Housing manufacturing method, housing, battery cell, battery, and electric device

Abstract

The present application relates to the field of batteries, and provides a housing manufacturing method, a housing, a battery cell, a battery, and an electric device. The housing manufacturing method comprises: providing a material sheet; and processing the material sheet to form a housing. The housing is provided with a pressure relief groove, and during pressure relief, the housing can crack along at least part of the pressure relief groove, to release pressure in the housing. The housing manufactured by the housing manufacturing method is provided with the pressure relief groove, so that when the pressure or temperature in the housing reaches explosion initiation pressure, the housing can crack along at least part of the pressure relief groove, to release pressure in the housing. In the housing manufacturing method, the pressure relief groove is directly formed in the housing, without welding, thereby avoiding liquid leakage caused by welding defects, and prolonging the service life of battery cells.

Description

Shell manufacturing method, shell, battery cell, battery and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application entitled “Shell manufacturing method, shell, battery cell, battery and electrical equipment” (application number: 202410239007.2) filed on March 1, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of batteries, and more specifically, to a shell manufacturing method, a shell, a battery cell, a battery, and an electrical device. Background Art

[0004] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles. These have become a new trend in the automotive industry. The development of battery technology requires consideration of multiple design factors, including performance parameters such as energy density, discharge capacity, and charge / discharge rate. Furthermore, battery life must be considered. However, current batteries have a relatively short lifespan.

[0005] Summary of the Invention

[0006] The purpose of the embodiments of the present application is to provide a shell manufacturing method, a shell, a battery cell, a battery and an electrical device, which are intended to improve the problem of short battery life in related technologies.

[0007] In a first aspect, an embodiment of the present application provides a shell manufacturing method, which includes providing a sheet; processing the sheet into a shell, wherein the shell is provided with a pressure relief groove, and the shell can be cracked along at least part of the pressure relief groove during pressure relief to release the pressure inside the shell.

[0008] In the above-mentioned technical solution, the shell produced by this shell manufacturing method is provided with a pressure relief groove. When the pressure or temperature inside the shell reaches the detonation pressure, the shell can rupture along at least a portion of the pressure relief groove, thereby releasing the internal pressure of the shell. In this shell manufacturing method, the pressure relief groove is directly formed in the shell, eliminating the need for welding, avoiding leakage caused by welding defects, and promoting the life of the battery cells.

[0009] As an optional technical solution of an embodiment of the present application, the pressure relief groove includes a first groove; processing the sheet into a shell includes: processing the sheet into a preformed shell with an accommodating space; processing the first groove on the preformed shell.

[0010] In the above technical solution, the residual thickness of the shell is smallest at the location of the first groove. During pressure relief, the shell is most likely to rupture at the location of the first groove to release the pressure inside the shell. During shell manufacturing, the sheet is first processed into a preformed shell with a accommodating space, and the first groove is then machined into the preformed shell. This avoids the impact of shell processing on the precision of the first groove, ensuring a higher precision of the first groove. In the event of thermal runaway of the battery cell, the first groove can rupture and release pressure in a timely manner, which is beneficial to improving the reliability of the battery cell.

[0011] As an optional technical solution of an embodiment of the present application, the pressure relief groove also includes a second groove; processing the sheet into a shell also includes: processing the second groove; processing the first groove on the preformed shell includes: processing the first groove on the bottom surface of the second groove.

[0012] In the above technical solution, the pressure relief groove includes a first groove and a second groove, and the first groove is arranged on the bottom surface of the second groove. In this case, the pressure relief groove is a multi-level groove. During processing, the second groove is processed first, and finally the first groove is processed on the bottom surface of the second groove. Processing the first groove is the last step in the entire shell manufacturing, so the accuracy of the first groove is not easily affected by other processing steps, so that the first groove has higher accuracy. When the battery cell thermal runaway occurs, the first groove can be cracked and the pressure can be released in time, which is beneficial to improving the reliability of the battery cell. By processing the first groove and the second groove separately, it is beneficial to reduce the forming force applied during a single processing process, which is beneficial to reducing the risk of the sheet or preformed shell being damaged during the processing process. In addition, when processing the first groove, the second groove can also play a buffering role to a certain extent, so that the preformed shell is not easily deformed due to factors such as local extrusion during the processing of the first groove, which is beneficial to improving the yield rate of the shell, thereby improving the life and reliability of the battery cell.

[0013] As an optional technical solution of an embodiment of the present application, processing the first groove on the bottom surface of the second groove includes: processing multiple levels of grooves step by step on the bottom surface of the second groove to form the first groove on the bottom surface of the second groove.

[0014] In the above technical solution, the first groove is a multi-stage groove. By gradually machining the multi-stage grooves on the bottom surface of the second groove to form the first groove, the forming force applied during the first machining process is reduced, which helps to reduce the risk of damage to the preformed shell during the machining process.

[0015] As an optional technical solution of an embodiment of the present application, processing the first groove on the bottom surface of the second groove includes: simultaneously processing multiple levels of grooves on the bottom surface of the second groove to form the first groove on the bottom surface of the second groove.

[0016] In the above technical solution, the first groove is a multi-level groove. By simultaneously machining the multi-level grooves on the bottom surface of the second groove to form the first groove, it is beneficial to reduce production processes, reduce processing equipment, and reduce processing costs.

[0017] As an optional technical solution of the embodiment of the present application, after the sheet is processed and formed into a preformed shell with an accommodating space, the second groove is processed on the preformed shell.

[0018] In the above technical solution, when manufacturing the shell, the sheet is first processed into a preformed shell with an accommodating space, and then a second groove is processed on the preformed shell, and finally a first groove is processed on the bottom surface of the second groove, thereby avoiding the influence of the shell processing on the accuracy of the second groove and the first groove, so that the pressure relief groove has higher precision. When the battery cell thermal runaways, the pressure relief groove can be cracked and the pressure can be released in time, which is beneficial to improving the reliability of the battery cell.

[0019] As an optional technical solution of the embodiment of the present application, before the sheet is processed and formed into a preformed shell with an accommodating space, the second groove is processed on the sheet.

[0020] In the above technical solution, when manufacturing the shell, a second groove is first processed on the sheet, and then the sheet is processed into a preformed shell. The preformed shell is not easily affected by the processing of the second groove. The processed preformed shell has a regular shape and a smooth surface, which is conducive to improving the processing accuracy of the preformed shell.

[0021] As an optional technical solution of the embodiment of the present application, the second groove is processed in the process of processing the sheet into a preformed shell with an accommodating space.

[0022] In the above technical solution, the second groove is machined during the process of processing the blank into the preformed shell, which helps reduce the impact of machining the second groove on the preformed shell, thereby ensuring that the preformed shell has higher precision. In addition, the second groove is machined during the process of processing the blank into the preformed shell, which also has less impact on the second groove during the preformed shell processing, thereby improving the precision of the second groove. In short, the second groove is machined during the process of processing the blank into the preformed shell, which can ensure the precision of both the preformed shell and the second groove.

[0023] As an optional technical solution of an embodiment of the present application, the volume of the second groove is greater than the volume of the first groove.

[0024] In the above technical solution, by making the volume of the second groove larger than that of the first groove, the second groove can play a better buffering role during the processing of the first groove, reducing the risk of deformation of the preformed shell due to factors such as local extrusion, which is beneficial to improving the yield rate of the shell, thereby improving the life and reliability of the battery cell.

[0025] As an optional technical solution of an embodiment of the present application, processing the second groove includes: processing multiple levels of grooves to form the second groove; processing the first groove on the bottom surface of the second groove includes: processing the first groove on the bottom surface of the first level of the groove that is farthest from the groove opening of the second groove.

[0026] In the above technical solution, the second groove is a multi-level groove, and the first groove is formed on the bottom surface of the first-level groove that is farthest from the groove opening of the second groove. In this way, the second groove can provide a larger buffer space, thereby reducing the risk of deformation of the preformed shell due to factors such as local extrusion during the processing of the first groove, which is beneficial to improving the yield rate of the shell, thereby improving the life and reliability of the battery cell.

[0027] As an optional technical solution of the embodiment of the present application, processing the second groove includes: stamping out the second groove.

[0028] In the above technical solution, the second groove is formed by stamping, which is simple and convenient. Furthermore, stamping the second groove causes the groove wall to undergo cold work hardening (changing the grain arrangement, causing lattice distortion, reducing the metal's plasticity, and increasing the material's hardness). This enhances its ability to resist external impact and makes it less susceptible to damage from external impact. This helps reduce the risk of battery cell leakage and extend the battery cell lifespan.

[0029] As an optional technical solution of an embodiment of the present application, before processing the first groove on the bottom surface of the second groove, processing the sheet into a shell also includes: processing a third groove; wherein the third groove and the pressure relief groove define a predetermined pressure relief area, and the third groove is configured to guide the predetermined pressure relief area to at least partially flip open.

[0030] In the above technical solution, when the battery cell releases pressure, the pressure relief groove splits open, allowing the fluid medium inside the battery cell to flow out and release pressure. By providing the third groove, the strength of the shell at the location of the third groove is weakened, making it easier for the predetermined pressure relief area to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area opening, but also increases the speed of the predetermined pressure relief area opening, achieving rapid pressure relief, reducing the risk of battery cell explosion and fire, and promoting the reliability of the battery cell.

[0031] As an optional technical solution of an embodiment of the present application, the second groove is processed before the third groove is processed.

[0032] In the above technical solution, during processing, the second groove is processed first, and then the third groove is processed. The second groove can play a buffering role to a certain extent, absorbing the deformation of the sheet caused by processing the third groove.

[0033] As an optional technical solution of the embodiment of the present application, the third groove is processed before the second groove is processed.

[0034] In the above technical solution, before processing the second groove, the third groove is processed first. The third groove can play a buffering role and absorb the deformation caused by processing the second groove, so that during the processing of the second groove, it is not easy for the sheet or preformed shell to be drastically deformed due to factors such as local extrusion, which is beneficial to improving the yield rate of the shell, thereby improving the life and reliability of the battery cell.

[0035] As an optional technical solution of the embodiment of the present application, the second groove and the third groove are processed simultaneously.

[0036] In the above technical solution, by processing the second groove and the third groove at the same time, the processing of the first groove and the third groove is not likely to affect each other, and the number of workstations required for processing can be reduced, which is conducive to improving production efficiency.

[0037] As an optional technical solution of an embodiment of the present application, processing the third groove includes: processing two third grooves, so that the second groove is located between the two third grooves.

[0038] In the above technical solution, two third grooves are machined, each corresponding to at least one predetermined pressure relief area. When the battery cell releases pressure, each predetermined pressure relief area flips open under the guidance of its corresponding third groove, giving the battery cell a larger pressure relief area, which helps improve the pressure relief rate and reliability of the battery cell. Furthermore, during the subsequent machining of the first groove, both third grooves can act as a buffer to a certain extent, absorbing the deformation of the housing caused by machining the first groove, which helps improve the precision of the housing and the reliability of the battery cell.

[0039] As an optional technical solution of the embodiment of the present application, the second groove and the third groove are respectively processed on two opposite surfaces.

[0040] In the above technical solution, the second groove and the third groove are respectively arranged on two opposite surfaces, so that the second groove and the third groove are respectively located on both sides of the first wall of the sheet or the preformed shell, thereby facilitating the processing of the second groove and the third groove on both sides of the first wall of the sheet or the preformed shell, which is beneficial to reducing the mutual influence of the second groove and the third groove during the processing process.

[0041] As an optional technical solution of the embodiment of the present application, the second groove and the third groove are processed on the same surface.

[0042] In the above technical solution, the second groove and the third groove are arranged on the same surface, and the second groove and the third groove can be processed at one time during processing, which reduces the number of times the sheet is moved and is conducive to simplifying manufacturing.

[0043] As an optional technical solution of an embodiment of the present application, before processing the first groove on the preformed shell, processing the sheet into a shell also includes: processing a third groove; wherein the third groove and the pressure relief groove define a predetermined pressure relief area, and the third groove is configured to guide the predetermined pressure relief area to at least partially flip open.

[0044] In the above technical solution, when the battery cell releases pressure, the pressure relief groove splits open, allowing the fluid medium inside the battery cell to flow out and release pressure. By providing the third groove, the strength of the shell at the location of the third groove is weakened, making it easier for the predetermined pressure relief area to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area opening, but also increases the speed of the predetermined pressure relief area opening, achieving rapid pressure relief, reducing the risk of battery cell explosion and fire, and promoting the reliability of the battery cell.

[0045] As an optional technical solution of the embodiment of the present application, before the sheet is processed and formed into a preformed shell with an accommodating space, a third groove is processed on the sheet.

