Top cover assembly and battery

Abstract

The utility model provides a top cover assembly and a battery. The top cover assembly comprises a cover plate, lower plastic, a pole and a tab welding piece, a pole mounting hole is formed in the cover plate; the lower plastic is arranged on one side of the cover plate; the pole is arranged in the pole mounting hole in a penetrating manner, and at least part of the pole is exposed on one side, deviating from the cover plate, of the lower plastic; the tab welding piece is mounted on one side, deviating from the cover plate, of the lower plastic, and the tab welding piece is electrically connected with the pole; wherein the tab welding piece is at least provided with two welding parts used for being welded with the same tab. According to the utility model, the welding difficulty when the number of stacked layers of the tabs is large can be reduced, so that the electric connection performance of the battery can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a battery technical field, concretely relates to a top cover subassembly and battery. BACKGROUND

[0002] With the rapid development of battery technology, consumers' requirements for the fast charging performance of batteries are higher and higher. At present, in order to improve the fast charging performance of batteries, most manufacturers usually increase the number of battery tabs. Because a larger number of tabs can reduce the impedance of the battery and improve the large-rate charging and discharging performance of the battery, it can support higher-rate discharging.

[0003] However, due to the increase in the number of battery tabs, the number of tab stacking layers also increases. A larger number of stacking layers greatly increases the welding difficulty of the tabs, which often leads to a variety of problems such as virtual welding, poor current-carrying capacity, and difficult control of welding heat during tab welding, thereby affecting the electrical connection performance inside the battery. SUMMARY

[0004] The utility model provides a top cover subassembly and battery can reduce the welding difficulty when the number of tab stacking layers is larger, thereby improving the electrical connection performance of the battery.

[0005] To achieve the above object and other related objects, the utility model provides a top cover subassembly, which comprises a cover plate, a lower plastic, a pole and a tab welding piece. The cover plate is provided with a pole mounting hole. The lower plastic is arranged on one side of the cover plate. The pole is fitted into the pole mounting hole and at least partially exposed on the side of the lower plastic away from the cover plate. The tab welding piece is installed on the side of the lower plastic away from the cover plate, and the tab welding piece is electrically connected with the pole. The tab welding piece has at least two welding parts for welding with the same tab.

[0006] In one example of the utility model top cover subassembly, the tab welding piece further comprises a body part, both welding parts are connected to the body part, the pole is electrically connected with the body part, and both welding parts extend obliquely along the length direction of the cover plate.

[0007] In one example of the utility model top cover subassembly, the welding part comprises a welding surface, the welding surface faces outward in the width direction of the lower plastic, and abuts against and welds with the tab.

[0008] In one example of the utility model top cover subassembly, the pole comprises a first electrical connection part and a second electrical connection part. One of the first electrical connection part and the second electrical connection part is arranged on the side of the cover plate away from the lower plastic to conduct with an external electrical connection piece, and the other is fitted into the pole mounting hole and electrically connected with the tab welding piece through the thickness of the lower plastic.

[0009] In the utility model top cover assembly one example, the lower plastic and the tab welding piece between setting has the positioning portion, the tab welding piece is positioned and is connected with the lower plastic through the positioning portion.

[0010] In the utility model top cover assembly one example, the positioning portion includes the first protruding portion setting in the lower plastic, and the first protruding portion at least with one of two welding portions is in abutment.

[0011] In the utility model top cover assembly one example, the first protruding portion is integrally connected with the lower plastic, and the tab welding piece is detachably connected with the first protruding portion.

[0012] In the utility model top cover assembly one example, the lower plastic includes two first protruding portions, and the two first protruding portions correspond to two welding portions respectively, and the two first protruding portions form an opening at one end away from the pole, and the lower plastic further includes a second protruding portion, and at least a partial region of the second protruding portion blocks the opening.

[0013] In the utility model top cover assembly one example, the second protruding portion is provided with an explosion-proof valve exhaust hole.

