Top cover assembly, battery monomer, battery pack and preparation method of battery monomer

Abstract

The invention relates to a top cover assembly, a battery monomer, a battery pack and a preparation method of the battery monomer, the top cover assembly is adapted to the battery monomer, and comprises a battery connecting piece, a substrate, a pole and a tab connecting piece; a mounting hole is formed in the base plate; a through hole is formed in the pole; the pole is positioned in the mounting hole; the extension direction of the through hole is parallel to the extension direction of the mounting hole; the tab connecting piece comprises a connecting piece body and a convex connecting part; the protruding connecting part extends outwards from the plane where the connecting piece body is located. The battery connecting piece is used for connecting a current single battery and an external element, and comprises a convex mounting part; the battery connecting piece is attached to the edge of the mounting hole in the substrate, and the convex mounting part is positioned in the first section of the through hole; and the convex connecting part is positioned in the second section of the through hole and is in contact with the convex mounting part. According to the top cover assembly, the concave parts formed on the lug connecting pieces and the pole columns are used for accommodating the convex mounting parts, so that the probability of explosion in the welding process is reduced, and the production yield of the top cover assembly is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a top cover assembly, a battery cell, a battery pack, and a method for preparing a battery cell. Background Art

[0002] The battery cell is usually connected to external components or other battery cells through a battery connector such as a tab, and is usually achieved by welding the battery connector to a top cover assembly of another battery cell.

[0003] At present, most of the top cover components are welded with battery connectors. Due to the inability to evenly disperse the heat during welding and the limited contact area between the shielding gas and the welding part, fire is prone to occur during welding. As a result, the welding yield is not high enough.

[0004] In other words, the structural design of most current top cover components results in a low yield rate during their production process. Summary of the invention

[0005] The purpose of the present application is to provide a top cover assembly, a battery cell, a battery pack and a method for preparing a battery cell, which can effectively avoid the explosion phenomenon during the welding process between the battery connector and the top cover assembly, thereby improving the production yield of the top cover assembly.

[0006] In the first aspect, the present application provides a top cover assembly, which is adapted for a battery cell and includes a battery connector, a substrate, a pole and a tab connecting piece; a mounting hole is provided on the substrate; a through hole is provided on the pole; the pole is located in the mounting hole; wherein the extension direction of the through hole is parallel to the extension direction of the mounting hole; the tab connecting piece includes a connecting piece body and a raised connecting portion; the raised connecting portion extends outward from the plane where the connecting piece body is located; the battery connector is used to connect the current battery cell and an external component, and includes a raised mounting portion; the battery connector is attached to the edge of the mounting hole on the substrate, and the raised mounting portion is located in the first section of the through hole; the raised connecting portion is located in the second section of the through hole and contacts with the raised mounting portion.

[0007] The above-mentioned top cover assembly can accommodate the raised mounting portion of the battery connector through the recessed portion formed on the pole lug connector installed on the substrate and the pole column. When the recessed portion accommodates the raised mounting portion, the contact portion is welded. The recessed portion formed by the pole column and the pole lug connector can increase the concentrated area of ​​heat. Accordingly, the raised mounting portion of the battery connector helps to disperse the heat and distribute the heat more evenly, thereby avoiding the rapid evaporation of materials and the rapid expansion of gases caused by high temperature. Ultimately, the probability of fire explosion during welding is reduced. Correspondingly, the production yield of the top cover assembly is improved.

[0008] In combination with the first aspect, optionally, the inner diameter of the first section of the through hole is larger than the inner diameter of the second section of the through hole; the outer diameter of the raised mounting portion matches the inner diameter of the first section of the through hole; the edge portion of the raised mounting portion abuts against the first step, and the middle portion of the raised mounting portion abuts against the raised connecting portion; wherein the first step is located at the connection between the first section of the through hole and the second section of the through hole.