[0046] In the above technical solution, when manufacturing the shell, the third groove is first processed on the sheet, and then the sheet is processed into a preformed shell. The preformed shell is not easily affected by the processing of the third groove. The processed preformed shell has a regular shape and a smooth surface, which is conducive to improving the processing accuracy of the preformed shell.

[0047] As an optional technical solution of the embodiment of the present application, after the sheet is processed and formed into a preformed shell with an accommodating space, a third groove is processed on the preformed shell.

[0048] In the above technical solution, when manufacturing the shell, the material sheet is first processed into a preformed shell with an accommodating space, and then the third groove is processed on the preformed shell, which avoids the influence of the shell processing on the accuracy of the third groove, and is conducive to improving the guiding effect of the third groove on the flipping of the predetermined pressure relief area when the battery cell is depressurized.

[0049] As an optional technical solution of the embodiment of the present application, in the process of processing the sheet into a preformed shell with an accommodating space, the third groove is processed.

[0050] In the above technical solution, the third groove is machined during the process of processing the blank into the preformed shell, which helps reduce the impact of machining the third groove on the preformed shell, thereby ensuring that the preformed shell has higher precision. In addition, the third groove is machined during the process of processing the blank into the preformed shell, which also reduces the impact of the preformed shell machining on the third groove, thereby improving the precision of the third groove. In short, the third groove is machined during the process of processing the blank into the preformed shell, which can ensure the precision of both the preformed shell and the third groove.

[0051] As an optional technical solution of the embodiment of the present application, processing the third groove includes: stamping the third groove.

[0052] In the above technical solution, the third groove is formed by stamping, which is simple and convenient. Furthermore, stamping the third groove causes the groove wall to undergo cold work hardening (changing the grain arrangement, causing lattice distortion, reducing the metal's plasticity, and increasing the material's hardness). This enhances its resistance to external impact and makes it less susceptible to damage from external impact. This helps reduce the risk of battery cell leakage and increases the lifespan of the battery cells.

[0053] As an optional technical solution of an embodiment of the present application, the volume of the third groove is greater than the volume of the first groove.

[0054] In the above technical solution, by making the volume of the third groove larger than the volume of the first groove, the third groove can play a better buffering role during the processing of the first groove, absorb the deformation of the preformed shell caused by the processing of the first groove, and reduce the risk of deformation of the preformed shell due to factors such as local extrusion, which is beneficial to improving the yield rate of the shell, thereby improving the life and reliability of the battery cell.

[0055] As an optional technical solution of an embodiment of the present application, before processing the first groove on the preformed shell, processing the sheet into a shell also includes: facing the opening of the preformed shell downward and sleeved on a positioning piece to position the preformed shell; processing the first groove on the preformed shell includes: processing the first groove on the first wall of the preformed shell opposite to the opening.

[0056] In the above technical solution, during processing, the preformed shell opening is placed downward on the positioning piece to achieve rapid positioning of the preformed shell, thereby facilitating the processing of the first groove on the first wall of the preformed shell opposite to the opening, reducing the risk of the preformed shell running off course during processing, and helping to improve the processing accuracy of the first groove.

[0057] As an optional technical solution of an embodiment of the present application, before processing the first groove on the preformed shell, processing the sheet into a shell also includes: clamping the preformed shell by a clamp, and making the opening of the preformed shell face upward; processing the first groove on the preformed shell includes: processing the first groove on the first wall of the preformed shell opposite to the opening.

[0058] In the above technical solution, during processing, the preformed shell is clamped by a fixture so that the opening of the preformed shell faces upward, thereby facilitating the processing of the first groove on the first wall of the preformed shell opposite to the opening, reducing the risk of the preformed shell running off course during processing, and helping to improve the processing accuracy of the first groove.

[0059] As an optional technical solution of the embodiment of the present application, processing the first groove on the preformed shell includes: punching the first groove on the preformed shell.

[0060] In the above technical solution, the first groove is formed by stamping, which is simple and convenient. Furthermore, stamping the first groove causes the groove wall to undergo cold work hardening (changing the grain arrangement, causing lattice distortion, reducing the metal's plasticity, and increasing the material's hardness). This enhances its resistance to external impact and makes it less susceptible to damage from external impact. This helps reduce the risk of battery cell leakage.

[0061] As an optional technical solution of an embodiment of the present application, processing and forming the sheet into a preformed shell having an accommodating space includes: stretching and forming the sheet into a preformed shell having an accommodating space.

[0062] In the above technical solution, the sheet is processed into a preformed shell by stretching, which is simple in direction, low in cost and easy to operate.

[0063] As an optional technical solution of an embodiment of the present application, before processing the sheet into a shell, the shell manufacturing method further includes: processing the pressure relief groove on the sheet.

[0064] In the above technical solution, a pressure relief groove is first processed on the sheet, and then the sheet with the pressure relief groove is processed into a shell. In this way, the influence of the pressure relief groove on the shell can be avoided, so that the shell has higher precision, regular shape and smooth surface, which is beneficial to improving the life of the battery cell.

[0065] As an optional technical solution of the embodiment of the present application, the sheet has an elliptical structure.

[0066] In the above technical solution, the sheet is an elliptical structure, so that it is more economical to process the sheet into a shell.

[0067] In a second aspect, an embodiment of the present application further provides a shell, which is manufactured according to the above-mentioned shell manufacturing method.

[0068] As an optional technical solution of an embodiment of the present application, the shell has a first wall and a second wall connected to each other, the pressure relief groove is arranged on the first wall, and the second wall is located on one side of the first wall along the first direction; the first wall is also provided with a third groove, and along the first direction, the second wall has a first outer surface facing away from the interior of the shell, and the third groove is located between the first outer surface and the pressure relief groove.

[0069] In the above technical solution, the shell has a first wall and a second wall connected to each other, and a pressure relief groove is provided on the first wall, so that the first wall can crack along the pressure relief groove when the battery cell is depressurized to release the internal pressure of the battery cell, wherein a third groove is also provided on the first wall, and the third groove is located between the pressure relief groove and the first outer surface in the first direction. The third groove can play a certain separation role. On the one hand, the third groove can absorb the excess material squeezed out of the pressure relief groove during the forming process of the pressure relief groove, so as to alleviate the phenomenon that the first outer surface of the second wall or the first wall is locally arched due to local extrusion during the processing of the pressure relief groove on the first wall, thereby reducing the battery cell in the first direction. The problems such as the increase of the upward local size or the decrease of the flatness of the first wall are solved to improve the dimensional consistency of the shell, which is beneficial to improving the production quality of the battery cell. On the other hand, when the battery cell is subjected to internal and external impact forces and deformed, the third groove can also absorb the deformation energy of the battery cell, so that the third groove can play a buffering role between the pressure relief groove and the second wall, so as to play a certain protective role for the area of ​​the first wall where the pressure relief groove is provided, thereby effectively reducing the deformation or damage of the area of ​​the first wall where the pressure relief groove is provided when the battery cell is subjected to internal and external impact forces, so as to alleviate the situation where the battery cell is prematurely actuated to release pressure during use, which is beneficial to improving the reliability and service life of the battery cell.

[0070] As an optional technical solution of an embodiment of the present application, the third groove and the pressure relief groove define a predetermined pressure relief area, and the third groove is configured to guide the predetermined pressure relief area to at least partially flip open.

[0071] In the above technical solution, by setting the third groove, the strength of the first wall at the position of the third groove is weakened, making it easier for the predetermined pressure relief area to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area opening, but also increases the opening speed of the predetermined pressure relief area, thereby achieving rapid pressure relief, reducing the risk of battery cell explosion and fire, and helping to improve the reliability of the battery cell.

[0072] As an optional technical solution of the embodiment of the present application, the pressure relief groove and the third groove are located on two surfaces of the first wall that are respectively arranged opposite to each other.

[0073] In the above technical solution, the pressure relief groove and the third groove are respectively arranged on two opposite surfaces of the first wall, so that the pressure relief groove and the third groove are respectively located on both sides of the first wall, thereby facilitating the processing of the pressure relief groove and the third groove on both sides of the first wall, which is beneficial to reducing the mutual influence between the pressure relief groove and the third groove during the processing.

[0074] As an optional technical solution of the embodiment of the present application, along the first direction, the pressure relief groove and the projection of the third groove at least partially overlap.

[0075] In the above technical solution, by arranging the projections of the pressure relief groove and the third groove in the first direction to overlap at least part of each other, the pressure relief groove and the third groove have overlapping areas in the first direction, thereby, on the one hand, being able to enhance the absorption effect of the third groove on the residual material, so as to reduce the phenomenon that the local size of the battery cell is increased or the flatness of the first wall is poor due to local squeezing of the material in the process of processing the pressure relief groove of the first wall of the shell; on the other hand, being able to enhance the absorption effect of the pressure relief groove on the deformation energy of the battery cell when the battery cell is subjected to internal and external impact forces and deformed, thereby enhancing the buffering effect of the third groove between the pressure relief groove and the second wall, thereby being able to effectively reduce the phenomenon that the area of ​​the first wall where the pressure relief groove is provided is deformed or damaged when the battery cell is subjected to internal and external impact forces.

[0076] As an optional technical solution of the embodiment of the present application, two ends of the third groove in the extension direction of the projection along the thickness direction of the first wall respectively exceed two ends of the pressure relief groove.

[0077] In the above technical solution, by making the two ends of the extension direction of the projection of the third groove along the thickness direction of the first wall respectively extend beyond the two ends of the pressure relief groove, the separation effect of the third groove between the pressure relief groove and the second wall can be improved, so as to improve the absorption effect of the third groove on the residual material squeezed out during the forming process of the pressure relief groove, and can improve the blocking effect of the third groove on the deformation energy of the battery cell when the battery cell is subjected to internal and external impact forces.

[0078] As an optional technical solution of an embodiment of the present application, the pressure relief groove includes a plurality of groove segments, the plurality of groove segments are connected, and the plurality of groove segments and the third groove jointly define at least one predetermined pressure relief area.

[0079] In the above technical solution, the multiple groove segments and the third groove jointly define a predetermined pressure relief area. When the battery cell releases pressure, the first wall can rupture along the multiple groove segments, opening the predetermined pressure relief area to release pressure within the battery cell. Furthermore, the connection between the two groove segments is weaker, making it easier to rupture and open the predetermined pressure relief area for pressure relief, further increasing the pressure relief area and pressure relief rate of the battery cell.

[0080] As an optional technical solution of an embodiment of the present application, the multiple slot segments include a first slot segment, a second slot segment and a third slot segment, the first slot segment and the third slot segment are arranged opposite to each other, the second slot segment connects the first slot segment and the third slot segment, and the first slot segment, the second slot segment, the third slot segment and the third groove jointly define at least one predetermined pressure relief area.

[0081] In the above technical solution, the multiple slot segments include a first slot segment, a second slot segment and a third slot segment. The second slot segment connects the first slot segment and the third slot segment, so that the first wall can be cracked along the first slot segment, the second slot segment and the third slot segment when the battery cell is depressurized, so as to open the predetermined pressure relief area to release the internal pressure of the battery cell. The connection position between the first slot segment and the second slot segment and the connection position between the first slot segment and the third slot segment are weaker, easier to crack and open the predetermined pressure relief area for pressure relief, and can further improve the pressure relief area and pressure relief rate of the battery cell.

[0082] As an optional technical solution of an embodiment of the present application, the connection position of the first slot segment and the second slot segment deviates from the two ends of the first slot segment, and the connection position of the third slot segment and the second slot segment deviates from the two ends of the third slot segment, so that the predetermined pressure relief area is formed on both sides of the second slot segment.

[0083] In the above technical solution, by setting the connection position of the first slot segment and the second slot segment to be located between the two ends of the first slot segment, and setting the connection position of the third slot segment and the second slot segment to be located between the two ends of the third slot segment, so that the first slot segment, the second slot segment and the third slot segment form a structure similar to an "H" shape, predetermined pressure relief areas can be formed on both sides of the second slot segment of the pressure relief groove, and the two predetermined pressure relief areas can be opened in a split manner to relieve pressure when the battery cell is relieved, which is beneficial to further increase the pressure relief effect of the battery cell and can effectively improve the pressure relief rate of the battery cell.

[0084] In a third aspect, an embodiment of the present application further provides a battery cell, which includes the above-mentioned shell.

[0085] In a fourth aspect, an embodiment of the present application further provides a battery, which includes the above-mentioned battery cell.