[0014] In the utility model top cover assembly one example, the cover plate is provided with a first pole mounting hole and a second pole mounting hole along the length direction of the cover plate respectively, and the top cover assembly further includes a first pole and a second pole, the first pole is installed in the first pole mounting hole, the second pole is installed in the second pole mounting hole, and the first pole and / or the second pole is electrically connected with the tab welding piece.

[0015] The utility model further provides a kind of battery, and the battery includes the top cover assembly of any one of the above.

[0016] The top cover assembly of the utility model, by setting the tab welding piece electrically connected with the pole, and making the tab welding piece at least have two welding portions for welding with the tab of electrode assembly, such setting, can make a part of tab stack layer and one welding portion weld, another part of tab stack layer and another welding portion weld, and then can play the role of tab dispersion welding, reduce the number of tab stack layer welded on each welding portion, reduce the welding problems such as poor welding, overcurrent capacity, welding heat difficult to control in tab welding process, so as to improve the welding difficulty when the number of tab stack layer is more, improve the electrical connection performance inside battery. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and other embodiments can be obtained according to these drawings without creative labor for those skilled in the art.

[0018] Figure 1 It is the whole structure schematic view of one embodiment of the utility model top cover assembly;

[0019] Figure 2 It is the structure schematic view of the tab welding piece and the tab welding in one embodiment of the utility model top cover assembly;

[0020] Figure 3 It is the part explosion schematic view of one embodiment of the utility model top cover assembly;

[0021] Figure 4 It is the whole structure schematic view of one embodiment of the utility model battery.

[0022] Element number explanation

[0023] 100, top cover assembly;110, cover plate;111, pole mounting hole;1111, first pole mounting hole;1112, second pole mounting hole;120, lower plastic;121, first protruding part;1211, mounting screw hole;122, second protruding part;1221, explosion-proof valve exhaust hole;123, third through hole;124, open mouth;130, pole;131, first electric connection part;1311, first through hole;132, second electric connection part;133, first pole;134, second pole;140, tab welding piece;141, welding part;1411, welding surface;1412, mounting through hole;142, body part;1421, opening;150, positioning part;160, upper plastic;161, second through hole;170, connecting gasket;180, sealing washer;190, explosion-proof valve structure;191, explosion-proof valve piece;192, explosion-proof valve piece mounting hole;20, tab;30, welding mark;200, battery;210, shell;211, opening. DETAILED DESCRIPTION

[0024] The embodiments of the present application will be described in detail with specific examples. Those skilled in the art can easily understand other advantages and functions of the present application from the content disclosed in the specification. The present application can also be implemented or applied by different specific embodiments, and each detail in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present application are for describing specific specific embodiments, not for limiting the protection scope of the present application. The test methods not specified in the following embodiments are usually performed under conventional conditions or under the conditions recommended by the manufacturers.

[0025] When the embodiments give a numerical range, it should be understood that, unless the utility model otherwise specifies, both ends of each numerical range and any numerical value between the two ends can be selected. Unless otherwise defined, all technical and scientific terms used in the utility model are used in the same meaning as those of the prior art and the description of the utility model, and any method, equipment and material of the prior art similar or equivalent to the method, equipment and material described in the embodiments of the utility model can be used to realize the utility model.

[0026] It should be understood that the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in the specification are only for the convenience of clear description, and are not used to limit the scope of the utility model, and the change or adjustment of the relative relationship is also regarded as the scope of the utility model without substantial change of the technical content.

[0027] Please refer to Figures 1 to 4 The utility model provides a kind of top cover assembly 100 and battery 200, top cover assembly 100 can realize the dispersion welding between multiple layers of tab 20 by setting tab welding piece 140 on lower plastic 120, reduce the welding difficulty when the number of tab stack is more, improve the electrical connection performance inside battery 200.

