Top cover assembly and battery

Abstract

A top cover assembly, comprising a cover module component and a top cover component, wherein the cover module component comprises a cover plate and a terminal post, the cover plate being connected to an opening of a housing, a first through hole being provided in the cover plate, one end of the terminal post being located on the inner side of the cover plate and being electrically connected to a tab of a battery cell, and the other end of the terminal post extending out of the first through hole to the outer side of the cover plate; and the top cover component comprises a first connector, a PTC and a top cover body, which are connected in sequence in a direction away from the housing, the first connector being located above the cover plate and being electrically connected to the terminal post.

Description

Top cover assembly and battery

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 30, 2024, with application number 202422135024.X. The entire contents of the above application are incorporated by reference into this application.

[0002] Technical Field

[0003] The present application relates to the field of battery technology, for example, to a top cover assembly and a battery.

[0004] Background Art

[0005] Lithium batteries are widely used in electronic instruments, digital devices, and household appliances due to their high specific energy, low self-discharge, light weight, long life, and environmentally friendly properties. A lithium battery typically consists of a casing, a battery cell, and a top cover assembly. The casing is a shell-like structure with an open end and a chamber within it. The battery cell can be placed into the chamber through the opening of the casing, and the top cover assembly seals the opening of the casing.

[0006] Technical issues

[0007] In the related art, the top cover assembly and the outer shell are usually assembled in two ways: the first is that both the top cover assembly and the outer shell adopt a semi-sealed structure, and a positive temperature coefficient (PTC) structure is integrated on the top cover assembly, resulting in an overall sealing area that is too large, a poor sealing effect, and relatively low safety; the second is that both the top cover assembly and the outer shell adopt a fully sealed structure, and the PTC structure is not integrated on the top cover assembly, resulting in the inability to prevent battery cell short circuits during the assembly process between the top cover assembly and the outer shell 10.

[0008] Technical Solutions

[0009] An embodiment of the present application provides a top cover assembly that covers the opening of a battery housing, wherein a battery cell is housed within the housing. The top cover assembly includes:

[0010] The cover assembly includes a cover plate and a pole, wherein the cover plate is connected to the opening of the housing, a first through-hole is formed on the cover plate, one end of the pole is located on the inner side of the cover plate and is electrically connected to the tab of the battery cell, and the other end of the pole extends from the first through-hole to the outer side of the cover plate;

[0011] The top cover assembly comprises a first connector, a PTC and a top cover body which are sequentially connected in a direction away from the shell. The first connector is located above the cover plate and is electrically connected to the pole.

[0012] An embodiment of the present application also provides a battery, including a shell, a battery cell and a top cover assembly as described above. The shell is a shell-like structure with one end open, the battery cell is arranged in the shell, the top cover assembly is sealed at the opening of the shell, and the pole of the top cover assembly is electrically connected to the pole ear of the battery cell.

[0013] Beneficial effects

[0014] The top cover assembly and battery provided in the present application have good overcurrent protection function while ensuring the sealing performance of the battery, so as to ensure the safety of the top cover assembly during the assembly process.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG1 is a schematic diagram of the assembly of the top cover and the housing provided in an embodiment of the present application;

[0017] FIG2 is another schematic diagram of the assembly of the top cover and the housing provided in an embodiment of the present application;

[0018] FIG3 is a schematic cross-sectional view of a battery according to an embodiment of the present invention;

[0019] FIG4 is a schematic cross-sectional view of a top cover assembly according to an embodiment of the present application;

[0020] FIG5 is a schematic cross-sectional view of a top cover assembly according to an embodiment of the present application;

[0021] FIG6 is a schematic diagram of a top view of the top cover body provided in an embodiment of the present application;

[0022] FIG7 is a schematic cross-sectional view of the top cover body provided in an embodiment of the present application;

[0023] FIG8 is a schematic top view of the top cover assembly provided in an embodiment of the present application;

[0024] FIG9 is a schematic diagram of a top view of a PTC structure provided in an embodiment of the present application;

[0025] FIG10 is a schematic cross-sectional view of a PTC according to an embodiment of the present application;

[0026] FIG11 is a schematic top view of the structure of the first connecting member provided in an embodiment of the present application;

[0027] FIG12 is a schematic cross-sectional view of a first connecting member provided in an embodiment of the present application;

[0028] FIG13 is a schematic cross-sectional view of a cover assembly according to an embodiment of the present application;

[0029] FIG14 is a schematic structural diagram of the components of the cover assembly provided in an embodiment of the present application before assembly.