[0086] In a fifth aspect, an embodiment of the present application further provides an electrical device, which includes the above-mentioned battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0088] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0089] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0090] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0091] FIG4 is an exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0092] FIG5 is a schematic block diagram of a method for manufacturing a housing according to some embodiments of the present application;

[0093] FIG6 is a schematic block diagram of a casing manufacturing method provided in some other embodiments of the present application;

[0094] FIG7 is a schematic block diagram of a casing manufacturing method provided in some further embodiments of the present application;

[0095] FIG8 is a schematic block diagram of a casing manufacturing method provided in some embodiments of the present application;

[0096] FIG9 is a schematic block diagram of a casing manufacturing method provided in some other embodiments of the present application;

[0097] FIG10 is a schematic block diagram of a casing manufacturing method provided in some other embodiments of the present application;

[0098] FIG11 is a schematic block diagram of a casing manufacturing method provided in some other embodiments of the present application;

[0099] FIG12 is a schematic diagram of the structure of a sheet provided in some embodiments of the present application;

[0100] FIG13 is a schematic structural diagram of a sheet (processed with a second groove) provided in some embodiments of the present application;

[0101] FIG14 is a schematic structural diagram of a preformed shell provided in some embodiments of the present application;

[0102] FIG15 is a schematic diagram of the back structure of a housing provided in some embodiments of the present application;

[0103] FIG16 is a schematic block diagram of a casing manufacturing method provided in some other embodiments of the present application;

[0104] FIG17 is a schematic block diagram of a casing manufacturing method provided in some other embodiments of the present application;

[0105] FIG18 is a schematic block diagram of a casing manufacturing method provided in yet other embodiments of the present application;

[0106] FIG19 is a schematic structural diagram of a sheet (processed with a third groove) provided in some embodiments of the present application;

[0107] FIG20 is a schematic structural diagram of a sheet (processed with a second groove and a third groove) provided in some embodiments of the present application;

[0108] FIG21 is a schematic structural diagram of a preformed shell (processed with a second groove and a third groove) provided in some embodiments of the present application;

[0109] FIG22 is a schematic structural diagram of a housing (having a first groove, a second groove, and a third groove) provided in some embodiments of the present application;

[0110] FIG23 is a schematic block diagram of a casing manufacturing method provided in yet other embodiments of the present application;

[0111] FIG24 is a schematic block diagram of a casing manufacturing method provided in some further embodiments of the present application;

[0112] FIG25 is a schematic block diagram of a casing manufacturing method provided in yet other embodiments of the present application;

[0113] FIG26 is a schematic block diagram of a casing manufacturing method provided in still other embodiments of the present application;

[0114] FIG27 is a schematic block diagram of a casing manufacturing method provided in yet other embodiments of the present application;

[0115] FIG28 is a schematic block diagram of a casing manufacturing method provided in yet other embodiments of the present application;

[0116] FIG29 is a schematic block diagram of a casing manufacturing method provided in yet other embodiments of the present application;

[0117] FIG30 is a schematic diagram of the front structure of a housing provided in some embodiments of the present application;

[0118] FIG31 is a bottom view of a housing provided in some embodiments of the present application;

[0119] Figure 32 is a cross-sectional view of a shell provided in some embodiments of the present application.

[0120] Icons: 1000-vehicle; 100-battery; 10-casing; 11-first casing body; 12-second casing body; 20-battery cell; 21-casing; 211-first wall; 2111-pressure relief groove; 2111a-first groove section; 2111b-second groove section; 2111c-third groove section; 21111-second groove; 21112-first groove; 2112-third groove; 2113-predetermined pressure relief area; 212-second wall; 2121-first outer surface; 215-casing; 2151-opening; 2152-preformed casing; 216-end cover; 22-electrode assembly; 221-ear; 23-electrode terminal; 24-current collecting member; 30-casing manufacturing method; 31-sheet; 200-controller; 300-motor. DETAILED DESCRIPTION

[0121] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0122] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0123] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0124] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0125] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0126] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0127] The term "plurality" used in this application refers to two or more (including two).

[0128] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0129] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0130] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0131] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0132] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0133] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may 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.).

[0134] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides 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, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and at least one of its modified compounds, etc.

[0135] In some embodiments, a positive electrode may utilize a metal foam. The metal foam may include nickel foam, copper foam, aluminum foam, alloy foam, or the like. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not include a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled or / and deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0136] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0137] As an example, the negative electrode current collector may be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. may be used. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may 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.).

[0138] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0139] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0140] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells that is well known in the art. 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, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0141] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0142] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0143] In some embodiments, the separator is a separator membrane. There are many types of separator membranes, and any known separator membrane with a porous structure having good chemical stability and mechanical stability can be selected.

[0144] As an example, the separator can be made of at least one of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film. In the case of a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0145] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0146] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0147] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0148] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0149] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0150] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0151] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, or the like.

[0152] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0153] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0154] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0155] In some embodiments, the electrode assembly is a laminate structure.

[0156] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0157] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0158] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded segments that are stacked.

[0159] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0160] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0161] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0162] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0163] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0164] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include but are not limited to square-shell, blade-shaped, and polygonal batteries, such as hexagonal batteries.

[0165] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0166] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0167] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0168] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0169] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0170] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles. These have become a new trend in the automotive industry. The development of battery technology requires consideration of multiple design factors, including reliability, energy density, discharge capacity, charge / discharge rate, and other performance parameters. Furthermore, battery life must be considered. However, current batteries have a relatively short lifespan.

[0171] For battery cells, in order to improve the safety of battery cells, the existing technology is to weld a pressure relief mechanism on the end cover of the battery cell. The pressure relief mechanism is provided with a notched groove. When the internal pressure of the battery cell reaches the detonation pressure, the notched groove cracks to release the pressure inside the battery cell, thereby reducing the risk of battery cell explosion and fire.

[0172] However, welding the pressure relief mechanism to the end cap is prone to welding defects, which can cause electrolyte leakage from the battery cell. Furthermore, the high temperatures generated by welding the pressure relief mechanism to the end cap can affect the scored grooves. Furthermore, welding can cause thermal expansion and contraction of the material, stretching the scored grooves and shortening the life of the pressure relief mechanism. This can also easily cause the pressure relief mechanism to open under the action of electrolyte, leading to leakage.

[0173] In view of this, an embodiment of the present application provides a method for manufacturing a housing, comprising providing a sheet; and processing the sheet into a housing. The housing is provided with a pressure relief groove, and the housing can be split along at least a portion of the pressure relief groove during pressure relief to release pressure inside the housing.

[0174] The casing manufactured using this method is equipped with a pressure relief groove. When the pressure or temperature inside the casing reaches the detonation pressure, the casing can rupture along at least a portion of the pressure relief groove, thereby releasing the internal pressure. In this casing manufacturing method, the pressure relief groove is directly formed in the casing, eliminating the need for welding, avoiding leakage caused by welding defects, and promoting the life of the battery cells.

[0175] The technical solution described in the embodiment of the present application is applicable to the manufacture of a shell, which can be used for a battery cell. The battery cell made of a shell manufactured using the shell manufacturing method has a longer life.

[0176] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0177] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device according to an embodiment of the present application.

[0178] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 can be arranged at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can be used as an operating power source or a power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0179] In some embodiments of the present application, the battery 100 can not only serve as the operating power source or usage power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0180] 2 and 3 , FIG2 is an exploded view of a battery 100 according to some embodiments of the present invention, and FIG3 is a schematic diagram of a battery cell 20 according to some embodiments of the present invention. The battery 100 includes a housing 10 and a battery cell 20 , wherein the battery cell 20 is accommodated in the housing 10 .

[0181] The housing 10 is used to provide assembly space for the battery cells 20 and can adopt a variety of structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12. The first housing body 11 and the second housing body 12 cover each other, and the first housing body 11 and the second housing body 12 jointly define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open, and the first housing body 11 can be a plate-like structure. The first housing body 11 covers the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define the assembly space. The first housing body 11 and the second housing body 12 can also be hollow structures with one end open, and the open side of the first housing body 11 covers the open side of the second housing body 12.

[0182] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid or a cube, etc. For example, in FIG2 , the box body 10 is in the shape of a cuboid.

[0183] In the battery 100, there can be one or more battery cells 20 disposed within the housing 10. When there are multiple battery cells 20 disposed within the housing 10, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel configurations within the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure formed by the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery 100 can be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module, which is then further connected in series, in parallel, or in a hybrid configuration to form a single structure, which is then housed within the housing 10.

[0184] In some embodiments, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which is used to connect the multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20 .

[0185] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be a rectangular parallelepiped, a cylinder, a prism, or other shapes. For example, in FIG3 , the battery cell 20 is a rectangular parallelepiped.

[0186] The battery cell 20 is the smallest unit that makes up the battery 100. Please refer to Figures 3 and 4. Figure 3 is a schematic diagram of the structure of the battery cell 20 provided in some embodiments of the present application. Figure 4 is an exploded view of the structure of the battery cell 20 provided in some embodiments of the present application. The battery cell 20 includes an end cap 216, a housing 215, and an electrode assembly 22. The housing 215 has a storage space with an opening 2151 at one end for accommodating the electrode assembly 22. The end cap 216 is connected to the housing 215 and closes the opening 2151.

[0187] The end cap 216 refers to a component that covers the opening 2151 of the shell 215 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 216 can be adapted to the shape of the shell 215 to match the shell 215. Optionally, the end cap 216 can be made of a material with a certain hardness and strength (such as an aluminum alloy), so that the end cap 216 is not easily deformed when squeezed or collided, so that the battery cell 20 can have a higher structural strength and improved safety performance. The material of the end cap 216 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application are not particularly limited to this. In some embodiments, the battery cell 20 also includes an insulating member, which is arranged on the inner side of the end cap 216. The insulating member can be used to isolate the electrical connection components in the shell 215 from the end cap 216 to reduce the risk of short circuit. Exemplary, the insulating member can be plastic, rubber, etc.

[0188] The housing 215 is a component used to cooperate with the end cap 216 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 215 and the end cap 216 can be independent components. An opening 2151 can be provided on the housing 215, and the end cap 216 is closed at the opening 2151 to form the internal environment of the battery cell 20. Without limitation, the end cap 216 and the housing 215 can also be integrated. Specifically, the end cap 216 and the housing 215 can form a common joint surface before other components are inserted into the housing. When the interior of the housing 215 needs to be encapsulated, the end cap 216 is closed to the housing 215. The housing 215 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the housing 215 can be determined according to the specific shape and size of the electrode assembly 22. The shell 215 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0189] The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be contained in the housing 21. The electrode assembly 22 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 22, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab 221. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 100, the positive electrode active material and the negative electrode active material react with the electrolyte.

[0190] In some embodiments, as shown in Figures 3 and 4, the battery cell 20 may further include an electrode terminal 23, which is insulated and mounted on the housing 21 and electrically connected to the electrode assembly 22 to output or input electrical energy of the battery cell 20.

[0191] It should be noted that the electrode terminal 23 is insulated and mounted on the housing 21 , that is, there is no electrical connection between the electrode terminal 23 and the housing 21 .

[0192] 3 and 4 , the battery cell 20 includes two electrode terminals 23 , which are spaced apart on the end cover 216 . Correspondingly, each electrode assembly 22 has two pole tabs 221 , and the polarities of the two pole tabs 221 are opposite. The two electrode terminals 23 are electrically connected to the two pole tabs 221 of the electrode assembly 22 , respectively, to realize the input or output of the positive and negative poles of the battery cell 20 .

[0193] Exemplarily, the electrode terminal 23 may be made of a variety of materials. For example, the electrode terminal 23 may be made of copper, iron, aluminum, steel, or aluminum alloy.

[0194] Optionally, the electrode terminals 23 may be mounted on the housing 21 in various configurations. For example, in Figures 3 and 4 , both electrode terminals 23 are mounted on the end cap 216 of the housing 21. Of course, the structure of the battery cell 20 is not limited thereto. In other embodiments, both electrode terminals 23 may be mounted on the shell 215 of the housing 21. Similarly, one electrode terminal 23 may be mounted on the shell 215 of the housing 21, while the other electrode terminal 23 may be mounted on the end cap 216 of the housing 21.

[0195] In some embodiments, as shown in Figures 3 and 4, the battery cell 20 may also include two current collecting components 24, both of which are arranged in the outer shell 21, and each current collecting component 24 is used to connect an electrode terminal 23 and a plurality of electrode assemblies 22 with the same polarity. The tabs 221 are used to achieve electrical connection between the electrode terminal 23 and the electrode assembly 22, which is beneficial to reduce the difficulty of assembly between the tabs 221 and the electrode terminal 23.

[0196] For example, the current collecting member 24 may be made of a variety of materials. For example, the current collecting member 24 may be made of copper, iron, aluminum, steel, or aluminum alloy.