[0028] Please refer to Figure 1 And Figure 3 The utility model provides a kind of top cover assembly 100, top cover assembly 100 is adapted to square cell battery 200, and top cover assembly 100 is used to be fixedly connected with the shell 210 of square cell battery 200.The top cover assembly 100 includes cover plate 110, lower plastic 120, pole 130 and tab welding piece 140.The shape of cover plate 110 is substantially cuboid structure, to adapt the opening 211 of the shell 210 of square cell battery 200.The material of cover plate 110 is light aluminum plate, stainless steel and a variety of materials satisfying use requirement.Cover plate 110 is provided with pole mounting hole 111, and the setting number of pole mounting hole 111 is not limited, can be one, also can be multiple, and the setting number of pole 130 is determined.Lower plastic 120 is arranged on the one side of the thickness direction of cover plate 110, and is fixedly connected with cover plate 110.Fixed connection mode can be bolt fixed connection, adhesive connection or pole 130 rivet connection and a variety of ways.Lower plastic 120 is substantially cuboid structure, and the shape and size of cover plate 110 are adapted.

[0029] The pole column 130 is sleeved in the pole column mounting hole 111, one end of the pole column 130 extends to the side of the cover plate 110 away from the lower plastic 120, i.e. the outside of the shell 210, through the pole column mounting hole 111, for connecting with external bus bars and other parts; the other end of the pole column 130 penetrates the thickness of the lower plastic 120 and is at least partially exposed to the side of the lower plastic 120 away from the cover plate 110. Under the condition of meeting the installation requirements and flow guiding requirements of the pole column 130, the specific structure and shape of the pole column 130 are not limited, for example, the pole column 130 can be a one-piece structure, or a split assembly structure, etc.

[0030] Please refer to Figure 1 and Figure 3 The tab welding piece 140 is arranged on the side of the lower plastic 120 away from the cover plate 110 and is fixedly connected with the lower plastic 120. The fixed connection mode can be various, for example, bolted connection, adhesive connection, etc. The tab welding piece 140 is electrically connected with the part of the pole column 130 exposed on the surface of the lower plastic 120. Among them, the tab welding piece 140 has at least two welding parts 141 for welding with the same tab 20. The two welding parts 141 can be arranged in the same structure or in different structures, and the embodiment does not make specific limitation on this. It should be noted that the same tab 20 refers to the same polarity of the tab 20, for example, they can all be positive tabs or all be negative tabs. The positions of the two welding parts 141 arranged on the lower plastic 120 are not limited, for example, they can extend to both sides along the length direction of the lower plastic 120, or extend to both sides along the width direction of the cover plate 110, etc. When welding the welding part 141 and the tab, the side surface of the welding part 141 can be in abutment with the tab for welding, or the top surface of the welding part 141 (i.e. the surface on the side of the lower plastic 120 away from the lower plastic 120 in the thickness direction of the lower plastic 120) can be in abutment with the tab for welding, and the specific welding process shall meet the requirements of the tab 20 welding process.

[0031] The top cover assembly 100 in the embodiment can make a part of the tab stack layer welded with one of the welding parts 141 and another part of the tab stack layer welded with the other welding part 141 by arranging the tab welding piece 140 and making the tab welding piece 140 have at least two welding parts 141 for welding with the tabs 20 of the electrode assembly 220, so as to play a role in dispersing the welding of the tabs 20, reduce the number of tab stack layers welded on each welding part 141, and reduce the welding problems such as virtual welding, poor current-carrying capacity and difficult welding heat control in the welding process of the tabs 20, so as to reduce the welding difficulty when the number of tab stack layers is large and improve the electrical connection performance inside the battery 200.