[0009] The top cover assembly is designed such that the inner diameter of the first section of the through hole is larger than the inner diameter of the second section of the through hole, so that a first step is formed inside the through hole, and the end surface of the protruding mounting portion is in contact with the step and the end surface of the protruding connecting portion, respectively, so that the stress applied by the protruding mounting portion toward the pole lug connecting piece is dispersed. In addition, the contact area between the protruding mounting portion and the pole is increased, thereby further improving the welding yield.

[0010] In combination with the first aspect, optionally, it further includes an outer plastic; the outer plastic is filled between the pole and the inner wall of the mounting hole and between the battery connector and the substrate.

[0011] The top cover assembly fills the gap between the battery connector and the substrate with the outer plastic, thereby sealing the space formed by the battery connector and the through hole of the substrate, thereby protecting the internal parts of the top cover assembly.

[0012] In combination with the first aspect, optionally, it also includes inner plastic; the mounting hole includes a lower section of the mounting hole close to one end of the connecting piece body, an upper section of the mounting hole away from one end of the connecting piece body, and a middle section of the mounting hole between the lower section of the mounting hole and the upper section of the mounting hole; the inner diameter of the middle section of the mounting hole is larger than the inner diameter of the upper section of the mounting hole and the inner diameter of the lower section of the mounting hole; the outer plastic is filled between the inner wall of the upper section of the mounting hole and the pole and between the battery connector and the substrate; the inner plastic is filled between the inner wall of the middle section of the mounting hole and the pole.

[0013] The top cover assembly further improves the sealing performance of the space formed by the battery connector and the substrate through hole by means of a structure of the middle section of the mounting hole equivalent to a circle of grooves on the inner wall of the mounting hole and filling the gap between the middle section of the mounting hole and the pole with inner plastic, thereby better protecting the internal parts of the top cover assembly.

[0014] In combination with the first aspect, optionally, a sealing ring is further included; the sealing ring is filled between the inner wall of the lower section of the mounting hole and the pole and between the inner plastic and the pole.

[0015] The top cover assembly fills the gap between the inner wall of the lower section of the mounting hole and the pole with a sealing ring, thereby sealing the lower section of the mounting hole and the pole, effectively isolating the positive and negative electrode materials and various conductive elements inside the battery cell, and effectively preventing electrical short circuits, thereby improving the safety of the battery cell.

[0016] In combination with the first aspect, optionally, the inner plastic includes an inner plastic upper part close to the connecting piece body, an inner plastic lower part away from the connecting body, and an inner plastic middle part between the inner plastic upper part and the inner plastic lower part; the inner plastic upper part is fitted to the second step and surrounds the outer plastic; wherein the second step is located at the connection between the upper section of the mounting hole and the middle section of the mounting hole; the inner plastic middle part surrounds the pole; the inner plastic lower part is fitted to the third step and surrounds the sealing ring; wherein the third step is located at the connection between the lower section of the mounting hole and the middle section of the mounting hole.

[0017] The top cover assembly further improves the sealing performance of the connection between the substrate and the pole by covering the middle section of the pole with the inner plastic and contacting the sealing ring and the outer plastic respectively, thereby better protecting the internal parts of the top cover assembly.

[0018] In combination with the first aspect, optionally, the pole includes a pole lower section close to one end of the connecting piece body, a pole upper section away from one end of the connecting piece body, and a pole middle section between the pole lower section and the pole upper section; the outer diameter of the pole middle section is greater than the outer diameter of the pole upper section and the outer diameter of the pole lower section.

[0019] The top cover assembly is formed by the outer diameter of the middle section of the pole being larger than the outer diameters of the two sections of the pole, and being covered by the inner plastic, and the inner plastic filling the gap between the middle section of the pole and the mounting hole, thereby increasing the contact area between the pole and the inner plastic, thereby further improving the sealing effect. In addition, the protruding structure of the middle section of the pole also prevents the inner plastic from shifting.

[0020] In the second aspect, the present application provides a battery cell, comprising a battery cell and the top cover assembly described in the first aspect; the top cover assembly is installed at the end of the battery cell; the battery cell also includes a battery cell and a pole ear; the pole ear extends from the edge of the end of the battery cell to the middle of the end of the battery cell and is attached to the end of the battery cell; the connecting sheet body is attached to the end of the battery cell and contacts the pole ear.

