Metal case, battery, and manufacturing method for battery

Abstract

A metal case (1), a battery (100), and a manufacturing method for the battery (100). A substrate (101) is folded along a first straight line (6) to respectively form a first case portion (102) and a second case portion (103); the first case portion (102) is in a flat plate shape; the second case portion (103) is provided with a first accommodation recess (2) and a second accommodation recess (3) which are spaced apart from each other; the first accommodation recess (2) and the second accommodation recess (3) are recessed inwardly toward the direction moving away from the first case portion (102); one side surface of the first case portion (102) is opposite to one side surface of the second case portion (103); the edge of the first case portion (102) is connected to the edge of the second case portion (103), such that the first accommodation recess (2) and the second accommodation recess (3) are closed by the first case portion (102); the first accommodation recess (2) is used for accommodating a cell (9); and the second accommodation recess (3) is used for gas discharge or liquid injection. During liquid injection and formation, an electrolyte is stored in the second accommodation recess (3) and enters the first accommodation recess (2) for wetting, the electrolyte is supplemented, and gas generated by formation enters the second accommodation recess (3) through the first accommodation recess (2), such that a complicated operation in the prior art of blocking a liquid injection hole for multiple times is not needed.

Description

Metal shell, battery, and battery preparation method

[0001] This application claims priority to three Chinese patent applications filed with the China Patent Office on December 5, 2023, with application number 202311664975X and invention name “A Battery”, application number 202311656305.3 and invention name “Battery Manufacturing Method”, and application number 202311664984.9 and invention name “Metal Shell and Battery”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention belongs to the technical field of batteries, and in particular relates to a metal shell, a battery, and a method for preparing the battery. Background Art

[0003] At present, many lithium battery filling processes usually include primary filling and secondary filling. Among them, after the primary filling, formation is required, that is, through a high-temperature aging room, the electrolyte is allowed to penetrate into the electrode and diaphragm, participate in the chemical reaction, and realize the conversion of chemical energy into electrical energy; the secondary filling is the process of replenishing the electrolyte after formation.

[0004] Because gas is generated during the formation process, the injection port needs to be open (usually under a continuous negative pressure state), while the injection port needs to be sealed at other times. Therefore, the industry typically seals the injection port with a rubber stopper after the first injection, removes it before formation, seals it again after formation, and removes it before the second injection. As can be seen from the above, the existing injection formation process is complicated.

[0005] Summary of the Invention

[0006] The technical problem to be solved by the present invention is: to provide a metal shell, a battery and a method for preparing the battery in view of the problem that the liquid injection and chemical formation process in the prior art is complicated.

[0007] In order to solve the above technical problems, on the one hand, an embodiment of the present invention provides a metal shell, including a first shell and a second shell respectively formed by folding a substrate along a first straight line; the first shell is in the shape of a flat plate; the second shell is provided with a first accommodating groove and a second accommodating groove arranged at intervals, and the first accommodating groove and the second accommodating groove are both recessed in the direction away from the first shell; one side surface of the first shell and one side surface of the second shell are arranged opposite to each other, and the outer edges of the first shell and the second shell are fixedly connected by welding and sealing, so that the first shell closes the first accommodating groove and the second accommodating groove, and the first accommodating groove is used to accommodate the pole core; the volume of the first accommodating groove is greater than or equal to the volume of the second accommodating groove.

[0008] In the second aspect, an embodiment of the present invention also provides a battery, comprising a pole core, a cover plate assembly and the metal shell described above, wherein the pole core is connected to the cover plate assembly, and the metal shell comprises a accommodating portion and a storage portion, and the accommodating portion is provided with a first accommodating cavity and a second accommodating cavity, the first accommodating cavity being used to accommodate the pole core, the first accommodating cavity being formed by the first shell closing the first accommodating groove, the second accommodating cavity being arranged at one end of the first accommodating cavity, and the second accommodating cavity being communicated with the first accommodating cavity, and the second accommodating cavity being used to accommodate the cover plate assembly; the storage portion comprises an air bag for storing electrolyte or gas and an injection edge for injection, the air bag being formed by the first shell closing the second accommodating groove, the air bag being arranged on one side of the first accommodating cavity and being communicated with the first accommodating cavity; a sealing end is provided on the side of the air bag away from the first accommodating cavity.

[0009] In a third aspect, the present application provides a battery manufacturing method, comprising: connecting a cover assembly to a tab of a battery core; placing the battery core in a first receiving groove of a metal shell, and placing the cover assembly on a cover mounting position connected to the first receiving groove; bending the metal shell along a first straight line so that the first receiving groove of the metal shell forms a first receiving cavity, and the second receiving groove of the battery shell forms an air bag; connecting two first side surfaces of the metal shell and injecting liquid into the first receiving cavity; welding a side surface opposite to the first side edge of the metal shell and forming the first receiving cavity; cutting off the air bag and vacuuming the first receiving cavity; and sealing the first receiving cavity.

[0010] According to the metal shell and battery of the embodiments of the present invention, during liquid injection formation, the electrolyte stored in the second holding tank enters the first holding tank for infiltration and replenishment, and the gas generated by the formation enters the second holding tank from the first holding tank, eliminating the need for the complicated operation of plugging the injection hole multiple times as in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG1 is an overall schematic diagram of the manufacturing process of the metal housing provided by the first embodiment of the present application;

[0012] FIG2 is a schematic diagram of an expanded substrate of a metal housing provided in the first embodiment of the present application;

[0013] FIG3 is a side view of a metal housing provided in the first embodiment of the present application;

[0014] FIG4 is a schematic diagram of the exhaust of the second receiving groove of the metal shell provided by the first embodiment of the present application after being flattened;

[0015] FIG5 is a schematic structural diagram of a battery (including an extension portion) provided in another embodiment of the present application;

[0016] FIG6 is a schematic structural diagram of a battery (excluding an extension portion) provided in accordance with another embodiment of the present application;

[0017] FIG7 is a schematic diagram of an explosion of a battery (excluding an extension portion) provided in another embodiment of the present application;

[0018] FIG8 is a schematic structural diagram of a battery (the storage portion is perpendicular to the first accommodating cavity) provided in another embodiment of the present application;

[0019] FIG9 is a cross-sectional view of a battery provided in accordance with another embodiment of the present application;

[0020] FIG10 is an enlarged view of portion A in FIG9 ;

[0021] FIG11 is a schematic structural diagram of a cover plate assembly according to another embodiment of the present application;

[0022] FIG12 is a flow chart of the battery manufacturing method in this application;

[0023] FIG13 is a schematic diagram of the first sealing method in the battery manufacturing method of this application;

[0024] FIG14 is a schematic diagram of a second sealing method in the battery manufacturing method of this application;

[0025] FIG15 is a schematic diagram of a third sealing method in the battery manufacturing method of this application;

[0026] FIG16 is an enlarged view of point A in FIG15 ;

[0027] FIG17 is a diagram showing the steps of the battery manufacturing method in this application

[0028] FIG18 is an exploded view of the cover plate assembly in the present application;

[0029] FIG19 is an isometric view of the battery housing in the present application;

[0030] FIG20 is an isometric view of the battery core in the present application.

[0031] The reference numerals in the specification are as follows:

[0032] 100. Battery; 1. Metal housing; 101. Substrate; 102. First housing; 103. Second housing; 2. First receiving slot; 3. Second receiving slot; 4. First groove; 5. Second groove; 6. First straight line; 7. Filling edge; 8. Extension; 81. First cutting piece; 82. Second cutting piece; 9. Electrode core; 91. Electrode tab; 10. Storage portion; 11. Cover mounting position; 13. Cover assembly; 130. Lead-out tab; 132. Insulator; 1321. Second mounting hole; 1322. Insulating body; 1323. Limiting portion; 1324. Clamping portion; 133. Cover body; 134. First welding surface; 135. Second welding surface; 1351. Plane; 1352. Inclined surface; 1353. Arc surface; 136. First mounting hole; 137. Clamping slot; 14. Inner insulating film; 15. Outer insulating film; 16. Heat dissipation fins. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] First embodiment

[0035] As shown in Figures 1 to 3, a metal housing 1 provided in a first embodiment of the present invention includes a first housing 102 and a second housing 103 formed by folding a base plate 101 along a first line 6. In other words, the first housing 102 and the second housing 103 are integrally formed, and are artificially divided into the first and second housings 102, 103 by folding the flat base plate 101 along the first line 6. The first housing 102 is flat; the second housing 103 is provided with first and second receiving grooves 2, 3 arranged at intervals. The first and second receiving grooves 2, 3 are recessed away from the first housing 102. In this embodiment, the first and second receiving grooves 2, 3 are formed by stamping. One side surface of the first housing 102 and one side surface of the second housing 103 are disposed opposite each other. The edges of the first and second housings 102, 103 are welded and sealed, so that the first housing 102 encloses the first and second receiving grooves 2, 3. The first receiving groove 2 is used to accommodate the electrode core, and the second receiving groove 3 is used for exhaust or injection.