[0032] Please refer to Figure 2 and Figure 3In the top cover assembly 100 example of the utility model, the tab welding piece 140 further comprises a body part 142, and the two welding parts 141 are connected to the body part 142. The welding part 141 and the body part 142 can be an integrally formed piece, or can be separately formed and then welded, etc. Preferably, in the embodiment, the welding part 141 and the body part 142 are an integrally formed piece, which facilitates the manufacturing of the tab welding piece 140. The body part is provided with an opening 1421, the pole 130 is sleeved in the opening 1421, and the body part 142 forms an abutting and pressing relationship, thereby realizing the electrical connection between the body part 142 and the pole 130. The two welding parts 141 are arranged at an angle along the outer periphery of the body part 142, and the two welding parts 141 extend obliquely along the length direction of the lower plastic 120. The two welding parts 141 can extend towards the same side of the length direction of the lower plastic 120, or can extend towards both sides of the length direction of the lower plastic 120. Alternatively, in the embodiment, the two welding parts 141 extend towards the same side of the length direction of the lower plastic 120, thereby forming a nearly triangular structure. Such an arrangement can reduce the length space occupied by the lower plastic 120.

[0033] By making the welding part 141 extend obliquely along the length direction of the lower plastic 120, the welding part 141 can obtain a longer extension area in the limited installation space, thereby increasing the weldable area between the welding part 141 and the tab 20, which is more conducive to the dispersed arrangement of the tab 20 on the welding part 141, and can further improve the welding quality of the tab 20. At the same time, due to the increase of the weldable area of the welding part 141, the overlapping area between the tab 20 and the welding part 141 in the length direction of the lower plastic 120 is further increased, which is conducive to reducing the alignment difficulty of the tab 20 during winding of the pole piece, thereby reducing the winding difficulty of the battery 200.

[0034] Although the side surface and the top surface of the welding part 141 can be welded with the tab 20, preferably, in the top cover assembly 100 example of the utility model, please refer to Figures 2 to 3The welding portion 141 comprises a welding surface 1411 which faces the outer side of the lower plastic 120 in the width direction, and the welding surfaces 1411 on the two welding portions 141 are oppositely arranged, i.e. respectively face the two sides of the lower plastic 120 in the width direction. One of the welding surfaces 1411 abuts and welds with a part of the tab 20 to form a welding point 30, and the other welding surface 1411 abuts and welds with another part of the tab 20 to form a welding point 30. It should be noted that the number of stacked layers of the tabs welded on the two welding surfaces 1411 can be the same or different. Preferably, in the embodiment, the number of stacked layers of the tabs on the two welding surfaces 1411 is substantially the same, which can facilitate the adjustment of process parameters during welding, thereby improving the welding efficiency. In the embodiment, by arranging the welding surface 1411 to face the outer side of the lower plastic 120 in the width direction, the tab 20 does not need to be folded in the height direction to directly weld with the welding surface 1411, thereby saving the height space of the shell 210, thereby facilitating the improvement of the energy density of the battery 200.

[0035] In an example of the top cover assembly 100 of the utility model, please refer to Figure 1 and Figure 3 The pole 130 comprises a first electric connection portion 131 and a second electric connection portion 132, the first electric connection portion 131 is arranged on the side of the cover plate 110 away from the lower plastic 120 to conduct with external electric connection members, such as external bus bars, etc. The first electric connection portion 131 can be a columnar structure, a cuboid structure, a polyhedral structure, etc. Optionally, in the embodiment, the first electric connection portion 131 is a cuboid structure which is approximately flat. The center of the first electric connection portion 131 is provided with a first through hole 1311. In order to increase the conduction resistance between the shell 210 and the pole 130, the upper plastic 160 is usually arranged between the pole 130 and the cover plate 110, i.e. the pole 130 indirectly abuts with the cover plate 110 through the upper plastic 160. In this way, when the battery 200 short-circuits, the resistance is increased, the loop current is reduced, and the use safety of the battery 200 is improved.

