Top cover structure for secondary battery, top cover assembly and secondary battery

Abstract

To provide a top cover structure of a secondary battery, a top cover assembly, and a secondary battery, which are related to the technical fields of secondary batteries.SOLUTION: A top cover structure includes an insulating plate having a lower penetration hole penetrating vertically, a top cover plate disposed at a top part of the insulating plate and having an upper penetration hole continuing to the lower penetration hole and penetrating vertically, and a conductor fixedly connected to the top cover plate and the insulating plate through the upper penetration hole and the lower penetration hole and having a penetration hole penetrating the conductor. In this application, the penetration hole that penetrates the conductor is provided in the conductor. The conductor can not just electrically connect the secondary battery and the inside of the secondary battery from the outside to the inside but also easily inject or add liquid to the inside of the secondary battery through the penetration hole, so that the production efficiency of the secondary battery can be improved.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present application relates to the technical field of secondary batteries, and in particular to a top cover structure, a top cover assembly, and a secondary battery. [Background technology]

[0002] A secondary battery, also called a rechargeable battery or storage battery, refers to a battery that can be used continuously after being discharged by activating the active material by charging it, and is in high demand in industries such as electric vehicles and power tools, and is an important component in related products, directly affecting the performance of each related product. Generally, a secondary battery includes a case, an electric core, and a top cover, the electric core is disposed in the case and packaged by the top cover, the top cover includes a top cover plate and a pole disposed on the top cover plate, the pole is connected to the tab of the electric core, and when in use, the pole is connected to an external electric device to supply power, or is connected to an external power source to charge.

[0003] Among related technologies, the top cover structure of secondary batteries is usually assembled by traditional riveting and welding structure and injection molding structure, and these structures have disadvantages. Firstly, the structure and process flow are complicated, and the material and manufacturing costs are relatively high. Secondly, the weight of the top cover structure is heavy, which affects the energy density of the secondary battery. Thirdly, the top cover structure occupies too much space inside and outside the secondary battery, which has a great impact on the improvement of the energy density of the secondary battery.

[0004] The pole in the top cover structure of a secondary battery is usually a sealed structure, the tab inside the battery is first connected to an adapter piece, the adapter piece is then further connected to the top cover pole inside to complete the connection between the inside and outside of the secondary battery, and finally the top cover and the case are welded to finally complete the packaging of the secondary battery. Because the pole adopts a sealed structure and the adapter piece needs to be connected to the top cover pole inside, the welding of the top cover structure of the secondary battery is more difficult and the production efficiency is reduced. Summary of the Invention

[0005] (Contents of the invention) The technical problem to be solved by the present application is to provide a top cover structure, a top cover assembly, and a secondary battery for a secondary battery, and to solve the problem that in the related art, the pole adopts a sealed structure and the adapter piece needs to be joined to the top cover internally, which increases the difficulty of welding the top cover structure of the secondary battery and reduces production efficiency.

[0006] In order to solve the above technical problems, the present application provides a top cover structure for a secondary battery, comprising: an insulating plate having a lower through hole that penetrates vertically; a top cover plate that is arranged on the top of the insulating plate and has an upper through hole that communicates with the lower through hole and penetrates vertically; and a conductor that penetrates the upper through hole and the lower through hole, and is fixedly connected to the top cover plate and the insulating plate, and has a through hole that penetrates the conductor.

[0007] Preferably, the secondary battery includes an adapter piece, the adapter piece being provided with a transfer pad, and when the top cover structure is connected to the adapter piece, the transfer pad protrudes into a through hole of a conductor in the top cover structure.

[0008] Preferably, the insulating plate has a top with a pad extending upward, the lower through-hole is located on the pad, the bottom of the pad has a lower sinkhole communicating with the lower through-hole, and the diameter of the lower sinkhole is larger than that of the lower through-hole. The top cover plate has a bottom with an upper sinkhole that accommodates the pad and communicates with the upper through-hole, and the diameter of the upper sinkhole is larger than that of the upper through-hole.

[0009] Preferably, the conductor comprises a lower pole located in the lower sink hole and extending upward through the lower through hole, and an upper pole located at the top of the top cover plate and extending downward through the upper through hole, and the lower pole and the upper pole are joined by welding. The through holes comprise an upper pole through hole penetrating both upper and lower ends of the upper pole, and a lower pole through hole penetrating both upper and lower ends of the lower pole, and the upper pole through hole and the lower pole through hole are in communication with each other.

[0010] Preferably, an upper plastic is provided between the upper pole and the top cover plate to insulate the upper pole from the top cover plate, and the upper plastic is provided with a step hole having a larger diameter at the top and a smaller diameter at the bottom, the step hole communicates with the upper through hole, and the upper pole is located inside the step hole.

[0011] Preferably, an upper bump is provided at a bottom of the upper pole and welded to the lower pole through the step hole and the upper through hole, the cross section of the upper pole is larger than that of the upper bump, and the upper pole and the upper bump are integrally molded. A lower bump is provided at a top of the lower pole and welded to the upper pole through the lower through hole, the cross section of the lower pole is larger than that of the lower bump, and the lower pole and the lower bump are integrally molded.

[0012] Preferably, the device further includes an upper seal ring located inside the upper through hole, and an annular flange is provided on the top of the upper seal ring to seal between the upper pole and the top cover plate, the annular flange and the upper seal ring being integrally molded, and a lower seal ring is provided within the lower through hole, and the lower seal ring seals between the lower pole and the top cover plate.

[0013] Preferably, the lower through hole of the insulating plate corresponds one-to-one with the upper through hole of the top cover plate and communicates with each other to form a first through hole, the conductor has a pole, and the top cover structure further has an upper plastic part and a lower sealing part, the pole, the upper plastic part, and the lower sealing part are arranged in order from top to bottom, wherein the pole and the upper plastic part are arranged above the top cover plate, the upper plastic part is arranged between the pole and the top cover plate, and the lower sealing part is arranged to penetrate the lower through hole of the insulating plate and the upper through hole of the top cover plate. The conductor through hole has a pole through hole, the upper plastic part has an upper plastic through hole, and the lower seal part has a lower seal through hole, and the pole through hole, the upper plastic through hole, and the lower seal through hole are connected to each other to form a second through hole, and a second projection along the vertical direction of the second through hole is located inside a first projection along the vertical direction of the first through hole.

[0014] Preferably, the top cover plate includes an upper sink platform, the upper sink platform is recessed relative to an upper surface of the top cover plate, the upper through hole of the top cover plate is located on the upper sink platform, and the upper plastic part is located on the upper sink platform.

[0015] Preferably, the upper plastic parthas a first bottom wall and a first side wall connected to each other, the upper sink platform has an upper sink platform surface and an upper sink platform wall, the pole has an outer wall and a lower surface, the first bottom wall is sandwiched between the upper sink platform surface and the lower surface, and the first side wall is sandwiched between the upper sink platform wall and the outer wall.

[0016] Preferably, the lower sealing part includes a second bottom and a second protrusion connected to each other, the second protrusion including a first outer wall and a first apex, the pole has a lower surface, the first apex abuts against the lower surface, and the second bottom and the first outer wall both abut against the hole wall of the first through hole.

[0017] Preferably, the first outer wall also abuts against a wall of the upper plastic through hole.

[0018] Preferably, the top cover plate further comprises a lower sink platform, the lower sink platform being recessed relative to the underside of the top cover plate, the lower sink platform having a lower sink platform surface and a lower sink platform wall, the second bottom having a second outer wall and a second apex, the second outer wall abutting the lower sink platform wall and the second apex abutting the lower sink platform surface.

[0019] Preferably, the size of the upper plastic through hole is equal to or larger than the size of the pole through hole.

[0020] Preferably, the size of the upper through hole of the top cover plate is equal to or larger than the size of the upper plastic through hole.

[0021] Preferably, the size of the lower through hole of the insulating plate is equal to or larger than the size of the through hole of the top cover plate.

[0022] Preferably, the central axis of the first through hole and the central axis of the second through hole coincide with each other.

[0023] Preferably, the top cover plate has a first extension surface, and the cross-sectional shapes of the first through hole and the second through hole along the first extension surface are any one of a square, a rectangle, a runway shape, a circle, an ellipse, a pentagon, a hexagon, and an octagon.