[0036] In the liquid injection process of the second receiving tank 3 of the present invention, the two edges of the substrate 101 adjacent to the first straight line 6 are welded, and there is only one unwelded edge between the first shell 102 and the second shell 103. This edge is the edge for electrolyte injection, which is called the liquid injection edge 7. The electrolyte enters the second receiving tank 3 through the liquid injection edge 7 and then flows into the first receiving tank 2. The second receiving tank 3 is a liquid injection bag, and electrolyte can also be stored in the liquid injection bag. In the subsequent infiltration process, the liquid in the liquid injection bag can gradually infiltrate into the pole core 9, and the liquid injection is completed at one time and the liquid injection is fast, and the processing cycle is greatly shortened.

[0037] 3 and 4 , in the formation process, the second containing tank 3 is an exhaust bag, which discharges the gas generated by the electrode core 9 during the formation process from the first containing tank 2 into the second containing tank 3 for collection. Finally, the second containing tank 3 is flattened by external equipment to achieve one-time gas discharge, and no continuous vacuum exhaust is required during the formation process.

[0038] During the injection process, the second receiving tank 3 stores excess electrolyte so that it can later enter the first receiving tank 2 for infiltration and replenishment. The gas generated by the formation enters from the first receiving tank 2 and accumulates in the second receiving tank 3. In this embodiment, during the injection formation process, after the excess or spare electrolyte is pre-injected into the second receiving tank 3, the injection edge 7 is temporarily closed. After the formation is completed, the gas in the second receiving tank 3 is emptied once and for all, without the need to close the injection hole multiple times as in the prior art. It should be noted that the metal shell 1 in this embodiment is not an aluminum-plastic film shell, but a shell made of metal with a certain hardness. Compared with the present application, the traditional soft-pack aluminum-plastic film has relatively poor sealing properties because the soft-pack aluminum-plastic film adopts hot melting instead of laser welding as in the present application. In addition, the poor thermal conductivity of the soft-pack aluminum-plastic film causes poor heat dissipation of the battery 100, and thus the soft-pack aluminum-plastic film easily causes a short service life of the battery 100.

[0039] In this embodiment, the first receiving groove 2 is located near the first straight line 6, and the second receiving groove 3 is located on the side of the first receiving groove 2 away from the first straight line 6. The second housing 103 is provided with a first groove 4 and a second groove 5, each opening outward. The first groove 4 communicates with the second receiving groove 3, and the second groove 5 communicates with the second receiving groove 3. The first groove 4 and the second groove 5 are respectively used to receive the cover assembly 13 of the battery 100.

[0040] 2 and 3 , the first groove 4 and the second groove 5 in this embodiment can be arranged on opposite sides of the first accommodating groove 2 or on the same side of the first accommodating groove 2 . This is not limited in this embodiment and is determined by actual application.

[0041] The substrate 101 further includes a first cutting piece 81 and a second cutting piece 82. The first cutting piece 81 and the first housing 102 are integrally formed, with the first cutting piece 81 being positioned on the side of the first housing 102 away from the first straight line 6. The second cutting piece 82 and the second housing 103 are integrally formed, with the second cutting piece 82 being positioned on the side of the second housing 103 away from the first straight line 6. The projections of the first cutting piece 81 and the second cutting piece 82 on the first housing 102 partially or completely overlap. The first cutting piece 81 and the second cutting piece 82 are positioned opposite each other. A clamp of an external device or manual operation is used to clamp the first cutting piece 81 and the second cutting piece 82, respectively, to spread the unwelded edges between the first housing 102 and the second housing 103, thereby facilitating liquid injection.

[0042] In this embodiment, the first cutting piece 81 and the second cutting piece 82 are retained. In other embodiments, for aesthetic and volume considerations, the first cutting piece 81 and the second cutting piece 82 can be cut off after welding the injection edge 7, so that the metal shell 1 is in a cube shape.

[0043] In this embodiment, the volume of the first receiving tank 2 is greater than or equal to the volume of the second receiving tank 3. The second receiving tank 3 in the metal housing 1 serves as a liquid reservoir during the subsequent injection process of the battery 100. It can temporarily store the electrolyte required for soaking the battery cells in the first receiving tank 2. During the soaking process, the electrolyte temporarily stored in the second receiving tank 3 will gradually seep into the first receiving tank 2. Furthermore, the second receiving tank 3 serves as a venting bag during the subsequent formation process of the battery 100, temporarily storing gases generated during the formation of the battery 100. After the formation process is completed, the second receiving tank 3 can be separated from the first receiving tank 2 by cutting or flattened by venting, forming heat dissipation fins 16 in the metal housing 1 at the second receiving tank 3. Therefore, while meeting the processing requirements of the battery cells in the first receiving tank 2, the volume of the second receiving tank 3 should be as small as possible, and the volume of the first receiving tank 2 must be greater than or equal to the volume of the second receiving tank 3.

[0044] The length of the first receiving tank 2 is the same as the length of the second receiving tank 3. In this embodiment, the volume of the first receiving tank 2 is larger than that of the second receiving tank 3, but the two are the same length, and the length direction of the second receiving tank 3 is parallel to the first straight line 6. The ratio of the cross-sectional area of ​​the first receiving tank 2 to the cross-sectional area of ​​the second receiving tank 3 is 1:0.05 to 1:0.5. The cross-sectional area of ​​the first receiving tank 2 is related to the cross-sectional area of ​​the second receiving tank 3. The larger the cross-sectional area of ​​the first receiving tank 2, the larger the cross-sectional area of ​​the second receiving tank 3. Generally speaking, under the premise that the lengths of the first receiving tank 2 and the second receiving tank 3 are the same, the cross-sectional area of ​​the first receiving tank 2 is 6 times the cross-sectional area of ​​the second receiving tank 3, which can meet the requirements of exhaust and liquid injection of the battery cells inside the first receiving tank 2 during processing. That is, the ratio of the cross-sectional area of ​​the first receiving tank 2 to the cross-sectional area of ​​the second receiving tank 3 is 1:0.166. If the ratio of the cross-sectional area of ​​the first receiving groove 2 to the cross-sectional area of ​​the second receiving groove 3 is less than 1:0.05, the second receiving groove 3 will not be able to meet the exhaust requirements of the formation process during the subsequent processing of the battery 100, and the gas in the formation process will cause irreversible damage to the metal shell 1. If the ratio of the cross-sectional area of ​​the first receiving groove 2 to the cross-sectional area of ​​the second receiving groove 3 exceeds 1:0.5, the volume of the entire metal shell 1 increases, especially the excessive proportion of the second receiving groove 3, which will affect the overall size of the battery 100 after the metal shell 1 is processed, and is not conducive to the arrangement of the battery 100 module and battery 100 pack.

[0045] In this embodiment, the depth of the first receiving groove 2 is 5-40 mm. The depth of the first receiving groove 2 is determined by the subsequent capacity requirement of the battery 100. The larger the capacity of the battery 100, the larger the volume of the first receiving groove 2, and the corresponding greater the depth of the first receiving groove 2. The depth of the first receiving groove 2 is affected by the thickness of the substrate 101. In order to ensure the structural strength of the first receiving groove 2, it is preferred that when the thickness of the substrate 101 is 0.2 mm, the depth of the first receiving groove 2 is controlled between 10-14 mm. Preferably, a second receiving groove 3 is formed, and the air bag is set at 12.1 mm.

[0046] The depth of the second receiving groove 3 is 2-20 mm. The depth of the second receiving groove 3 is related to the capacity of the battery 100 in the first receiving groove 2. The larger the capacity of the battery 100, the larger the volume of the corresponding second receiving groove 3, and the deeper the corresponding second receiving groove 3. The depth of the second receiving groove 3 is affected by the thickness of the substrate 101. In order to ensure the structural strength of the second receiving groove 3, it is preferably 7 mm when the thickness of the substrate 101 is 0.2 mm.