[0036] The upper plastic 160 is provided with a second through hole 161 corresponding to the first through hole 1311. The lower plastic 120 is provided with a third through hole 123 corresponding to the second through hole 161, that is, the first through hole 1311. The second electric connection part 132 is in a rivet structure and sequentially passes through the opening 1421, the third through hole 123, the pole post mounting hole 111, the second through hole 161 and the first through hole 1311 from one side of the lower plastic 120 and is riveted with the first electric connection part 131 outside the cover plate 110 to realize the fixed connection between the first electric connection part 131 and the second electric connection part 132 and realize the electrical connection between the first electric connection part 131 and the tab welding piece 140. Generally, in order to improve the sealing performance between the pole post 130 and the lower plastic 120, a connecting gasket 170 and a sealing ring 180 are arranged between the main body and the lower plastic 120. It should be noted that in other embodiments, the second electric connection part 132 can be arranged on the side of the cover plate 110 away from the lower plastic 120 to conduct with the external electric connection part, and the first electric connection part 131 is in a rivet structure and sequentially passes through the tab welding piece 140, the lower plastic 120, the cover plate 110, the upper plastic 160 and the second electric connection part 132. In the embodiment, the pole post 130 is arranged as the first electric connection part 131 and the second electric connection part 132, so that the electrical connection between the pole post 130 and the tab welding piece 140 can be realized, and the connection between the pole post 130, the cover plate 110, the lower plastic 120 and the upper plastic 160 can also be realized, so that other connection structures do not need to be additionally arranged, the structure of the top cover assembly 100 is simpler, the number of parts is smaller and the manufacturing cost is lower.

[0037] In order to improve the installation and positioning precision between the tab welding piece 140 and the lower plastic 120, optionally, in an example of the top cover assembly 100 of the utility model, please refer to Figure 2 and Figure 3The positioning portion 150 is arranged between the lower plastic 120 and the tab welding piece 140, and the tab welding piece 140 is fixedly connected with the lower plastic 120 through the positioning portion 150. The positioning portion 150 can be a long strip structure arranged on the lower plastic 120, and the long strip structure is at least partially abutted with the tab welding piece 140 to realize the installation and positioning of the tab welding piece 140 relative to the lower plastic 120. The positioning portion 150 can also be partially arranged on the lower plastic 120 and partially arranged on the tab welding piece 140, for example, the positioning portion 150 includes a groove and a protrusion, the groove is arranged on one of the lower plastic 120 and the tab welding piece 140, the protrusion is arranged on the other one, and the groove and the protrusion are clamped with each other to realize the positioning of the tab welding piece 140 on the lower plastic 120. In actual production design, the specific arrangement position and arrangement structure of the positioning portion 150 need to be determined in combination with the production process. The positioning portion 150 can be arranged between the two welding portions 141 and the lower plastic 120, or can be arranged only between one of the welding portions 141 and the lower plastic 120. By arranging the positioning portion 150 between the lower plastic 120 and the tab welding piece 140, the installation and positioning accuracy of the tab welding piece 140 on the lower plastic 120 can be improved, which is beneficial to ensuring the consistency of the battery 200 assembly quality; and the installation and positioning efficiency of the tab welding piece 140 on the lower plastic 120 can be improved, the auxiliary positioning time before welding is reduced, and the welding efficiency of the tab 20 is improved.

[0038] Optionally, in an example of the top cover assembly 100 of the utility model, referring to Figure 2 and Figure 3 The positioning portion 150 includes a first protruding portion 121, the first protruding portion 121 is arranged on the lower plastic 120 and connected with the side of the lower plastic 120 away from the cover plate 110. Under the premise of meeting the positioning requirements of the first protruding portion 121 on the tab welding piece 140, the first protruding portion 121 can be arranged one, and one first protruding portion 121 is abutted with one of the two welding portions 141. The first protruding portion 121 can also be arranged two, and the two protruding portions are respectively abutted with the two welding portions 141. The structure of the first protruding portion 121 can be various, for example, it can be a plurality of block structures arranged at intervals along the length direction of the welding portion 141, or it can be an integral long strip structure extending along the length direction of the welding portion 141, etc. By arranging the first protruding portion 121 on the lower plastic 120, the tab welding piece 140 only needs to be abutted with the first protruding portion 121 to realize the positioning and installation of the tab welding piece 140 relative to the lower plastic 120. This positioning mode is simple and fast, and is beneficial to improving the positioning speed of the tab welding piece 140 on the lower plastic 120. Further, in the embodiment, referring to Figure 3The first protruding part 121 is a long strip plate structure arranged along the extending direction of the welding part 141, and the length of the long strip plate structure is approximately equal to the length of the welding part 141. In this way, a relatively uniform abutting force can be formed on the back of the welding part 141, and thus the probability of deformation of the welding part 141 during welding of the tab 20 and the welding part 141 can be reduced, thereby facilitating to improve the stability of the welding precision of the tab 20.