[0024] Preferably, the insulating plate is provided with a lower injection hole and a vent hole, and an anti-ejection plate is provided at the bottom of the lower injection hole, the top cover plate is provided with an upper injection hole communicating with the lower injection hole and an anti-explosion valve hole communicating with the vent hole, the bottom of the top cover plate is provided with an explosion-proof plate closing the explosion-proof valve hole, and the top of the top cover plate is provided with an explosion-proof plate protective sheet closing the explosion-proof valve hole.

[0025] Preferably, the insulating plate has a plurality of undercuts arranged on both sides thereof at intervals along the length of the insulating plate, the undercuts being an integral injection molded structure with the insulating plate.

[0026] Another aspect of the present application provides a top cover assembly for a secondary battery comprising: a top cover structure; an adapter piece for connecting a conductor in the top cover structure; and an insulating gasket provided on a bottom of the adapter piece, wherein the adapter piece is provided with a transfer pad that protrudes into a through hole in the conductor, and the transfer part is joined to the conductor by welding.

[0027] Preferably, the secondary battery comprises an electric core, the electric core is provided with a number of tabs on its top, the number of the adapter pieces is two, and the two adapter pieces are provided on the top of the electric core, the number of tabs is welded to the surfaces of the two adapter pieces respectively to form welding areas, and at least one double-sided protective adhesive layer is attached on the top of the two adapter pieces, both sides of the double-sided protective adhesive layer are adhesive surfaces, and when the double-sided protective adhesive layer is attached on the top of the adapter pieces, it covers at least the welding area.

[0028] Another aspect of the present application provides a top cover assembly for a secondary battery, comprising the top cover structure and a deflector, the deflector being positioned below an insulating plate in the top cover structure, a deflector pole being provided on an upper surface of the deflector, the deflector pole comprising a pole main body and a chassis, the pole main body being positioned on the chassis, suitable for penetrating a first through hole and a second through hole in the top cover structure, and abutting against a hole wall of the second through hole.

[0029] Preferably, the chassis abuts against a hole wall of the first through hole of the insulating plate.

[0030] Preferably, the electrical core assembly further comprises an electrical core assembly and a case, the electrical core assembly being disposed within the case and having at least one unitary electrical core, the unitary electrical core having an upwardly projecting tab, the deflector being located above the electrical core assembly, the deflector being provided with a tab assembly part for passing therethrough and bending a corresponding tab therethrough to electrically connect the tab to an upper surface of the deflector for intimate contact therewith and for electrically conductive connection therewith.

[0031] Another aspect of the present application provides a secondary battery comprising the top cover assembly and a case housing a plurality of electric cores, the case having a plurality of electric cores disposed therein, the tabs of the electric cores being welded to an adapter piece via an insulating gasket in the top cover assembly.

[0032] Preferably, the electric core has a plurality of tabs on its top, the number of the adapter pieces is two, and the two adapter pieces are provided on the top of the electric core, and the plurality of tabs are respectively welded to the surfaces of the two adapter pieces to form welding areas, and the secondary battery has at least one double-sided protective adhesive layer, both sides of the double-sided protective adhesive layer are adhesive surfaces, and the double-sided protective adhesive layer is attached above the adapter pieces and covers at least the welding areas.

[0033] Preferably, the double-sided protective adhesive layer comprises two adhesive layers and a carbonate protective layer disposed between the two tacky layers.

[0034] Preferably, the carbonate protection layer is a sodium bicarbonate or sodium carbonate layer structure.

[0035] Preferably, the two adhesive layers are double-sided adhesive layers, and the carbonate protection layer has a powder layer structure spread and adhered between the two viscous layers.

[0036] Preferably, the double-sided protective adhesive layer is a full sheet structure, which simultaneously adheres and covers the welding areas on the two adapter pieces, wherein the adapter pieces are provided with injection holes, and the double-sided protective adhesive layer has first holes corresponding to the transfer pads on the top cover assembly and second holes corresponding to the injection holes.

[0037] Preferably, a plurality of double-sided protective adhesive layers are provided, each of which adheres to and covers one or more of the welding areas on the two adapter sheets.

[0038] Preferably, the shape and size of the first hole corresponds to the periphery of the transfer pad, and the shape and size of the second hole corresponds to the periphery of the injection hole.

[0039] Preferably, the double-sided protective adhesive layer completely covers the adapter sheet, and both ends of the double-sided protective adhesive layer extend beyond both side edges of the gasket and are adhered to the side walls of the electric core.

[0040] Preferably, the present application provides a secondary battery comprising an electric core having a plurality of tabs on its top, two adapter pieces provided on the top of the electric core and having the plurality of tabs welded to their surfaces to form a welding area, and at least one double-sided protective adhesive layer having both adhesive surfaces attached to the top of the adapter pieces and covering at least the welding area.

[0041] The beneficial effects of the technical solution provided by this application include the following aspects:

[0042] The present application provides a top cover structure for a secondary battery, a top cover assembly, and a secondary battery. The top cover structure according to the present application includes an insulating plate having a lower through-hole penetrating vertically, a top cover plate disposed on the top of the insulating plate and having an upper through-hole penetrating vertically and communicating with the lower through-hole, and a conductor penetrating the upper through-hole and the lower through-hole, fixedly connected to the top cover plate and the insulating plate, and having a through-hole penetrating the conductor.

[0043] The adapter piece in the secondary battery top cover assembly of the present application is provided with a transfer pad recessed inside the through hole of the conductor, and a welded connection can be realized between the transfer pad and the conductor by seam welding. In the present application, the conventional through welding between the tab or adapter piece and the top cover pole is changed to seam welding, and the risk of the connection inside the battery being cut off due to the false welding of the through welding is reduced, and at the same time, the seam welding increases the contact area between the adapter piece and the conductor, reduces the internal resistance, increases the overcurrent capacity, and improves the performance of the secondary battery. In addition, the top cover structure of the present application has a lower through hole that penetrates vertically in the insulating plate, an upper through hole that communicates with the lower through hole and penetrates vertically in the top cover plate, the conductor is fixedly connected to the top cover plate and the insulating plate through the upper through hole and the lower through hole, and the conductor has a through hole that penetrates the conductor. The conductor not only enables electrical conduction between the secondary battery and the interior of the secondary battery from the outside to the inside, but also allows electrolyte injection or replenishment to be easily performed through the through holes, thereby improving the production efficiency of the secondary battery. In addition, by injecting electrolyte or replenishment to the secondary battery through the through holes, the cycle performance of the secondary battery can be improved.

[0044] In the secondary battery of the present application, packaging of the secondary battery from the outside to the inside can be completed by first completing the packaging of the top cover assembly and the case, and then seam welding the through hole of the conductor and the transfer pad of the adapter piece, thereby optimizing the assembly structure of the internal tab, raising the height of the tab, and further increasing the energy density and volumetric energy density of the secondary battery.

[0045] In some embodiments described below, a double-sided protective adhesive layer, which is an adhesive layer on both sides, is installed on the adapter piece, so that the double-sided protective adhesive layer is attached to and covers the welding area, and further, the welding slag that may fall on the welding area can be effectively prevented from falling off the welding area and into the inside of the winding core. At the same time, since there is an adhesive layer on the opposite side, foreign matter such as welding slag and dust particles attached to the double-sided protective adhesive layer can be attached in the subsequent processing steps, effectively reducing the possibility of foreign matter entering the winding core, and the double-sided protective adhesive layer covering the welding area also effectively prevents the welding area from contacting the electrolyte after the secondary battery is injected, reducing the speed of its corrosion, and finally realizing the effective protection of the secondary battery by the double-sided protective adhesive layer.