[0047] In this embodiment, the first accommodating groove 2 and the second accommodating groove 3 have a smaller depth and a smaller number of stamping times, thereby reducing production costs.

[0048] Moreover, the side wall of the second accommodating groove 3 close to the first accommodating groove 2 is inclined, so that the inclined side wall gradually approaches the first accommodating groove 2 along the direction from the bottom of the second accommodating groove 3 to the first shell 102 .

[0049] In this embodiment, the spacing between the first receiving groove 2 and the second receiving groove 3 is X, the depth of the first receiving groove 2 is H, and 3H≥X≥0.5H. When the length of the first receiving groove 2 is the same as the length of the second receiving groove 3, that is, the structure shown in Figure 1, the spacing X between the first receiving groove 2 and the second receiving groove 3 must be greater than H, preferably X=1.5H. If X is less than H at this time, the stamping quality of the first receiving groove 2 and the second receiving groove 3 cannot be guaranteed, and the structural strength of the adjacent groove edges is weakened; when the length of the first receiving groove 2 is less than the length of the second receiving groove 3, the spacing X between the first receiving groove 2 and the second receiving groove 3 can be less than or equal to H. The smaller the length of the second receiving groove 3, the smaller the spacing X between the first receiving groove 2 and the second receiving groove 3. However, if X is less than 0.5H, the stamping quality of the first receiving groove 2 and the second receiving groove 3 is reduced, and the structural strength of the two grooves cannot be guaranteed to meet the subsequent processing requirements of the battery 100. If the distance X between the first receiving groove 2 and the second receiving groove 3 is too large, that is, exceeds 3H, the overall external size of the battery 100 during subsequent processing will be too large, which is not conducive to the overall structural layout of the battery 100.

[0050] In other embodiments, the depth of the first accommodating groove 2 may be equal to the depth of the second accommodating groove 3 , as long as the volume of the first accommodating groove 2 is greater than the volume of the second accommodating groove 3 .

[0051] In this embodiment, the thickness of the substrate 101 is 0.1-0.4 mm. Optimally, the thickness of the substrate 101 is 0.2 mm. Compared to the conventional metal shell 1, which is mostly 0.4-0.6 mm thick and the blade battery 100, which is 0.3 mm thick, the shell thickness in this embodiment offers the advantages of ultra-thinness, light weight, low cost, and increased battery 100 capacity per unit volume.

[0052] Second embodiment

[0053] 5 , a battery 100 according to a second embodiment of the present invention includes an inner insulating film 14 , an outer insulating film 15 , an electrode core 9 , a positive electrode cover plate, a negative electrode cover plate, and a metal shell 1 according to any of the above embodiments. The inner insulating film 14 is disposed on opposing sides of a first shell 102 and a second shell 103 , respectively, and the outer insulating film 15 is disposed on outer surfaces of the first shell 102 and the second shell 103 .

[0054] The pole core 9 is placed in the first receiving groove 2 , the positive electrode cover is installed in one of the first groove 4 and the second groove 5 , and the negative electrode cover is installed in the other of the first groove 4 and the second groove 5 .

[0055] The three edges of the metal shell 1 except the edge where the first straight line 6 is located are all welded together.

[0056] In the metal shell 1 of this embodiment, the first cutting piece 81 and the second cutting piece 82 are cut off after welding the injection edge 7 .

[0057] As shown in Figures 5 to 11, an embodiment of the present application provides a battery 100, including a pole core 9, a cover plate assembly 13 and a metal shell 1, wherein the pole core 9 is connected to the cover plate assembly 13, and the metal shell 1 includes a accommodating portion and a storage portion 10, wherein the accommodating portion is provided with a first accommodating cavity and a second accommodating cavity, wherein the first accommodating cavity is used to accommodate the pole core 9, and the first accommodating cavity is formed by the first shell 102 closing the first accommodating groove 2, and the second accommodating cavity is arranged at one end of the first accommodating cavity, and the second accommodating cavity is communicated with the first accommodating cavity, and the second accommodating cavity is used to accommodate the cover plate assembly 13, and the storage portion 10 includes an air bag for storing electrolyte or gas and an injection edge 7 for injection, wherein the air bag is formed by the first shell 102 closing the second accommodating groove 3, and the air bag is arranged on one side of the first accommodating cavity and is communicated with the first accommodating cavity; the injection edge 7 is provided on the side of the air bag away from the first accommodating cavity.

[0058] Specifically, as shown in Figures 5-8, the battery 100 provided in this application includes two cover plate assemblies 13, one of which is a positive electrode cover plate assembly 13 and the other is a negative electrode cover plate assembly 13. The positive electrode cover plate assembly 13 is welded to the positive electrode tab of the electrode core 9, and the negative electrode cover plate assembly 13 is welded to the negative electrode tab of the electrode core 9. It should be noted that the first direction and the second direction of this application are shown in Figure 5, for example, the first direction is the x-direction and the second direction is the y-direction, and the first direction is perpendicular to the second direction.

[0059] As shown in Figures 5-7, the pole core 9 is connected to the cover plate assembly 13. Preferably, the pole core 9 and the cover plate assembly 13 are connected by welding, which can be laser welding. In the first direction, a second accommodating cavity is provided at each end of the first accommodating cavity, and each second accommodating cavity accommodates a cover plate assembly 13. The first accommodating cavity in the metal shell 1 is used to accommodate the pole core 9. The second accommodating cavity is connected to the first accommodating cavity, so that the second accommodating cavity can be used to accommodate the cover plate assembly 13.

[0060] The storage portion 10 includes an air bag and a liquid injection edge 7. The air bag is provided at one end of the first accommodating cavity in the second direction, and the liquid injection edge 7 is provided on the side of the air bag away from the first accommodating cavity. The air bag is used to store electrolyte or gas. As shown in Figures 5-7, the air bag is mainly used to store electrolyte or gas. The gas here refers to the gas generated during the charging and discharging process of the battery 100. The electrolyte is stored because the battery 100 provided in this application is injected once, and the pole core 9 cannot completely absorb the electrolyte. Excess electrolyte may be stored in the air bag. As the battery 100 is left standing for an increasing amount of time, the electrolyte in the air bag can flow into the first accommodating cavity, so that the electrolyte can be absorbed by the pole core 9. Before the battery 100 is filled with liquid, the filling edge 7 is an open end before the battery 100 is sealed, and except for the shell at the open end which is not sealed, the other two sides of the battery 100 have been sealed and welded. When the battery 100 is filled with liquid, the open end is directly opened, the filling end in the filling device is aligned with the open end, and the electrolyte is injected into the battery 100 through the open end. Injecting the electrolyte through the open end can make the electrolyte quickly infiltrate the pole core 9, thereby improving the infiltration efficiency of the electrolyte; after the filling is completed, the open end is sealed and welded to form the filling edge 7, and the sealing method can be selected from laser welding or resistance welding.

[0061] Compared with the prior art, the battery 100 provided in the present application has the following main effects: 1) Compared with the injection through the injection hole, the battery 100 provided in the present application is provided with an injection edge 7 for injection, and the injection port is large, which speeds up the injection speed, shortens the injection process time, and improves production efficiency. 2) Compared with the existing battery 100, the battery 100 provided in the present application is provided with an air bag, which directly performs a single injection, and the excess electrolyte is directly stored in the air bag, without the need for multiple injections, thus simplifying the injection steps; at the same time, in the subsequent infiltration process, the electrolyte in the air bag can gradually flow into the first accommodating cavity so that the electrolyte in the air bag can be completely infiltrated into the pole core 9. 3) The air bag can collect the gas generated by the battery 100 during the formation process, and there is no need for a continuous vacuum exhaust process during the formation process, thus saving costs. 4) Compared with the soft-pack battery 100, the battery 100 provided in the present application has an air bag for storing electrolyte and gas generated by the formation of the battery 100, so as to avoid problems such as bloating of the battery cell or poor appearance caused by insufficient storage unit 10; after the formation is completed, the air bag is directly flattened to discharge the gas from the battery 100 without vacuum exhaust, thereby reducing the extraction of electrolyte. In some embodiments, the metal shell 1 includes a folded edge and two shell bodies, one of which is provided with a first receiving groove 2, a second receiving groove 3 and a first groove 4, and the first groove 4 is provided at the end of the first receiving groove 2 in the first direction, and the first receiving groove 2 is connected to the first groove 4; in the second direction, the first receiving groove 2 and the second receiving groove 3 are spaced apart, and the first direction is perpendicular to the second direction;

[0062] The two shell bodies are folded along the folded edge, the first accommodating groove 2 of one shell body and the other shell body form the first accommodating cavity, the first groove 4 of one shell body and the other shell body form the second accommodating cavity, and the second accommodating groove 3 of one shell body and the other shell body form the air bag.