[0021] The above-mentioned battery cell has the same beneficial effects as the first aspect or any optional implementation of the first aspect, which will not be described in detail here.

[0022] In a third aspect, the present application provides a battery pack, comprising at least two battery cells described in the second aspect; the battery cells are electrically connected via the battery connector.

[0023] The above-mentioned battery pack has the same beneficial effects as the second aspect, which will not be described in detail here.

[0024] In a fourth aspect, the present application provides a method for preparing a battery cell, which is used to prepare a battery cell as described in the second aspect; the method comprises: fitting the connector body of the pole tab connector in the top cover assembly to the end of the battery cell, and welding it to the pole tab of the battery cell; installing the pole post in the mounting hole of the substrate; inserting the protruding connecting portion of the pole tab connector into the through hole of the pole post, and welding the protruding connecting portion to the inner wall of the through hole to obtain a bare battery cell; and wrapping the battery cell in the bare battery cell with an outer shell, and welding the contact between the outer shell and the top cover assembly.

[0025] The method for preparing the battery cell mentioned above has the same beneficial effects as the second aspect, which will not be described in detail here.

[0026] In summary, the top cover assembly, battery cell, battery pack and preparation method of the battery cell provided in the present application can accommodate the protruding mounting portion of the battery connector through the recessed portion formed on the pole lug connector installed on the substrate and the pole. When the protruding mounting portion is accommodated in the recessed portion, the contact portion is welded, which reduces the probability of fire during welding, and correspondingly improves the production yield of the top cover assembly. By designing that the inner diameter of the first section of the through hole is larger than the inner diameter of the second section of the through hole, a first step is formed inside the through hole, which increases the contact area between the protruding mounting portion and the pole, thereby further improving the welding yield. The gap between the inner wall of the lower section of the mounting hole and the pole is filled with a sealing ring, so that the sealing between the lower section of the mounting hole and the pole is achieved, so that the positive and negative electrode materials and each conductive element inside the battery cell are effectively isolated, and electrical short circuits are effectively prevented. The pole ear extends from the edge of the end of the battery cell to the middle of the end of the battery cell and fits against the end of the battery cell, so that the pole ear is bent into an L shape. Compared with the S-shape bent pole ear in most current battery cells, the space in the height direction between the battery cell and the top cover assembly is saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. 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 related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A first exploded view of a top cover assembly provided in an embodiment of the present application;

[0029] Figure 2 A top view of a top cover assembly provided in an embodiment of the present application and a cross-sectional view cut along line aa;

[0030] Figure 3 for Figure 2 A partial enlarged view of the middle A;

[0031] Figure 4 A second exploded view of the top cover assembly provided in an embodiment of the present application;

[0032] Figure 5 A schematic diagram of the structure of the inner plastic in the top cover assembly provided in an embodiment of the present application;

[0033] Figure 6 A front view of a battery cell provided in an embodiment of the present application and a cross-sectional view cut along line bb;

[0034] Figure 7 for Figure 6A partial enlarged view of point B in the middle;

[0035] Figure 8 A three-dimensional diagram of a battery pack provided in an embodiment of the present application;

[0036] Fig. 9 A flow chart of a method for preparing a battery cell provided in an embodiment of the present application.