[0046] In some embodiments described in detail below, the top cover assembly of the present application includes fewer parts. The pole assembly includes only three parts, namely, the pole, the upper plastic part, and the lower sealing part, and each part can be manufactured independently, greatly simplifying the top cover structure and reducing the structure and material cost. By adopting the top cover assembly of the present application, there is no need to adopt processes such as riveting, injection molding, and welding when assembling, and the production cost and quality cost of the top cover assembly can be greatly reduced. Since there is no need to adopt processes such as welding, and metal chips generated by welding do not enter the inside of the battery, the risk of short circuit of the secondary battery can be avoided. Since there are fewer parts and the structure is simple, the weight of the top cover assembly can be reduced and the energy density of the secondary battery can be improved. The height of the top cover assembly in the vertical direction Z is relatively low, the occupancy rate of the top cover assembly in the height space inside and outside the secondary battery is reduced, the space utilization rate in the height direction of the secondary battery is greatly improved, and the energy density and volumetric energy density of the secondary battery are greatly improved. [Brief description of the drawings]

[0047] Description of the drawings In order to more clearly explain the technical solutions in the embodiments of the present application, the following will briefly describe the drawings that need to be used in the description of the embodiments. However, the drawings in the following description are only some embodiments of the present application, and it is obvious to those skilled in the art that they can obtain other drawings from these drawings without paying inventive labor. [Figure 1] FIG. 1 is a structural perspective view of a top cover structure according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a structural exploded view of the top cover structure of the embodiment of the present application. [Diagram 3] FIG. 3 is a structural plan view of a top cover structure according to an embodiment of the present invention. [Figure 4] FIG. 4 is a structural top view of the top cover structure according to the embodiment of the present application. [Diagram 5] FIG. 5 is a structural cross-sectional view taken along the direction AA in FIG. [Figure 6] FIG. 6 is a partially enlarged view of A in FIG. [Figure 7] FIG. 7 is a partially enlarged view of B in FIG. [Figure 8] FIG. 8 is a structural plan view of a top cover plate according to an embodiment of the present application. [Figure 9] FIG. 9 is a structural top view of the top cover plate according to the embodiment of the present application. [Figure 10] FIG. 10 is a structural plan view of an insulating plate according to an embodiment of the present invention. [Figure 11] FIG. 11 is a top view of the structure of an insulating plate according to an embodiment of the present invention. [Figure 12] FIG. 12 is a structural cross-sectional view taken along the line BB in FIG. [Figure 13] FIG. 13 is a structural cross-sectional view taken along the CC direction in FIG. [Figure 14] FIG. 14 is a partially enlarged view of C in FIG. [Figure 15] FIG. 15 is a structural plan view of the upper pole of the embodiment of the present application. [Figure 16] FIG. 16 is a cross-sectional view of the structure of an upper pole according to an embodiment of the present invention. [Figure 17] FIG. 17 is a top view of the structure of the upper pole of the embodiment of the present application. [Figure 18] FIG. 18 is a structural plan view of the lower pole of the embodiment of the present application. [Figure 19] FIG. 19 is a cross-sectional view of the structure of the lower pole of the embodiment of the present application. [Figure 20] FIG. 20 is a top view of the structure of the lower pole of an embodiment of the present application. [Figure 21] FIG. 21 is a structural exploded view of a top cover structure according to another embodiment of the present invention. [Figure 22] FIG. 22 is a structural explosion diagram of a secondary battery according to an embodiment of the present invention. [Figure 23A] FIG. 23A is a schematic diagram of an explosion of a secondary battery according to one embodiment of the present application. [Figure 23B] FIG. 23B is a schematic diagram of the structure of the secondary battery shown in FIG. 23A after assembly is completed. [Figure 24] FIG. 24 is a schematic diagram of a top cover structure of a secondary battery according to one embodiment of the present invention. [Diagram 25] FIG. 25 is an explosion schematic diagram of the embodiment shown in FIG. [Figure 26] FIG. 26 is a cross-sectional view taken along line B2-B2' in FIG. [Figure 27] FIG. 27 is an enlarged schematic view of a partial region C of FIG. [Figure 28] FIG. 28 is a top and bottom view of the top cover structure of the secondary battery shown in FIG. [Figure 29] FIG. 29 is an explosion diagram of an assembly structure of a secondary battery according to one embodiment of the present application. [Diagram 30] FIG. 30 is a cross-sectional view of the assembly structure of the embodiment shown in FIG. 29 after assembly. [Diagram 31] FIG. 31 is a schematic diagram of the assembly structure of the embodiment shown in FIG. 30 after the flap is attached. [Diagram 32] FIG. 32 is a cross-sectional view taken along line B1-B1' of B2 in FIG. [Diagram 33] FIG. 33 is a structural schematic diagram of a secondary battery according to an embodiment of the present invention. [Diagram 34] FIG. 34 is a schematic diagram showing the structure of the double-sided protective adhesive layer in the embodiment shown in FIG. [Diagram 35] FIG. 35 is a schematic diagram partially comparing two-sided protective adhesive layers of a secondary battery according to one embodiment of the present application. [Diagram 36] FIG. 36 is a schematic diagram partially comparing two-sided protective adhesive layers of a secondary battery according to one embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] (Specific embodiment) In order to clarify the purpose, technical solutions and advantages of the embodiments of the present application, the technical solutions in the embodiments of the present application are described below clearly and completely with the aid of the accompanying drawings, but it is clear that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive work belong to the scope of protection of the present application.

[0049] The embodiments of the present application provide a top cover structure, a top cover assembly, and a secondary battery, which solve the problems that it is difficult to improve the efficiency of injecting and replacing electrolyte into a secondary battery because the pole adopts a sealed structure, and that it is necessary to internally join an adapter piece to the top cover pole, making it difficult to weld the top cover structure of a secondary battery and reducing production efficiency.

[0050] As shown in FIGS. 1 to 4 and 8 to 12, a first aspect of an embodiment of the present application provides a top cover structure of a secondary battery.

[0051] The top cover structure 1 includes an insulating plate 15 having a lower through hole extending vertically therethrough; The insulating plate 15 is provided with a top cover plate 11 located on top of the insulating plate 15 and having an upper through hole that communicates with the lower through hole and penetrates vertically, and a conductor that penetrates the upper through hole and the lower through hole, is fixedly connected to the top cover plate 11 and the insulating plate 15, and has a through hole that penetrates the conductor.

[0052] Here, the insulating plate 15 may be a rectangular plastic plate, which is located below the top cover plate 11, the lower through-hole of the insulating plate 15 coincides with the position dimensions of the upper through-hole of the top cover plate 11, and the conductor passes through the upper through-hole and the lower through-hole and is fixedly connected to the top cover plate 11 and the insulating plate 15.

[0053] Here, the conductor may be a pole, and the pole may be one piece or may be configured by combining a plurality of structures. The embodiment of the present application does not limit the specific shape and combination method of the conductor. The conductor has a through hole penetrating the conductor, and this through hole not only connects the secondary battery and the inside of the secondary battery from the outside to the inside via the conductor, but also makes it easy to inject or replenish the electrolyte into the secondary battery through the through hole of the conductor, thereby improving the production efficiency of the secondary battery.

[0054] In addition, in the embodiments of the present application, there are no specific limitations on the size, position and shape of the through hole. For example, the through hole may be elliptical, circular, runway-shaped, rectangular, etc., and the size of the through hole can be set according to specific requirements in order to better realize the requirements of liquid injection and liquid replenishment.

[0055] In some embodiments, as shown with reference to Figs. 1 to 4 and 8 to 12, a first aspect of the embodiment of the present application provides a top cover structure for a secondary battery. In the top cover structure 1, the insulating plate 15 is a rectangular plastic plate, and an upwardly extending pad is provided on the top of the insulating plate 15, and a lower through-hole is provided on the top of the pad to allow the lower pole to protrude. A lower sink hole communicating with the lower through-hole is provided on the bottom of the pad, and the hole diameter of the lower sink hole is larger than the hole diameter of the lower through-hole. In the embodiment of the present application, two pads, a first pad 153 and a second pad 154, are provided on both ends of the top of the insulating plate 15, respectively.

[0056] The top of the first pad 153 is provided with a first lower through hole 151 protruding from the first lower pole 17, and the bottom of the first pad 153 is provided with a first lower sink hole 155 communicating with the first lower through hole 151, and the hole diameter of the first lower sink hole 155 is larger than the hole diameter of the first lower through hole 151. The top of the second pad 154 is provided with a second lower through hole 152 protruding from the second lower pole 22, and the bottom of the second pad 154 is provided with a second lower sink hole 156 communicating with the second lower through hole 152, and the hole diameter of the second lower sink hole 156 is larger than the hole diameter of the second lower through hole 152. The first lower through hole 151 and the second lower through hole 152 are preferably long waist holes, but are not limited thereto. The first lower sink hole 155 and the second lower sink hole 156 are preferably rectangular holes, but are not limited thereto.

[0057] The top cover plate 11 is a rectangular metal plate, and the top cover plate 11 is located on the top of the insulating plate 15 and is in close contact with the insulating plate 15. The bottom of the top cover plate 11 is provided with an upper sink hole that accommodates a pad and communicates with the upper through hole, and the hole diameter of the upper sink hole is larger than the hole diameter of the upper through hole. In the embodiment of the present application, two upper through holes are disposed at both ends of the top of the top cover plate 11, and the two upper through holes are respectively a first upper through hole 112 and a second upper through hole 113. The first upper through hole 112 and the first lower through hole 151 have the same shape and size and communicate with each other, and the second upper through hole 113 and the second lower through hole 152 have the same shape and size and communicate with each other.

