Top cover assembly and battery

Abstract

The utility model relates to the technical field of batteries, and discloses a top cover assembly and a battery. The top cover assembly comprises a cover group assembly and a top cover assembly, the cover group assembly comprises a cover plate and a pole, the cover plate is connected with the opening of the shell, a first through hole is formed in the cover plate, one end of the pole is positioned on the inner side of the cover plate and is electrically connected with the tab of the battery cell, and the other end of the pole extends out of the outer side of the cover plate from the first through hole; the top cover assembly comprises a first connecting piece, a PTC and a top cover body which are sequentially connected in the direction away from the shell, and the first connecting piece is located above the cover plate and electrically connected with the pole. By adopting the arrangement mode, the top cover assembly can be connected with the opening of the shell by adopting a full-sealing structure, so that the battery has good sealing performance; by integrating the PTC, the over-current protection function in the assembling process of the top cover assembly can be achieved, and therefore the safety and reliability of the assembling process of the top cover assembly are guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a top cover assembly and a battery. Background Art

[0002] Lithium batteries are widely used in the fields of electronic instruments, digital and household appliances due to their advantages such as high specific energy, low self-discharge, light weight, long life and environmental friendliness. A lithium battery usually includes a housing, a battery cell and a top cover assembly. The housing is a shell-like structure with an opening at one end, and a receiving cavity is provided therein. The battery cell can be placed into the receiving cavity from the opening of the housing, and the top cover assembly is hermetically sealed at the opening of the housing.

[0003] In the prior art, the top cover assembly and the housing are usually assembled in the following two ways:

[0004] 1) As shown in Figure 1 , the top cover assembly 20' and the housing 10' adopt a semi-sealed structure. Among them, the top cover assembly 20' includes a top cover body 201', a bottom cover 202' and a PTC 203'. An installation groove 101' is formed on the inner wall of the opening of the housing 10'. The bottom cover 202', the PTC 203' and the top cover body 201' are arranged in sequence from the inside to the outside and are all accommodated in the installation groove 101'. The bottom cover 202' is electrically connected to the tab of the battery cell 30' inside the housing 10'. Among them, the setting of the PTC 203' can prevent the battery cell from short-circuiting during the assembly process between the top cover assembly 20' and the housing 10' to ensure the safety of the assembly process. However, this setting method requires sealing treatment between the top cover assembly 20' and the installation groove 101', resulting in an overly large overall sealing area, poor sealing effect and relatively low safety.

[0005] 2) As shown in Figure 2As shown in the figure, the top cover assembly 20'' and the outer shell 10'' adopt a fully sealed structure. Among them, the top cover assembly 20'' includes a cover body 201'', a pole column 202'', and an insulating part 203''. The cover body 201'' is welded to the opening of the outer shell 10''. A first through hole 2011'' is provided on the cover body 201''. One end of the pole column 202'' is located outside the cover body 201'', and the other end passes through the first through hole 2011'' and is electrically connected to the tab of the battery cell 30'' inside the outer shell 10''. An insulating part 203'' is provided between the cover body 201'' and the pole column 202'' to achieve insulated connection between the cover body 201'' and the pole column 202''; a sealing part 204'' is provided between the insulating part 203'' and the pole column 202''. Compared with the first assembly method, the sealing area of this assembly structure is greatly reduced, and its sealing performance is improved. However, since the PTC structure is not integrated on the top cover assembly 20'', it is impossible to prevent the short circuit of the battery cell during the assembly process between the top cover assembly 20'' and the outer shell 10''; this assembly structure will increase the connection of the PTC during grouping, the overall structure is relatively complex, and it is impossible to achieve automated batch production, resulting in a relatively high processing cost.

[0006] Therefore, it is urgent to propose a top cover assembly to solve the above problems. Utility Model Content

[0007] The purpose of the present utility model is to provide a top cover assembly and a battery, which have a 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.