[0197] Please refer to FIG5 , which is a schematic block diagram of a housing manufacturing method 30 provided in some embodiments of the present application. The present application provides a housing manufacturing method 30 , which includes:

[0198] Step S1: providing a sheet 31;

[0199] Step S2: Processing and shaping the sheet 31 into the housing 215 .

[0200] The shell 215 is provided with a pressure relief groove 2111 , and the shell 215 can be split along at least a portion of the pressure relief groove 2111 during pressure relief, so as to release the pressure inside the shell 215 .

[0201] The material sheet 31 refers to a blank material for manufacturing the housing 215. The material sheet 31 may be in a sheet-like structure, so that the material sheet 31 can be processed into the housing 215 later.

[0202] The shell 215 is provided with a pressure relief groove 2111, which serves to relieve pressure. When the internal pressure or temperature of the battery cell 20 reaches the detonation pressure, the shell 215 can be ruptured along the pressure relief groove 2111 to release the pressure inside the battery cell 20. The pressure relief groove 2111 can be processed at any time. The pressure relief groove 2111 can be a groove of various shapes, such as arc shape, H shape, U shape, ring shape, etc. The pressure relief groove 2111 can be processed and formed in various ways, such as stamping, cold heading, etc.

[0203] The housing 215 manufactured using this housing manufacturing method 30 is provided with a pressure relief groove 2111. When the pressure or temperature inside the housing 215 reaches the detonation pressure, the housing 215 can rupture along at least a portion of the pressure relief groove 2111, thereby releasing the pressure inside the housing 215. In this housing manufacturing method 30, the pressure relief groove 2111 is formed directly on the housing 215, eliminating the need for welding. This avoids leakage caused by welding defects and helps extend the life of the battery cells 20.

[0204] Please refer to FIG6 , which is a schematic block diagram of a shell manufacturing method 30 provided in some other embodiments of the present application. In some other embodiments, the pressure relief groove 2111 includes a first groove 21112. Processing the sheet 31 into the shell 215 includes:

[0205] Step S21: Processing the sheet 31 into a preformed housing 2152 having an accommodating space;

[0206] Step S22 : machining a first groove 21112 on the preformed shell 2152 .

[0207] The process of processing the material piece 31 into the shell 215 can be further divided into the following steps: firstly processing the material piece 31 into a preformed shell 2152 having an accommodating space, and then processing a first groove 21112 on the preformed shell 2152 .

[0208] The pressure relief groove 2111 includes a first groove 21112. The residual thickness of the shell 215 is smallest at the location of the first groove 21112. When the pressure is released, the shell 215 is most likely to be broken at the location of the first groove 21112 to release the pressure inside the shell 215.

[0209] The first groove 21112 can be a groove of various shapes, such as arc shape, H shape, U shape, ring shape, etc. The first groove 21112 can be formed by various methods, such as stamping, cold heading, etc.

[0210] The preformed shell 2152 has an accommodating space with an opening 2151 at one end for accommodating the electrode assembly 22. The end cap 216 can be connected to the preformed shell 2152 and close the opening 2151. The difference between the preformed shell 2152 and the shell 215 is that the preformed shell 2152 does not have the first groove 21112 machined therein, while the shell 215 already has the first groove 21112 machined therein.

[0211] When manufacturing the shell 215, the material sheet 31 is first processed into a preformed shell 2152 with an accommodating space, and then the first groove 21112 is processed on the preformed shell 2152, thereby avoiding the influence of the shell 215 processing on the accuracy of the first groove 21112, so that the first groove 21112 has higher accuracy. When the battery cell 20 thermally runs away, the first groove 21112 can be cracked and the pressure can be released in time, which is beneficial to improving the reliability of the battery cell 20.

[0212] Please refer to FIG7 , which is a schematic block diagram of a shell manufacturing method 30 provided in some other embodiments of the present application. In some other embodiments, the pressure relief groove 2111 further includes a second groove 21111. Processing the sheet 31 into the shell 215 further includes:

[0213] Step S23: machining a second groove 21111;

[0214] Machining the first groove 21112 on the preformed shell 2152 includes:

[0215] Step S221 : machining a first groove 21112 on the bottom surface of the second groove 21111 .

[0216] The pressure relief groove 2111 includes a first groove 21112 and a second groove 21111. The first groove 21112 is disposed on the bottom surface of the second groove 21111. In this case, the pressure relief groove 2111 is a multi-stage groove. When the pressure relief groove 2111 is a multi-stage groove, the second groove 21111 is first machined, and then the first groove 21112 is machined on the bottom surface of the second groove 21111.

[0217] The second groove 21111 can be a groove of various shapes, such as arc shape, H shape, U shape, ring shape, etc. The second groove 21111 can be formed by various methods, such as stamping, cold heading, etc.

[0218] During processing, the second groove 21111 is first machined, and finally, the first groove 21112 is machined on the bottom surface of the second groove 21111. Machining the first groove 21112 is the last step in the entire manufacturing of the housing 215. Therefore, the precision of the first groove 21112 is less susceptible to the impact of other machining steps, resulting in higher precision for the first groove 21112. In the event of thermal runaway of the battery cell 20, the first groove 21112 can promptly rupture and release pressure, thereby improving the reliability of the battery cell 20. By machining the first groove 21112 and the second groove 21111 separately, the forming force applied during the single machining process is reduced, thereby lowering the risk of damage to the sheet 31 or the preformed housing 2152 during machining. Furthermore, during machining of the first groove 21112, the second groove 21111 acts as a buffer to a certain extent, preventing deformation of the preformed housing 2152 due to factors such as localized material extrusion during machining of the first groove 21112. This improves the yield rate of the housing 215, thereby enhancing the lifespan and reliability of the battery cell 20.

[0219] Please refer to FIG8 , which is a schematic block diagram of a housing manufacturing method 30 provided in some embodiments of the present application. In some other embodiments, machining the first groove 21112 on the bottom surface of the second groove 21111 includes:

[0220] Step S2211 : machining multiple levels of grooves step by step on the bottom surface of the second groove 21111 to form a first groove 21112 on the bottom surface of the second groove 21111 .

[0221] In the embodiment shown in FIG8 , the first groove 21112 is a multi-stage groove. In this case, a first-stage groove can be first machined on the bottom surface of the second groove 21111, a second-stage groove can be machined on the bottom surface of the first groove 21112, and a third-stage groove can be machined on the bottom surface of the second-stage groove. This process is repeated by analogy, with the next-stage groove being machined on the bottom surface of the previous-stage groove until the multi-stage groove is completely machined. For example, if the first groove 21112 is a secondary groove, a first-stage groove can be first machined on the bottom surface of the second groove 21111, and a second-stage groove can be machined on the bottom surface of the first-stage groove to form the first groove 21112.

[0222] The first groove 21112 is a multi-stage groove. By gradually machining the multi-stage grooves on the bottom surface of the second groove 21111 to form the first groove 21112, it is helpful to reduce the forming force applied during the first machining process and reduce the risk of damage to the preformed shell 2152 during the machining process.

[0223] Please refer to FIG9 , which is a schematic block diagram of a housing manufacturing method 30 provided in some other embodiments of the present application. In some other embodiments, machining the first groove 21112 on the bottom surface of the second groove 21111 includes:

[0224] Step S2212 : simultaneously machining multiple levels of grooves on the bottom surface of the second groove 21111 to form a first groove 21112 on the bottom surface of the second groove 21111 .

[0225] In the embodiment shown in FIG9 , the first groove 21112 is a multi-level groove. In this case, the multi-level grooves can be simultaneously machined on the bottom surface of the second groove 21111. For example, the multi-level grooves can be simultaneously stamped on the bottom surface of the second groove 21111 to form the first groove 21112. In another example, the multi-level grooves can be simultaneously etched on the bottom surface of the second groove 21111 to form the first groove 21112.

[0226] The first groove 21112 is a multi-level groove. By simultaneously machining the multi-level grooves on the bottom surface of the second groove 21111 to form the first groove 21112, it is beneficial to reduce the production process, reduce the processing equipment, and reduce the processing cost.

[0227] Please refer to Figure 10, which is a schematic block diagram of a housing manufacturing method 30 provided in some other embodiments of the present application. In some other embodiments, after the sheet 31 is processed into a preformed housing 2152 having an accommodating space, a second groove 21111 is processed on the preformed housing 2152.

[0228] "After the material sheet 31 is processed into the preformed housing 2152 with an accommodating space, the second groove 21111 is processed in the preformed housing 2152" means that steps S21 and S23 are performed in a sequential order, with step S21 performed first and then step S23. In other words, the material sheet 31 is first processed into the preformed housing 2152 with an accommodating space, and then the second groove 21111 is processed. In this case, processing the second groove 21111 is specifically step S231: processing the second groove 21111 in the preformed housing 2152.

[0229] When manufacturing the shell 215, the sheet 31 is first processed into a preformed shell 2152 with an accommodating space, and then a second groove 21111 is processed on the preformed shell 2152. Finally, the first groove 21112 is processed on the bottom surface of the second groove 21111. This avoids the influence of the shell 215 processing on the accuracy of the second groove 21111 and the first groove 21112, so that the pressure relief groove 2111 has higher accuracy. When the battery cell 20 thermally runs away, the pressure relief groove 2111 can be cracked and the pressure can be released in time, which is beneficial to improving the reliability of the battery cell 20.

[0230] Please refer to Figures 11, 12, 13, 14 and 15. Figure 11 is a schematic block diagram of a shell manufacturing method 30 provided in some other embodiments of the present application. Figure 12 is a schematic structural diagram of a sheet 31 provided in some embodiments of the present application. Figure 13 is a schematic structural diagram of a sheet 31 (processed with a second groove 21111) provided in some embodiments of the present application. Figure 14 is a schematic structural diagram of a preformed shell 2152 provided in some embodiments of the present application. Figure 15 is a schematic structural diagram of the back side of a shell 215 provided in some embodiments of the present application. Before the sheet 31 is processed into a preformed shell 2152 with an accommodating space, a second groove 21111 is processed on the sheet 31.

[0231] "Before the material sheet 31 is processed into the preformed shell 2152 with an accommodating space, the second groove 21111 is processed on the material sheet 31" means: Step S21 and Step S23 are in a sequential order, and Step S23 is performed first, and then Step S21 is performed. In other words, the second groove 21111 is processed first, and then the material sheet 31 is processed into the preformed shell 2152 with an accommodating space. In this case, processing the second groove 21111 is specifically step S232: processing the second groove 21111 on the material sheet 31, and then processing the material sheet 31 with the second groove 21111 into the preformed shell 2152 with an accommodating space.

[0232] Please refer to Figure 12, which shows the blank 31 obtained after step S1. Please refer to Figure 13, which shows the blank 31 after step S232. At this point, the second groove 21111 has been machined into the blank 31. Please refer to Figure 14, which shows the preformed housing 2152 formed after step S21. At this point, the preformed housing 2152 already has the second groove 21111. Please refer to Figure 15, which shows the housing 215 formed after step S221. At this point, the first groove 21112 has been machined into the housing 215, completing the manufacture of the housing 215.

[0233] When manufacturing the shell 215, the second groove 21111 is first processed on the sheet 31, and then the sheet 31 is processed into a preformed shell 2152. The preformed shell 2152 is not easily affected by the processing of the second groove 21111. The processed preformed shell 2152 has a regular shape and a smooth surface, which is conducive to improving the processing accuracy of the preformed shell 2152.

[0234] In some embodiments, the second groove 21111 is formed during the process of forming the sheet 31 into the preformed shell 2152 having an accommodating space.

[0235] Processing the sheet 31 into the preformed housing 2152 may include multiple processing steps. For example, the sheet 31 may be pre-processed to form the sheet 31 into a blank housing 215, and then the second groove 21111 may be formed on the blank housing 215, and then the blank housing 215 may be processed into the preformed housing 2152. In this way, the second groove 21111 is formed during the process of processing the sheet 31 into the preformed housing 2152 having an accommodating space.

[0236] During the process of machining the sheet 31 into the preformed housing 2152, machining the second groove 21111 helps reduce the impact of machining the second groove 21111 on the preformed housing 2152, thereby ensuring that the preformed housing 2152 has a higher precision. Furthermore, during the process of machining the sheet 31 into the preformed housing 2152, machining the second groove 21111 also minimizes the impact of machining the preformed housing 2152 on the second groove 21111, thereby improving the precision of the second groove 21111. In short, machining the second groove 21111 during the process of machining the sheet 31 into the preformed housing 2152 ensures that both the precision of the preformed housing 2152 and the precision of the second groove 21111 are maintained.