[0058] The upper sink holes are located at both ends of the bottom of the top cover plate 11, and include a first upper sink hole 114 located at the bottom of the first upper through hole 112 and communicating with each other, and a second upper sink hole 115 located at the bottom of the second upper through hole 113 and communicating with each other. The first upper sink hole 114 is for accommodating the first pad 153, and the first upper sink hole 114 is a rectangular hole that fits the first pad 153, and the first pad 153 is located inside the first upper sink hole 114. The second upper sink hole 115 is for accommodating the second pad 154, and the second upper sink hole 115 is a rectangular hole that fits the second pad 154, and the second pad 154 is located inside the second upper sink hole 115.

[0059] Specifically, the conductor includes a lower pole located inside the lower sink hole of the insulating plate 15 and extending upward through the lower through hole, and an upper pole located at the top of the top cover plate 11 and extending downward through the upper through hole. The lower pole and the upper pole are joined by welding to be integrated. The lower pole of the embodiment of the present application includes a first lower pole 17 and a second lower pole 22, and the upper pole includes a first upper pole 12 and a second upper pole 18. The first lower pole 17 is located inside the first lower sink hole 155 and extends upward through the first lower through hole 151, and the first upper pole 12 is located at the top of the top cover plate 11 and extends downward through the first upper through hole 112. The first upper pole 12 and the first lower pole 17 are joined by welding to form a positive pole.

[0060] The second lower pole 22 is located inside the second lower sink hole 156 and extends upward through the second lower through hole 152, and the second upper pole 18 is located at the top of the top cover plate 11 and extends downward through the second upper through hole 113. The second upper pole 18 and the second lower pole 22 are joined by welding to form a negative pole. The first lower pole 17 is located inside the first lower sink hole 155 and then joined to the first upper pole 12 by welding, and the bottom surface of the first lower pole 17 is flush with the bottom surface of the insulating plate 15, and the second lower pole 22 is located inside the second lower sink hole 156 and then joined to the second upper pole 18 by welding, and the bottom surface of the second lower pole 22 is flush with the bottom surface of the insulating plate 15. The first lower sink hole 155 and the second lower sink hole 156 reduce the spatial height of the top cover structure 1, allowing the internal height of the secondary battery to be spatially maximized, thereby improving the volumetric energy density of the secondary battery.

[0061] In the top cover structure according to the embodiment of the present invention, a lower through hole penetrating vertically is provided in insulating plate 15, an upper through hole communicating with the lower through hole and penetrating vertically is provided in top cover plate 11, a conductor is fixed and connected to top cover plate 11 and insulating plate 15 via the upper through hole and the lower through hole, and a through hole is provided in the conductor penetrating the conductor. The conductor not only connects the secondary battery to an external device, but also allows injection or replacement of electrolyte into the secondary battery to be easily performed via the through hole, improving the production efficiency of secondary batteries.

[0062] In the top cover structure 1 according to the embodiment of the present application, a pad extending upward is provided on the top of the insulating plate 15, a lower through-hole is provided on the top of the pad, and a lower sink hole communicating with the lower through-hole is provided on the bottom surface of the pad. An upper through-hole communicating with the lower through-hole is provided on the top of the top cover plate 11, and an upper sink hole for accommodating the pad is provided on the bottom of the top cover plate 11. The lower pole is located in the lower sink hole and extends upward through the lower through-hole, and the upper pole is located on the top of the top cover plate 11 and extends downward through the upper through-hole, and the lower pole and the upper pole are joined to each other by welding. By positioning the pad of the insulating plate 15 inside the upper sink hole of the top cover plate 11, the distance between the lower pole located inside the lower sink hole and the bottom of the top cover plate 11 can be significantly shortened, the height space of the top cover structure 1 can be reduced, the height space inside the secondary battery can be fully utilized, and the volumetric energy density of the secondary battery can be improved.

[0063] The top cover structure 1 according to the embodiment of the present application reduces the distance from the surface of the lower pole to the bottom of the top cover plate 11 by using the upper sink hole provided at the bottom of the top cover plate 11, thereby reducing the height space and making the most of the height space inside the secondary battery, thereby improving the volumetric energy density of the secondary battery. The through-hole structure provided in the upper pole and the lower pole allows the secondary battery to be connected by welding from the outside to the inside through the through-holes of the upper pole and the lower pole in the internal assembly process of the secondary battery, thereby simplifying the height space of the electric core internal structure and improving the battery energy density. The secondary battery assembly connection can be completed by injecting electrolyte into the inside of the secondary battery through the through-holes of the upper pole and the lower pole and sealing it by welding an aluminum nail, for example.

[0064] The top cover structure 1 according to the embodiment of the present application can be sealed by welding an aluminum nail or the like due to the through-hole structure provided in the upper pole and the lower pole, and the assembly and connection of the secondary battery is completed. At the same time, the through-holes can be used to easily inject or replenish electrolyte into the interior of the secondary battery, resulting in a higher efficiency of electrolyte injection and a larger amount of electrolyte injection than in conventional top cover structures. By mounting the pad extending upward at the top of the insulating plate 15 and the lower pole to the top cover structure through the upper sink hole provided at the bottom of the top cover plate 11, it is possible to provide a function of preventing twisting and rotation.

[0065] In some embodiments, as shown with reference to Figs. 2, 3, 6 and 7, the present application provides a top cover structure for a secondary battery. The top cover structure 1 has an upper plastic between its upper pole and top cover plate, which insulates the upper pole from the top cover plate 11. The upper plastic has a step hole with a large upper diameter and a small lower diameter, which communicates with the upper through hole, and the upper pole is located inside the step hole. In the embodiment of the present application, two upper plastics are provided, and the two upper plastics are located at both ends of the top of the top cover plate 11, respectively, and the two upper plastics are a first upper plastic 13 and a second upper plastic 19, respectively. The first upper plastic 13 is located at the top of the first upper through hole 112, and the second upper plastic 19 is located at the top of the second upper through hole 113.

[0066] The first upper plastic 13 and the second upper plastic 19 are provided with step holes having a larger diameter at the top and a smaller diameter at the bottom. The step hole of the first upper plastic 13 accommodates the first upper pole 12 and communicates with the first upper through hole 112, and the step hole of the second upper plastic 19 accommodates the second upper pole 18 and communicates with the second upper through hole 113. The first upper pole 12 located on the first upper plastic 13 is located inside the step hole and is joined to the first lower pole 17 through the first upper through hole 112 by welding. The second upper pole 18 located on the second upper plastic 19 is located inside the step hole and is joined to the second lower pole 22 through the second upper through hole 113 by welding.

[0067] The first upper plastic 13 and the second upper plastic 19 are both insulators. The first upper plastic 13 is used to form a safe electrical gap between the first upper pole 12 and the top cover plate 11. The second upper plastic 19 is used to form a safe electrical gap between the second upper pole 18 and the top cover plate 11. The stepped holes in the first upper plastic 13 are used to shorten the distance between the first upper pole 12 and the upper surface of the insulating plate 15, and the stepped holes in the second upper plastic 19 are used to shorten the distance between the second upper pole 18 and the upper surface of the insulating plate 15, thereby reducing the spatial height of the top cover structure 1 as a whole, making maximum spatial use of the internal height of the secondary battery, and improving the volumetric energy density of the secondary battery.

[0068] In some embodiments, as shown with reference to Figs. 5 to 7 and Figs. 15 to 20, the embodiments of the present application provide a top cover structure for a secondary battery. In the top cover structure 1, an upper bump is provided at the bottom of the upper pole, which passes through a step hole and an upper through-hole and is joined to the lower pole by welding. The cross section of the upper pole is larger than the cross section of the upper bump. The upper pole and the upper bump are of an integrally molded structure. A lower bump is provided at the top of the lower pole, which passes through a lower through-hole and is joined to the upper pole by welding. The cross section of the lower pole is larger than the cross section of the lower bump. The lower pole and the lower bump are of an integrally molded structure.