[0008] With the above concept, the technical solution adopted by the present utility model is as follows:

[0009] A top cover assembly is sealed at the opening of the outer shell of the battery. The outer shell contains a battery cell. The top cover assembly includes:

[0010] A cover group assembly, including a cover plate and a pole column. The cover plate is connected to the opening of the outer shell. A first through hole is provided on the cover plate. One end of the pole column is located inside the cover plate and is electrically connected to the tab of the battery cell, and the other end of the pole column extends from the first through hole to the outside of the cover plate;

[0011] A top cover assembly, including a first connecting part, a PTC, and a top cover body that are sequentially connected in a direction away from the outer shell. The first connecting part is located above the cover plate and is electrically connected to the pole column.

[0012] As a preferred solution of the top cover assembly provided by the present utility model, a recessed portion is provided on the top cover body and recessed in a direction away from the housing. The recessed portion is disposed opposite to the first through hole. A first through hole is provided on the first connecting member and is disposed opposite to the first through hole. A second through hole is provided on the PTC and is disposed opposite to the first through hole. One end of the pole column extending out of the first through hole sequentially passes through the first through hole and the second through hole and is received in the recessed portion.

[0013] As a preferred solution of the top cover assembly provided by the present utility model, there is a gap between the inner wall of the second through hole on the PTC and the outer wall of the pole column.

[0014] As a preferred solution of the top cover assembly provided by the present utility model, the cover group assembly further includes a second connecting member. The second connecting member is located above the cover plate, and a second through hole is provided on the second connecting member and is disposed opposite to the first through hole. One end of the pole column away from the housing sequentially passes through the first through hole and the second through hole.

[0015] As a preferred solution of the top cover assembly provided by the present utility model, a clamping portion is convexly provided on the inner wall of the second through hole towards its center. The clamping portion is clamped in the pole column, and the first connecting member is connected to the second connecting member.

[0016] As a preferred solution of the top cover assembly provided by the present utility model, along the axial direction of the pole column, the distance between the surface of the clamping portion away from the housing and the cover plate is less than the distance between the surface of the second connecting member away from the housing and the cover plate.

[0017] As a preferred solution of the top cover assembly provided by the present utility model, the pole column includes a pole column body and a protruding portion protruding from the pole column body. The pole column body is located inside the cover plate and is electrically connected to the pole ear of the battery cell. The outer diameter of the pole column body is greater than the inner diameter of the first through hole. The protruding portion sequentially passes through the first through hole and the second through hole and extends to the outside of the cover plate.

[0018] As a preferred solution of the top cover assembly provided by the present utility model, the cover group assembly further includes an insulating member. The insulating member is provided between the cover plate and the pole column and between the second connecting member and the cover plate.

[0019] As a preferred embodiment of the top cover assembly provided by the present utility model, a receiving groove is formed on one side of the insulating member away from the outer shell. The second connecting member, the first connecting member, the PTC, and a part of the top cover body are all located in the receiving groove. A sealing portion is provided between the outer edges of the second connecting member, the first connecting member, the PTC, and a part of the top cover body and the groove wall of the receiving groove.

[0020] As a preferred embodiment of the top cover assembly provided by the present utility model, a limiting groove is provided at the top of the sealing portion facing the central axis of the first through hole. The edge portion of the top cover body is limited in the limiting groove.

[0021] As a preferred embodiment of the top cover assembly provided by the present utility model, the edge portion of the PTC is inserted into the sealing portion.

[0022] As a preferred embodiment of the top cover assembly provided by the present utility model, the insulating member includes a bearing portion and an intermediate connecting portion connected in sequence. The bearing portion is located outside the cover plate, and the receiving groove is formed thereon. The intermediate connecting portion is located between the hole wall of the first through hole and the protruding portion.

[0023] As a preferred embodiment of the top cover assembly provided by the present utility model, the insulating member further includes an inner extension portion. The inner extension portion is located inside the cover plate and between the pole column body and the cover plate, and the inner extension portion is connected to one end of the intermediate connecting portion away from the bearing portion.

[0024] As a preferred embodiment of the top cover assembly provided by the present utility model, the cross-sectional shape of the inner extension portion is L-shaped to form a receiving groove for receiving the pole column body.

[0025] As a preferred embodiment of the top cover assembly provided by the present utility model, a first protrusion is further provided on the pole column body, and a first clamping groove matching with the first protrusion is provided on the inner extension portion.