[0237] In some embodiments, the volume of the second groove 21111 is greater than the volume of the first groove 21112 .

[0238] When measuring the volume of the first groove 21112, liquid can be added to the first groove 21112, and the volume of the first groove 21112 can be determined based on the amount of liquid added. When measuring the volume of the second groove 21111, liquid can be added to the first groove 21112 and the second groove 21111, and the volume of the second groove 21111 can be calculated based on the amount of liquid added minus the amount of liquid that the first groove 21112 can accommodate.

[0239] By making the volume of the second groove 21111 larger than the volume of the first groove 21112, the second groove 21111 can play a better buffering role during the processing of the first groove 21112, reducing the risk of deformation of the preformed shell 2152 due to factors such as local extrusion, which is beneficial to improving the yield of the shell 215, thereby improving the life and reliability of the battery cell 20.

[0240] Please refer to FIG16 , which is a schematic block diagram of a housing manufacturing method 30 provided in some other embodiments of the present application. In some other embodiments, machining the second groove 21111 includes:

[0241] Step S233: machining a multi-level groove to form a second groove 21111;

[0242] Machining the first groove 21112 on the bottom surface of the second groove 21111 includes:

[0243] Step S2213 : machining a first groove 21112 on the groove bottom surface of the first-level groove that is farthest from the groove opening of the second groove 21111 .

[0244] The second groove 21111 is a multi-stage groove. When processing the second groove 21111, the multi-stage grooves can be processed step by step to form the second groove 21111. When processing the second groove 21111, the multi-stage grooves can also be processed simultaneously to form the second groove 21111.

[0245] If the second groove 21111 is a multi-stage groove, machining the first groove 21112 on the bottom surface of the second groove 21111 can specifically be performed by machining the first groove 21112 on the bottom surface of the first-stage groove farthest from the notch of the second groove 21111. For example, the second groove 21111 comprises two stages of grooves, namely a first-stage groove and a second-stage groove, and the second-stage groove is machined on the bottom surface of the first-stage groove. In this case, the second-stage groove is the first-stage groove farthest from the notch of the second groove 21111, and therefore, the first groove 21112 should be machined on the bottom surface of the second-stage groove.

[0246] The second groove 21111 is a multi-level groove, and the first groove 21112 is formed on the bottom surface of the first-level groove that is farthest from the groove opening of the second groove 21111. In this way, the second groove 21111 can provide a larger buffer space, thereby reducing the risk of deformation of the preformed shell 2152 due to factors such as local extrusion during the processing of the first groove 21112, which is beneficial to improving the yield of the shell 215, thereby improving the life and reliability of the battery cell 20.

[0247] In some embodiments, machining the second groove 21111 includes: stamping the second groove 21111.

[0248] The second groove 21111 is formed by stamping, which is simple and convenient. Furthermore, stamping the second groove 21111 causes the groove wall of the second groove 21111 to undergo cold work hardening (changing the grain arrangement, causing lattice distortion, reducing the metal's plasticity, and increasing the material's hardness). This enhances its ability to resist external impacts and makes it less susceptible to damage from external impacts. This helps reduce the risk of leakage from the battery cell 20 and increases the lifespan of the battery cell 20.

[0249] Please refer to FIG17, which is a schematic block diagram of a shell manufacturing method 30 provided in some other embodiments of the present application. In some other embodiments, before machining the first groove 21112 on the bottom surface of the second groove 21111, machining the sheet 31 into the shell 215 further includes:

[0250] Step S24: machining the third groove 2112 .

[0251] The third groove 2112 and the pressure relief groove 2111 define a predetermined pressure relief area 2113 , and the third groove 2112 is configured to guide the predetermined pressure relief area 2113 to at least partially flip open.

[0252] The third groove 2112 and the pressure relief groove 2111 define a predetermined pressure relief area 2113 . When the battery cell 20 releases pressure, the pressure relief groove 2111 cracks along the edge of the predetermined pressure relief area 2113 , allowing the predetermined pressure relief area 2113 to open and release pressure.

[0253] The third groove 2112 serves to guide at least a portion of the predetermined pressure relief area 2113 to flip open. Optionally, the residual thickness of the shell 215 at the location of the third groove 2112 is greater than the residual thickness of the shell 215 at the location of the pressure relief groove 2111. When the battery cell 20 releases pressure, the pressure relief groove 2111 first ruptures to allow the fluid medium within the battery cell 20 to flow out and release pressure. Subsequently, under the influence of the fluid medium, the predetermined pressure relief area 2113 can flip outward with the third groove 2112 as the rotation axis, opening a larger pressure relief opening and achieving rapid pressure relief.

[0254] The third groove 2112 can be a groove of various shapes, such as an arc groove, a straight groove, etc. The second groove 21111 can be formed by various methods, such as stamping, cold heading, etc.

[0255] It should be noted that there is no particular order in which the second groove 21111 and the third groove 2112 are machined. The second groove 21111 can be machined first, followed by the third groove 2112. The third groove 2112 can also be machined first, followed by the second groove 21111. Alternatively, the second groove 21111 and the third groove 2112 can be machined simultaneously.

[0256] When the battery cell 20 releases pressure, the pressure relief groove 2111 splits, allowing the fluid medium in the battery cell 20 to flow out and release pressure. The provision of the third groove 2112 weakens the strength of the housing 215 at the location of the third groove 2112, making it easier for the predetermined pressure relief area 2113 to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area 2113 opening, but also increases the speed of opening of the predetermined pressure relief area 2113, achieving rapid pressure relief, reducing the risk of explosion or fire of the battery cell 20, and improving the reliability of the battery cell 20.

[0257] Referring to FIG. 17 , in some embodiments, the second groove 21111 is processed before the third groove 2112 is processed.

[0258] During processing, the second groove 21111 is processed first, and then the third groove 2112 is processed. The second groove 21111 can play a buffering role to a certain extent, absorbing the deformation of the sheet 31 caused by processing the third groove 2112.

[0259] Please refer to Figures 18, 19, 20, 21 and 22. Figure 19 is a schematic diagram of the structure of the sheet 31 (processed with the third groove 2112) provided in some embodiments of the present application. Figure 20 is a schematic diagram of the structure of the sheet 31 (processed with the second groove 21111 and the third groove 2112) provided in some embodiments of the present application. Figure 21 is a schematic diagram of the structure of the preformed shell 2152 (processed with the second groove 21111 and the third groove 2112) provided in some embodiments of the present application. Figure 22 is a schematic diagram of the structure of the shell 215 (processed with the first groove 21112, the second groove 21111 and the third groove 2112) provided in some embodiments of the present application. Figure 18 is a schematic block diagram of the shell manufacturing method 30 provided in still other embodiments of the present application. In still other embodiments, the third groove 2112 is processed before the second groove 21111 is processed.

[0260] Before processing the second groove 21111, the third groove 2112 is processed first. The third groove 2112 can play a buffering role and absorb the deformation caused by processing the second groove 21111, so that during the processing of the second groove 21111, it is not easy for the sheet 31 or the preformed shell 2152 to be greatly deformed due to factors such as local extrusion, which is beneficial to improving the yield of the shell 215, thereby improving the life and reliability of the battery cell 20.

[0261] Please refer to Figure 19, which shows the sheet 31 after step S24. At this point, the sheet 31 has been processed into the third groove 2112. Please refer to Figure 20, which shows the sheet 31 after step S23. At this point, the sheet 31 has been processed into the second groove 21111 and the third groove 2112. Please refer to Figure 21, which shows the preformed shell 2152 formed after step S21. At this point, the preformed shell 2152 has the second groove 21111 and the third groove 2112. Please refer to Figure 22, which shows the shell 215 formed after step S221. At this point, the first groove 21112 has been processed into the shell 215, completing the manufacture of the shell 215.

[0262] In some embodiments, the second groove 21111 and the third groove 2112 are processed simultaneously.

[0263] The second groove 21111 and the third groove 2112 can be processed simultaneously by stamping, or by etching.

[0264] By processing the second groove 21111 and the third groove 2112 at the same time, the processing of the first groove 21112 and the third groove 2112 is less likely to affect each other, and the number of workstations required for processing can be reduced, which is conducive to improving production efficiency.

[0265] 19 , 20 , 21 and 22 , in some embodiments, machining the third groove 2112 includes machining two third grooves 2112 such that the second groove 21111 is located between the two third grooves 2112 .

[0266] The two third grooves 2112 are spaced apart, and the second groove 21111 is located between the two third grooves 2112 .

[0267] Two third grooves 2112 are machined, each corresponding to at least one predetermined pressure relief area 2113. When the battery cell 20 releases pressure, each predetermined pressure relief area 2113 flips open under the guidance of its corresponding third groove 2112, providing the battery cell 20 with a larger pressure relief area. This helps increase the pressure relief rate and reliability of the battery cell 20. Furthermore, during the subsequent machining of the first groove 21112, both third grooves 2112 can act as a buffer to a certain extent, absorbing the deformation of the housing 215 caused by machining the first groove 21112. This helps improve the precision of the housing 215 and the reliability of the battery cell 20.

[0268] In some embodiments, a second groove 21111 and a third groove 2112 are respectively machined on two opposite surfaces.

[0269] When the second groove 21111 and the third groove 2112 are both processed before the sheet 31 is formed into the preformed shell 2152, the sheet 31 includes a first surface and a second surface arranged opposite to each other, the second groove 21111 is arranged on the first surface, and the third groove 2112 is arranged on the second surface.

[0270] When the second groove 21111 and the third groove 2112 are both processed after the sheet 31 is formed into the preformed shell 2152, the shell 215 has a first wall 211, the first wall 211 includes a third surface and a fourth surface arranged opposite to each other, the second groove 21111 is arranged on the third surface, and the third groove 2112 is arranged on the fourth surface.

[0271] When one of the second groove 21111 and the third groove 2112 is processed before the sheet 31 is formed into the preformed shell 2152, and the other is processed after the sheet 31 is formed into the preformed shell 2152, the completed shell 215 has a first wall 211, the first wall 211 includes a third surface and a fourth surface arranged opposite to each other, the second groove 21111 is arranged on the third surface, and the third groove 2112 is arranged on the fourth surface.

[0272] By respectively arranging the second groove 21111 and the third groove 2112 on two oppositely arranged surfaces, so that the second groove 21111 and the third groove 2112 are respectively located on both sides of the first wall 211 of the sheet 31 or the preformed shell 2152, it is convenient to process the second groove 21111 and the third groove 2112 on both sides of the first wall 211 of the sheet 31 or the preformed shell 2152, which is beneficial to reduce the mutual influence of the second groove 21111 and the third groove 2112 during the processing process.

[0273] In some embodiments, the second groove 21111 and the third groove 2112 are machined on the same surface.

[0274] When the second groove 21111 and the third groove 2112 are both processed before the material sheet 31 is formed into the preformed shell 2152 , the material sheet 31 includes a first surface, and the second groove 21111 and the third groove 2112 are both provided on the first surface.

[0275] When the second groove 21111 and the third groove 2112 are both processed after the sheet 31 is formed into the preformed shell 2152, the shell 215 has a first wall 211, the first wall 211 includes a third surface, and the second groove 21111 and the third groove 2112 are both arranged on the third surface.

[0276] When one of the second groove 21111 and the third groove 2112 is processed before the sheet 31 is formed into the preformed shell 2152, and the other is processed after the sheet 31 is formed into the preformed shell 2152, the completed shell 215 has a first wall 211, the first wall 211 includes a third surface, and the second groove 21111 and the third groove 2112 are both arranged on the third surface.

[0277] The second groove 21111 and the third groove 2112 are arranged on the same surface. The second groove 21111 and the third groove 2112 can be processed at one time, which reduces the number of times the sheet 31 is moved and is conducive to simplifying manufacturing.

[0278] Please refer to FIG23, which is a schematic block diagram of a shell manufacturing method 30 provided in some other embodiments of the present application. In some other embodiments, before processing the first groove 21112 on the preformed shell 2152, processing the sheet 31 into the shell 215 further includes:

[0279] Step S24: machining a third groove 2112;

[0280] The third groove 2112 and the pressure relief groove 2111 define a predetermined pressure relief area 2113 , and the third groove 2112 is configured to guide the predetermined pressure relief area 2113 to at least partially flip open.

[0281] When the battery cell 20 releases pressure, the pressure relief groove 2111 ruptures, allowing the fluid medium within the battery cell 20 to flow out and release pressure. The provision of the third groove 2112 weakens the strength of the housing 215 at the location of the third groove 2112, making it easier for the predetermined pressure relief area 2113 to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area 2113 opening, but also increases the speed of opening of the predetermined pressure relief area 2113, achieving rapid pressure relief, reducing the risk of explosion or fire in the battery cell 20, and thus improving the reliability of the battery cell 20.