[0039] The fixed connection mode between the first protruding part 121 and the lower plastic 120 is various, for example, bolt fixed connection, integrated connection and the like, but preferably, in an example of the utility model top cover assembly 100, please refer to Figure 3 The first protruding part 121 and the lower plastic 120 are integrally connected, that is, the first protruding part 121 and the lower plastic 120 are integrally injection molded parts. The side of the first protruding part 121 towards the tab welding part 140 is provided with a mounting screw hole 1211, and the tab welding part 140 is correspondingly provided with a mounting through hole 1412, and after the mounting bolt passes through the mounting through hole 1412, it is screwed in the mounting screw hole 1211, thereby realizing the detachable connection between the tab welding part 140 and the first protruding part 121. By integrally connecting the first protruding part 121 and the lower plastic 120, the assembly process between the first protruding part 121 and the lower plastic 120 can be saved, and the assembly time can be reduced; the installation and positioning precision of the first protruding part 121 on the lower plastic 120 can be better guaranteed, thereby facilitating to guarantee the installation and positioning precision between the tab welding part 140 and the lower plastic 120.

[0040] In an example of the utility model top cover assembly 100, please refer to Figure 2 and Figure 3The lower plastic 120 includes two first protruding portions 121, and the two first protruding portions 121 correspond to the two welding portions 141 respectively, that is, one first protruding portion 121 corresponds to one welding portion 141. The two first protruding portions 121 gradually approach each other at one end close to the body portion 142, and gradually move away from each other at one end away from the body portion 142, and form an opening 124. The first lower plastic 120 further includes a second protruding portion 122, and at least a part of the second protruding portion 122 blocks the opening 124 formed between the two first protruding portions 121. The protruding height of the second protruding portion 122 and the protruding height of the first protruding portion 121 can be equal or not equal. The specific shape of the second protruding portion 122 is not limited, which can be a long strip structure extending along the width direction of the lower plastic 120, or a rectangular block structure, and the like. The second protruding portion 122 can be separately fixedly connected to the lower plastic 120, or can be integrally formed with the lower plastic 120. Preferably, in the embodiment, in order to facilitate the molding of the second protruding portion 122 and the connection between the second protruding portion 122 and the first protruding portion 121, the second protruding portion 122 is integrally formed with the lower plastic 120.

[0041] In the embodiment, by arranging the second protruding portion 122 and blocking the opening 124 formed between the two first protruding portions 121, the support strength and the support rigidity of the two first protruding portions 121 can be further increased, and the stability of the welding portion 141 when abutting and welding with the tab 20 can be further improved, the probability of the first protruding portion 121 shaking and deforming can be reduced, and thus the welding quality between the tab 20 and the tab welding piece 140 can be further ensured. At the same time, the arrangement of the first protruding portion 121 and the second protruding portion 122 can form a support structure on the lower plastic 120 to increase the overall support strength and rigidity of the lower plastic 120.