[0026] As a preferred embodiment of the top cover assembly provided by the present utility model, the first protrusion is an annular protrusion, and the first clamping groove is an annular clamping groove; or the number of the first protrusions is multiple, and the multiple first protrusions are arranged at intervals along the circumferential direction of the pole column body, and each first protrusion corresponds to a first clamping groove.

[0027] As a preferred embodiment of the top cover assembly provided by the present utility model, a second protrusion is provided on the side of the insulating member facing the second connecting member, and a second clamping groove matching with the second protrusion is provided on the second connecting member.

[0028] As a preferred solution of the top cover assembly provided by the present utility model, the first connecting member and the second connecting member are welded together. A first clearance spot welding position is provided on the PTC, and a second clearance spot welding position is provided on the top cover body. Both the first clearance spot welding position and the second clearance spot welding position are directly opposite to the welding position between the first connecting member and the second connecting member.

[0029] As a preferred solution of the top cover assembly provided by the present utility model, the first connecting member, the PTC and the top cover body are welded together.

[0030] As a preferred solution of the top cover assembly provided by the present utility model, a first positioning portion is provided on the first connecting member, a second positioning portion is provided on the PTC, and a third positioning portion is provided on the top cover body. The first positioning portion, the second positioning portion and the third positioning portion are arranged opposite to each other.

[0031] The present utility model also provides a battery, which includes a housing, an electric core and the top cover assembly as described above. The housing is a shell-like structure with one end open. The electric core is arranged inside the housing. The top cover assembly seals the opening of the housing, and the pole column of the top cover assembly is electrically connected to the pole ear of the electric core.

[0032] The beneficial effects of the present utility model are as follows:

[0033] The present utility model provides a top cover assembly, which includes a cover group assembly and a top cover component. The cover group assembly includes a cover plate and a pole column. The cover plate is connected to the opening of the housing. A first through hole is provided on the cover plate. One end of the pole column is located inside the cover plate and is electrically connected to the pole ear of the electric core. The other end of the pole column extends out of the cover plate through the first through hole to the outside of the cover plate. The top cover component includes a first connecting member, a PTC and a top cover body which are sequentially connected in a direction away from the housing. The first connecting member is located above the cover plate and is electrically connected to the pole column. By adopting this setting method, the top cover assembly can be connected to the opening of the housing in a fully sealed structure manner to ensure that the battery has good sealing performance. By integrating the PTC, an overcurrent protection function can be achieved during the assembly process of the top cover assembly, thereby ensuring the safety and reliability of its assembly process.

[0034] The present utility model also provides a battery. By applying the above-mentioned top cover assembly, while ensuring the sealing performance of the battery, it has a good overcurrent protection function to ensure the safety of the top cover assembly during the assembly process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is the first assembly schematic diagram of the top cover and the housing provided by the prior art;

[0036] Figure 2 is the second assembly schematic diagram of the top cover and the housing provided by the prior art;

[0037] Figure 3 is a schematic cross-sectional structure diagram of the battery provided by an embodiment of the present utility model;

[0038] Figure 4 is a schematic cross-sectional structure diagram of the top cover assembly provided by an embodiment of the present utility model;

[0039] Figure 5 is a schematic cross-sectional structure diagram of the top cover component provided by an embodiment of the present utility model;

[0040] Figure 6 is a schematic top view structure diagram of the top cover body provided by an embodiment of the present utility model;

[0041] Figure 7 is a schematic cross-sectional structure diagram of the top cover body provided by an embodiment of the present utility model;

[0042] Figure 8 is a schematic top view structure diagram of the top cover component provided by an embodiment of the present utility model;

[0043] Figure 9 is a schematic top view structure diagram of the PTC provided by an embodiment of the present utility model;

[0044] Figure 10 is a schematic cross-sectional structure diagram of the PTC provided by an embodiment of the present utility model;

[0045] Figure 11 is a schematic top view structure diagram of the first connecting member provided by an embodiment of the present utility model;

[0046] Figure 12 is a schematic cross-sectional structure diagram of the first connecting member provided by an embodiment of the present utility model;

[0047] Figure 13 is a schematic cross-sectional structure diagram of the cover group component provided by an embodiment of the present utility model;

[0048] Figure 14 is a schematic structure diagram of each component before assembling the cover group component provided by an embodiment of the present utility model.