[0282] Please refer to Figure 24, which is a schematic block diagram of a housing manufacturing method 30 provided in some further embodiments of the present application. In some further embodiments, before the sheet 31 is processed into a preformed housing 2152 having an accommodating space, a third groove 2112 is processed on the sheet 31.

[0283] "Before the material sheet 31 is processed into the preformed housing 2152 with an accommodating space, the third groove 2112 is processed on the material sheet 31" means: Step S21 and Step S24 are performed in a sequential order, and Step S24 is performed first, and then Step S21 is performed. In other words, the third groove 2112 is processed first, and then the material sheet 31 is processed into the preformed housing 2152 with an accommodating space. In this case, processing the third groove 2112 specifically involves step S241: processing the third groove 2112 on the material sheet 31, and then processing the material sheet 31 with the third groove 2112 into the preformed housing 2152 with an accommodating space.

[0284] When manufacturing the shell 215, the third groove 2112 is first processed on the sheet 31, and then the sheet 31 is processed into a preformed shell 2152. The preformed shell 2152 is not easily affected by the processing of the third groove 2112. The processed preformed shell 2152 has a regular shape and a smooth surface, which is conducive to improving the processing accuracy of the preformed shell 2152.

[0285] Please refer to Figure 25, which is a schematic block diagram of a housing manufacturing method 30 provided in yet other embodiments of the present application. In yet other embodiments, after the sheet 31 is processed into a preformed housing 2152 having an accommodating space, a third groove 2112 is processed on the preformed housing 2152.

[0286] "After the material sheet 31 is processed into the preformed housing 2152 with an accommodating space, the third groove 2112 is processed in the preformed housing 2152" means that steps S21 and S24 are performed in a sequential order, with step S21 performed first and then step S24. In other words, the material sheet 31 is first processed into the preformed housing 2152 with an accommodating space, and then the third groove 2112 is processed. In this case, processing the third groove 2112 specifically involves step S242: processing the third groove 2112 in the preformed housing 2152.

[0287] When manufacturing the shell 215, the sheet 31 is first processed into a preformed shell 2152 with an accommodating space, and then the third groove 2112 is processed on the preformed shell 2152, thereby avoiding the influence of the shell 215 processing on the accuracy of the third groove 2112, which is beneficial to improving the guiding effect of the third groove 2112 on the flipping of the predetermined pressure relief area 2113 when the battery cell 20 is depressurized.

[0288] In some embodiments, the third groove 2112 is machined during the process of molding the material sheet 31 into the preformed shell 2152 having the accommodation space.

[0289] Processing the sheet 31 into the preformed housing 2152 may include multiple processing steps. For example, the sheet 31 may be pre-processed to form the sheet 31 into a blank housing 215. The third groove 2112 may then be formed on the blank housing 215. The blank housing 215 may then be processed into the preformed housing 2152. In this way, the third groove 2112 is formed during the process of processing the sheet 31 into the preformed housing 2152 having an accommodating space.

[0290] During the process of forming the sheet 31 into the preformed housing 2152, machining the third groove 2112 helps reduce the impact of machining the third groove 2112 on the preformed housing 2152, thereby ensuring that the preformed housing 2152 has a higher precision. Furthermore, machining the third groove 2112 during the process of forming the sheet 31 into the preformed housing 2152 also minimizes the impact of machining the preformed housing 2152 on the third groove 2112, thereby improving the precision of the third groove 2112. In short, machining the third groove 2112 during the process of forming the sheet 31 into the preformed housing 2152 ensures that both the precision of the preformed housing 2152 and the precision of the third groove 2112 are maintained.

[0291] In some embodiments, machining the third groove 2112 includes: punching the third groove 2112 .

[0292] The third groove 2112 is formed by stamping, which is simple and convenient. Furthermore, stamping the third groove 2112 causes the groove wall to undergo cold work hardening (changing the grain arrangement, causing lattice distortion, reducing the metal's plasticity, and increasing the material's hardness). This enhances its resistance to external impact and makes it less susceptible to damage from external impact. This helps reduce the risk of battery cell 20 leakage and increases the lifespan of the battery cell 20.

[0293] In some embodiments, the volume of the third groove 2112 is greater than the volume of the first groove 21112 .

[0294] When measuring the volume of the first groove 21112 , liquid may be added into the first groove 21112 , and the volume of the first groove 21112 may be determined based on the amount of liquid added.

[0295] When measuring the volume of the third groove 2112 , liquid may be added into the third groove 2112 , and the volume of the third groove 2112 may be determined based on the amount of liquid added.

[0296] By making the volume of the third groove 2112 larger than the volume of the first groove 21112, the third groove 2112 can play a better buffering role during the processing of the first groove 21112, absorbing the deformation of the preformed shell 2152 caused by the processing of the first groove 21112, and reducing the risk of deformation of the preformed shell 2152 due to factors such as local extrusion, which is beneficial to improving the yield of the shell 215, thereby improving the life and reliability of the battery cell 20.

[0297] Please refer to Figure 26, which is a schematic block diagram of a shell manufacturing method 30 provided in some other embodiments of the present application. Before processing the first groove 21112 on the preformed shell 2152, processing the sheet 31 into the shell 215 further includes:

[0298] Step S251 : Place the preformed shell 2152 with its opening 2151 facing downward on the positioning member to position the preformed shell 2152 ;

[0299] Machining the first groove 21112 on the preformed shell 2152 includes:

[0300] Step S222 : machining a first groove 21112 on the first wall 211 of the preformed shell 2152 opposite to the opening 2151 .

[0301] Before machining the first groove 21112 on the preformed shell 2152, the preformed shell 2152 is first placed on the positioning member with the opening 2151 facing downward to position the preformed shell 2152 and reduce the risk of the preformed shell 2152 moving off course during machining. Next, the first groove 21112 is machined on the first wall 211 of the preformed shell 2152. The first wall 211 is the wall of the preformed shell 2152 opposite the opening 2151.

[0302] During processing, the opening 2151 of the preformed shell 2152 is placed downward on the positioning piece to achieve rapid positioning of the preformed shell 2152, thereby facilitating the processing of the first groove 21112 on the first wall 211 of the preformed shell 2152 opposite to the opening 2151, reducing the risk of the preformed shell 2152 running off during processing, and helping to improve the processing accuracy of the first groove 21112.

[0303] Please refer to FIG27, which is a schematic block diagram of a housing manufacturing method 30 provided in yet other embodiments of the present application. In yet other embodiments, before forming the first groove 21112 on the preformed housing 2152, forming the sheet 31 into the housing 215 further includes:

[0304] Step S252: Clamp the preformed shell 2152 with a fixture, with the opening 2151 of the preformed shell 2152 facing upward;

[0305] Machining the first groove 21112 on the preformed shell 2152 includes:

[0306] Step S222 : machining a first groove 21112 on the first wall 211 of the preformed shell 2152 opposite to the opening 2151 .

[0307] Before machining the first groove 21112 on the preformed shell 2152, the preformed shell 2152 is first clamped and positioned with the opening 2151 facing upward to reduce the risk of the preformed shell 2152 moving off course during machining. Next, the first groove 21112 is machined on the first wall 211 of the preformed shell 2152. The first wall 211 is the wall of the preformed shell 2152 opposite the opening 2151.

[0308] During processing, the preformed shell 2152 is clamped by a fixture so that the opening 2151 of the preformed shell 2152 faces upward, thereby facilitating the processing of the first groove 21112 on the first wall 211 of the preformed shell 2152 opposite to the opening 2151, reducing the risk of the preformed shell 2152 running off during processing, and helping to improve the processing accuracy of the first groove 21112.

[0309] In some embodiments, machining the first groove 21112 on the preformed shell 2152 includes: stamping the first groove 21112 on the preformed shell 2152 .

[0310] The first groove 21112 is formed by stamping, which is simple and convenient. Furthermore, stamping the first groove 21112 causes the groove wall to undergo cold work hardening (changing the grain arrangement, causing lattice distortion, reducing the metal's plasticity, and increasing the material's hardness). This enhances its ability to resist external impacts and makes it less susceptible to damage from external impacts. This helps reduce the risk of leakage from the battery cell 20.

[0311] Please refer to FIG28, which is a schematic block diagram of a housing manufacturing method 30 provided in yet another embodiment of the present application. In yet another embodiment, processing the sheet 31 into a preformed housing 2152 with an accommodating space includes:

[0312] Step S211: stretching the sheet 31 into a preformed shell 2152 having an accommodating space.

[0313] The material piece 31 can be stretched once to form the preformed shell 2152, or can be stretched multiple times to form the preformed shell 2152. When the material piece 31 is stretched multiple times to form the preformed shell 2152, the preformed shell 2152 has higher precision.

[0314] The sheet 31 is formed into the preformed shell 2152 by stretching, which is simple in direction, low in cost and easy to operate.

[0315] Please refer to FIG29, which is a schematic block diagram of a housing manufacturing method 30 provided in yet another embodiment of the present application. In yet another embodiment, before the sheet 31 is processed and formed into the housing 215, the housing manufacturing method 30 further includes:

[0316] Step S3: Processing a pressure relief groove 2111 on the sheet 31 .

[0317] In the embodiment shown in FIG. 29 , the pressure relief groove 2111 is firstly completely machined on the sheet 31 , and then the sheet 31 with the pressure relief groove 2111 is machined into the shell 215 .

[0318] First, a pressure relief groove 2111 is processed on the sheet 31, and then the sheet 31 with the pressure relief groove 2111 is processed into a shell 215. In this way, the influence of the processing pressure relief groove 2111 on the shell 215 can be avoided, so that the shell 215 has higher precision, the shell 215 has a regular shape and a smooth surface, which is beneficial to improving the life of the battery cell 20.

[0319] In some embodiments, the material sheet 31 is an oval structure.

[0320] The material piece 31 has an elliptical structure, so that it saves material when processing the material piece 31 into the housing 215 .

[0321] Please refer to Figure 30, which is a front structural diagram of a housing 215 provided in some embodiments of the present application. The present application also provides a housing 215, which is manufactured according to the housing manufacturing method 30 described above.

[0322] Please refer to Figures 30, 31 and 32. In some embodiments, Figure 31 is a bottom view of the shell 215 provided in some embodiments of the present application.

[0323] Figure 32 is a cross-sectional view of a housing 215 provided in some embodiments of the present application. The housing 215 comprises a first wall 211 and a second wall 212 connected to each other. A pressure relief groove 2111 is provided on the first wall 211, and the second wall 212 is located on one side of the first wall 211 along a first direction. The first wall 211 is further provided with a third groove 2112. Along the first direction, the second wall 212 has a first outer surface 2121 facing away from the interior of the housing 215. The third groove 2112 is located between the first outer surface 2121 and the pressure relief groove 2111.

[0324] The pressure relief groove 2111 serves to relieve pressure, and is used to enable the first wall 211 to rupture along the pressure relief groove 2111 when the internal pressure or temperature of the battery cell 20 reaches the detonation pressure, so as to release the pressure inside the battery cell 20 .

[0325] Optionally, the pressure relief groove 2111 may be provided on a side of the first wall 211 facing the interior of the shell 215 , or may be provided on a side of the first wall 211 facing away from the interior of the shell 215 .

[0326] Optionally, the third groove 2112 can be arranged on the same side of the first wall 211 as the pressure relief groove 2111, or can be arranged on both sides of the first wall 211 respectively. For example, the pressure relief groove 2111 is arranged on the side of the first wall 211 away from the interior of the shell 215, and the third groove 2112 is arranged on the side of the first wall 211 facing the interior of the shell 215.

[0327] Exemplarily, the pressure relief groove 2111 and the third groove 2112 are both formed by a stamping process.

[0328] The housing 215 has a first wall 211 and a second wall 212 connected to each other. That is, the first wall 211 and the second wall 212 are two adjacent and connected walls of the housing 215. For example, in Figures 30, 31, and 32, the housing 215 is a rectangular parallelepiped structure, and the first wall 211 and the second wall 212 are two perpendicular walls. It should be noted that in some embodiments, if the housing 215 is a cylindrical structure, the first wall 211 is a wall at one end of the housing 215 in the axial direction, and the second wall 212 is a side wall arranged around the first wall 211.

[0329] For example, in Figures 30, 31, and 32, the housing 215 is a rectangular parallelepiped structure, and correspondingly, the first wall 211 is a rectangular structure. The first direction may be the X direction shown in Figures 31 and 32. In the embodiment shown in Figures 32 and 33, the first direction X is the width direction of the first wall 211.