[0030] In the picture:

[0031] 10', housing; 101', mounting slot; 20', top cover assembly; 201', top cover body; 202', bottom cover; 203', PTC; 30', battery cell; 301', tab;

[0032] 10', housing; 20', top cover assembly; 201', cover body; 2011', first perforation; 202', pole; 203', insulating member; 204', sealing member; 30', battery cell; 301', tab;

[0033] 100. Top cover assembly;

[0034] 110, cover assembly; 111, cover plate; 1111, first through-hole; 112, pole; 1121, pole body; 11211, first protrusion; 1122, protruding portion; 113, second connecting member; 1131, second through-hole; 1132, engaging portion; 1133, second engaging groove; 114, insulating member; 1141, receiving groove; 1142, second protrusion; 11401, bearing portion; 11402, intermediate connecting portion; 11403, inner extension portion;

[0035] 120, top cover assembly; 121, first connector; 1211, first positioning portion; 1212, first via hole; 122, PTC; 1221, second positioning portion; 1222, first avoidance spot welding position; 1223, second via hole; 123, top cover body; 1231, recessed portion; 1232, third positioning portion; 1233, second avoidance spot welding position;

[0036] 130. Sealing portion; 131. Limiting groove;

[0037] 200, shell;

[0038] 300, battery cell; 301, tab.

[0039] Implementation Methods of the Application

[0040] In related technologies, the top cover assembly and the housing are usually assembled in the following two ways:

[0041] 1) As shown in Figure 1, the top cover assembly 20' and the outer shell 10' employ a semi-sealed structure. The top cover assembly 20' includes a top cover body 201', a bottom cover 202', and a PTC structure 203'. A mounting groove 101' is defined on the inner wall of the opening of the outer shell 10'. The bottom cover 202', PTC structure 203', and top cover body 201' are arranged sequentially from the inside out and housed within the mounting groove 101'. The bottom cover 202' is electrically connected to the tab 301' of the battery cell 30' within the outer shell 10'. The provision of the PTC structure 203' prevents battery cell short circuits during assembly of the top cover assembly 20' and the outer shell 10', thereby ensuring safety during the assembly process. However, this arrangement requires sealing between the top cover assembly 20 ′ and the mounting groove 101 ′, which results in an excessively large overall sealing area, poor sealing effect, and relatively low safety.

[0042] 2) As shown in FIG2 , the top cover assembly 20 ' ' and the housing 10 ' ' adopt a fully sealed structure, wherein the top cover assembly 20 ' ' comprises a cover body 201 ' ' , a pole 202 ' ' and an insulating member 203 ' ' , the cover body 201 ' ' is welded to the opening of the housing 10 ' ' , a first through hole 2011 ' ' is provided on the cover body 201 ' ' , one end of the pole 202 ' ' is located at the cover body 201 '', and the other end passes through the first through-hole 2011'' and is electrically connected to the tab 301'' of the battery cell 30'' in the housing 10''. An insulating member 203'' is provided between the cover body 201'' and the pole 202'' to achieve an insulating connection between the cover body 201'' and the pole 202''; a sealing member 204'' is provided between the insulating member 203'' and the pole 202''. Compared with the first assembly method, the sealing area of ​​this assembly structure is greatly reduced and the sealing performance is improved. However, since the PTC structure is not integrated on the top cover assembly 20', it is inevitable that the battery cell short circuit will occur during the assembly process between the top cover assembly 20' and the shell 10'; this assembly structure will increase the connection of the PTC when grouping, and the overall structure is relatively complex, which cannot be achieved through automated mass production, resulting in high processing costs.

[0043] Figure 3 shows a schematic cross-sectional view of the battery provided in this embodiment. As shown in Figure 3, this embodiment provides a battery comprising a housing 200, a battery cell 300, and a top cover assembly 100. The housing 200 is a shell-like structure with one end open, and the battery cell 300 is disposed within the housing 200. The top cover assembly 100 seals the opening of the housing 200 to ensure the battery's sealing. In this embodiment, the battery is a cylindrical battery, and the housing 200 is a cylindrical cavity structure with one end open. The battery cell 300 is placed into the inner cavity of the housing 200 through the opening of the housing 200.