[0049] In the figure:

[0050] 10', outer shell; 101', installation groove; 20', top cover component; 201', top cover body; 202', bottom cover; 203', PTC; 30', battery cell;

[0051] 10'', outer shell; 20'', top cover component; 201'', cover body; 2011'', first through hole; 202'', pole; 203'', insulating member; 204'', seal; 30'', battery cell;

[0052] 100. Top cover assembly

[0053] 110. Cover group assembly; 111. Cover plate; 1111. First through hole; 112. Terminal post; 1121. Terminal post body; 11211. First protrusion; 1122. Protruding part; 113. Second connecting piece; 1131. Second through hole; 1132. Clamping part; 1133. Second card slot; 114. Insulating part; 1141. Accommodating groove; 1142. Second protrusion; 11401. Bearing part; 11402. Intermediate connecting part; 11403. Inner extension part

[0054] 120. Top cover assembly; 121. First connecting piece; 1211. First positioning part; 1212. First through hole; 122. PTC; 1221. Second positioning part; 1222. First clearance spot welding position; 1223. Second through hole; 123. Top cover body; 1231. Depressed part; 1232. Third positioning part; 1233. Second clearance spot welding position

[0055] 130. Sealing part; 131. Limit groove

[0056] 200. Outer shell

[0057] 300. Battery cell Detailed implementation mode

[0058] The present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. In addition, it should be noted that for the convenience of description, only parts related to the present utility model rather than all structures are shown in the drawings

[0059] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations

[0060] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may also include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0061] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "left" and "right" are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for differentiation in description and have no special meaning.

[0062] Figure 3 The structural schematic diagram of the battery provided in this embodiment is shown. As Figure 3 shown, this embodiment provides a battery, which includes a housing 200, a battery cell 300 and a top cover assembly 100. Among them, the housing 200 is a shell-like structure with an open end, the battery cell 300 is arranged inside the housing 200, and the top cover assembly 100 seals the opening of the housing 200 to ensure the sealing of the battery. In this embodiment, the battery is a cylindrical battery, the housing 200 is a cylindrical cavity structure with an open end, and the battery cell 300 is placed into the inner cavity of the housing 200 from the opening of the housing 200.

[0063] In this embodiment, the battery cell 300 is a wound battery cell, which has the advantages of compact structure, strong charge and discharge capacity and high reliability.

[0064] It should be noted that the specific structure of the housing 200 in this embodiment is not limited, and all the housings in the prior art that can be used for cylindrical batteries are within the protection scope of this embodiment.

[0065] In order to ensure the sealing of the battery and the safety during the assembly process, this embodiment also provides a top cover assembly 100. The specific structure of the top cover assembly 100 will be introduced below with reference to the drawings.

[0066] Figure 4 The structural schematic diagram of the top cover assembly 100 provided in this embodiment is shown. As Figure 4 and in combination with Figure 3As shown in the figure, the top cover assembly 100 provided in this embodiment includes a cover group assembly 110 and a top cover assembly 120. The cover group assembly 110 includes a cover plate 111 and a terminal post 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 terminal post 112 is located inside the cover plate 111 and is electrically connected to the tab of the battery cell 300. The other end of the terminal post 112 extends out of the cover plate 111 through the first through hole 1111 to the outside of the cover plate 111. The top cover assembly 120 includes 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 terminal post 112. With this setting method, 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 achieved during the assembly process of the top cover assembly 100, thereby ensuring the safety and reliability of its assembly process. It should be particularly noted that the PTC 122 refers to a positive temperature coefficient thermistor (Positive Temperature Coefficient Thermistor). By integrating the PTC 122 into the top cover assembly 100, the following functions can be achieved: 1) Overheat protection: When the battery heats up due to overcharging, short circuit, or other abnormal conditions, the resistance value of the PTC 122 will increase rapidly, thereby limiting the current and preventing the internal temperature of the battery from being too high, 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 value to increase, thereby limiting the magnitude of the current and preventing the battery from being damaged due to overcurrent. Therefore, the top cover assembly 100 provided in this embodiment can realize real-time monitoring and protection of the working state of the battery, improving the safety and service life of the battery.

[0067] It should be noted that the outside of the cover plate 111 specifically refers to the side of the cover plate 111 away from the battery cell 300, and the inside of the cover plate 111 specifically refers to the side of the cover plate 111 close to the battery cell 300.