[0063] Specifically, the two shell bodies are defined as a first shell 102 and a second shell 103, and a first receiving groove 2, a second receiving groove 3, and a first groove 4 are provided on the first shell 102, wherein the first receiving groove 2, the second receiving groove 3, and the first groove 4 are preferably formed by stamping. The first receiving groove 2 is formed directly on the first shell 102, and no pits are punched on the second shell 103. Compared with the existing method of punching pits on both sides of the aluminum-plastic film in the soft-pack battery 100, the present application provides a battery 100 with reduced steps and shortened process time. As shown in Figures 5-7, the first groove 4, the first receiving groove 2, and the second receiving groove 3 are all stamped on the same shell body. The material of the metal shell 1 is preferably aluminum shell material, with uniform wall thickness and consistent overall structural strength. At the same time, it can also ensure that the structural strength of the four corners is consistent. Compared with the existing soft-pack aluminum-plastic film composite film material, the battery 100 provided by the present application has a better heat dissipation effect when the shell is made of metal material.

[0064] In some embodiments, the material of the metal housing 1 includes aluminum, aluminum alloy, etc.

[0065] In some embodiments, the thickness of the metal shell 1 is 0.2 mm.

[0066] The second receiving groove 3 and the second shell 103 form an air bag for storing electrolyte and gas generated by the battery 100. The first groove 4 and the second shell 103 form a second receiving cavity for accommodating the cover assembly 13.

[0067] In some embodiments, the volume of the first accommodating cavity is V1, the volume of the air bag is V2,

[0068] The range of V1:V2 is 1:(0.05~0.5). The air bag in the battery 100 is used as a liquid storage bag during the liquid injection process of the battery 100 processing. It can be used to temporarily store the electrolyte required for the infiltration of the pole core 9 in the first accommodating cavity. During the infiltration process of the pole core 9, the electrolyte temporarily stored in the air bag will gradually penetrate into the first accommodating cavity. In addition, the air bag is used as an exhaust bag during the formation process of the battery 100 processing. It can be used to temporarily store the gas generated by the formation of the battery 100. After the formation process is completed, the air bag can be separated from the first accommodating cavity by cutting, or the air bag can be flattened by exhausting gas, so that the battery 100 forms an extension 8 at the air bag. Therefore, under the premise of meeting the processing requirements of the pole core 9 in the first accommodating cavity, the smaller the volume of the air bag, the better.

[0069] Specifically, as shown in Figures 5-8, the height of the air bag is less than the height of the first accommodating cavity, limiting the volume V2 of the air bag to be less than the volume V1 of the first accommodating cavity. At the same time, the range of V1:V2 is limited to 1:(0.05-0.5). This can reduce the volume occupied by the air bag without increasing the overall thickness of the battery 100, while also providing an air bag with sufficient volume to store the gas generated by the battery 100 during formation, thereby avoiding or reducing the occurrence of bloating in the battery 100. At the same time, due to different processing techniques for the battery 100, the amount of gas discharged from the pole core 9 will also vary significantly. Therefore, under the premise of maintaining the same volume V1 of the first accommodating cavity, the volume V2 of the air bag can be adjusted according to different processing techniques so that the volume V2 of the air bag can meet the processing requirements of the battery 100.

[0070] More preferably, the range of V1:V2 is 1:(0.1-0.4). Still more preferably, the range of V1:V2 is 1:(0.1-0.3). Still more preferably, the range of V1:V2 is 1:(0.1-0.2).

[0071] In some preferred embodiments, the ratio of V1 to V2 is 1:0.166. The volume V1 of the first accommodating chamber is related to the volume V2 of the airbag. The larger the volume V1 of the first accommodating chamber, the larger the volume V2 of the airbag. Generally speaking, a volume V1 of the first accommodating chamber that is six times the volume V2 of the airbag can meet the requirements of venting and filling the pole core 9 within the first accommodating chamber during processing. In other words, the ratio of the volume V1 of the first accommodating chamber to the volume V2 of the airbag is 1:0.166.

[0072] In some embodiments, along the direction away from the first accommodating groove 2 , the distance between the side surface of the second accommodating groove 3 close to the first accommodating groove 2 and the other shell body gradually increases.

[0073] Specifically, as shown in Figure 5, the side surface of the second receiving tank 3 on the side closest to the first receiving tank 2 is inclined in a direction away from the first receiving tank 2, that is, along the y-axis. The inclination direction is from the bottom of the second receiving tank 3 toward the second housing 103, and the distance between the side surface of the first receiving tank 2 and the second housing 103 gradually increases. The inclined arrangement of the second receiving tank 3 on the side closest to the first receiving tank 2 facilitates the flow of electrolyte along the inclined side surface into the first receiving chamber. At the same time, when the battery 100 is vented after formation, the gas in the air pocket can be discharged along the inclined side surface, eliminating the need for vacuum venting and reducing the amount of electrolyte drawn out.

[0074] In some embodiments, in the first direction, the length of the first receiving groove 2 is L1, the length of the second receiving groove 3 is L2, L2≤L1, and the range of L2:L1 is (0.1~1.0):1.

[0075] Specifically, in the first direction, the length L1 of the first accommodating groove 2 is greater than or equal to the length L2 of the second accommodating groove 3, and the range of L2:L1 is (0.1~1.0):1, that is, the length of the second accommodating groove 3 is less than the length of the pole core 9, which does not increase the overall length of the battery 100 and reduces the volume occupied by the airbag.

[0076] Specifically, the ratio of L2:L1 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0, as long as the ratio of L2:L1 is within the range of (0.1-1.0):1. In this embodiment, as shown in FIG5 , the length L2 of the second receiving groove 3 is equal to the length L1 of the first receiving groove 2, that is, L1=L2.

[0077] In some embodiments, the cover plate assembly 13 includes a first welding surface 134 and a second welding surface 135 , wherein the first welding surface 134 is a plane 1351 structure, and the first welding surface 134 is welded to the other shell body;

[0078] The second welding surface 135 includes two arc surfaces 1353, a plane 1351 and two inclined surfaces 1352. The two inclined surfaces 1352 are connected to the two ends of the plane 1351 through the arc surfaces 1353 respectively.

[0079] The second welding surface 135 is welded to the first groove 4 of a shell body.

[0080] Specifically, the first welding surface 134 is set as a plane 1351 structure to facilitate welding the first welding surface 134 to the second shell 103, reduce welding difficulty, and improve welding efficiency; the welding method here includes laser welding or resistance welding, and laser welding is preferred.

[0081] The second welding surface 135 is composed of an arcuate surface 1353, a flat surface 1351, and an inclined surface 1352. This is because the cover plate assembly 13 has a certain thickness. Therefore, a first groove 4 is provided on the first shell 102 to accommodate the thick cover plate assembly 13. The shape of the first groove 4 is the same as that of the second welding surface 135 in the cover plate assembly 13, thereby facilitating the accommodation of the cover plate assembly 13. As shown in Figure 11, the second welding surface 135 includes a flat surface 1351 with an arcuate surface 1353 at each end of the flat surface 1351. The arcuate surfaces 1353 serve as transitions. Each arcuate surface 1353 is connected to an inclined surface 1352 at the end away from the flat surface 1351. The inclined surfaces 1352 facilitate the sealing welding of the second shell 103 and the first shell 102. Without the inclined surface 1352, the welds between the cover plate assembly 13 and the first and second shells 102, 103, would have gaps, affecting the sealing of the battery 100.

[0082] In some embodiments, the cover assembly 13 includes a lead-out piece 130, an insulating member 132 and a cover body 133, wherein a first mounting hole 136 is provided in the cover body 133, the insulating member 132 is inserted into the first mounting hole 136 and extends out of the cover body 133, a second mounting hole 1321 is provided in the insulating member 132, the lead-out piece 130 is provided in the second mounting hole 1321 and extends out of the insulating member 132, and the length of the lead-out piece 130 extending out of the insulating member 132 is greater than the length of the insulating member 132 extending out of the cover body 133.