[0069] In the embodiment of the present application, the top cover structure 1 has an upper bump at the bottom of the upper pole and a lower bump at the bottom of the lower pole. The upper bump can reduce the distance between the upper pole and the front of the top cover plate 11, and the lower pole can reduce the distance between the lower pole and the back of the top cover plate, so that the occupied space in the height direction of the top cover structure 1 can be reduced and the energy density of the secondary battery can be improved. In addition, the top cover structure 1 has an upper bump at the bottom of the upper pole and a lower bump at the top of the lower pole. This simplifies the top cover structure, and by joining the upper pole and the lower pole by welding, the design and process design of the top cover structure can be simplified, and the cost of the top cover structure can be reduced while the weight of the top cover structure can be reduced to improve the energy density of the electric core.

[0070] Specifically, the upper pole in the embodiment of the present application includes a first upper pole 12 and a second upper pole 18, and the lower pole includes a first lower pole 17 and a second lower pole 22. The upper bump includes a first upper bump 122 located on the bottom surface of the first upper pole 12 and a second upper bump 182 located on the bottom surface of the second upper pole 18, and the lower bump includes a first lower bump 172 located on the top of the first lower pole 17 and a second lower bump 222 located on the top of the second lower pole 22.

[0071] The first upper bump 122 of the first upper pole 12 is welded to the first lower bump 172 of the first lower pole 17 through the step hole and the first upper through hole 112 of the first upper plastic 13. The first lower bump 172 of the first lower pole 17 is welded to the first upper bump 122 of the first upper pole 12 through the first lower through hole 151. The second upper bump 182 of the second upper pole 18 is welded to the second lower bump 222 of the second lower pole 22 through the step hole and the second upper through hole 113 of the second upper plastic 19. The second lower bump 222 of the second lower pole 22 is welded to the second upper bump 182 of the second upper pole 18 through the second lower through hole 152.

[0072] The first upper pole 12 according to the embodiment of the present application is joined to the first lower pole 17 by welding via the first upper bump 122. The first lower pole 17 is joined to the first upper pole 12 by welding via the first lower bump 172. The second upper pole 18 is joined to the second lower pole 22 by welding via the second upper bump 182. The second lower pole 22 is joined to the second upper pole 18 by welding via the second lower bump 222. As a result, the distance between the first upper pole 12 and the first lower pole 17 is shortened, and the distance between the second upper pole 18 and the second lower pole 22 is shortened, so that the spatial height of the top cover structure 1 can be reduced as a whole, the internal height of the secondary battery can be spatially maximized, the volumetric energy density of the secondary battery can be improved, the structural design of the top cover structure 1 can be simplified, and the processing cost can be reduced.

[0073] In some embodiments, as shown with reference to FIG. 2, FIG. 5 to FIG. 7, and FIG. 21, the embodiment of the present application provides a top cover structure of a secondary battery. The top cover structure 1 further includes an upper seal ring located in the upper through hole. An annular flange is provided on the top of the upper seal ring to seal between the upper pole and the top cover plate, and the annular flange and the upper seal ring are integrally molded. A lower seal ring is provided inside the lower through hole, and the lower seal ring seals between the lower pole and the top cover plate. The upper seal ring according to the embodiment of the present application includes a first upper seal ring 14 located in the first upper through hole 112 and a second upper seal ring 20 located in the second upper through hole 113, and the lower seal ring includes a first lower seal ring 16 located in the first lower through hole 151 and a second lower seal ring 21 located in the second lower through hole 152.

[0074] The first upper seal ring 14 is for sealing the gap between the first upper pole 12 and the top cover plate 11. The first lower seal ring 16 is for sealing the gap between the first lower pole 17 and the top cover plate 11. The second upper seal ring 20 is for sealing the gap between the second upper pole 18 and the top cover plate 11. The second lower seal ring 21 is for sealing the gap between the second lower pole 22 and the top cover plate 11. This can prevent the electrolyte inside the electric core from leaking out of the gap or volatilizing to the outside of the secondary battery. In order to simplify the design, the top cover structure 1 can omit the first lower seal ring 16 and the second lower seal ring 21 as shown in FIG. 21.

[0075] In some embodiments, as shown with reference to Figs. 2 to 7 and Figs. 15 to 20, the present application provides a top cover structure for a secondary battery. In the top cover structure 1, an upper pole through-hole is provided in the upper pole, penetrating both upper and lower ends of the upper pole, and a lower pole through-hole is provided in the lower pole, penetrating both upper and lower ends of the lower pole, and the upper pole through-hole and the lower pole through-hole are in communication with each other. The upper pole according to the present application includes a first upper pole 12 and a second upper pole 18, and the lower pole includes a first lower pole 17 and a second lower pole 22. The upper pole through-hole includes a first upper pole through-hole 121 penetrating both upper and lower ends of the first upper pole 12 and a second upper pole through-hole 181 penetrating both upper and lower ends of the second upper pole 18.

[0076] The lower pole through-holes include a first lower pole through-hole 171 penetrating both upper and lower ends of the first lower pole 17, and a second lower pole through-hole 221 penetrating both upper and lower ends of the second lower pole 22. The first upper pole through-hole 121 and the first lower pole through-hole 171 communicate with each other, and the second upper pole through-hole 181 and the second lower pole through-hole 221 communicate with each other. A liquid injection passage to the positive pole is formed between the first upper pole through-hole 121 and the first lower pole through-hole 171, and a liquid injection passage to the negative pole is formed between the second upper pole through-hole 181 and the second lower pole through-hole 221. Injection or replacement of liquid into the inside of the secondary battery is performed quickly from the liquid injection passage of the positive pole and the liquid injection passage of the negative pole, and after the injection or replacement of liquid is completed, the secondary battery can be assembled and connected by sealing by welding an aluminum nail or the like, and the injection efficiency is higher and the amount of injection is larger than that of the conventional top cover structure.

[0077] In addition, in the embodiments of the present application, an upper pole through-hole is provided in the upper pole, penetrating both the upper and lower ends of the upper pole, and a lower pole through-hole is provided in the lower pole, penetrating both the upper and lower ends of the lower pole. By connecting from the outside to the inside by welding in the internal assembly connection process of the secondary battery, it is possible to simplify the height space of the internal structure of the electric core and improve the battery energy density.

[0078] In some embodiments, as shown with reference to Figs. 3, 4, 10 to 14, the present application provides a top cover structure for a secondary battery. In the top cover structure 1, a lower injection hole 157 and a vent hole 159 are provided in the insulating plate 15, and an ejection prevention plate is provided at the bottom of the lower injection hole 157. The top cover plate 11 is provided with an upper injection hole 111 communicating with the injection hole 157 and an explosion prevention valve hole communicating with the vent hole 159, an explosion prevention plate 24 is provided at the bottom of the top cover plate 11 to block the explosion prevention valve hole, and an explosion prevention plate protection sheet 23 is provided at the top of the top cover plate 11 to block the explosion prevention valve hole. On both sides of the insulating plate 15, a plurality of undercuts 158 are provided in sequence at intervals in the longitudinal direction of the insulating plate 15, and the plurality of undercuts 158 are formed integrally with the insulating plate 15 as an injection molding structure.

[0079] In the embodiment of the present application, the insulating plate 15 is provided with a lower injection hole 157, and the top cover plate 11 is provided with an upper injection hole 111 communicating with the lower injection hole 157. The lower injection hole 157 and the upper injection hole 111 are used to inject the electrolyte into the electric core. The anti-ejection plate at the bottom of the lower injection hole 157 is provided to prevent the electrolyte in the electric core from rising in pressure and erupting upward from the lower injection hole 157, and colliding with the pole piece inside the secondary battery. The vent hole 159 can quickly open the explosion-proof plate 24 through the vent hole 159 to release the pressure when the internal air pressure of the secondary battery rises abnormally, thereby ensuring the safety of the secondary battery. The multiple undercuts 158 are connected to the undercut holes on the adapter piece or insulating gasket to fix the adapter piece, insulating gasket 4, and electric core cell tab inside the secondary battery and harden the tab shape.

[0080] A splash prevention plate is provided at the bottom of the lower injection hole 157 of the insulating plate 15 to prevent the electrolyte from directly hitting the pole pieces inside the secondary battery when the pressure increases during injection. The undercut 158 ​​is designed to connect to the undercut hole of the adapter piece or insulating gasket 4 inside the secondary battery, thereby completely fixing the adapter piece, insulating gasket 4, and core cell tab inside the secondary battery and hardening the tab shape.