[0068] As Figure 4As shown, the terminal post 112 includes a terminal post body 1121 and a protruding portion 1122 protruding from the terminal post body 1121. The terminal post body 1121 is located inside the cover plate 111 and is electrically connected to the tab of the battery cell 300. The outer diameter of the terminal post body 1121 is greater than the inner diameter of the first through hole 1111, and the protruding portion 1122 extends from the first through hole 1111 to the outside of the cover plate 111. With this arrangement, the terminal post 112 can form a structure similar to a stepped shaft, and the stepped surface formed between the terminal post body 1121 and the protruding portion 1122 can form a snap-fit relationship with the cover plate 111 to prevent the terminal post 112 from disengaging from the first through hole 1111 of the cover plate 111 under the action of a large external force, thereby ensuring the reliability of the battery. In this embodiment, the terminal post 112 is made of aluminum alloy or stainless steel.

[0069] Figure 5 The cross-sectional structural schematic diagram of the top cover assembly 120 provided in this embodiment is shown. Figure 6 The top view structural schematic diagram of the top cover body 123 provided in this embodiment is shown. Figure 7 The cross-sectional structural schematic diagram of the top cover body 123 provided in this embodiment is shown. As Figures 5 - 7 and in combination with Figure 3 、 Figure 4 As shown, a recessed portion 1231 recessed in a direction away from the housing 200 is provided on the top cover body 123. The recessed portion 1231 is disposed opposite to the first through hole 1111. A first through hole 1212 opposite to the first through hole 1111 is provided on the first connecting member 121. A second through hole 1223 opposite to the first through hole 1111 is provided on the PTC 122. One end of the terminal post 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 recessed portion 1231. This design can protect the terminal post 112 to avoid damage to the terminal post 112 due to long-term exposure, and can improve the reliability of battery use.

[0070] Optionally, there is a gap between the hole wall of the second via 1223 on the PTC 122 and the outer wall of the terminal post 112. This design is to enable the PTC 122 to play a better overcurrent protection role. It should be explained that the overcurrent protection principle of the PTC 122 is as follows: Under normal operating conditions, the temperature of the PTC 122 is relatively low, and its resistance value is also relatively small, so the current can flow smoothly; when the current in the circuit exceeds the rated value, the power consumption generated when the current passes through the PTC 122 increases, resulting in a rapid increase in the temperature of the PTC 122. Since the PTC 122 has a positive temperature coefficient characteristic, that is, as the temperature increases, its 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 restricted and reduced, thereby playing the function of overcurrent protection. Therefore, the PTC 122 needs to be connected to the circuit. If the PTC 122 is in direct contact with the terminal post 112, the current on the terminal post 112 will flow directly from the top surface of the PTC 122 to the top cover body 123 without passing through the inside of the PTC 122. At this time, the PTC 122 cannot play the overcurrent protection function.

[0071] In this embodiment, the first connector 121, the PTC 122, and the top cover body 123 are connected by welding, which is convenient for assembly and has a firm connection.

[0072] Figure 8 The top view structural schematic diagram of the top cover assembly 120 provided in this embodiment is shown. Figure 9 The top view structural schematic diagram of the PTC 122 provided in this embodiment is shown. Figure 10 The cross-sectional structural schematic diagram of the PTC 122 provided in this embodiment is shown. Figure 11 The top view structural schematic diagram of the first connector 121 provided in this embodiment is shown. Figure 12 The cross-sectional structural schematic diagram of the first connector 121 provided in this embodiment is shown. As Figures 8 - 12 And in combination with Figure 6 As shown, in order to realize the welding fixation among 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. 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 connector 121, the PTC 122, and the top cover body 123 are stacked in sequence, and it is ensured that the first positioning portion 1211, the second positioning portion 1221, and the third positioning portion 1232 are arranged opposite to each other. Then, the first connector 121, the PTC 122, 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.

[0073] 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. 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.

[0074] 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.