[0083] The insulating member 132 extends beyond the cover body 133 to provide insulation and prevent short circuits in the battery 100. The lead tab 130 extends beyond the insulating member 132, with an extension 8 at one end welded to the tab 91 or connection tab of the electrode core 9, and an extension 8 at the other end for electrical connection to an external circuit.

[0084] Furthermore, the length of the lead-out tab 130 extending from the insulating member 132 is greater than the length of the insulating member 132 extending from the cover body 133 by 6-7 mm; this facilitates welding one end of the lead-out tab 130 to the tab 91 or connecting tab of the electrode core 9, while the other end of the lead-out tab 130 is used to electrically connect to an external circuit. In this embodiment, the cover assembly 13 has no injection hole, and the electrode is the lead-out tab 130, which can be as thin as 0.5 mm. Therefore, the thickness of the cover assembly 13 can be extremely thin, and the overall thickness of the corresponding battery 100 can also be extremely thin (the thinnest can be 6 mm thick). Existing batteries 100 are limited by the structure of the cover assembly 13, and generally 18 mm is considered very thin (because the cover assembly 13 of existing square batteries 100 includes the electrode, injection hole, explosion-proof valve, etc., and the width of the cover assembly 13 is relatively wide). Therefore, compared with the prior art, the battery 100 provided in this application is thinner, reducing the space occupied by the battery 100.

[0085] In some embodiments, in the second direction, the extension direction of the air bag is parallel to the extension direction of the first accommodating cavity; or in the second direction, the extension direction of the air bag is perpendicular to the extension direction of the first accommodating cavity.

[0086] One arrangement of the air bag and the first accommodating cavity is shown in FIG5-8 . In the second direction, the air bag and the first accommodating cavity are arranged side by side, and the extension direction of the air bag is arranged parallel to the extension direction of the first accommodating cavity.

[0087] Another arrangement of the air bag and the first accommodating cavity is shown in FIG8 , where the extending direction of the air bag is perpendicular to the extending direction of the first accommodating cavity.

[0088] It is understood that the extension direction of the air bag and the extension direction of the first accommodating cavity form an angle, and the angle can be in the range of 0-180 degrees. An angle of 0 or 180 degrees indicates a parallel arrangement, an angle of 90 degrees indicates a perpendicular arrangement, and other angles are also possible. When the angle is acute, the inclined surface 1352 is more conducive to the diversion of the electrolyte within the air bag.

[0089] In some embodiments, an inner insulating film 14 is provided on the inner surface of the metal shell 1 facing the pole core 9 , and the inner insulating film 14 is provided between the metal shell 1 and the pole core 9 , and the inner insulating film 14 covers the pole core 9 ;

[0090] An outer insulating film 15 is provided on the outer surface of the metal shell 1 facing away from the pole core 9 , and the outer insulating film 15 covers the outer circumference of the metal shell 1 .

[0091] The inner insulating film 14 covers the pole core 9 , and the outer insulating film 15 covers the outer periphery of the metal shell 1 , both of which prevent the battery 100 from short circuiting.

[0092] It is understood that the structure of the inner insulating film 14 is the same as that of the metal shell 1. Alternatively, the structure of the inner insulating film 14 may be different from that of the metal shell 1, as long as the inner insulating film 14 covers the periphery of the electrode core 9 and prevents short circuits in the battery 100. As shown in FIG7 , the structure of the outer insulating film 15 is preferably the same as that of the metal shell 1, so that the outer insulating film 15 completely covers the periphery of the metal shell 1, thereby preventing short circuits in the battery 100.

[0093] In some embodiments, as shown in FIG. 5-7 , the side surface of the first accommodating groove 2 close to the second accommodating groove 3 is an arc surface 1353 , and the side surface of the second accommodating groove 3 close to the first accommodating groove 2 is also an arc surface 1353 .

[0094] The first accommodating groove 2 and the second accommodating groove 3 are both formed by punching. The side of the first accommodating groove 2 close to the second accommodating groove 3 is punched into an arc surface 1353, and the side of the second accommodating groove 3 close to the first accommodating groove 2 is also an arc surface 1353, which can reduce material stress and effectively improve the punching efficiency of the first accommodating groove 2 and the second accommodating groove 3.

[0095] In some embodiments, the distance between the first receiving groove 2 and the second receiving groove 3 is X, the depth of the first receiving groove 2 is H, and H and X satisfy the following relationship: 0.5H≤X≤3H.

[0096] If X is too low, the distance between the first receiving groove 2 and the second receiving groove 3 is too close, making it easy to break through the first receiving groove 2 and / or the second receiving groove 3 during punching, increasing production costs. If X is too large, the volume of the metal housing 1 increases, increasing the cost of the battery 100 and reducing the volumetric energy density. The distance X between the first receiving groove 2 and the second receiving groove 3 and the depth H of the first receiving groove 2 satisfy the following relationship: 0.5H ≤ X ≤ 3H. This effectively improves the efficiency of punching to form the first receiving groove 2 and the second receiving groove 3.

[0097] It should be noted that the first accommodating groove 2 is close to the first side of the second accommodating groove 3, the second accommodating groove 3 is close to the second side of the first accommodating groove 2, and the first side and the second side are both arc surfaces 1353. The distance X between the first accommodating groove 2 and the second accommodating groove 3 defined in this embodiment is the distance between the side of the first side facing the opening of the first accommodating groove 2 and the side of the second side facing the opening of the second accommodating groove 3.

[0098] In some preferred embodiments, H and X satisfy the following relationship: 1.0H≤X≤2.5H.

[0099] More preferably, H and X satisfy the following relationship: 1.0H≤X≤2.0H; even more preferably, X=1.5H.

[0100] In some embodiments, an extension portion 8 is further provided at one end of the liquid injection edge 7 away from the air bag, and the cross section of the extension portion 8 is polygonal.

[0101] As shown in Figure 5 , the extension 8 can also be used to store gas. After the battery 100 is formed, gas is stored in the extension 8 . The extension 8 can be cut to release the gas pocket and the gas in the extension 8 . The cut portion can then be welded to seal the battery 100 . Laser welding or resistance welding can be used, with resistance welding being preferred. Alternatively, as shown in Figure 6 , the extension 8 can be cut off, leaving the injection edge 7 with a straight cross-section. The trimmed portion of the metal housing 1 can then be welded directly to the metal housing 1 using resistance welding or laser welding.

[0102] It should be noted that the cross section of the extension portion 8 is a polygon with n sides, where n≥3. For example, the extension portion 8 may be a square, a rectangle, a pentagon, etc. The cross section is preferably a square or a rectangle.

[0103] In some embodiments, the cross section of the injection edge 7 is linear or L-shaped.

[0104] As shown in Figure 6, when the extension portion 8 is cut off as a whole, the cross section of the injection edge 7 is a straight line. If the extension portion 8 is not cut off, the cross section of the injection edge 7 is an L-shaped. Whether to cut off the extension portion 8 can be selected according to actual needs and is not limited in this application.

[0105] It should be noted that the gas generated after the battery 100 is formed can be discharged from the battery 100 by flattening the air bag, because there is still electrolyte in the air bag. If the air bag is directly cut off and the metal shell 1 is sealed and welded, the presence of electrolyte will affect the welding of the shell. Therefore, the battery 100 provided in this application retains the air bag. The battery 100 with the air bag can improve the welding efficiency of the two bending surfaces and improve production efficiency. It can be seen from Figures 3 and 4 that Figure 3 is a structural diagram without flattening the air bag, and Figure 4 is a structural diagram with the air bag directly flattened after the gas is discharged. It can be understood that whether the air bag is flattened or not can be selected according to the actual situation, and this application does not limit it.

[0106] In a third aspect, an embodiment of the present invention provides a method for manufacturing a battery 100, referring to Figures 12-17, comprising:

[0107] S1: Connect the cover assembly 13 to the tab 91 of the battery core 9 of the battery 100;

[0108] S2: Place the battery cell 100 9 in the first receiving groove 2 of the metal housing 1 and place the cover assembly 13 on the cover mounting position 11 communicating with the first receiving groove 2;

[0109] S3: bending the metal shell 1 so that the first receiving groove 2 of the metal shell 1 forms an empty cavity and the second receiving groove 3 of the metal shell 1 forms an air pocket;

[0110] S4: Welding the two first side surfaces of the metal shell 1 and filling the first accommodating cavity with liquid;

[0111] S5: Welding the side surface of the metal shell 1 opposite to the first side surface to form the first accommodating cavity;

[0112] S6: Cut off the air bag and evacuate the first receiving chamber;

[0113] S7: sealing the first receiving cavity.