[0044] In this embodiment, the battery cell 300 is a wound battery cell, which has the advantages of compact structure, strong charge and discharge capability, and high reliability.

[0045] It should be noted that this embodiment does not limit the specific structure of the housing 200 .

[0046] In order to ensure the sealing of the battery and the safety during the assembly process, this embodiment further provides a top cover assembly 100. The specific structure of the top cover assembly 100 is introduced below with reference to the accompanying drawings.

[0047] FIG4 shows a schematic cross-sectional view of the top cover assembly 100 provided in this embodiment. As shown in FIG4 and in combination with FIG3 , the top cover assembly 100 provided in this embodiment includes a cover assembly 110 and a top cover assembly 120. The cover assembly 110 includes a cover plate 111 and a pole 112. The cover plate 111 is connected to the opening of the housing 200. A first through-hole 1111 is provided on the cover plate 111. One end of the pole 112 is located on the inner side of the cover plate 111 and is electrically connected to the tab 301 of the battery cell 300. The other end of the pole 112 extends from the first through-hole 1111 to the outer side of the cover plate 111. The top cover assembly 120 includes a first connector 121, a PTC 122, and a top cover body 123 connected in sequence in a direction away from the housing 200. The first connector 121 is located above the cover plate 111 and is electrically connected to the pole 112. With this arrangement, the top cover assembly 100 can be connected to the opening of the outer shell 200 in a fully sealed structure to ensure good sealing of the battery. By integrating the PTC 122, an overcurrent protection function can be provided during the assembly of the top cover assembly 100, thereby ensuring the safety and reliability of the assembly process of the top cover assembly 100. It should be noted that the PTC 122 refers to a positive temperature coefficient thermistor. By integrating the PTC 122 in the top cover assembly 100, the following functions can be achieved: 1) Overheat protection: When the battery heats up due to overcharging, short circuiting, or other abnormal conditions, the resistance of the PTC 122 will increase rapidly, thereby limiting the current and preventing the internal temperature of the battery from becoming too high, thus achieving overheat protection for the battery. 2) Overcurrent protection: When the current in the battery circuit exceeds the set value, the PTC 122 will heat up and cause the resistance to increase, thereby limiting the current and preventing the battery from being damaged by overcurrent. Therefore, the top cover assembly 100 provided in this embodiment can realize real-time monitoring and protection of the battery working status, thereby improving the safety and service life of the battery.

[0048] It should be noted that the outer side of the cover plate 111 specifically refers to the side of the cover plate 111 away from the battery cell 300 , and the inner side of the cover plate 111 specifically refers to the side of the cover plate 111 close to the battery cell 300 .

[0049] As shown in Figure 4, the pole 112 includes a pole body 1121 and a protrusion 1122 protruding from the pole body 1121. The pole body 1121 is located on the inner side of the cover plate 111 and is electrically connected to the tab 301 of the battery cell 300. The outer diameter of the pole body 1121 is larger than the inner diameter of the first through-hole 1111, and the protrusion 1122 extends from the first through-hole 1111 to the outside of the cover plate 111. With this arrangement, the pole 112 can form a structure similar to a stepped shaft, and the stepped surface formed between the pole body 1121 and the protrusion 1122 can form a snap-fit ​​relationship with the cover plate 111 to prevent the pole 112 from being dislodged from the first through-hole 1111 of the cover plate 111 under large external forces, thereby ensuring the reliability of the battery. In this embodiment, the pole 112 is made of aluminum alloy or stainless steel.

[0050] FIG5 shows a schematic cross-sectional view of the top cover assembly 120 provided in this embodiment. FIG6 shows a schematic top view of the top cover body 123 provided in this embodiment. FIG7 shows a schematic cross-sectional view of the top cover body 123 provided in this embodiment. As shown in FIG5-FIG7 and in combination with FIG3 and FIG4, the top cover body 123 is provided with a recessed portion 1231 that is recessed in a direction away from the housing 200. The recessed portion 1231 is arranged opposite the first through-hole 1111. The first connector 121 is provided with a first through-hole 1212 that is opposite the first through-hole 1111. The PTC 122 is provided with a second through-hole 1223 that is opposite the first through-hole 1111. The end of the pole 112 extending from the first through-hole 1111 passes through the first through-hole 1212 and the second through-hole 1223 in sequence and is accommodated in the recessed portion 1231. This design can protect the pole 112 to prevent the pole 112 from being damaged due to long-term exposure and improve the reliability of battery use.