[0075] Figure 13 FIG. 1 shows a schematic cross-sectional structural diagram of the cover assembly 110 provided in this embodiment. Figure 14 FIG. 1 shows a schematic structural diagram of the components of the cover assembly 110 provided in this embodiment before assembly. Figures 13 - 14 As shown, the cover assembly 110 also includes a second connecting member 113, which is located above the cover plate 111, and is provided with a second through-hole 1131 which is opposite to the first through-hole 1111. 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 protruding toward the center thereof, and the snap-fit portion 1132 is snap-fitted into the pole 112, and the first connecting member 121 is connected to the second connecting member 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, a stable electrical connection is achieved between the terminal 112 and the second connector 113; and on the other hand, a good seal is ensured between the second connector 113 and the terminal 112. Optionally, the second connector 113 is made of stainless steel.

[0076] To achieve an insulating connection between the terminal post 112 and the cover plate 111, the cover group assembly 110 further includes an insulating member 114, and the insulating member 114 is provided between the cover plate 111 and the terminal post 112 as well as between the second connecting member 113 and the cover plate 111.

[0077] Optionally, along the axial direction of the terminal post 112, the distance between the surface of the clamping portion 1132 away from the housing 200 and the cover plate 111 is less than the distance between the surface of the second connecting member 113 away from the housing 200 and the cover plate 111. By adopting this setting method, a stepped structure can be formed in the second through hole 1131. The stepped structure squeezes the terminal post 112 in the radial direction of the terminal post 112 and squeezes the insulating member 114 in the axial direction of the terminal post 112, so as to form good insulation and sealing between the terminal post 112 and the cover plate 111.

[0078] To achieve the electrical connection between the first connecting member 121 and the second connecting member 113, as Figure 8 and Figure 10 shown, the first connecting member 121 and the second connecting member 113 are welded. A first clearance spot welding position 1222 is provided on the PTC 122, and a second clearance spot welding position 1233 is provided on the top cover body 123. The first clearance spot welding position 1222 and the second clearance spot welding position 1233 are both opposite to the welding position between the first connecting member 121 and the second connecting member 113. The settings of the first clearance spot welding position 1222 and the second clearance spot welding position 1233 can play a role in avoiding the welding position between the first connecting member 121 and the second connecting member 113 to ensure the stable connection between the first connecting member 121 and the second connecting member 113; the first connecting member 121 serves as an intermediate connecting structure between the cover group assembly 110 and the top cover assembly 120, which can ensure the welding quality and connection stability between the cover group assembly 110 and the top cover assembly 120.

[0079] In this embodiment, the number of the first clearance spot welding positions 1222 is two. The two first clearance spot welding positions 1222 are symmetrically distributed on the PTC 122, and a first clearance spot welding position 1222 is provided between adjacent two second positioning portions 1221. Each first clearance spot welding position 1222 corresponds to a second clearance spot welding position 1233. That is to say, there are two welding connection positions between the first connecting member 121 and the second connecting member 113 to ensure the firmness of their connection. Of course, in other embodiments, the number and arrangement manner of the first clearance spot welding position 1222 and the second clearance spot welding position 1233 can also be adjusted according to actual needs, which is not limited herein.

[0080] Continuing as Figure 4As shown, on the side of the insulating member 114 away from the outer shell 200, a receiving groove 1141 is formed. 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. When manufacturing the top cover assembly 100, the cover group assembly 110 and the top cover assembly 120 can be assembled separately first, and then the first through hole 1212 of the first connecting member 121 on the top cover assembly 120 and the second through hole 1223 on the PTC 122 are aligned with the pole post 112 and installed in the receiving groove 1141 of the insulating member 114; then, through the first clearance spot welding position 1222 and the second clearance spot welding position 1233, the first connecting member 121 and the second connecting member 113 are connected by welding; finally, a glue sealing treatment is performed between the receiving groove 1141 and the top cover assembly 120 to form the sealing portion 130. Compared with the semi-sealed structure as shown in Figure 1 As shown, the sealing area of the top cover assembly 100 provided in this embodiment is smaller, and a good sealing effect can be achieved. Moreover, since the PTC 122 is integrated at the same time, the overcurrent protection function during the assembly process of the top cover assembly 100 can be realized, improving the safety of the battery.