[0037] Icons: 100, top cover assembly; 110, battery connector; 111, raised mounting portion; 120, substrate; 121, mounting hole; 1211, lower section of mounting hole; 1212, upper section of mounting hole; 1213, middle section of mounting hole; 1214, second step; 1215, third step; 130, pole; 131, through hole; 1311, first step; 132, lower section of pole; 13 3. Upper section of pole; 134. Middle section of pole; 140. Tab; 141. Tab body; 142. Raised connection part; 150. External plastic; 160. Internal plastic; 161. Upper part of internal plastic; 162. Lower part of internal plastic; 163. Middle part of internal plastic; 170. Sealing ring; 180. Lower plastic; 10. Battery cell; 200. Battery core; 210. Tab; 1. Battery pack. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0040] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0041] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0042] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0043] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] Please refer to Figures 1 to 4 , Figure 1 This is a first exploded view of the top cover assembly 100 provided in an embodiment of the present application; Figure 2 1 is a top view of the top cover assembly 100 provided in an embodiment of the present application and a cross-sectional view cut along line aa; Figure 3 yes Figure 2 A partial enlarged view of the middle A; Figure 4It is a second exploded view of the top cover assembly 100 provided in the embodiment of the present application. The top cover assembly 100 provided in the embodiment of the present application can be adapted to the battery cell 10, and may include a battery connector 110, a substrate 120, a pole 130, and a pole ear 210 connecting piece 140. A mounting hole 121 may be provided on the substrate 120. A through hole 131 may be provided on the pole 130. The pole 130 may be located in the mounting hole 121. Among them, the extension direction of the through hole 131 may be parallel to the extension direction of the mounting hole 121. The pole ear 210 connecting piece 140 may include a connecting piece body 141 and a raised connecting portion 142. The raised connecting portion 142 may extend outward from the plane where the connecting piece body 141 is located. The battery connector 110 may be used to connect the current battery cell 10 and an external component, and may include a raised mounting portion 111. The battery connector 110 may be attached to the edge of the mounting hole 121 on the substrate 120, and the protruding mounting portion 111 may be located in the first section of the through hole 131. The protruding connecting portion 142 may be located in the second section of the through hole 131 and may contact the protruding mounting portion 111.

[0045] The battery connector 110 may be a bar. The substrate 120 is generally used to integrate or support the various components in the top cover assembly 100, and it may be made of insulating material. The pole 130 is generally used as the output terminal of the battery cell 10. The tab 210 connecting piece 140 is generally used to connect the tab 210 of the battery cell 200 with the pole 130. The external component may be another battery cell 10 or other electrical equipment. For example: in a battery pack 1 composed of battery cells 10 arranged in a line, the battery cells 10 at the two ends may be connected to the electrical equipment through the battery connector 110.

[0046] In the through hole 131 of the pole 130, a part accommodates the protruding connection part 142 of the connecting piece 140 of the tab 210, and another part accommodates the protruding mounting part 111 of the battery connector 110. In other words, a recessed part matching with the protruding mounting part 111 is formed on the tab connector 140 installed on the substrate 120 and the pole 130. The protruding mounting part 111 is accommodated by the recessed part.

[0047] In the above implementation process, the protruding mounting portion 111 of the battery connector 110 can be accommodated by the recessed portion formed on the pole 130 and the pole lug connector 140 installed on the substrate 120. When the recessed portion accommodates the protruding mounting portion 111, the contact portion is welded. The recessed portion formed by the pole 130 and the pole lug connector 140 can increase the concentrated area of ​​heat, and accordingly, the protruding mounting portion 111 of the battery connector 110 helps to disperse the heat and distribute the heat more evenly, thereby avoiding rapid evaporation of materials and rapid expansion of gases caused by high temperature. Ultimately, the probability of fire explosion during welding is reduced. Correspondingly, the production yield of the top cover assembly 100 is also improved.

[0048] Please continue to refer to Figure 3 and Figure 4 In some optional embodiments, the inner diameter of the first section of the through hole 131 may be greater than the inner diameter of the second section of the through hole 131. The outer diameter of the raised mounting portion 111 may match the inner diameter of the first section of the through hole 131. The edge of the raised mounting portion 111 may abut against the first step 1311, and the middle portion of the raised mounting portion 111 may abut against the raised connecting portion 142. The first step 1311 may be located at the connection between the first section of the through hole 131 and the second section of the through hole 131.