[0081] As shown in FIG. 22, the second aspect of the embodiment of the present application provides a top cover assembly for a secondary battery. The top cover assembly includes the top cover structure 1 described in any one of the above embodiments, and an adapter piece for connecting a conductor. The adapter piece includes a positive adapter piece 2 and a negative adapter piece 3. An insulating gasket 4 is provided at the bottom of the positive adapter piece 2 and the negative adapter piece 3. The positive adapter piece 2 and the negative adapter piece 3 are provided with transfer pads protruding into the inside of the lower pole through hole and the upper pole through hole, respectively. The transfer parts are joined to the lower pole through hole and the upper pole through hole by welding. Compared with the through welding between the tab or adapter piece and the top cover pole in the prior art, the present application changes the through welding between the tab or adapter piece and the top cover pole to seam welding, reducing the risk of disconnection of the inside of the battery due to the false welding of the through welding, and at the same time, the seam welding can increase the contact area between the parts, reduce the internal resistance, increase the overcurrent capacity, and improve the performance of the secondary battery.

[0082] In addition, in the embodiment of the present application, the packaging of the top cover and the case is first completed, and then the packaging of the secondary battery from the outside to the inside can be completed by welding the through-hole of the conductor to the adapter piece, thereby optimizing the assembly structure of the internal tab and increasing the height of the tab, thereby further increasing the energy density and volumetric energy density of the secondary battery. The top cover assembly provided by the embodiment of the present application can reduce the difficulty of soldering the adapter piece and the conductor by fitting the transfer pad of the adapter piece to the through-hole of the conductor in the top cover structure, and then welding the adapter piece and the conductor of the top cover structure on the top cover structure, by assembling the bare electric core and the adapter piece and then fitting the top cover structure.

[0083] As shown in FIG. 22, a third aspect of the embodiment of the present application provides a secondary battery. The secondary battery includes the top cover assembly described in any one of the above embodiments and a case 6 that houses a plurality of electric cores 5. The case 6 has a plurality of electric cores 5 disposed therein. The positive electrode tabs of the plurality of electric cores 5 are welded to the positive electrode adapter piece 2 via an insulating gasket 4, and the negative electrode tabs of the plurality of electric cores 5 are welded to the negative electrode adapter piece 3 via an insulating gasket 4. In this embodiment, there is no specific limit to the number of electric cores included in each secondary battery, and it is possible to include, for example, 2, 4, 6, 8, etc. electric cores, and this embodiment is merely an example and is not limited thereto.

[0084] The mechanism of mounting the top cover is described below. The embodiments of the present application provide a top cover structure for a secondary battery, a top cover assembly, and a secondary battery. The top cover structure of the present application includes an insulating plate 15 having a lower through hole penetrating vertically, a top cover plate 11 arranged on the top of the insulating plate 15 and having an upper through hole penetrating vertically and communicating with the lower through hole, and a conductor fixedly connected to the top cover plate 11 and the insulating plate 15 via the upper through hole and the lower through hole, and the conductor has a through hole penetrating the conductor.

[0085] Therefore, in the top cover structure of the present application, a lower through-hole penetrating vertically is provided in insulating plate 15, an upper through-hole communicating with the lower through-hole and penetrating vertically is provided in top cover plate 11, the conductor is fixedly connected to top cover plate 11 and insulating plate 15 via the upper through-hole and the lower through-hole, and a through-hole is provided in the conductor penetrating the conductor. The conductor not only enables electrical conduction between the secondary battery and the inside of the secondary battery from the outside to the inside, but also allows injection or replacement of electrolyte into the secondary battery via the through-hole, thereby improving the production efficiency of secondary batteries.

[0086] In addition to the embodiment described above with reference to Fig. 1 to Fig. 22, a top cover structure for a secondary battery is also proposed, which is also suitable as a top cover structure having a through hole in a conductor. Hereinafter, this will be further described with reference to Figs. 23A to 32.

[0087] Fig. 23A is a schematic diagram of an explosion of a secondary battery according to an embodiment of the present application, and Fig. 23B is a structural schematic diagram of the secondary battery shown in Fig. 23A after assembly is completed. With reference to Figs. 23A and 23B, the secondary battery 200 includes a case 210, an electric core assembly 220, an insulating gasket 230, a deflector 240 (which may also be called an adapter piece in other embodiments of the present application), and a top cover structure 250. The electric core assembly 220 is disposed inside the case 210, and the insulating gasket 230 and the deflector 240 are sequentially stacked on the top of the electric core assembly 220 from bottom to top, and the top cover structure 250 is disposed above the deflector 240, and the top cover structure 250 covers the case 210 to form a sealed housing. Here, the deflector 240 includes two deflectors, a positive deflector 241 and a negative deflector 242. The positive deflector 241 has a positive deflector pole 243a, and the negative deflector 242 has a negative deflector pole 243b.

[0088] FIG. 24 is a structural schematic diagram of a top cover structure of a secondary battery according to an embodiment of the present application. FIG. 25 is a schematic diagram of an explosion of the embodiment shown in FIG. 24. As shown in relation to FIG. 24 and FIG. 25, the top cover structure 250 of the present embodiment includes a top cover sheet 310 (also called a top cover plate in other embodiments of the present application), an insulating part 320 (also called an insulating plate in other embodiments of the present application), and a pole assembly, and the top cover sheet 310 has top cover sheet through holes 311a and 311b (also called an upper through hole of the top cover sheet in other embodiments of the present application). The insulating part 320 is disposed below the top cover sheet 310, and the insulating part 320 has insulating part through holes 321a and 321b. The insulating part through holes 321a and 321b correspond one-to-one to the top cover sheet through holes 311a and 311b and communicate with each other to form a first through hole. As shown in Fig. 25, the top cover structure 250 has two pole assemblies, each of which includes poles 330a, 330b (also called conductors in other embodiments of the present application), upper plastic parts 340a, 340b (also called first upper plastic and second upper plastic in other embodiments of the present application), and lower seal parts 350a, 350b, which are arranged in order from top to bottom. Here, the pole 330a, the upper plastic part 340a, and the lower seal part 350a are one set of pole assemblies, and the three are combined with other parts of the secondary battery (e.g., the pole main body 2431 in Fig. 23A) to form one positive pole of the secondary battery. Similarly, the pole 330b, the upper plastic part 340b, and the lower seal part 350b are one set of pole assemblies, and the three are combined with other parts of the secondary battery to form one negative pole of the secondary battery. The positive and negative poles formed have similar structures, and the following description will be given taking the positive pole as an example, with the relevant content being analogous to the negative pole.

[0089] In the positive pole, a pole 330a and an upper plastic part 340a are provided above the top cover sheet 310. The upper plastic part 340a is disposed between the pole 330a and the top cover sheet 310. The lower seal part 350a is provided penetrating the insulating part through hole 321a and the top cover sheet through hole 311a, and the pole 330a has a pole through hole 331a (also called a conductor through hole in other embodiments of the present application). The upper plastic part has an upper plastic through hole 341a, and the lower seal part 350a has a lower seal through hole 351a, and the pole through hole 331a, the upper plastic through hole 341a, and the lower seal through hole 351a communicate with each other to form a second through hole. The second projection along the vertical direction of the second through hole is located inside the first projection along the vertical direction of the first through hole.

[0090] As shown in relation to Figures 23A and 25, after assembly, the positive deflector pole 243a is inserted from bottom up into the second and first through holes corresponding to the left positive pole, and the negative deflector post 243b is inserted from bottom up into the second and first through holes corresponding to the right negative pole, thereby conductively connecting the electric core assembly to the positive and negative poles on the top cover.

[0091] As shown in FIG. 25, the top cover sheet 310 is a rectangular sheet structure having a certain thickness. FIG. 25 shows the top surface of the top cover sheet 310. The insulating part 320 is also a rectangular sheet structure having a certain thickness. The size and shape of the insulating part 320 and the top cover sheet 310 are matched. The middle position of the insulating part 320 has an explosion-proof valve 322 covered with an explosion-proof plate 324, and the corresponding position of the top cover sheet 310 has one explosion-proof hole 312 covered with a protection plate 314. The shapes and sizes of the explosion-proof valve 322, the explosion-proof plate 324, the explosion-proof hole 312, and the protection plate 314 are matched with each other, and in this embodiment, they are all runway-shaped.