[0081] Optionally, a limiting groove 131 is provided at the top of the side of the sealing portion 130 facing the central axis of the first through hole 1111, and the edge portion of the top cover body 123 is limited in the limiting groove 131. The setting of the sealing portion 130 can connect the outer edge of the cover group assembly 110 with the groove wall of the receiving groove 1141, thereby realizing the sealed connection between the cover group assembly 110 and the top cover assembly 120.

[0082] Optionally, the 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.

[0083] Continuing as shown in Figure 4 As shown, 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 above-mentioned 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. This design can achieve a completely insulated connection between the pole post 112 and the cover plate 111, with a good insulating effect and can improve the use safety of the battery.

[0084] Optionally, 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. The inner extension portion 11403 is connected to one end of the intermediate connection portion 11402 away from the bearing portion 11401, so as to achieve an insulating connection between the upper surface of the pole column body 1121 and the cover plate 111, further improving the use safety of the battery. In this embodiment, 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.

[0085] Further, a first protrusion 11211 is provided on the pole column body 1121, and a first card slot matching with the first protrusion 11211 is provided on the inner extension portion 11403. Through the snap-fit of the first protrusion 11211 and the first card slot, the stable connection between the insulating member 114 and the pole column 112 can be further improved. Optionally, in this embodiment, the first protrusion 11211 is an annular protrusion, and the first card slot is an annular card slot, which is convenient for processing and assembly. Of course, in other embodiments, 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 pole column body 1121, and each first protrusion 11211 corresponds to a first card slot. This design can also achieve the above effects. In this example, when the first protrusion 11211 is inserted into the first card slot, the relative position between the pole column 112 and the insulating member 114 is fixed and not prone to relative rotation.

[0086] Optionally, a second protrusion 1142 is provided on the side of the insulating member 114 facing the second connecting member 113, and a second card slot 1133 matching with the second protrusion 1142 is provided on the second connecting member 113. Through the snap-fit of the second protrusion 1142 and the second card slot 1133, the stable connection between the insulating member 114 and the second connecting member 113 can be further improved. Optionally, in this embodiment, the second protrusion 1142 is an annular protrusion, and the second card slot 1133 is an annular card slot, which is convenient for processing and assembly. Of course, in other embodiments, the number of the second protrusions 1142 is multiple, and the multiple second protrusions 1142 are arranged at intervals along the circumferential direction of the insulating member 114, and each second protrusion 1142 corresponds to a second card slot 1133. This design can also achieve the above effects. In this example, when the second protrusion 1142 and the second card slot 1133 are inserted into each other, the relative position between the insulating member 114 and the second connecting member 113 is fixed and not prone to relative rotation.

[0087] The following Figures 3 - 14 Briefly describe the assembly process of the battery:

[0088] 1) Assembly of the top cover assembly 120: Stack the first connecting piece 121, the PTC 122, and the 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 to each other. Then, use soldering to connect the first connecting piece 121, the PTC 122, and the top cover body 123 at the first positioning portion 1211, the second positioning portion 1221, and the third positioning portion 1232.

[0089] 2) Assembly of the cover group assembly 110: Form the insulating part 114 on the cover plate 111 by injection molding. Pass the protruding portion 1122 of the pole column 112 through the first through hole 1111 and the second through hole 1131 in sequence. The clamping portion 1132 in the second through hole 1131 presses the protruding portion 1122, and at the same time, the clamping portion 1132 and the protruding portion 1122 press the insulating part 114, so as to form good insulation and sealing between the pole column 112 and the cover plate 111.

[0090] 3) Assembly of the top cover assembly 120 and the cover group assembly 110: Align the first through hole 1212 of the first connecting piece 121 on the top cover assembly 120 and the second through hole 1223 on the PTC 122 with the pole column 112 and install them in the accommodation groove 1141 of the insulating part 114; then, through the first clearance spot welding position 1222 and the second clearance spot welding position 1233, connect the first connecting piece 121 and the second connecting piece 113 by welding; finally, perform glue coating and sealing treatment between the accommodation groove 1141 and the top cover assembly 120 to form the sealing part 130.