[0042] In an example of the top cover assembly 100 of the utility model, please refer to Figure 1 and Figure 3The cover plate 110 is respectively provided with a first pole post mounting hole 1111 and a second pole post mounting hole 1112 along the length direction of the cover plate 110. The positions of the first pole post mounting hole 1111 and the second pole post mounting hole 1112 on the cover plate 110 are not limited, and preferably, in the embodiment, the first pole post mounting hole 1111 and the second pole post mounting hole 1112 are symmetrically arranged at the two ends of the length direction of the cover plate 110, so as to facilitate the positioning and machining of the first pole post mounting hole 1111 and the second pole post mounting hole 1112 on the cover plate 110. The top cover assembly 100 further comprises a first pole post 133 and a second pole post 134, which can be the same or different in structure. The first pole post 133 is correspondingly mounted in the first pole post mounting hole 1111, and the second pole post 134 is correspondingly mounted in the second pole post mounting hole 1112. The cover plate 110 assembly can be provided with a pole lug welding piece 140 which is electrically connected with any one of the first pole post 133 and the second pole post 134. The cover plate 110 assembly can also be provided with two pole lug welding pieces 140 which are respectively electrically connected with the first pole post 133 and the second pole post 134. Preferably, in the embodiment, the cover plate 110 assembly is provided with two pole lug welding pieces 140 which are respectively electrically connected with the first pole post 133 and the second pole post 134. In the embodiment, the first pole post 133 and the second pole post 134 are arranged on one side of the cover plate 110, so that the welding between the different pole posts 130 and the different pole lugs 20 can be completed on the same side of the cover plate 110 at the same time, thereby improving the welding efficiency of the pole lug 20. At the same time, since the pole lug welding piece 140 is arranged in the embodiment, the pole lug welding piece 140 can also play the role of dispersing the welding of the pole lug 20, thereby reducing the welding difficulty when the number of stacked layers of the pole lug is large, and improving the electrical connection performance inside the battery 200.

[0043] In order to ensure the safety of the battery 200, the battery 200 usually has an explosion-proof valve structure 190 on the top cover assembly 100. Please refer to Figure 3In the top cover assembly 100 example, the top cover assembly 100 further comprises an explosion-proof valve structure 190, the explosion-proof valve structure 190 comprises an explosion-proof valve sheet 191, an explosion-proof valve sheet mounting hole 192 arranged on the cover plate 110 and an explosion-proof valve exhaust hole 1221 opened on the lower plastic 120. The explosion-proof valve sheet 191 is sealingly installed in the explosion-proof valve sheet mounting hole 192, and the explosion-proof valve exhaust hole 1221 is opposite to the explosion-proof valve sheet 191. When the internal temperature of the battery 200 rises to the limit, the high-pressure gas will be discharged from the explosion-proof valve sheet mounting hole 192 and will lift the explosion-proof valve sheet 191, so that the explosion-proof valve sheet 191 is separated from the explosion-proof valve exhaust hole 1221, and the normal pressure relief of the battery 200 is realized. The setting position of the explosion-proof valve exhaust hole 1221 on the lower plastic 120 is not limited, but preferably, in the embodiment, the explosion-proof valve exhaust hole 1221 is arranged on the second protruding part 122, that is, along the thickness direction of the lower plastic 120, the explosion-proof valve exhaust hole 1221 penetrates the second protruding part 122. By setting in this way, since the thickness of the second protruding part 122 is relatively thick, the explosion-proof valve exhaust hole 1221 is opened at this position, which can reduce the weakening degree of the opening hole 1421 on the overall strength and rigidity of the lower plastic 120, and is more conducive to ensuring the supporting strength and rigidity of the lower plastic 120.

[0044] The embodiment also provides a battery 200, please refer to Figure 4 The battery 200 comprises the top cover assembly 100, the shell 210 and the electrode assembly (not shown in the figure) arranged in the shell 210 in the above-mentioned embodiments; the top of the shell 210 has an opening 211; the electrode assembly is accommodated in the interior of the shell 210 through the opening 211, and the top cover assembly 100 closes the opening 211. Since the top cover assembly 100 in the embodiment adopts the technical scheme in the above-mentioned embodiment, it at least has the beneficial effects brought by the technical scheme of the above-mentioned embodiment, which will not be repeated here.

