein: The first groove (12) is located on a surface of the cover plate (10) facing the housing (20).

3. The battery housing (100) according to any one of claims 1 to 2, wherein: A protrusion (11) is provided on one side of the cover plate (10) facing the inner cavity (21); an outer wall of the protrusion (11) contacts an inner surface of the inner cavity (21); and the first groove (12) is located on the outer wall of the protrusion (11).

4. The battery housing (100) as claimed in claim 3, wherein: The cover plate (10) further comprises a first surface (101) facing the inner cavity (21), the first surface (101) being arranged around the protrusion (11), the first groove (12) comprising a top surface (101) facing the first surface (101), and the distance between the top surface and the first surface (101) decreasing along a vertical direction from the middle of the cover plate (10) to the inner surface of the inner cavity (21).

5. The battery housing (100) according to any one of claims 1 to 4, wherein: Along the vertical direction from the middle of the cover plate (10) to the inner surface of the inner cavity (21), the thickness of the edge portion of the cover plate (10) increases.

6. The battery housing (100) according to any one of claims 3 to 4, wherein: The cover plate (10) further comprises a first surface (101) facing the inner cavity (21), the first surface (101) being arranged around the protrusion (11), the first groove (12) comprising a bottom surface (122) away from the first surface (101), and the brazing seam (30) being higher than or flush with the bottom surface (122) in the vertical direction.

7. The battery housing (100) according to claim 3, 4 or 6, wherein: The cover plate (10) further comprises a first surface (101) facing the inner cavity (21), the first surface (101) being arranged around the protrusion (11), the first groove (12) comprising a bottom surface (122) away from the first surface (101), and the distance between the bottom surface (122) and the first surface (101) increasing along a vertical direction from the middle of the cover plate (10) to the inner surface of the inner cavity (21).

8. The battery housing (100) according to claim 3, 4, 6 or 7, wherein: The housing (20) comprises an isolating ring (50), which is arranged on the inner surface of the inner cavity (21) and extends toward the center of the inner cavity (21), and the isolating ring (50) is spaced apart from the protrusion (11) in a vertical direction.

9. The battery housing (100) according to claim 8, wherein: The inner edge of the isolation ring (50) is located above the outer edge of the isolation ring (50) in the vertical direction; and / or The isolation ring (50) extends in a horizontal direction and is provided with a second groove, wherein the second groove is located on a surface of the isolation ring (50) facing the cover plate (10).

10. The battery housing (100) according to claim 3 or 4 or 6 or 7 or 8 or 9, wherein: The cover plate (10) further comprises a first surface (101) facing the inner cavity (21), the first surface (101) being arranged around the protrusion (11), and the cover plate (10) comprises a third groove, the third groove being located on the first surface (101), and the third groove being arranged circumferentially on the outer side of the protrusion (11).

11. The battery housing (100) according to any one of claims 1 to 10, wherein: There is a gap between two surfaces of the cover plate (10) and the shell (20) that contact each other, and the brazing seam (30) is located in the gap to seal and connect the cover plate (10) and the shell (20).

12. The battery housing (100) according to any one of claims 1 to 11, wherein: The brazing seam (30) is provided in the first groove (12).

13. The battery housing (100) according to any one of claims 1 to 12, wherein: The shell wall thickness of the shell (20) is in the range of 0.05 mm to 0.20 mm.

14. The battery housing (100) according to claim 6, 7, 8, 9 or 10, wherein: The distance between the side of the first groove (12) of the cover plate (10) away from the outer wall of the protrusion (11) and the outer wall of the protrusion (11) is D, and the range of D is 0.2 mm-1.0 mm; And / or, the distance from the top surface (121) to the bottom surface (122) of the first groove (12) is W, and the range of W is 0.2 mm-1.0 mm; And / or, the distance between the protrusion (11) and the inner surface of the inner cavity (21) in the horizontal direction ranges from 0.01 mm to 0.20 mm.

15. The battery housing (100) according to claim 6, 7 or 14, wherein: The distance between the top surface (121) of the first groove (12) and the first surface (101) of the cover plate (10) is L1, and the range of L1 is 0.2 mm-1.0 mm; And / or, the distance from the bottom surface (122) to the surface of the protrusion (11) facing the inner cavity (21) is L2, and the range of L2 is 0.2 mm-1.0 mm.

16. The battery housing (100) according to any one of claims 14 to 15, wherein: The cover plate (10) comprises a second surface 102 away from the inner cavity (21), the angle between the top surface (121) and the second surface (102) is α1, and the range of α1 is 15°-45°; And / or, the angle between the bottom surface (122) and the second surface (102) of the cover plate (10) is α2, and the range of α2 is 15°-45°.

17. The battery housing (100) according to any one of claims 8 to 16, wherein: An angle β1 is formed between a first surface (101) of an edge portion of the cover plate (10) facing the inner cavity (21) and a second surface (102) of the inner cavity (21), and the range of β1 is 3°-15°; And / or, the angle between the surface of the isolation ring (50) of the shell (20) away from the inner cavity (21) and the second surface (102) of the cover plate (10) is β2, and the range of β2 is 3°-15°.

18. A battery, wherein: It comprises a battery cell and a battery casing (100) according to any one of claims 1 to 17, wherein the battery cell is fixed in an inner cavity (21) of the battery casing (100).

19. A battery pack, wherein: It comprises the battery as claimed in claim 18 and a battery pack casing, wherein the battery is arranged in the battery pack casing.

20. An electricity system, wherein: Including the battery according to claim 18 or the battery pack according to claim 19.

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