[0114] As an example, in step S1 , the lead-out piece 130 of the cover assembly 13 is first connected to the tab 91 of the pole core 9 of the battery 100 to form an integral structure, which is convenient for installation in the metal shell 1 and improves installation efficiency.

[0115] As an example, in step S2, the battery 100 pole core 9 is then placed in the first receiving groove 2 of the metal shell 1, and the cover assembly 13 is placed on the cover mounting position 11 connected to the first receiving groove 2, so that it is convenient to assemble the cover assembly 13, the battery 100 pole core 9 and the metal shell 1 together, thereby improving production efficiency.

[0116] As an example, in step S3, the metal shell 1 includes a first shell 102 and a second shell 103; the metal shell 1 is bent at the junction of the first shell 102 and the second shell 103, with the first shell 102 serving as the bottom shell and the second shell 103 serving as the top shell. The first shell 102 is provided with a first receiving groove 2 and a second receiving groove 3, which cooperate to form an empty cavity in the first receiving groove 2 of the metal shell 1, and an air bag in the second receiving groove 3 of the metal shell 1. The battery 100 pole core 9 is installed in the first receiving cavity for later injection of electrolyte; the air bag is connected to the first receiving cavity, and is used to guide liquid to the first receiving cavity in the early stage and to exhaust the first receiving cavity in the later stage. The periphery of the first receiving cavity and the periphery of the air bag are hot-melt areas for later welding; the width of the hot-melt area is 2mm.

[0117] As an example, in step S4, the two first side surfaces of the metal shell 1 are welded to form a liquid storage chamber in the first accommodating cavity, and a liquid injection channel in the air bag. Electrolyte is injected into the first accommodating cavity from the opening side of the air bag. However, the air bag cannot be used to store electrolyte.

[0118] As an example, in step S5, after the electrolyte is injected, the side of the metal shell 1 opposite the first side, i.e., the opening of the air bag, is welded, and then the first receiving cavity is formed. The weld must be cleaned of electrolyte to prevent leakage from the battery 100 due to a loose weld.

[0119] As an example, in step S6, after the formation is completed, the air bag is cut off and the first accommodating chamber is evacuated. This can quickly discharge the gas in the first accommodating chamber without flattening the air bag, thereby reducing the risk of rupture of the metal shell 1.

[0120] As an example, in step S7, when the exhaust meets the requirements, the first receiving cavity is sealed to complete the production of the battery 100 structure. The electrolyte needs to be cleaned at the sealing to avoid leakage of the battery 100 structure due to loose sealing.

[0121] During the manufacturing process of the existing battery 100 structure, the battery 100 pole core 9 is slowly pushed in from a side opening of the metal shell 1, which has low installation efficiency and a risk of damage to the battery 100 pole core 9; and there is zero tolerance for burrs at the opening of the metal shell 1, resulting in high manufacturing costs. In this example, the battery 100 core 9 is first placed in the metal shell 1, and then the metal shell 1 is bent to form a first accommodating cavity and an air bag, and then the two first side surfaces of the metal shell 1 are welded to form a liquid storage chamber in the first accommodating cavity and a liquid injection channel in the air bag. The electrolyte is injected into the first accommodating cavity from the open side of the air bag, and the side opposite to the first side of the metal shell 1, i.e., the open side of the air bag, is welded. Then, the first accommodating cavity is chemically formed, and then the air bag is cut off, and the first accommodating cavity is vacuumed. Finally, the first accommodating cavity is sealed to complete the manufacture of the battery 100 structure. Compared with the existing battery 100 manufacturing method, the installation of the battery 100 core 9 is more convenient, and the battery 100 core 9 is prevented from being damaged. The metal shell 1 is bent into the first accommodating cavity, which can reduce process requirements and thus reduce manufacturing costs. The volume of the air bag is designed to be 65 ml, and the formation gas production of 65.00 mL is greater than the designed volume of the air bag. Two exhausts may be required during the formation process. The gas production during the circulation process is (20%) 13.00 mL. The designed volume of the air bag can meet the circulation gas production requirements. The welding method generally adopts any one of resistance welding, EPMT and ultrasonic roll welding.

[0122] Compared with the existing battery 100 manufacturing method, the installation of the battery 100 pole core 9 is more convenient. The battery 100 pole core 9 is directly placed in the metal shell 1 and can be assembled in one time, thereby avoiding damage to the battery 100 pole core 9 during the assembly process. The metal shell 1 used in the battery 100 manufacturing method mentioned in the present invention has a first accommodating groove 2 and a second accommodating groove 3. The second accommodating groove 3 is used to effectively solve the problems of insufficient liquid injection in the liquid injection process and exhaust in the formation process during the processing of the battery 100, thereby simplifying the cover structure of the hard shell battery 100, making the structure of the cover assembly 13 simpler. The cover assembly 13 is not only simple in structure and easy to process, but also meets the basic requirements of the battery 100 in assembly and sealing, and can realize an extremely thin design of the cover assembly 13. The overall thickness of the cover assembly 13 can be as thin as 6 mm. At the same time, in the entire battery 100 manufacturing method, since the second receiving groove 3 set on the metal shell 1 forms an air bag, the efficiency of the liquid injection process and the formation process can be effectively improved, and the manufacturing time of the entire battery 100 structure can be greatly shortened, and the air bag is cut off last in the battery 100 manufacturing method.

[0123] In one embodiment, referring to Figures 18, 19 and 20, the cover assembly 13 includes a cover body 133 connected to the metal shell 1; the outer ring surface of the cover body 1 has a first welding surface 134 and a second welding surface 135 connected end to end, the first welding surface 134 includes a first plane, the second welding surface 135 includes two first inclined surfaces and a second inclined surface respectively connected to the first welding surface 134, and a second plane connecting the first inclined surface and the second inclined surface, the first plane and the second plane are arranged parallel to each other, and a first mounting hole 136 is provided on the cover body 133, and the first mounting hole 136 is located between the first plane and the second plane.

[0124] As an example, the cover assembly 13 includes a cover body 133 connected to the metal shell 1. The cover body 133 is made of 3003 aluminum and serves as a fixed seat for being installed on the cover mounting position 11 of the metal shell 1. A first mounting hole 136 is provided on the cover body 133 for assembling the structure in the cover assembly 13 connected to the battery 100 pole core 9. The outer ring surface of the cover body 1 has a first welding surface 134 and a second welding surface 135 connected end to end. The first welding surface 134 includes a first plane, and the second welding surface 135 includes two first inclined surfaces and a second inclined surface respectively connected to the first welding surface 134, and a second plane connecting the first inclined surface and the second inclined surface. The first plane and the second plane are arranged parallel to each other, which facilitates welding the cover body 133 to the metal shell 1; the first inclined surface, the second inclined surface and the second plane cooperate to form a mounting surface, which matches the cover mounting position 11 of the metal shell 1, making it convenient to install the cover body 133 on the metal shell 1; a first mounting hole 136 is provided on the cover body 133, and the first mounting hole 136 is located between the first plane and the second plane to ensure that the structure connected to the battery 100 pole core 9 is installed on the cover body 133.

[0125] In one embodiment, referring to Figures 18, 11, 19 and 20, the cover plate assembly 13 also includes a lead-out piece 130 arranged in the cover plate body 133; the lead-out piece 130 includes a main body portion with a rectangular sheet structure and an annular groove surrounding the main body portion, so that the lead-out piece 130 forms a first end and a second end on both sides of the annular groove; the first end of the lead-out piece 130 is connected to the pole ear 91 of the pole core 9 of the battery 100 in the metal shell 1, and the second end of the lead-out piece 130 is used to connect to an external circuit.