[0051] In some embodiments, there is a gap between the hole wall of the second through hole 1223 on the PTC 122 and the outer wall of the pole 112. This design is to enable the PTC 122 to play a better role in overcurrent protection. It should be explained that the overcurrent protection principle of the PTC 122 is: under normal working conditions, the temperature of the PTC 122 is low and the resistance value is relatively small, so the current can pass smoothly; when the current in the circuit exceeds the rated value, the power consumption generated when the current passes through the PTC 122 increases, causing the temperature of the PTC 122 to rise rapidly, and because the PTC 122 has a positive temperature coefficient characteristic, that is, as the temperature rises, the resistance value will also increase accordingly. Therefore, in the overcurrent state, the resistance value of the PTC 122 will increase rapidly. At this time, the current passing through it will be limited and reduced, thereby playing the role of overcurrent protection. Therefore, PTC122 needs to be connected to the circuit. If PTC122 is in direct contact with the pole 112, the current on the pole 112 will flow directly from the top surface of PTC122 to the top cover body 123 without passing through the inside of PTC122. At this time, PTC122 will not have the overcurrent protection function.

[0052] In this embodiment, the first connecting member 121, the PTC 122 and the top cover body 123 are connected by welding, which facilitates assembly and ensures a stable connection.

[0053] FIG8 shows a schematic diagram of the top cover assembly 120 provided in this embodiment from above. FIG9 shows a schematic diagram of the top structure of the PTC 122 provided in this embodiment from above. FIG10 shows a schematic diagram of the cross-sectional structure of the PTC 122 provided in this embodiment. FIG11 shows a schematic diagram of the top structure of the first connector 121 provided in this embodiment. FIG12 shows a schematic diagram of the cross-sectional structure of the first connector 121 provided in this embodiment. As shown in FIG8 to FIG12 and in combination with FIG6 , in order to achieve welding fixation between the first connector 121, the PTC 122 and the top cover body 123, a first positioning portion 1211 is provided on the first connector 121, a second positioning portion 1221 is provided on the PTC 122, and a third positioning portion 1232 is provided on the top cover body 123, and the first positioning portion 1211, the second positioning portion 1221 and the third positioning portion 1232 are arranged opposite to each other. Before welding, the first connecting member 121, PTC122 and the top cover body 123 are stacked in sequence, and the first positioning portion 1211, the second positioning portion 1221 and the third positioning portion 1232 are ensured to be arranged opposite each other. Then, the first connecting member 121, the PTC122 and the top cover body 123 are connected by soldering at the first positioning portion 1211, the second positioning portion 1221 and the third positioning portion 1232.

[0054] In some embodiments, the first positioning portion 1211, the second positioning portion 1221, and the third positioning portion 1232 are all positioning grooves provided at the edge of the corresponding structure. In other embodiments, the first positioning portion 1211, the second positioning portion 1221, and the third positioning portion 1232 are all positioning holes provided on the corresponding structure. This embodiment does not limit the specific shapes of the first positioning portion 1211, the second positioning portion 1221, and the third positioning portion 1232, and they can be circular, semicircular, square, or other irregular shapes, as long as the first connector 121, the PTC 122, and the top cover body 123 can be welded and fixed.

[0055] In this embodiment, there are two first positioning portions 1211, which are symmetrically arranged on the first connector 121. Each first positioning portion 1211 corresponds to one second positioning portion 1221 and one third positioning portion 1232. That is, there are two welding connection points between the first connector 121, the PTC 122, and the top cover body 123 to ensure the stability of the connection between the three. Of course, in other embodiments, the number of first positioning portions 1211, second positioning portions 1221, and third positioning portions 1232 can be adjusted according to actual needs and is not limited here.