[0049] The first section of the through hole 131 may be the upper section of the through hole 131, and the second section of the through hole 131 may be the lower section of the through hole 131. The inner diameter of the upper section of the through hole 131 may be greater than the inner diameter of the lower section of the through hole 131. When the outer diameter of the protruding mounting portion 111 matches the inner diameter of the lower section of the through hole 131, the end surface of the protruding mounting portion 111 may contact the end surface of the first step 1311 and the protruding connecting portion 142, respectively.

[0050] In the above implementation process, the inner diameter of the first section of the through hole 131 is designed to be larger than the inner diameter of the second section of the through hole 131, so that a first step 1311 is formed inside the through hole 131, and the end surface of the protruding mounting portion 111 is respectively in contact with the step and the end surface of the protruding connecting portion 142, thereby dispersing the stress applied by the protruding mounting portion 111 toward the connecting piece 140 of the pole lug 210. In addition, the contact area between the protruding mounting portion 111 and the pole 130 is increased, thereby further improving the welding yield.

[0051] Please continue to refer to Figure 3 and Figure 4 In some optional implementations, the top cover assembly 100 provided in the embodiment of the present application may further include an outer plastic 150. The outer plastic 150 may be filled between the pole 130 and the inner wall of the mounting hole 121 and between the battery connector 110 and the substrate 120.

[0052] The outer plastic 150 fills a portion of the gap between the pole 130 and the mounting hole 121 , and may also fill the entire gap between the pole 130 and the mounting hole 121 .

[0053] In the above implementation process, the gap between the battery connector 110 and the substrate 120 is filled with the outer plastic 150 to seal the space formed by the battery connector 110 and the through hole 131 of the substrate 120, thereby protecting the internal parts of the top cover assembly 100.

[0054] Please continue to refer to Figure 3 and Figure 4 In some optional embodiments, the top cover assembly 100 provided in the embodiment of the present application may further include an inner plastic 160. The mounting hole 121 may include a mounting hole lower section 1211 close to one end of the connecting piece body 141, a mounting hole upper section 1212 away from one end of the connecting piece body 141, and a mounting hole middle section 1213 between the mounting hole lower section 1211 and the mounting hole upper section 1212. The inner diameter of the mounting hole middle section 1213 may be greater than the inner diameter of the mounting hole upper section 1212 and the inner diameter of the mounting hole lower section 1211. The outer plastic 150 may be filled between the inner wall of the mounting hole upper section 1212 and the pole 130 and between the battery connector 110 and the substrate 120. The inner plastic 160 may be filled between the inner wall of the mounting hole middle section 1213 and the pole 130.

[0055] That is, the inner wall of the mounting hole 121 has a circle of grooves, which can be equivalent to the middle section 1213 of the mounting hole. Optionally, the inner diameter of the lower section 1211 of the mounting hole can be smaller than the inner diameter of the upper section 1212 of the mounting hole. The thickness at the edge of the mounting hole 121 on the substrate 120 can be greater than the thickness at other positions on the substrate 120.

[0056] In the above implementation process, the structure of the middle section 1213 of the mounting hole is equivalent to a circle of grooves on the inner wall of the mounting hole 121, and the gap between the middle section 1213 of the mounting hole and the pole 130 is filled with the inner plastic 160, so as to further improve the sealing of the space formed by the battery connector 110 and the through hole 131 of the substrate 120. Therefore, the internal parts of the top cover assembly 100 are better protected.

[0057] Please continue to refer to Figure 3 and Figure 4 In some optional implementations, the top cover assembly 100 provided in the embodiment of the present application may further include a sealing ring 170. The sealing ring 170 may be filled between the inner wall of the lower section 1211 of the mounting hole and the pole 130 and between the inner plastic 160 and the pole 130.

[0058] As an optional implementation, the top cover assembly 100 provided in the embodiment of the present application may further include a lower plastic 180, the lower plastic 180 may be provided with a lower plastic 180 through hole 131, and the lower plastic 180 may be attached to a side of the substrate 120 that is away from the battery connector 110. Accordingly, the lower plastic 180 may be sleeved on an end of the pole 130 that is away from the battery connector 110.