[0126] As an example, the cover plate assembly 13 also includes a lead-out piece 130 arranged in the cover plate body 133; the lead-out piece 130 is made of 1060 aluminum, and the lead-out piece 130 is assembled in the cover plate body 133; the lead-out piece 130 includes a main body portion with a rectangular sheet structure and an annular groove surrounding the main body portion, so that the lead-out piece 130 forms a first end and a second end on both sides of the annular groove; the first end of the lead-out piece 130 is connected to the pole ear 91 of the battery 100 pole core 9 in the metal shell 1, and the second end of the lead-out piece 130 is used to connect to the external circuit to realize the electrical connection between the pole ear 91 of the battery 100 pole core 9 and the external circuit.

[0127] In one embodiment, referring to FIG. 18 , FIG. 11 , FIG. 19 and FIG. 20 , the cover assembly 13 further includes an insulating member 132 disposed between the cover body 133 and the lead-out piece 130 ;

[0128] Before connecting the cover plate assembly 13 to the tab 91 of the pole core 9 of the battery 100, the manufacturing method of the battery 100 further includes:

[0129] The cover body 133 and the lead-out plate 130 are injection molded to form an insulating member 132 between the cover body 133 and the lead-out plate 130 . The insulating member 132 fixes the cover body 133 and the lead-out plate 130 together.

[0130] As an example, the plate assembly further includes an insulating member 132 disposed between the cover plate body 133 and the lead tab 130. Before the cover plate assembly 13 is connected to the tab 91 of the battery cell 100, the cover plate body 133 and the lead tab 130 are injection molded to form the insulating member 132 between the cover plate body 133 and the lead tab 130. The insulating member 132 secures the cover plate body 133 and the lead tab 130 together. The insulating member 132 is made of PPS-SGX-120 and provides insulation protection. The insulating member 132 is assembled into a first mounting hole 136. The insulating member 132 is provided with a second mounting hole 1321 for mounting the lead tab 130. Compared to the existing cover assembly 13, the explosion-proof valve and injection hole are eliminated. The thickness of the cover body 133, the insulating member 132, and the lead-out tab 130 can all be adjusted according to actual needs. The overall thickness can be significantly reduced, and the overall thickness can be used to make an extremely thin battery 100. The welding between the cover body 133 and the metal shell 1 is also easier to achieve. Referring to Figure 18, the insulating member 132 includes an insulating body 1322 and two limiting portions 1323. The two limiting portions 1323 extend from both ends of the insulating body 1322. The insulating body 1322 is assembled into the first mounting hole 136. The two limiting portions 1323 respectively abut against the two side surfaces of the cover body 133 along the axial direction of the first mounting hole 136, which can limit the cover body 133 and ensure that the cover body 133 is firmly mounted on the insulating member 132. The insulating body 1322 is provided with a second mounting hole 1321, which is oriented in the same axial direction as the first mounting hole 136 and is used to mount the lead-out tab 130. The insulating member 132 also includes a snap-fit ​​portion 1324 extending from the retaining portion 1323 and arranged parallel to and opposite the insulating body 1322. The cover body 133 is provided with a snap-fit ​​groove 137, which mates with the snap-fit ​​groove 137, providing a position-limiting fixation for the installation of the cover body 133 and ensuring a more stable and secure connection between the cover body 133 and the insulating member 132.

[0131] In one embodiment, referring to FIG. 12 and FIG. 17 , step S1, that is, connecting the cap assembly 13 to the tab 91 of the battery core 9 of the battery 100 , includes:

[0132] S11: Pre-welding and cutting the tabs 91 of the battery core 9 of the battery 100;

[0133] S12: Welding the first end of the lead-out piece 130 of the cover plate assembly 13 to the tab 91 of the pole core 9 of the battery 100, and applying glue at the welding point;

[0134] S13 : Extend the second end of the lead-out piece 130 of the cover assembly 13 through the cover body 133 to the outside of the metal housing 1 .

[0135] As an example, in step S11, the pole ear 91 of the battery 100 pole core 9 is first pre-welded. After the pole ear 91 is pre-welded, it deviates from the center by 4.1 mm in the thickness direction, and then the pole ear 91 is cut with a cutting chamfer of 5 mm*8 mm to facilitate the connection between the pole ear 91 of the battery 100 pole core 9 and the lead-out piece 130 of the cover assembly 13. This arrangement can ensure that the top of the battery 100 pole core 9 and the cover assembly 13 remain on the same horizontal plane, which is convenient for installation in the metal shell 1.

[0136] As an example, in step S12, the first end of the lead-out piece 130 of the cover plate assembly 13 is welded to the pole ear 91 of the pole core 9 of the battery 100, and glue is applied at the welding point, which can make the connection between the pole ear 91 of the pole core 9 of the battery 100 and the lead-out piece 130 of the cover plate assembly 13 more stable.

[0137] As an example, in step S13, the second end of the lead-out piece 130 of the cover assembly 13 is extended through the cover body 133 to the outside of the metal shell 1 for connecting to an external circuit to achieve electrical connection between the tab 91 of the battery core 9 of the battery 100 and the external circuit.

[0138] In one embodiment, referring to Figures 12 and 19, the metal shell 1 includes a first shell 102 and a second shell 103 extending from a first side of the first shell 102 by bending; the first shell 102 is provided with a first accommodating groove 2, a second accommodating groove 3 and two cover mounting positions 11 connected to the first accommodating groove 2; the two cover mounting positions 11 are respectively arranged on two first side surfaces opposite to each other on the first shell 102, and the first side surfaces are side surfaces perpendicular to the first side surfaces; the first shell 102 and the second shell 103 are connected, and the two cooperate to form a first accommodating cavity and an air bag.

[0139] As an example, the metal shell 1 includes a first shell 102 and a second shell 103 bent and extended from the first side of the first shell 102; the first shell 102 is provided with a first accommodating groove 2, a second accommodating groove 3 and two cover mounting positions 11 connected to the first accommodating groove 2; the two cover mounting positions 11 are respectively arranged on two first side surfaces opposite to each other on the first shell 102, and the first side surface is a side surface perpendicular to the first side surface. The first shell 102 and the second shell 103 are connected, and the two cooperate to form a first accommodating cavity and an air bag. The first accommodating cavity is used to place the battery 100 pole core 9, and a cover assembly 13 is assembled in each cover mounting position 11. This arrangement facilitates the assembly of the battery 100 structure and improves production efficiency. When manufacturing the battery 100 structure, first integrate the first accommodating groove 2, the second accommodating groove 3 and the two cover mounting positions 11 connected to the first accommodating groove 2 in the first shell 102, and then bend the second shell 103 to connect the second shell 103 with the first shell 102, so that the first cavity 421 cooperates with the second shell 103 to form a first accommodating cavity, and the second cavity 422 cooperates with the second shell 103 to form an air bag. The battery 100 pole core 9 is installed in the first accommodating cavity for later injection of electrolyte; the air bag is connected to the first accommodating cavity, and is used to guide liquid to the first accommodating cavity in the early stage and to exhaust the first accommodating cavity in the later stage, which provides convenience for manufacturing the battery 100 structure.

[0140] In one embodiment, referring to Figures 12 and 17, the two first side surfaces of the welded metal shell 1 include: the front-side weld is the connection between the second welding surface 135 of the cover plate body 133 on the first side and the cover plate mounting position 11 of the first shell 102, and the back-side weld is the connection between the first welding surface 134 of the cover plate body 133 on the first side and the second shell 103, as well as the overlapping portion of the first shell 102 and the second shell 103.

[0141] As an example, the cover assembly 13 is installed on the cover mounting position 11 of the metal shell 1. When welding the two first side surfaces of the metal shell 1, the cover assembly 13 is located between the two bent parts of the metal shell 1. Therefore, during welding, the weld of the front welding is the connection between the second welding surface 135 of the cover body 133 on the first side and the cover mounting position 11 of the first shell 102, and the weld of the back welding is the connection between the first welding surface 134 of the cover body 133 on the first side and the second shell 103, as well as the overlapping part of the first shell 102 and the second shell 103. This can ensure the sealing of the connection between the metal shell 1 and the cover assembly 13, and avoid leakage during liquid injection.

[0142] In one embodiment, referring to FIG. 12 , before sealing the first receiving cavity, the method for manufacturing the battery 100 further includes:

[0143] Heat dissipation fins 16 are reserved on opposite sides of the first straight line 6 of the metal housing 1 .