[0330] The third groove 2112 is located between the first outer surface 2121 and the pressure relief groove 2111, that is, in the first direction, the pressure relief groove 2111, the third groove 2112 and the first outer surface 2121 of the second wall 212 are arranged in sequence along the first direction, so that the pressure relief groove 2111 and the first outer surface 2121 of the second wall 212 are respectively located on both sides of the third groove 2112 in the first direction.

[0331] The first outer surface 2121 is a surface of the second wall 212 facing away from the interior of the housing 215 in the first direction.

[0332] The shell 21 has a first wall 211 and a second wall 212 connected to each other, and a pressure relief groove 2111 is provided on the first wall 211, so that the first wall 211 can be cracked along the pressure relief groove 2111 when the battery cell 20 is depressurized, so as to release the internal pressure of the battery cell 20, wherein a third groove 2112 is also provided on the first wall 211, and the third groove 2112 is located between the pressure relief groove 2111 and the first outer surface 2121 in the first direction. The third groove 2112 can play a certain separation role. On the one hand, the third groove 2112 can absorb the excess material squeezed out of the pressure relief groove 2111 during the molding process of the pressure relief groove 2111, so as to alleviate the phenomenon that the first outer surface 2121 of the second wall 212 or the first wall 211 appears locally arched due to local extrusion during the processing of the pressure relief groove 2111 on the first wall 211, thereby being able to The problem of local size increase of the battery cell 20 in the first direction or reduction in the flatness of the first wall 211 is reduced, so as to improve the dimensional consistency of the shell 215, which is beneficial to improving the production quality of the battery cell 20. On the other hand, when the battery cell 20 is subjected to internal and external impact forces and deformed, the third groove 2112 can also absorb the deformation energy of the battery cell 20, so that the third groove 2112 can play a buffering role between the pressure relief groove 2111 and the second wall 212, so as to play a certain protective role for the area of ​​the first wall 211 where the pressure relief groove 2111 is provided, thereby effectively reducing the deformation or damage of the area of ​​the first wall 211 where the pressure relief groove 2111 is provided when the battery cell 20 is subjected to internal and external impact forces, thereby alleviating the situation where the battery cell 20 is prematurely actuated to release pressure during use, which is beneficial to improving the reliability and service life of the battery cell 20.

[0333] 30 , 31 and 32 , in some embodiments, the third groove 2112 and the pressure relief groove 2111 define a predetermined pressure relief area 2113 , and the third groove 2112 is configured to guide the predetermined pressure relief area 2113 to at least partially flip open.

[0334] The third groove 2112 and the pressure relief groove 2111 define a predetermined pressure relief area 2113. When the battery cell 20 releases pressure, the pressure relief groove 2111 cracks along the edge of the predetermined pressure relief area 2113, allowing the predetermined pressure relief area 2113 to open and release pressure. The third groove 2112 serves to guide at least a portion of the predetermined pressure relief area 2113 to flip open. Optionally, the residual thickness of the shell 215 at the location of the third groove 2112 is greater than the residual thickness of the shell 215 at the location of the pressure relief groove 2111. When the battery cell 20 releases pressure, the pressure relief groove 2111 first cracks to allow the fluid medium within the battery cell 20 to flow out and release pressure. Subsequently, under the action of the fluid medium, the predetermined pressure relief area 2113 can flip outward with the third groove 2112 as the rotation axis to open a larger pressure relief port, achieving rapid pressure relief. The third groove 2112 can be a groove of various shapes, such as an arc groove, a straight groove, etc. The second groove 21111 can be formed by various methods, such as stamping, cold heading, etc.

[0335] By providing the third groove 2112, the strength of the first wall 211 at the position of the third groove 2112 is weakened, making it easier for the predetermined pressure relief area 2113 to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area 2113 opening, but also increases the opening speed of the predetermined pressure relief area 2113, thereby achieving rapid pressure relief and reducing the risk of explosion or fire of the battery cell 20, which is beneficial to improving the reliability of the battery cell 20.

[0336] 30 , 31 and 32 , in some embodiments, the pressure relief groove 2111 and the third groove 2112 are located on two opposite surfaces of the first wall 211 .

[0337] The first wall 211 includes a third surface and a fourth surface disposed opposite each other, wherein the third surface faces the interior of the housing 215, and the fourth surface faces away from the interior of the housing 215. The third groove 2112 can be disposed on the third surface, and the pressure relief groove 2111 can be disposed on the fourth surface. Of course, in other embodiments, the third groove 2112 can be disposed on the fourth surface, and the pressure relief groove 2111 can be disposed on the third surface.

[0338] By respectively arranging the pressure relief groove 2111 and the third groove 2112 on two opposite surfaces of the first wall 211, so that the pressure relief groove 2111 and the third groove 2112 are respectively located on both sides of the first wall 211, it is convenient to process the pressure relief groove 2111 and the third groove 2112 on both sides of the first wall 211, which is beneficial to reduce the mutual influence between the pressure relief groove 2111 and the third groove 2112 during the processing.

[0339] 30 , 31 , and 32 , in some embodiments, along the first direction, the pressure relief groove 2111 and the projection of the third groove 2112 at least partially overlap.

[0340] The projection of the third groove 2112 in the first direction covers at least a portion of the pressure relief groove 2111 .

[0341] By arranging the projections of the pressure relief groove 2111 and the third groove 2112 in the first direction to overlap at least partially, the pressure relief groove 2111 and the third groove 2112 have mutually overlapping areas in the first direction, thereby, on the one hand, improving the absorption effect of the third groove 2112 on the residual material, thereby reducing the phenomenon that the local size of the battery cell 20 increases or the flatness of the first wall 211 is poor due to local squeezing of material during the processing of the pressure relief groove 2111 by the first wall 211 of the shell 215; on the other hand, it can improve the absorption effect of the pressure relief groove 2111 on the deformation energy of the battery cell 20 when the battery cell 20 is subjected to internal and external impact forces and deformed, thereby improving the buffering effect of the third groove 2112 between the pressure relief groove 2111 and the second wall 212, thereby effectively reducing the phenomenon that the area of ​​the first wall 211 where the pressure relief groove 2111 is provided with the pressure relief groove 2111 is deformed or damaged when the battery cell 20 is subjected to internal and external impact forces.

[0342] In some embodiments, two ends of the third groove 2112 in the extension direction of the projection along the thickness direction of the first wall 211 respectively extend beyond two ends of the pressure relief groove 2111 .

[0343] The third groove 2112 can extend along the second direction. Referring to FIG. 31 , the second direction can be the Y direction shown in the figure. In some embodiments, both ends of the third groove 2112 in the second direction extend beyond the pressure relief groove 2111. That is, the length of the third groove 2112 in the second direction is greater than the length of the pressure relief groove 2111 in the second direction, and both ends of the third groove 2112 extend beyond the ends of the pressure relief groove 2111.

[0344] By making the two ends of the third groove 2112 in the extension direction of the projection along the thickness direction of the first wall 211 respectively extend beyond the two ends of the pressure relief groove 2111, the separation effect of the third groove 2112 between the pressure relief groove 2111 and the second wall 212 can be improved, so as to improve the absorption effect of the third groove 2112 on the residual material squeezed out during the molding process of the pressure relief groove 2111, and can also improve the blocking effect of the third groove 2112 on the deformation energy of the battery cell 20 when the battery cell 20 is subjected to internal and external impact forces.

[0345] 30 , 31 and 32 , in some embodiments, the pressure relief groove 2111 includes a plurality of groove segments, the plurality of groove segments are connected, and the plurality of groove segments and the third groove 2112 together define at least one predetermined pressure relief area 2113 .

[0346] The pressure relief groove 2111 includes multiple groove segments. Each groove segment can be a straight groove, or a curved groove. Alternatively, some groove segments can be straight grooves and some can be curved grooves. The multiple groove segments are connected to form the pressure relief groove 2111. The multiple groove segments and the third groove 2112 together define at least one predetermined pressure relief area 2113.

[0347] The multiple groove segments and the third groove 2112 together define a predetermined pressure relief area 2113. When the battery cell 20 releases pressure, the first wall 211 can rupture along the multiple groove segments, thereby opening the predetermined pressure relief area 2113 and releasing pressure within the battery cell 20. Furthermore, the connection between the two groove segments is weaker, making it easier to rupture and open the predetermined pressure relief area 2113 for pressure relief, further increasing the pressure relief area and pressure relief rate of the battery cell 20.

[0348] Referring to Figures 30, 31, and 32, in some embodiments, the plurality of slot segments include a first slot segment 2111a, a second slot segment 2111b, and a third slot segment 2111c. The first slot segment 2111a and the third slot segment 2111c are disposed opposite each other, and the second slot segment 2111b connects the first slot segment 2111a and the third slot segment 2111c. The first slot segment 2111a, the second slot segment 2111b, and the third slot segment 2111c collectively define at least one predetermined pressure relief area 2113.

[0349] The first slot section 2111a and the third slot section 2111c are spaced apart and at least partially opposite to each other. Optionally, the first slot section 2111a and the third slot section 2111c both extend along the first direction.

[0350] The second slot segment 2111b connects the first slot segment 2111a and the third slot segment 2111c, that is, the second slot segment 2111b is located between the first slot segment 2111a and the third slot segment 2111c, and the two ends of the second slot segment 2111b are respectively connected to the first slot segment 2111a and the third slot segment 2111c. Of course, in other embodiments, the two ends of the second slot segment 2111b can extend out of the first slot segment 2111a and the third slot segment 2111c, respectively.

[0351] 31 , the extension line of the first slot section 2111a intersects the third groove 2112, and the extension line of the third slot section 2111c intersects the third groove 2112. The enclosed area formed by the first slot section 2111a, the extension line of the first slot section 2111a toward the third groove 2112, the second slot section 2111b, the third slot section 2111c, the extension line of the third slot section 2111c toward the third groove 2112, and the third groove 2112 is the predetermined pressure relief area 2113. That is to say, the first groove section 2111a, the second groove section 2111b and the third groove section 2111c are structures arranged along the edge of the predetermined pressure relief area 2113, so that the predetermined pressure relief area 2113 can be opened with the first groove section 2111a, the second groove section 2111b and the third groove section 2111c as boundaries, that is, the predetermined pressure relief area 2113 is formed in the area enclosed by the first groove section 2111a, the second groove section 2111b and the third groove section 2111c, so that the part of the first wall 211 located in the predetermined pressure relief area 2113 can be opened with the first groove section 2111a, the second groove section 2111b and the third groove section 2111c as boundaries when the battery cell 20 is depressurized, thereby releasing the internal pressure of the battery cell 20.

[0352] The multiple groove sections include a first groove section 2111a, a second groove section 2111b and a third groove section 2111c. The second groove section 2111b connects the first groove section 2111a and the third groove section 2111c, so that the first wall 211 can be split along the first groove section 2111a, the second groove section 2111b and the third groove section 2111c when the battery cell 20 is depressurized, so as to open the predetermined pressure relief area 2113 to release the internal pressure of the battery cell 20. The connection position between the first groove section 2111a and the second groove section 2111b and the connection position between the first groove section 2111a and the third groove section 2111c are weaker, easier to split and open the predetermined pressure relief area 2113 for pressure relief, and can further improve the pressure relief area and pressure relief rate of the battery cell 20.

[0353] Please refer to Figures 30, 31 and 32. In some embodiments, the connection position of the first slot segment 2111a and the second slot segment 2111b deviates from the two ends of the first slot segment 2111a, and the connection position of the third slot segment 2111c and the second slot segment 2111b deviates from the two ends of the third slot segment 2111c, so that a predetermined pressure relief area 2113 is formed on both sides of the second slot segment 2111b.

[0354] Among them, the connection position of the second slot segment 2111b and the first slot segment 2111a deviates from the two ends of the first slot segment 2111a, that is, the second slot segment 2111b is connected between the two ends of the first slot segment 2111a. Similarly, the connection position of the third slot segment 2111c and the second slot segment 2111b deviates from the two ends of the third slot segment 2111c, that is, the second slot segment 2111b is connected between the two ends of the third slot segment 2111c, so that the shape of the first groove 21112 formed by the first slot segment 2111a, the second slot segment 2111b and the third slot segment 2111c is an approximately "H"-shaped structure.