[0056] FIG13 shows a schematic cross-sectional view of the cover assembly 110 provided in this embodiment. FIG14 shows a schematic view of the structure of the components of the cover assembly 110 provided in this embodiment before assembly. As shown in FIG13-FIG14, the cover assembly 110 also includes a second connector 113, the second connector 113 is located above the cover plate 111, and the second connector 113 is provided with a second through-hole 1131 that is directly opposite to the first through-hole 1111, and the end of the pole 112 away from the housing 200 passes through the first through-hole 1111 and the second through-hole 1131 in sequence; a snap-fit ​​portion 1132 is formed on the wall of the second through-hole 1131 toward the center of the second through-hole 1131, and the snap-fit ​​portion 1132 is snap-fitted into the pole 112, and the first connector 121 is connected to the second connector 113. By providing the second connector 113, the second connector 113 engages with the terminal 112 via the engaging portion 1132. This, on the one hand, secures the terminal 112, preventing it from coming off the cover 111 during use and affecting the battery's performance; on the other hand, it achieves a stable electrical connection between the terminal 112 and the second connector 113; and on the other hand, it ensures good sealing between the second connector 113 and the terminal 112. In some embodiments, the second connector 113 is made of stainless steel.

[0057] To achieve an insulating connection between the pole 112 and the cover plate 111 , the cover assembly 110 further includes an insulating member 114 . The insulating member 114 is provided between the cover plate 111 and the pole 112 and between the second connector 113 and the cover plate 111 .

[0058] In some embodiments, along the axis of the pole 112, the distance between the surface of the clamping portion 1132 away from the housing 200 and the cover 111 is smaller than the distance between the surface of the second connector 113 away from the housing 200 and the cover 111. With this arrangement, a stepped structure can be formed within the second through-hole 1131. This stepped structure compresses the pole 112 in the radial direction of the pole 112 and compresses the insulating member 114 in the axial direction of the pole 112, thereby achieving good insulation and sealing between the pole 112 and the cover 111.

[0059] To achieve electrical connection between the first connector 121 and the second connector 113, as shown in Figures 8 and 10, the first connector 121 and the second connector 113 are welded together. A first avoidance spot welding position 1222 is provided on the PTC 122, and a second avoidance spot welding position 1233 is provided on the top cover body 123. The first avoidance spot welding position 1222 and the second avoidance spot welding position 1233 are both directly opposite the welding position between the first connector 121 and the second connector 113. The provision of the first avoidance spot welding position 1222 and the second avoidance spot welding position 1233 can play a role in avoiding the welding position between the first connector 121 and the second connector 113, thereby ensuring a stable connection between the first connector 121 and the second connector 113; the first connector 121 serves as an intermediate connection structure between the cover assembly 110 and the top cover assembly 120, which can ensure the welding quality and connection stability between the cover assembly 110 and the top cover assembly 120.

[0060] In this embodiment, there are two first avoidance welding positions 1222, which are symmetrically distributed on the PTC 122. A first avoidance welding position 1222 is provided between two adjacent second positioning portions 1221, and each first avoidance welding position 1222 corresponds to a second avoidance welding position 1233. In other words, there are two welding connection positions between the first connector 121 and the second connector 113 to ensure the stability of the connection between the two. Of course, in other embodiments, the number and arrangement of the first avoidance welding positions 1222 and the second avoidance welding positions 1233 can also be adjusted according to actual needs and are not limited here.

[0061] Continuing with Figure 4, a receiving groove 1141 is formed on the side of the insulating member 114 away from the outer shell 200, and the second connecting member 113, the first connecting member 121, the PTC 122 and part of the top cover body 123 are all located in the receiving groove 1141, and a sealing portion 130 is provided between the outer edges of the second connecting member 113, the first connecting member 121, the PTC 122 and part of the top cover body 123 and the groove wall of the receiving groove 1141. When processing the top cover assembly 100, the cover group component 110 and the top cover component 120 can be assembled separately first, and then the first through hole 1212 of the first connector 121 on the top cover component 120 and the second through hole 1223 on the PTC 122 are aligned with the pole 112 and installed in the receiving groove 1141 of the insulating member 114; then the first connector 121 and the second connector 113 are connected by welding through the first avoidance spot welding position 1222 and the second avoidance spot welding position 1233; finally, a glue sealing process is performed between the receiving groove 1141 and the top cover component 120 to form a sealing portion 130. Compared with the semi-sealed structure shown in Figure 1, the sealing area of ​​the top cover assembly 100 provided in this embodiment is smaller, which can achieve a good sealing effect, and because the PTC 122 is integrated at the same time, the overcurrent protection function of the top cover assembly 100 during the assembly process can be realized, thereby improving the safety of the battery.