[0059] On the basis that the sealing ring 170 fills the gap between the inner wall of the lower section 1211 of the mounting hole and the pole 130 , the sealing ring 170 may also contact the edge of the through hole 131 of the lower plastic 180 .

[0060] In the above implementation process, the gap between the inner wall of the lower section 1211 of the mounting hole and the pole 130 is filled by the sealing ring 170, so as to achieve the sealing between the lower section 1211 of the mounting hole and the pole 130, so that the positive and negative electrode materials and each conductive element inside the battery cell 10 are effectively isolated, and the electrical short circuit is effectively prevented. Thus, the safety of the battery cell 10 is improved.

[0061] Please combine Figure 3 Reference Figure 5 , Figure 5 A schematic diagram of the structure of the inner plastic 160 in the top cover assembly 100 provided in an embodiment of the present application. In some optional embodiments, the inner plastic 160 may include an inner plastic upper portion 161 close to the connecting piece body 141, an inner plastic lower portion 162 away from the connecting body, and an inner plastic middle portion 163 between the inner plastic upper portion 161 and the inner plastic lower portion 162. The inner plastic upper portion 161 is attached to the second step 1214 and can surround the outer plastic 150. Among them, the second step 1214 can be located at the connection between the upper section 1212 of the mounting hole and the middle section 1213 of the mounting hole. The inner plastic middle portion 163 surrounds the pole 130. The inner plastic lower portion 162 can be attached to the third step 1215 and can surround the sealing ring 170. Among them, the third step 1215 can be located at the connection between the lower section 1211 of the mounting hole and the middle section 1213 of the mounting hole.

[0062] For example, Figure 3 In the cross-sectional view shown, the interface of the inner plastic 160 may be in a U-shape after being rotated 90° counterclockwise. The inner plastic 160 may cover the middle section 134 of the pole and contact the sealing ring 170 and the outer plastic 150 respectively.

[0063] In the above implementation process, the inner plastic 160 covers the middle section 134 of the pole and contacts the sealing ring 170 and the outer plastic 150 respectively, thereby further improving the sealing performance of the connection between the substrate 120 and the pole 130 and better protecting the internal parts of the top cover assembly 100.

[0064] Please continue to refer to Figure 3 and Figure 4 In some optional embodiments, the pole 130 may include a pole lower section 132 close to one end of the connecting piece body 141, a pole upper section 133 away from one end of the connecting piece body 141, and a pole middle section 134 between the pole lower section 132 and the pole upper section 133. The outer diameter of the pole middle section 134 may be greater than the outer diameter of the pole upper section 133 and the outer diameter of the pole lower section 132.

[0065] As an optional implementation, the outer diameter of the pole upper section 133 may be greater than the outer diameter of the pole lower section 132 .

[0066] The pole middle section 134 can be equivalent to a circle of flange. The flange can be covered by the inner plastic 160.

[0067] In the above implementation process, the outer diameter of the pole middle section 134 is larger than the outer diameters of the two sections of the pole 130, and is covered by the inner plastic 160, and the inner plastic 160 fills the gap between the pole middle section 134 and the mounting hole 121, thereby increasing the contact area between the pole 130 and the inner plastic 160, thereby further improving the sealing effect. In addition, the protruding structure of the pole middle section 134 also plays a role in preventing the inner plastic 160 from shifting.

[0068] Please refer to Figure 6 and Figure 7 , Figure 6 1 is a front view of a battery cell 10 provided in an embodiment of the present application and a cross-sectional view cut along line bb; Figure 7 yes Figure 6 A partial enlarged view of point B in the figure. Based on the same concept, an embodiment of the present application provides a battery cell 10, which may include a battery cell 200 and the top cover assembly 100 described above. The top cover assembly 100 may be installed at the end of the battery cell 200. The battery cell 10 may also include a battery cell 200 and a tab 210. The tab 210 may extend from the edge of the end of the battery cell 200 to the middle of the end of the battery cell 200, and may be attached to the end of the battery cell 200. The connecting sheet body 141 may be attached to the end of the battery cell 200, and may be in contact with the tab 210.