[0144] As an example, during the manufacture of the battery 100 structure, heat dissipation fins 16 can be reserved on the opposite side of the first straight line 6 of the metal shell 1 before sealing the first accommodating cavity. This facilitates heat dissipation from the completed battery 100 structure later, improving device safety. The portion of the metal shell 1 retained on the side of the first accommodating cavity serves as the heat dissipation fins 16 of the battery 100 structure. Removing the air pocket effectively controls the size of the heat dissipation fins on the side of the battery 100, utilizing the portion of the shell between the first accommodating cavity and the air pocket for heat dissipation, and further extending the service life of the processed battery 100. The height of the heat dissipation fins 16 is not limited by the size of the air pocket and can be freely designed. The heat dissipation fins 16 can be provided solely on the first shell 102 or the second shell 103, or on both the first shell 102 and the second shell 103, located on the side opposite the first side, effectively dissipating heat from the first accommodating cavity and ensuring device safety.

[0145] In one embodiment, referring to FIG. 13 , FIG. 14 , FIG. 15 and FIG. 16 , sealing the first accommodating cavity includes any one of direct welding sealing, edge welding sealing and double rolling sealing.

[0146] As an example, sealing the first accommodating cavity includes any one of the following sealing methods: direct welding sealing method, edge welding sealing method and double rolling sealing method; the direct welding sealing method is to use laser welding to directly weld two welds on the opposite sides of the first straight line 6 of the metal shell 1, thereby sealing the first accommodating cavity and ensuring the sealing effect; the edge welding sealing method is to first wrap a layer of edge on the opposite side of the first straight line 6 of the metal shell 1, and then use laser welding to weld the edge to the opposite side of the first straight line 6 of the metal shell 1, thereby sealing the first accommodating cavity and ensuring the sealing effect; the double rolling sealing method is to fold the opposite sides of the first straight line 6 of the metal shell 1 twice, thereby sealing the first accommodating cavity and ensuring the sealing effect.

[0147] As an example, referring to Figure 19 , before placing the battery cell 100 pole core 9 in the first receiving slot 2 of the metal housing 1 and placing the cover plate assembly 13 on the cover plate mounting position 11 connected to the first receiving slot 2, an inner insulating film 14 is pre-installed on the inner wall of the entire first receiving cavity. This provides effective insulation between the battery cell 100 pole core 9 and the inner wall of the first receiving cavity, ensuring good insulation within the battery 100 structure. After sealing the first receiving cavity, an outer insulating film 15 is installed on the outside of the entire metal housing 1 to provide insulation protection for the entire metal housing 1 and ensure safe use of the device.

[0148] In one embodiment, referring to FIG. 14 , the edge welding sealing method includes: wrapping a layer of edge wrapping on the opposite sides of the first straight line 6 of the metal shell 1; and welding the edge wrapping on the opposite sides of the first straight line 6 of the metal shell 1 to seal the first accommodating cavity.

[0149] As an example, in the edging welding sealing method, a layer of edging is first wrapped on the opposite side of the first straight line 6 of the metal shell 1 so that the edging covers the opening of the first accommodating cavity, and then laser welding is used to weld the edging to the opposite side of the first straight line 6 of the metal shell 1, thereby sealing the first accommodating cavity and ensuring the sealing effect.

[0150] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A metal shell, characterized in that: It comprises a first shell and a second shell respectively formed by folding a substrate along a first straight line; The first shell is in the shape of a flat plate; The second shell is provided with a first accommodating groove and a second accommodating groove arranged at intervals, and the first accommodating groove and the second accommodating groove are both recessed in a direction away from the first shell; One side surface of the first shell and one side surface of the second shell are arranged opposite to each other, and the outer edges of the first shell and the second shell are fixedly connected by welding and sealing, so that the first shell closes the first receiving groove and the second receiving groove, and the first receiving groove is used to receive the pole core; The volume of the first containing tank is greater than or equal to the volume of the second containing tank.

2. The metal housing according to claim 1, characterized in that: The first accommodating groove is close to the first straight line, and the second accommodating groove is located on a side of the first accommodating groove away from the first straight line; The second housing is provided with a first groove and a second groove opening outward, the first groove is connected to the second receiving groove, and the second groove is connected to the second receiving groove; The first groove and the second groove are used to place the positive electrode cover plate assembly and the negative electrode cover plate assembly of the battery respectively.

3. The metal housing according to claim 2, characterized in that: It also includes a first cutting piece and a second cutting piece, wherein the first cutting piece and the first shell are integrally formed, and the first cutting piece is arranged on a side of the first shell away from the first straight line; The second cutting piece and the second shell are integrally formed, and the second cutting piece is arranged on a side of the second shell away from the first straight line.

4. The metal housing according to claim 1, characterized in that: The length of the first receiving groove is the same as the length of the second receiving groove; Ratio of the cross-sectional area of ​​the first receiving groove to the cross-sectional area of ​​the second receiving groove: 1:0.05 to 1:0.5; The depth of the first receiving groove is greater than or equal to the depth of the second receiving groove; The depth of the first receiving groove is 5-40 mm; The depth of the second receiving groove is 2-20 mm.

5. The metal housing according to claim 1, characterized in that: The distance between the first accommodating groove and the second accommodating groove is X, the depth of the first accommodating groove is H, and 3H≥X≥0.5H.

6. The metal housing according to claim 1, characterized in that: The substrate has a thickness of 0.1-0.4 mm.

7. A battery, characterized in that: It includes a pole core, a cover plate assembly and a metal shell as described in any one of claims 1 to 6, the pole core is connected to the cover plate assembly, the metal shell includes a accommodating portion and a storage portion, the accommodating portion is provided with a first accommodating cavity and a second accommodating cavity, the first accommodating cavity is used to accommodate the pole core, the first accommodating cavity is formed by the first shell closing the first accommodating groove, the second accommodating cavity is arranged at one end of the first accommodating cavity, and the second accommodating cavity is communicated with the first accommodating cavity, the second accommodating cavity is used to accommodate the cover plate assembly; the storage portion includes an air bag for storing electrolyte or gas and an injection edge for injection, the air bag is formed by the first shell closing the second accommodating groove, the air bag is arranged on one side of the first accommodating cavity, and is communicated with the first accommodating cavity; a sealing end is provided on the side of the air bag away from the first accommodating cavity.

8. The battery according to claim 7, characterized in that The volume of the first accommodating chamber is V1, the volume of the air bag is V2, The range of V1:V2 is 1:(0.05~0.5).

9. The battery according to claim 7, characterized in that Along the direction away from the first accommodating groove, the distance between the side surface of the second accommodating groove close to the first accommodating groove and the other shell body gradually increases.

10. The battery according to claim 7, characterized in that In the first direction, the length of the first receiving groove is L1, the length of the second receiving groove is L2, L2≤L1, and the range of L2:L1 is (0.1~1.0):

1.

11. The battery according to claim 7, characterized in that An inner insulating film is provided on the inner surface of the metal shell facing the pole core, the inner insulating film is provided between the metal shell and the pole core, and the inner insulating film covers the pole core; An outer insulating film is disposed on the outer surface of the metal shell facing away from the pole core, and the outer insulating film covers the outer circumference of the metal shell.

12. A method for manufacturing a battery according to any one of claims 7 to 11, characterized in that: include: Connecting the cover plate assembly to the pole ear of the battery pole core; Placing the battery core in the first receiving groove of the metal housing, and placing the cover plate assembly on the cover plate mounting position communicating with the first receiving groove; The metal shell is bent along a first straight line so that the first receiving groove of the metal shell forms a first receiving cavity and the second receiving groove of the battery shell forms an air bag; Welding the two first side surfaces of the metal shell and injecting liquid into the first accommodating cavity; Welding a side surface of the metal shell opposite to the first side edge to form the first accommodating cavity; Cut off the air bag and evacuate the first containing chamber; The first accommodating cavity is sealed.

13. The battery manufacturing method according to claim 12, characterized in that: Before sealing the first receiving cavity, the battery manufacturing method further includes: Heat dissipation fins are reserved on opposite sides of the metal shell to the first straight line.

14. The battery manufacturing method according to claim 12, characterized in that: The sealing of the first accommodating cavity includes any one of a direct welding sealing method, an edge welding sealing method and a double rolling sealing method.

15. The battery manufacturing method according to claim 14, characterized in that: The edge welding sealing method includes: Wrapping a layer of hemming on opposite sides of the first straight line of the metal shell; The edging is welded on the opposite sides of the first straight line of the metal shell to seal the accommodating cavity.

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