[0092] As shown in FIG. 25, the top cover sheet 310 and the insulating part 320 are provided with injection holes 313 and 323, respectively, but otherwise the top cover sheet 310 and the insulating part 320 are basically symmetrical in structure. That is, the top cover sheet through hole 311a and the top cover sheet through hole 311b have the same structure and are symmetrically positioned. The insulating part through hole 321a and the insulating part through hole 321b have the same structure and are symmetrically positioned. In the following, the top cover sheet through hole 311a and the insulating part through hole 321a corresponding to the positive pole will be described as an example, but they can be inferred to be the top cover sheet through hole 311b and the insulating part through hole 321b.

[0093] As shown in FIG. 25, the pole through-hole 331a, the upper plastic through-hole 341a, the top cover sheet through-hole 311a, the insulating part through-hole 321a and the lower seal through-hole 351a are all substantially elliptical in shape.

[0094] Fig. 26 is a cross-sectional view taken along the line B2-B2' in Fig. 24. Fig. 27 is an enlarged schematic view of a partial region C in Fig. 26. As shown in Fig. 27, a first through hole 610 formed by the insulating part through hole 321a and the top cover sheet through hole 311a communicating with each other, and a second through hole 620 formed by the pole through hole 331a, the upper plastic through hole 341a, and the lower seal through hole 351a communicating with each other are shown. Note that in Fig. 27, the ranges in which the first through hole 610 and the second through hole 620 are located are shown by dotted lines, but this does not strictly limit the positions of the through holes in both locations. Assuming that the surface of the top cover sheet 310 is a first extension plane, the cross-sectional shapes of the first through hole 610 and the second through hole 620 obtained by cutting along the first extension plane are not limited in the present application, and may be any one of a square, a rectangle, a runway shape, a circle, an ellipse, a pentagon, a hexagon, and an octagon.

[0095] 25 and 27 show the vertical direction Z. The vertical direction Z also represents the height direction of the top cover structure, that is, the height direction of the secondary battery shown in FIG. 23A and FIG. 23B. As shown in FIG. 27, the second projection portion of the second through hole 620 along the vertical direction Z is located inside the first projection portion of the first through hole 610 along the vertical direction Z, that is, the minimum hole diameter of the first through hole 610 is larger than the maximum hole diameter of the second through hole 620, and the second through hole 620 is located inside the first through hole 610, and the hole wall of the second through hole 620 does not exceed the boundary defined by the hole wall of the first through hole 610. In some embodiments, the first through hole 610 and the second through hole 610 are coaxial, and the central axis lines of both are coincident, that is, the center points of the cross sections of both are the same point.

[0096] As shown in Figures 25 and 27, in some embodiments, the top cover sheet 310 includes an upper sink platform 315a. The upper sink platform 315a is recessed with respect to the upper surface of the top cover sheet 310. The top cover sheet through-hole 311a is located in the upper sink platform 315a, and the upper plastic part 340a is located in the upper sink platform 315a. In the present application, the position of the top cover sheet through-hole 311a in the upper sink platform 315a is not limited, and in the embodiment shown in Figure 25, the top cover sheet through-hole 311a is located in the center position of the upper sink platform 315a.

[0097] As shown in FIGS. 25 and 27, in some embodiments, the upper plastic part 340a has a first bottom wall 342a and a first side wall 343a connected to each other, upper sink platform 315a has an upper sink platform surface 316a and an upper sink platform wall 317a, and pole 330a has an outer wall 332a and a lower surface 333a, with first bottom wall 342a sandwiched between upper sink platform surface 316a and lower surface 333a, and first side wall 343a sandwiched between upper sink platform wall 317a and outer wall 332a.

[0098] As shown in FIG. 27, the pole 330a has a certain height. When the pole 330a is fitted to the upper plastic part 340a, the upper surface of the pole 330a has a height H1 based on the lower surface of the top cover sheet 310, and the upper plastic part 340a has a height H2 smaller than the height H1. Most of the pole 330a is located in a space surrounded by the first bottom wall 342a and the first side wall 343a of the upper plastic part 340a, and only a part of the pole 330a protrudes from this space, and the outer wall 332a of the pole 330a is adjacent to the inner wall of the first side wall 343a, and the lower surface 333a of the pole 330a is adjacent to the upper surface of the first bottom wall 342a. In other embodiments, the height H2 can be equal to the height H1 or smaller than the height H1 by adjusting the dimensions. That is, since the entire pole 330a is located in this space, the overall height of the top cover structure 250 can be reduced.

[0099] As shown in FIG. 27, the upper sink platform surface 316a has a height H4. With respect to the lower surface of the top cover sheet 310 as a reference, the upper surface of the top cover sheet 310 has a height H3 smaller than H2. A part of the lower portion of the first side wall 343a is located inside the upper sink platform 315a and adjacent to the upper sink platform wall 317a, and the remaining part is located above the upper surface of the top cover sheet 310. The lower surface of the first bottom wall 342a is entirely adjacent to the upper sink platform surface 316a. According to such a design, the height of the top cover structure 250 itself does not need to be very high, and the weight of the top cover structure 250 can be reduced.

[0100] Also shown in FIG. 27 is the X-direction. The X-direction is perpendicular to the vertical direction Z, and is the direction along which the length of the top cover sheet 310 extends. In the embodiment shown in FIG. 27, the pole 330a has a thickness T1 between the outer wall 332a and the inner wall 334a along the X-direction, and the first side wall 343a has a thickness T2 along the X-direction, where T2 is smaller than T1. In other embodiments, T2 may be greater than or equal to T1.

[0101] 25 and 27, in some embodiments, the lower seal part 350a includes a second bottom 352a and a second protrusion 353a connected to each other, and the second protrusion 353a includes a first outer wall 3531 and a first apex 3532. The pole 330a has a lower surface 333a, the first apex 3532 abuts against the lower surface 333a, and the second bottom 352a and the first outer wall 3531 abut against the hole wall of the first through hole 610. As shown in FIG. 27, the cross-sectional shape of the second bottom 352a and the second protrusion 353a along the line B-B' is L-shaped, that is, the second bottom 352a extends outward in a plane to form an outer ring of the lower seal part 350a.

[0102] In some embodiments, the first outer wall 3531 also abuts against the wall of the upper plastic through-hole 341a. As shown in FIG. 27, the first outer wall 3531 abuts against the wall of the upper plastic through-hole 341a and the wall of the first through-hole 610 at the same time.

[0103] In some embodiments, the dimensions of the top cover sheet through hole 311a and the insulating part through hole 321a are not the same. The size here refers to the hole diameter. As shown in FIG. 27, the outer ring formed by the second bottom 352a of the lower seal part 350a and the outer wall of the second protrusion 353a are obviously different in size, so the size of the top cover sheet through hole 311a matches the size of the outer wall of the second protrusion 353a, and the size of the insulating part through hole 321a matches the size of the second bottom 352a. In this embodiment, the size of the insulating part through hole 321a is larger than the size of the top cover sheet through hole 311a, so the size of the hole wall of the first through hole 610 does not become equal from top to bottom, but changes.

[0104] As shown in FIG. 25 and FIG. 27, in some embodiments, the size of the upper plastic through hole 341a is equal to or larger than the size of the pole through hole 331a. Since the second protrusion 353a has a constant thickness T3, the size difference between the size of the upper plastic through hole 341a and the size of the pole through hole 331a may be equal to this thickness T3. In these embodiments, the size of the hole wall of the second through hole 620 is not the same from top to bottom, but varies. Since both the upper plastic part 340a and the lower seal part 350a are made of materials having elasticity and flexibility and both have compressibility, the size difference between the size of the upper plastic through hole 341a and the size of the pole through hole 331a can also be smaller than this thickness T3, so that when the positive electrode deflector pole 243a penetrates the first through hole 610 and the second through hole 620, the second protrusion 353a is pressed by the positive electrode deflector pole 243a and compressed in the direction of the hole wall of the first through hole 620.

[0105] Because the lower seal part 350a is made of an elastic material, the size of the top cover sheet through hole 311a does not need to be the same as the size of the upper plastic through hole 341a. In some embodiments, the size of the top cover sheet through hole 311a is equal to or larger than the size of the upper plastic through hole 341a.

[0106] In the embodiment shown in FIG. 27, the top cover sheet 310 further includes a lower sink platform 318a, which is recessed with respect to the lower surface of the top cover sheet 310. The lower sink platform 318a has a lower sink platform surface 3181 and a lower sink platform wall 3182. The second bottom 352a has a second outer wall 3521 and a second apex 3522, the second outer wall 3521 abuts against the lower sink platform wall 3182, and the second apex 3522 abuts against the lower sink platform surface 3181. According to these embodiments, the whole or a part of the second bottom 352a of the L-shaped lower seal part 350a is located inside the lower sink platform 318a, and the height of the top cover structure 250 is further reduced. The size of the lower sink platform wall 3182 can be equal to the size of the outer ring of the second bottom 352a, and the size of the insulating part through hole 321a can be equal to the size of the lower sink platform wall 3182.