[0355] By setting the connection position of the first slot section 2111a and the second slot section 2111b to be located between the two ends of the first slot section 2111a, and setting the connection position of the third slot section 2111c and the second slot section 2111b to be located between the two ends of the third slot section 2111c, so that the first slot section 2111a, the second slot section 2111b and the third slot section 2111c form a structure similar to an "H" shape, predetermined pressure relief areas 2113 can be formed on both sides of the second slot section 2111b of the pressure relief slot 2111, and the two predetermined pressure relief areas 2113 can be opened in a split manner for pressure relief when the battery cell 20 is relieved of pressure, which is beneficial to further increase the pressure relief effect of the battery cell 20 and can effectively improve the pressure relief rate of the battery cell 20.

[0356] The embodiment of the present application further provides a battery cell 20 , which includes the above-mentioned housing 215 .

[0357] The embodiment of the present application further provides a battery 100 , which includes the above-mentioned battery cell 20 .

[0358] An embodiment of the present application further provides an electrical device, which includes the above-mentioned battery cell 20.

[0359] According to some embodiments of the present application, please refer to Figures 5 to 27.

[0360] The embodiment of the present application provides a housing manufacturing method 30, which includes:

[0361] Step S1: providing a sheet 31;

[0362] Step S24: machining a third groove 2112;

[0363] Step S23: machining a second groove 21111;

[0364] Step S21: Processing the sheet 31 into a preformed housing 2152 having an accommodating space;

[0365] Step S221 : machining a first groove 21112 on the bottom surface of the second groove 21111 .

[0366] The housing 215 manufactured using this housing manufacturing method 30 is provided with a pressure relief groove 2111. When the pressure or temperature inside the housing 215 reaches the detonation pressure, the housing 215 can rupture along at least a portion of the pressure relief groove 2111, thereby releasing the pressure within the housing 215. In this housing manufacturing method 30, the pressure relief groove 2111 is formed directly on the housing 215, eliminating the need for welding. This avoids leakage caused by welding defects and improves the lifespan of the battery cells 20. When manufacturing the housing 215, a second groove 21111 is first machined into the sheet 31, which is then formed into a preformed housing 2152. The preformed housing 2152 is less susceptible to the effects of machining the second groove 21111. The resulting preformed housing 2152 has a regular shape and a smooth surface, which improves the machining precision of the preformed housing 2152. When the pressure in the battery cell 20 is released, the pressure relief groove 2111 ruptures, allowing the fluid medium within the battery cell 20 to escape and release pressure. The provision of the third groove 2112 weakens the strength of the housing 215 at the location of the third groove 2112, making it easier for the predetermined pressure relief area 2113 to flip open under the action of the fluid medium. This not only increases the probability of the predetermined pressure relief area 2113 opening, but also increases the speed of opening of the predetermined pressure relief area 2113, achieving rapid pressure relief, reducing the risk of explosion or fire of the battery cell 20, and thus improving the reliability of the battery cell 20. When manufacturing the housing 215, the third groove 2112 is first machined into the sheet 31, and then the sheet 31 is machined into a preformed housing 2152. The preformed housing 2152 is not easily affected by the machining of the third groove 2112. The machined preformed housing 2152 has a regular shape and a smooth surface, which helps improve the machining accuracy of the preformed housing 2152.

[0367] The residual thickness of the shell 215 is smallest at the location of the first groove 21112. During pressure relief, the shell 215 is most likely to rupture at the location of the first groove 21112 to release pressure within the shell 215. During the manufacturing of the shell 215, the sheet 31 is first processed into a preformed shell 2152 with a accommodating space, and then the first groove 21112 is machined into the preformed shell 2152. This prevents the machining of the shell 215 from affecting the precision of the first groove 21112, ensuring a higher precision for the first groove 21112. In the event of thermal runaway of the battery cell 20, the first groove 21112 can rupture and release pressure in a timely manner, thereby improving the reliability of the battery cell 20.

[0368] The pressure relief groove 2111 includes a first groove 21112 and a second groove 21111. The first groove 21112 is arranged on the bottom surface of the second groove 21111. In this case, the pressure relief groove 2111 is a multi-stage groove. During processing, the second groove 21111 is processed first, and finally the first groove 21112 is processed on the bottom surface of the second groove 21111. Processing the first groove 21112 is the last step in the manufacture of the entire shell 215. Therefore, the accuracy of the first groove 21112 is not easily affected by other processing steps, so that the first groove 21112 has a higher accuracy. When the battery cell 20 thermally runs away, the first groove 21112 can be cracked and released in time, which is beneficial to improving the reliability of the battery cell 20. By processing the first groove 21112 and the second groove 21111 separately, it is beneficial to reduce the forming force applied during a single processing process, which is beneficial to reducing the risk of damage to the sheet 31 or the preformed shell 2152 during processing. In addition, when processing the first groove 21112, the second groove 21111 can also play a buffering role to a certain extent, so that the pre-formed shell 2152 is not easily deformed due to factors such as local extrusion during the processing of the first groove 21112, which is beneficial to improving the yield of the shell 215, thereby improving the life and reliability of the battery cell 20.

[0369] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for manufacturing a housing, wherein: include: providing a blank; The sheet is processed and formed into a shell, and the shell is provided with a pressure relief groove. When the pressure is released, the shell can be split along at least a part of the pressure relief groove to release the pressure inside the shell.

2. The shell manufacturing method according to claim 1, wherein: The pressure relief groove includes a first groove; The step of forming the sheet into a housing comprises: Processing and shaping the sheet into a preformed shell having an accommodating space; The first groove is machined on the preformed shell.

3. The method for manufacturing a housing according to claim 2, wherein: The pressure relief groove further includes a second groove; The step of forming the sheet into a housing further comprises: machining the second groove; Processing the first groove on the preformed shell includes: The first groove is machined on the groove bottom surface of the second groove.

4. The method for manufacturing a housing according to claim 3, wherein: Processing the first groove on the bottom surface of the second groove includes: Multi-level grooves are machined step by step on the groove bottom surface of the second groove to form the first groove on the groove bottom surface of the second groove.

5. The method for manufacturing a housing according to claim 3, wherein: Processing the first groove on the bottom surface of the second groove includes: Multi-level grooves are simultaneously machined on the groove bottom surface of the second groove to form the first groove on the groove bottom surface of the second groove.

6. The method for manufacturing a housing according to any one of claims 3 to 5, wherein: After the material sheet is processed and formed into a preformed shell having an accommodating space, the second groove is processed on the preformed shell.

7. The method for manufacturing a housing according to any one of claims 3 to 5, wherein: Before the material sheet is processed and formed into a preformed shell with an accommodating space, the second groove is processed on the material sheet.

8. The method for manufacturing a housing according to any one of claims 3 to 5, wherein: The second groove is formed during the process of processing the material sheet into a preformed shell having an accommodating space.

9. The method for manufacturing a housing according to any one of claims 3 to 8, wherein: The volume of the second groove is greater than that of the first groove.

10. The method for manufacturing a housing according to any one of claims 3 to 9, wherein: The processing of the second groove comprises: Processing a multi-level groove to form the second groove; Processing the first groove on the bottom surface of the second groove includes: The first groove is machined on the groove bottom surface of the first-level groove farthest from the groove opening of the second groove.

11. The method for manufacturing a housing according to any one of claims 3 to 10, wherein: Machining the second groove includes: The second groove is punched out.

12. The method for manufacturing a housing according to any one of claims 3 to 5, wherein: Before forming the first groove on the bottom surface of the second groove, the step of forming the sheet into a shell further comprises: Processing a third groove; The third groove and the pressure relief groove define a predetermined pressure relief area, and the third groove is configured to guide the predetermined pressure relief area to at least partially flip open.

13. The method for manufacturing a housing according to claim 12, wherein: The second groove is machined before the third groove is machined.

14. The method for manufacturing a housing according to claim 12, wherein: The third groove is machined before the second groove is machined.

15. The method for manufacturing a housing according to claim 12, wherein: The second groove and the third groove are processed at the same time.

16. The method for manufacturing a housing according to any one of claims 12 to 15, wherein: The processing of the third groove comprises: The two third grooves are processed so that the second groove is located between the two third grooves.

17. The method for manufacturing a housing according to any one of claims 12 to 16, wherein: The second groove and the third groove are respectively processed on two oppositely arranged surfaces.

18. The method for manufacturing a housing according to any one of claims 12 to 16, wherein: The second groove and the third groove are machined on the same surface.

19. The method for manufacturing a housing according to any one of claims 2 to 11, wherein: Before forming the first groove on the preformed shell, forming the sheet into the shell further comprises: Processing a third groove; The third groove and the pressure relief groove define a predetermined pressure relief area, and the third groove is configured to guide the predetermined pressure relief area to at least partially flip open.

20. The method for manufacturing a housing according to claim 19, wherein: Before the material sheet is processed and formed into a preformed shell with an accommodating space, a third groove is processed on the material sheet.

21. The method for manufacturing a housing according to claim 19, wherein: After the material sheet is processed and formed into a preformed shell having an accommodating space, a third groove is processed on the preformed shell.

22. The method for manufacturing a housing according to claim 19, wherein: The third groove is formed during the process of processing the material sheet into a preformed shell having an accommodating space.

23. The method for manufacturing a housing according to any one of claims 19 to 22, wherein: The processing of the third groove comprises: The third groove is punched out.

24. The method for manufacturing a housing according to any one of claims 19 to 23, wherein: The volume of the third groove is greater than that of the first groove.

25. The method for manufacturing a housing according to any one of claims 2 to 24, wherein: Before forming the first groove on the preformed shell, forming the sheet into the shell further comprises: The opening of the preformed shell is facing downward and is placed on the positioning piece to position the preformed shell; Processing the first groove on the preformed shell includes: The first groove is machined on a first wall of the preformed shell opposite to the opening.

26. The method for manufacturing a housing according to any one of claims 2 to 24, wherein: Before forming the first groove on the preformed shell, forming the sheet into the shell further comprises: Clamp the preformed shell with a clamp, and make the opening of the preformed shell face upward; Processing the first groove on the preformed shell includes: The first groove is machined on a first wall of the preformed shell opposite to the opening.

27. The method for manufacturing a housing according to any one of claims 2 to 26, wherein: Processing the first groove on the preformed shell includes: The first groove is punched out on the preformed shell.

28. The method for manufacturing a housing according to any one of claims 2 to 27, wherein: The step of processing the sheet into a preformed shell having an accommodating space comprises: The blank is stretch-formed into a preformed shell having an accommodating space.

29. The method for manufacturing a housing according to claim 1, wherein: Before forming the sheet into a shell, the shell manufacturing method further includes: The pressure relief groove is processed on the material sheet.

30. The method for manufacturing a housing according to any one of claims 1 to 29, wherein: The material sheet is an oval structure.

31. A housing, wherein: Manufactured according to the shell manufacturing method according to any one of claims 1 to 30.

32. The housing according to claim 31, wherein The housing has a first wall and a second wall connected to each other, the pressure relief groove is provided on the first wall, and the second wall is located on one side of the first wall along the first direction; The first wall is further provided with a third groove. Along the first direction, the second wall has a first outer surface facing away from the interior of the shell. The third groove is located between the first outer surface and the pressure relief groove.

33. The housing according to claim 32, wherein: The third groove and the pressure relief groove define a predetermined pressure relief area, and the third groove is configured to guide the predetermined pressure relief area to at least partially flip open.

34. The housing according to claim 33, wherein: The pressure relief groove and the third groove are respectively arranged on two opposite surfaces of the first wall.

35. The housing of claim 34, wherein: Along the first direction, the pressure relief groove overlaps with at least a portion of a projection of the third groove.

36. The housing according to any one of claims 33 to 35, wherein: Two ends of the third groove in an extension direction of a projection along the thickness direction of the first wall respectively exceed two ends of the pressure relief groove.

37. The housing according to any one of claims 33 to 36, wherein: The pressure relief groove includes a plurality of groove segments, the plurality of groove segments are connected, and the plurality of groove segments and the third groove jointly define at least one predetermined pressure relief area.

38. The housing of claim 37, wherein: The multiple slot segments include a first slot segment, a second slot segment and a third slot segment, the first slot segment and the third slot segment are arranged opposite to each other, the second slot segment connects the first slot segment and the third slot segment, and the first slot segment, the second slot segment, the third slot segment and the third groove jointly define at least one predetermined pressure relief area.

39. The housing according to claim 38, wherein The connection position of the first trough section and the second trough section deviates from the two ends of the first trough section, and the connection position of the third trough section and the second trough section deviates from the two ends of the third trough section, so that the predetermined pressure relief area is formed on both sides of the second trough section.

40. A battery cell, wherein: Comprising a housing according to any one of claims 31-39.

41. A battery, wherein Comprising the battery cell according to claim 40.

42. An electrical device, wherein: Comprising the battery cell according to claim 40.

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