[0045] The top cover assembly is provided with the tab welding piece electrically connected with the pole column, and the tab welding piece has at least two welding parts for welding with the tab of the electrode assembly, so that a part of the tab stacking layers is welded with one of the welding parts, and the other part of the tab stacking layers is welded with the other welding part, thereby the function of dispersed welding of the tab can be achieved, the number of the tab stacking layers welded on each welding part is reduced, and the welding problems such as virtual welding, poor current-carrying capacity, difficult control of welding heat and the like in the tab welding process are reduced, so that the welding difficulty when the number of the tab stacking layers is large can be improved, and the electrical connection performance in the battery is improved. Therefore, the utility model effectively overcomes some practical problems in the prior art and has high utilization value and use significance. The above embodiment only exemplarily illustrates the principle and effect of the utility model, and is not used for limiting the utility model. Any person skilled in the art can modify or change the above embodiment without departing from the spirit and scope of the utility model. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical concept disclosed by the utility model should be covered by the claims of the utility model.

Claims

1. A top cover assembly of a battery, characterized by comprising: The application relates to a top cover assembly. The top cover assembly comprises: a cover plate provided with a pole mounting hole; a lower plastic layer arranged on one side of the cover plate; a pole arranged in the pole mounting hole and at least partially exposed on the side of the lower plastic layer away from the cover plate; a tab welding piece arranged on the side of the lower plastic layer away from the cover plate and electrically connected with the pole; 2. The roof assembly of claim 1, wherein, wherein the tab welding piece has at least two welding portions for welding with the same tab.

3. The roof assembly of claim 1, wherein, The tab welding piece further comprises a body portion, the two welding portions are connected to the body portion, the pole is electrically connected with the body portion, and the two welding portions are inclinedly extended along the length direction of the cover plate.

4. The roof assembly of claim 1, wherein, The welding portion comprises a welding surface, the welding surface is directed to the outside of the lower plastic layer in the width direction, and abuts against and welds with the tab.

5. The roof assembly of claim 1, wherein, The pole comprises a first electric connection portion and a second electric connection portion, one of the first electric connection portion and the second electric connection portion is arranged on the side of the cover plate away from the lower plastic layer to be in conductive connection with an external electric connection piece, and the other is arranged in the pole mounting hole and penetrates through the thickness of the lower plastic layer to be in electric connection with the tab welding piece.

6. The roof assembly of claim 5, wherein, A positioning portion is arranged between the lower plastic layer and the tab welding piece, and the tab welding piece is positioned and connected with the lower plastic layer through the positioning portion.

7. The roof assembly of claim 6, wherein, The positioning portion comprises a first protruding portion arranged on the lower plastic layer, and the first protruding portion abuts against one of the two welding portions.

8. The roof assembly of claim 6, wherein, The first protruding portion is integrally connected with the lower plastic layer, and the tab welding piece is detachably connected with the first protruding portion.

9. The roof assembly of claim 8, wherein, The lower plastic layer comprises two first protruding portions corresponding to the two welding portions respectively, and the two first protruding portions are formed with openings at the ends away from the pole; the lower plastic layer further comprises a second protruding portion, and at least a partial region of the second protruding portion blocks the openings.

10. The roof assembly of claim 1, wherein, The second protruding portion is provided with an explosion-proof valve exhaust hole.

11. A battery, characterized by The cover plate is respectively provided with a first pole mounting hole and a second pole mounting hole along the length direction of the cover plate, the top cover assembly further comprises a first pole and a second pole, the first pole is arranged in the first pole mounting hole, the second pole is arranged in the second pole mounting hole, and the first pole and / or the second pole is electrically connected with the tab welding piece. The application further relates to a top cover assembly comprising any one of the top cover assemblies in claims 1 to 10.

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