[0069] The pole tab 210 extends from the edge of the end of the battery cell 200 to the middle of the end of the battery cell 200 and fits the end of the battery cell 200, so that the pole tab 210 is bent into an L shape. Compared with the S-shape bend of the pole tab 210 in most current battery cells 10, the space in the height direction between the battery cell 200 and the top cover assembly 100 is saved.

[0070] The above implementation process may be the same as the top cover assembly 100 described above, and will not be repeated here.

[0071] Please refer to Figure 8 , Figure 8 1 is a three-dimensional diagram of a battery pack 1 provided in an embodiment of the present application. Based on the same concept, an embodiment of the present application provides a battery pack 1, which may include at least two battery cells 10 as described above. The battery cells 10 are electrically connected via a battery connector 110.

[0072] The above implementation process may be the same as the battery cell 10 described above, and will not be described again here.

[0073] Please refer to Fig. 9 , Fig. 9 is a flow chart of a method for preparing a battery cell provided in an embodiment of the present application. Based on the same concept, an embodiment of the present application provides a method for preparing a battery cell, which can be used to prepare the battery cell 10 described above. The method may include:

[0074] Step S110: attaching the connector body of the tab connector in the top cover assembly to the end of the battery cell and welding it to the tab of the battery cell.

[0075] In the above step S110, the welding between the connector body and the tab may be ultrasonic welding.

[0076] Step S120: Install the pole in the installation hole of the substrate.

[0077] Step S130: inserting the protruding connection portion of the tab connector into the through hole of the pole, and welding the protruding connection portion to the inner wall of the through hole to obtain a bare battery cell.

[0078] In the above step S130, the welding between the protruding connection portion and the inner wall of the through hole may be laser welding.

[0079] Step S140: Wrap the cells in the bare battery cell with a shell, and weld the contact points between the shell and the top cover assembly.

[0080] In the above step S140, the welding at the contact point between the outer shell and the top cover assembly may also be laser welding.

[0081] The above implementation process may be the same as that of the battery cell described above, and will not be repeated here.

[0082] In summary, the top cover assembly 100, the battery cell 10, the battery pack 1 and the preparation method of the battery cell provided in each embodiment of the present application can accommodate the protruding mounting portion 111 of the battery connector 110 through the recessed portion formed on the pole lug connector 140 installed on the substrate 120 and the pole 130. When the protruding mounting portion 111 is accommodated in the recessed portion, the contact portion is welded, which reduces the probability of explosion during the welding process, and correspondingly improves the production yield of the top cover assembly 100. By designing that the inner diameter of the first section of the through hole 131 is larger than the inner diameter of the second section of the through hole 131, a first step 1311 is formed inside the through hole 131, which increases the contact area between the protruding mounting portion 111 and the pole 130, thereby further improving the welding yield. The gap between the inner wall of the lower section 1211 of the mounting hole and the pole 130 is filled by the sealing ring 170, so as to achieve the sealing between the lower section 1211 of the mounting hole and the pole 130, so that the positive and negative electrode materials and each conductive element inside the battery cell 10 are effectively isolated, and the electrical short circuit is effectively prevented. The pole ear 210 extends from the edge of the end of the battery cell 200 to the middle of the end of the battery cell 200 and fits the end of the battery cell 200, so that the bending of the pole ear 210 is L-shaped. Compared with the bending of the pole ear 210 in most current battery cells 10 in which the bending is S-shaped, the space between the battery cell 200 and the top cover assembly 100 in the height direction is saved.