[0062] In some embodiments, a limiting groove 131 is provided at the top of the sealing portion 130 on a side facing the central axis of the first through-hole 1111, and an edge portion of the top cover body 123 is retained in the limiting groove 131. The provision of the sealing portion 130 can connect the outer edge of the cover assembly 110 with the groove wall of the receiving groove 1141, thereby achieving a sealed connection between the cover assembly 110 and the top cover assembly 120.

[0063] In some embodiments, an edge portion of the PTC 122 is inserted into the sealing portion 130 to achieve a snap fit between the PTC 122 and the sealing portion 130 , further improving the stable fixation of the PTC 122 .

[0064] Continuing with FIG. 4 , the insulating member 114 includes a supporting portion 11401 and an intermediate connecting portion 11402, which are connected in sequence. The supporting portion 11401 is located outside the cover plate 111 and has a receiving groove 1141 formed therein. The intermediate connecting portion 11402 is located between the wall of the first through-hole 1111 and the protrusion 1122. This design achieves a completely insulated connection between the terminal 112 and the cover plate 111, providing excellent insulation and enhancing battery safety.

[0065] In some embodiments, insulating member 114 further includes an inner extension portion 11403, which is located inside cover plate 111 and between terminal body 1121 and cover plate 111. Inner extension portion 11403 is connected to the end of intermediate connecting portion 11402 away from bearing portion 11401, thereby achieving an insulated connection between the upper surface of terminal body 1121 and cover plate 111, further improving battery safety. In this embodiment, inner extension portion 11403 has an L-shaped cross-section to form a receiving groove for receiving terminal body 1121.

[0066] In some embodiments, the pole body 1121 is further provided with a first protrusion 11211, and the inner extension 11403 is provided with a first latching groove that mates with the first protrusion 11211. The latching engagement between the first protrusion 11211 and the first latching groove further enhances the stable connection between the insulating member 114 and the pole 112. In some embodiments, in this embodiment, the first protrusion 11211 is an annular protrusion, and the first latching groove is an annular latching groove, which facilitates processing and assembly. Of course, in other embodiments, there are multiple first protrusions 11211, each of which corresponds to a first latching groove. This design also facilitates processing and assembly. In this example, when the first protrusion 11211 is plugged into the first latching groove, the relative position between the pole 112 and the insulating member 114 is fixed, and relative rotation is not easily caused.

[0067] In some embodiments, a second protrusion 1142 is provided on the side of the insulating member 114 facing the second connector 113, and a second retaining groove 1133 is provided on the second connector 113 to mate with the second protrusion 1142. The engagement between the second protrusion 1142 and the second retaining groove 1133 further enhances the stability of the connection between the insulating member 114 and the second connector 113. In some embodiments, in this embodiment, the second protrusion 1142 is an annular protrusion, and the second retaining groove 1133 is an annular retaining groove, which facilitates processing and assembly. Of course, in other embodiments, there are multiple second protrusions 1142, and the multiple second protrusions 1142 are arranged at circumferential intervals along the insulating part 114, and each second protrusion 1142 corresponds to a second slot 1133. This design can also achieve the effect of convenient processing and easy assembly. In this example, when the second protrusion 1142 and the second slot 1133 are plugged into each other, the relative position between the insulating part 114 and the second connecting part 113 is fixed, and relative rotation is not easy to occur.

[0068] The following is a brief description of the battery assembly process in conjunction with Figures 3 to 14:

[0069] 1) Assembly of the top cover assembly 120: stack the first connector 121, PTC 122 and top cover body 123 in sequence, and ensure that the first positioning portion 1211, the second positioning portion 1221 and the third positioning portion 1232 are arranged opposite each other, and then use soldering to connect the first connector 121, PTC 122 and top cover body 123 at the first positioning portion 1211, the second positioning portion 1221 and the third positioning portion 1232.