[0091] 4) Assembly of the battery: Stack the positive electrode plate, the separator, and the negative electrode plate in sequence and wind them into a cylindrical core structure; connect the negative end of the core structure to the negative insulating sheet, then place the core structure into the cavity of the outer shell 200, and then connect the negative electrode tab to the bottom of the outer shell 200 by resistance welding; connect the positive end of the core structure to the positive insulating sheet, then connect the positive electrode tab to the pole column 112 of the top cover assembly 100 by laser welding, and then inject electrolyte into the outer shell 200; connect the cover plate 111 of the top cover assembly 100 to the opening of the outer shell 200 by laser welding.

[0092] It should be noted that the first connecting piece 121 is made of nickel-plated metal material, and the current outflow path is: tab - pole column 112 - second connecting piece 113 - first connecting piece 121 - PTC 122 - top cover body 123.

[0093] The above embodiments only illustrate the basic principles and characteristics of the present utility model. The present utility model is not limited by the above embodiments. Without departing from the spirit and scope of the present utility model, there are various changes and modifications to the present utility model, and these changes and modifications all fall within the scope of the present utility model claimed. The scope of protection claimed for the present utility model is defined by the appended claims and their equivalents.

Claims

1. A top cover assembly, which seals an opening of a battery housing (200), and an electric core (300) is disposed in the housing (200), characterized in that, The top cover assembly includes: A cover group assembly (110), including a cover plate (111) and a terminal post (112). The cover plate (111) is connected to the opening of the outer shell (200). A first through hole (1111) is formed on the cover plate (111). One end of the terminal post (112) is located inside the cover plate (111) and is electrically connected to the tab of the battery cell (300). The other end of the terminal post (112) extends out of the cover plate (111) from 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 terminal post (112).

2. The top cover assembly according to claim 1, characterized in that, A recessed portion (1231) that is recessed in a direction away from the outer shell (200) is provided on the top cover body (123). The recessed portion (1231) is disposed opposite to the first through hole (1111). A first through hole (1212) that is opposite to the first through hole (1111) is provided on the first connecting member (121). A second through hole (1223) that is opposite to the first through hole (1111) is provided on the PTC (122). The end of the terminal post (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 recessed portion (1231).

3. The top cover assembly according to claim 2, characterized in that, There is a gap between the inner wall of the second through hole (1223) on the PTC (122) and the outer wall of the terminal post (112).

4. The top cover assembly according to claim 1, characterized in that, 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 opposite to the first through hole (1111) is provided on the second connecting member (113). The end of the terminal post (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, characterized in that, 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 terminal post (112). The first connecting member (121) is connected to the second connecting member (113).

6. The top cover assembly according to claim 5, characterized in that, Along the axial direction of the terminal post (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, characterized in that, 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 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 claim 7, characterized in that, The cover group assembly (110) further includes an insulating member (114). 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, characterized in that, A receiving groove (1141) is formed on a side of the insulating member (114) away from the outer shell (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, characterized in that, 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, wherein, An edge portion of the PTC (122) is inserted into the sealing portion (130).

12. The top cover assembly according to claim 9, characterized in that, 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, characterized in that, The insulating member (114) further includes an inner extension portion (11403). The inner extension portion (11403) is located inside the cover plate (111) and is between the pole column body (1121) and the cover plate (111). The inner extension portion (11403) is connected to an end of the intermediate connecting portion (11402) away from the bearing portion (11401).

14. The top cover assembly according to claim 13, characterized in that, 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 cooperating with the first protrusion (11211) is provided on the inner extension portion (11403).

16. The top cover assembly according to claim 15, characterized in that, The first protrusion (11211) is an annular protrusion, and the first card slot is an annular card slot; 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 pole column body (1121), and each first protrusion (11211) corresponds to one first card slot.

17. The top cover assembly according to claim 8, characterized in that, A second protrusion (1142) is arranged on one side of the insulating part (114) facing the second connecting part (113), and a second card slot (1133) matching with the second protrusion (1142) is arranged on the second connecting part (113).

18. The top cover assembly according to claim 4, characterized in that, 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, characterized in that, 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 directly opposite to each other.

21. A battery, characterized in that, It includes a housing (200), a battery cell (300) and a top cover assembly as described in any one of claims 1 to 20. The housing (200) is a shell-like structure with one end open. The battery cell (300) is arranged inside the housing (200). The top cover assembly seals the opening of the housing (200), and the pole column (112) of the top cover assembly is electrically connected to the pole ear of the battery cell (300).

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