[0083] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A top cover assembly, characterized in that: Adapted to the battery monomer, and includes a battery connector, a substrate, a pole and a pole ear connecting piece; The base plate is provided with a mounting hole; The pole is provided with a through hole; the pole is located in the mounting hole; wherein the extending direction of the through hole is parallel to the extending direction of the mounting hole; The tab connecting piece includes a connecting piece body and a protruding connecting portion; the protruding connecting portion extends outward from the plane where the connecting piece body is located; The battery connector is used to connect the current battery cell and the external component, and includes a raised mounting portion; the battery connector is attached to the edge of the mounting hole on the substrate, and the raised mounting portion is located in the first section of the through hole; The protruding connection portion is located in the second section of the through hole and contacts the protruding mounting portion.

2. The top cover assembly according to claim 1, characterized in that: The inner diameter of the first section of the through hole is greater than the inner diameter of the second section of the through hole; The outer diameter of the protruding mounting portion matches the inner diameter of the first section of the through hole; The edge of the protruding mounting portion abuts against the first step, and the middle portion of the protruding mounting portion abuts against the protruding connecting portion; wherein the first step is located at the connection between the first section of the through hole and the second section of the through hole.

3. The top cover assembly according to claim 1, characterized in that: It also includes outer plastics; The outer plastic is filled between the pole and the inner wall of the mounting hole and between the battery connector and the substrate.

4. The top cover assembly according to claim 3, characterized in that: It also includes inner plastic; The mounting hole comprises a mounting hole lower section close to one end of the connecting piece body, a mounting hole upper section away from one end of the connecting piece body, and a mounting hole middle section between the mounting hole lower section and the mounting hole upper section; The inner diameter of the middle section of the mounting hole is larger than the inner diameter of the upper section of the mounting hole and the inner diameter of the lower section of the mounting hole; The outer plastic is filled between the inner wall of the upper section of the mounting hole and the pole and between the battery connector and the substrate; The inner plastic is filled between the inner wall of the middle section of the mounting hole and the pole.

5. The top cover assembly according to claim 4, characterized in that: Also includes a sealing ring; The sealing ring is filled between the inner wall of the lower section of the mounting hole and the pole and between the inner plastic and the pole.

6. The top cover assembly according to claim 5, characterized in that: The inner plastic includes an inner plastic upper portion close to the connecting piece body, an inner plastic lower portion away from the connecting body, and an inner plastic middle portion between the inner plastic upper portion and the inner plastic lower portion; The upper part of the inner plastic is attached to the second step and surrounds the outer plastic; wherein the second step is located at the connection between the upper section of the mounting hole and the middle section of the mounting hole; The middle part of the inner plastic surrounds and fits the pole; The lower part of the inner plastic is fitted on the third step and surrounds and fits the sealing ring; wherein the third step is located at the connection between the lower section of the mounting hole and the middle section of the mounting hole.

7. The top cover assembly according to claim 1, characterized in that: The pole comprises a pole lower section close to one end of the connecting piece body, a pole upper section away from one end of the connecting piece body, and a pole middle section between the pole lower section and the pole upper section; The outer diameter of the middle section of the pole is greater than the outer diameter of the upper section of the pole and the outer diameter of the lower section of the pole.

8. A battery cell, characterized in that: A battery cell and a top cover assembly as claimed in any one of claims 1 to 6; The top cover assembly is mounted on the end of the battery cell; The battery cell also includes a battery cell and a tab; The electrode tab extends from the edge of the end of the battery cell to the middle of the end of the battery cell and is attached to the end of the battery cell; The connecting sheet body is attached to the end of the battery core and is in contact with the tab.

9. A battery pack, characterized in that: comprising at least two battery cells according to any one of claims 1 to 6; The battery cells are electrically connected via the battery connector.

10. A method for preparing a battery monomer, characterized in that: Used to prepare the battery cell as claimed in claim 8; The method comprises: The connector body of the tab connector in the top cover assembly is attached to the end of the battery cell and welded to the tab of the battery cell; Install the pole in the mounting hole of the base plate; Inserting the protruding connection part of the tab connector into the through hole of the pole column, and welding the protruding connection part to the inner wall of the through hole to obtain a bare cell; and The battery cells in the bare battery cell are wrapped with a shell, and the contact portion between the shell and the top cover assembly is welded.

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