[0070] 2) Assembly of the cover assembly 110: An insulating member 114 is formed on the cover plate 111 by injection molding, and the protrusion 1122 of the pole 112 is sequentially passed through the first through-hole 1111 and the second through-hole 1131. The clamping portion 1132 in the second through-hole 1131 squeezes the protrusion 1122. At the same time, the clamping portion 1132 and the protrusion 1122 squeeze the insulating member 114, so that good insulation and sealing are formed between the pole 112 and the cover plate 111.

[0071] 3) Assemble the top cover assembly 120 and the cover assembly 110: align the first through hole 1212 of the first connector 121 on the top cover assembly 120 and the second through hole 1223 on the PTC 122 with the pole 112 and install them in the receiving groove 1141 of the insulating member 114; then connect the first connector 121 and the second connector 113 by welding through the first avoidance spot welding position 1222 and the second avoidance spot welding position 1233; finally, apply glue and seal between the receiving groove 1141 and the top cover assembly 120 to form a sealing portion 130.

[0072] 4) Battery assembly: The positive electrode sheets, separators, and negative electrode sheets are stacked in sequence and then wound into a cylindrical core structure; the negative end of the core structure is connected to the negative insulating sheet, and the core structure is placed in the cavity of the shell 200, and the negative electrode tab is connected to the bottom of the shell 200 by resistance welding; the positive end of the core structure is connected to the positive insulating sheet, and the positive electrode tab is connected to the pole 112 of the top cover assembly 100 by laser welding, and then the electrolyte is injected into the shell 200; the cover plate 111 of the top cover assembly 100 is connected to the opening of the shell 200 by laser welding.

[0073] It should be explained that the first connector 121 is made of nickel-plated metal, and the outflow path of the current is: the pole ear 301 - the pole 112 - the second connector 113 - the first connector 121 - the PTC 122 - the top cover body 123.

Claims

1. A top cover assembly is sealed at the opening of the outer shell (200) of a battery, and an electric core (300) is disposed inside the outer shell (200). The top cover assembly includes: A cover group assembly (110), including a cover plate (111) and a pole column (112). The cover plate (111) is connected to the opening of the outer shell (200). A first through hole (1111) is formed in the cover plate (111). One end of the pole column (112) is located inside the cover plate (111) and is electrically connected to the tab (301) of the electric core (300). The other end of the pole column (112) extends out of the first through hole (1111) to the outside of the cover plate (111). A top cover assembly (120), including a first connecting member (121), a PTC (122), and a top cover body (123) that are sequentially connected in a direction away from the outer shell (200). The first connecting member (121) is located above the cover plate (111) and is electrically connected to the pole column (112).

2. The top cover assembly according to claim 1, wherein, A concave portion (1231) that is recessed in a direction away from the outer shell (200) is provided on the top cover body (123). The concave portion (1231) is disposed opposite to the first through hole (1111). A first through hole (1212) that is disposed opposite to the first through hole (1111) is provided on the first connecting member (121). A second through hole (1223) that is disposed opposite to the first through hole (1111) is provided on the PTC (122). One end of the pole column (112) extending out of the first through hole (1111) sequentially passes through the first through hole (1212) and the second through hole (1223) and is received in the concave portion (1231).

3. The top cover assembly according to claim 1 or 2, wherein, A gap exists between the inner wall of the second through hole (1223) on the PTC (122) and the outer wall of the pole column (112).

4. The top cover assembly according to claim 1 or 2, wherein The cover group assembly (110) further includes a second connecting member (113). The second connecting member (113) is located above the cover plate (111). A second through hole (1131) that is disposed opposite to the first through hole (1111) is provided on the second connecting member (113). One end of the pole column (112) away from the outer shell (200) sequentially passes through the first through hole (1111) and the second through hole (1131).

5. The top cover assembly according to claim 4, wherein, A clamping portion (1132) is convexly formed on the inner wall of the second through hole (1131) toward its center. The clamping portion (1132) is clamped inside the pole column (112). The first connecting member (121) is connected to the second connecting member (113).

6. The top cover assembly according to claim 5, wherein, Along the axial direction of the pole column (112), the distance between the surface of the clamping portion (1132) away from the outer shell (200) and the cover plate (111) is less than the distance between the surface of the second connecting member (113) away from the outer shell (200) and the cover plate (111).

7. The top cover assembly according to claim 4, wherein, The pole column (112) includes a pole column body (1121) and a protruding portion (1122) protruding from the pole column body (1121). The pole column body (1121) is located inside the cover plate (111) and is electrically connected to the tab (301) of the battery cell (300). The outer diameter of the pole column body (1121) is greater than the inner diameter of the first through hole (1111). The protruding portion (1122) sequentially passes through the first through hole (1111) and the second through hole (1131) and extends to the outside of the cover plate (111).

8. The top cover assembly according to any one of claims 5 to 7, wherein the cover group assembly (110) further includes an insulating member (114), and insulation is provided between the cover plate (111) and the pole column (112) and between the second connecting member (113) and the cover plate (111) through the insulating member (114).

9. The top cover assembly according to claim 8, wherein, A receiving groove (1141) is formed on a side of the insulating member (114) away from the housing (200). The second connecting member (113), the first connecting member (121), the PTC (122), and a part of the top cover body (123) are all located in the receiving groove (1141). A sealing portion (130) is provided between the outer edges of the second connecting member (113), the first connecting member (121), the PTC (122), and a part of the top cover body (123) and the groove wall of the receiving groove (1141).

10. The top cover assembly according to claim 9, wherein, A limiting groove (131) is provided at the top of a side of the sealing portion (130) facing the central axis of the first through hole (1111). An edge portion of the top cover body (123) is limited in the limiting groove (131).

11. The top cover assembly according to claim 9 or 10, wherein, An edge portion of the PTC (122) is inserted into the sealing portion (130).

12. The top cover assembly according to claim 9, wherein, The insulating member (114) includes a bearing portion (11401) and an intermediate connecting portion (11402) connected in sequence. The bearing portion (11401) is located outside the cover plate (111), and the receiving groove (1141) is formed thereon. The intermediate connecting portion (11402) is located between the hole wall of the first through hole (1111) and the protruding portion (1122).

13. The top cover assembly according to claim 12, wherein the insulating member (114) further includes an inner extension portion (11403). The inner extension portion (11403) is located inside the cover plate (111) and between the pole column body (1121) and the cover plate (111), and the inner extension portion (11403) is connected to one end of the intermediate connecting portion (11402) away from the bearing portion (11401).

14. The top cover assembly according to claim 13, wherein, The cross-sectional shape of the inner extension portion (11403) is L-shaped to form a receiving groove for receiving the pole column body (1121).

15. The top cover assembly according to claim 13, wherein, A first protrusion (11211) is further provided on the pole column body (1121), and a first card slot matching the first protrusion (11211) is provided on the inner extension portion (11403).

16. The top cover assembly according to claim 15, wherein, The first protrusion (11211) is an annular protrusion, and the first clamping groove is an annular clamping groove; or the number of the first protrusions (11211) is multiple, and the multiple first protrusions (11211) are arranged at intervals along the circumferential direction of the terminal body (1121), and each first protrusion (11211) corresponds to a first clamping groove.

17. The top cover assembly according to claim 8, wherein, A second protrusion (1142) is arranged on one side of the insulating part (114) facing the second connecting part (113), and a second clamping groove (1133) matched with the second protrusion (1142) is arranged on the second connecting part (113).

18. The top cover assembly according to claim 4, wherein, The first connecting part (121) and the second connecting part (113) are connected by welding. A first clearance spot welding position (1222) is arranged on the PTC (122), and a second clearance spot welding position (1233) is arranged on the top cover body (123). The first clearance spot welding position (1222) and the second clearance spot welding position (1233) are both directly opposite to the welding position between the first connecting part (121) and the second connecting part (113).

19. The top cover assembly according to any one of claims 1 to 18, wherein, The first connecting part (121), the PTC (122) and the top cover body (123) are connected by welding.

20. The top cover assembly according to claim 19, wherein, A first positioning part (1211) is arranged on the first connecting part (121), a second positioning part (1221) is arranged on the PTC (122), and a third positioning part (1232) is arranged on the top cover body (123). The first positioning part (1211), the second positioning part (1221) and the third positioning part (1232) are arranged opposite to each other.

21. A battery, comprising a housing (200), an electric core (300) and a top cover assembly according to any one of claims 1 to 20. The housing (200) is a shell-like structure with an opening at one end. The electric core (300) is arranged in the housing (200). The top cover assembly covers the opening of the housing (200), and the terminal (112) of the top cover assembly is electrically connected to the tab (301) of the electric core (300).

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