[0107] By providing the lower sink platform 318a, the gap that occurs between the insulating part through hole 321a and the top cover sheet through hole 311a due to lack of alignment after the lower seal part 350a expands under force can be sufficiently filled, thereby reducing the risk of voltage on the secondary battery side due to electrolyte infiltration.

[0108] Fig. 28 is a top and bottom view of the top cover structure of the secondary battery shown in Fig. 24. As shown in Fig. 28, the structure of the bottom of top cover structure 250, such as insulating part through-holes 321a and 321b, second bottom portion 352a of lower seal part 350a, and second bottom portion 352b of lower seal part 350b, are shown.

[0109] Compared to the top cover structure shown in FIG. 2, the pole assembly of this embodiment does not have a lower pole structure, and most or all of the lower seal part 350a extends inside the first through hole 610, allowing the overall height of the top cover structure 250 to be reduced without increasing the height in the Z direction.

[0110] 24 to 28, when assembling the top cover structure 250, the pole 330a in the pole assembly is placed inside the upper plastic part 340a, the upper plastic part 340a is placed on the upper sink platform 315a, the lower seal part 350a is placed inside the first through hole 610 and the second through hole 620, and then the next positive deflector pole 243a is fitted into the corresponding first through hole 610 and the second through hole 620, and then the positive deflector pole 243a and the pole assembly can be pressed with a pressing force, so there is no need to adopt a process such as riveting, injection molding, welding, etc. In some embodiments, a seam welding process can be adopted in some structures after assembly, for example, after the pole 330a is placed in the upper plastic part 340a, a seam welding process can be adopted between the pole 330a and the upper plastic part 340a to fasten and connect between both slots. Compared with full penetration welding, the seam welding process is relatively simple, generates relatively little metal debris, and ensures the structural strength of the secondary battery without reducing the overcurrent capability of the battery.

[0111] In some embodiments, the poles in the pole assembly may be fabricated using pure aluminum material, thereby reducing the height and weight of the poles.

[0112] The top cover structure 250 of this embodiment has fewer components than the top cover structure shown in FIG. 2, and the pole assembly is composed of only three parts: a pole, an upper plastic part, and a lower seal part. Each part can be manufactured independently, greatly simplifying the top cover structure and reducing the structure and material costs. By adopting the top cover structure 250 of the present application, there is no need to adopt processes such as riveting, injection molding, and welding when assembling, and the production cost and quality cost of the top cover structure can be greatly reduced. There is no need to adopt processes such as welding, and metal chips generated by the welding do not enter the inside of the battery, so the risk of short circuiting of the secondary battery can be avoided. Since the number of parts is small, the structure is simple, the top cover structure can be made lighter, and the energy density of the secondary battery can be improved. The height of the top cover structure in the vertical direction Z is relatively low, the occupancy rate of the top cover structure in the height space inside and outside the secondary battery is reduced, the space utilization rate in the height direction of the secondary battery is greatly improved, and the energy density and volumetric energy density of the secondary battery are greatly improved.

[0113] Based on the above-mentioned improvement method in which the top cover assembly is optimized, the present application provides a secondary battery as shown in FIG. 23A. In addition to the above-mentioned top cover structure 250, the secondary battery includes a deflector 240 disposed below the insulating part 320. As described above, the deflector 240 includes a positive electrode deflector 241 and a negative electrode deflector 242, both of which have the same configuration and are symmetrically positioned. The upper surface of the deflector 240 is provided with deflector poles, such as a positive electrode deflector pole 243a and a negative electrode deflector pole 243b. Taking the positive electrode deflector pole 243a as an example, the deflector pole includes a pole main body 2431 and a chassis 2432. The pole main body 2431 is on the chassis 2432, and is configured to pass through the first through hole and the second through hole and abut against the hole wall of the second through hole.

[0114] The top cover structure 250 in the secondary battery of the present application is as described above, and will not be described further below. The secondary battery of the present application will be described below with reference to Figs.

[0115] FIG. 29 is an exploded view of an assembly structure of a secondary battery according to an embodiment of the present application. The electric core assembly 220, the insulating gasket 230, and the deflector 240 here are given the same reference numerals as in FIG. 23A, and show the same structure. As shown in FIG. 29, the electric core assembly 220 includes four single electric cores 221-224, and the single electric core 221 has two tabs 221a, 221b protruding upward. The single electric core 222 has two tabs 222a, 222b protruding upward. The single electric core 223 has two tabs 223a, 223b protruding upward. The single electric core 224 has two tabs 224a, 224b protruding upward. For each single electric core, one tab is a positive tab, and the other tab is a negative tab. 29, the deflector 240 is provided with tab assembly parts, for example, the positive electrode deflector 241 is provided with tab assembly parts 244a, 245a, 246a, 247a corresponding to the tabs 221a, 222a, 223a, 224a, respectively. The negative electrode deflector 242 is provided with tab assembly parts 244b, 245b, 246b, 247b corresponding to the tabs 221b, 222b, 223b, 224b, respectively. Similarly, the insulating gasket 230 is provided with tab assembly part holes corresponding to each electrode tab.

[0116] When assembling the secondary battery 200, each tab first passes through a tab assembly part hole in the insulating gasket 230, and then passes through a tab assembly part in the deflector 240. The cross-sectional view is as shown in Fig. 30. After the tabs are bent, they are brought into close contact with the upper surface of the deflector as shown in Fig. 31 for conductive connection. Taking the positive electrode deflector 241 as an example, the tabs 221a, 222a, 223a, and 224a are all welded to the upper surface of the deflector 241 after bending.

[0117] FIG. 32 is a cross-sectional view taken along the line B1-B1' in FIG. 23. As shown in FIG. 32, in the complete structure of the secondary battery 200, the top cover structure 250 and the case 210 are covered, and the electric core assembly 220, the insulating gasket 230, and the deflector 240 are enclosed in the cover space. A part of the pole main body 2431 penetrates the first through hole and the second through hole at the same time and abuts against the hole wall of the second through hole, and the upper surface of the pole main body 2431 is flush with the upper surface of the pole 330a. The pole main body 2431 does not protrude from the pole 330a. As shown in FIG. 32, a part or the whole of the outer wall of the chassis 2432 abuts against the hole wall of the insulating part through hole in the first through hole, and a part of the outer wall of the chassis 2432 abuts against the hole wall of the insulating part through hole.

[0118] Due to the advantages of the top cover structure 250 described above, the top cover structure 250 has a reduced height, which can save the height space of the secondary battery 200. For a secondary battery having the same height, the secondary battery of the present application can increase the height of the electric core assembly 220 of the secondary battery by reducing the height of the top cover structure 250, thereby improving the energy density and volumetric energy density of the secondary battery. Furthermore, the advantages described above about the top cover structure 250 are also beneficial effects of this secondary battery.

[0119] Based on the above-mentioned embodiment of the top cover assembly having two sets of through holes and the secondary battery, the embodiment of the present application further provides a secondary battery, which can further optimize the problem of the secondary battery tape to improve the safety during use of the secondary battery in the top cover structure having the conductive through holes, the top cover assembly and the secondary battery.

[0120] Referring to Fig. 33, another embodiment of the present invention provides a secondary battery. The secondary battery includes an electric core 41, two adapter pieces 411, and at least one double-sided protective adhesive layer 42. The electric core 41 has a plurality of tabs on its top. The two adapter pieces 411 are provided on the top of the electric core 41, and the tabs are welded to the surfaces of the two adapter pieces 411, forming a welding area 412. The double-sided protective adhesive layer 42 has both adhesive surfaces and is attached on the top of the adapter pieces 411, covering at least the welding area 412.

[0121] With this configuration, the double-sided protective adhesive layer 42, which has adhesive layers 422 on both sides, is provided on the adapter piece 411, and the double-sided protective adhesive layer 42 sticks and covers the welding area 412, and can effectively prevent the solder slag that may fall onto the welding area 412 from falling off the welding area 412 and falling into the inside of the electric core 41. At the same time, since the opposite side also has an adhesive layer 422, in the subsequent processing step, the double-sided protective adhesive layer 42 can also adhere foreign matter such as welding slag and dust particles that have fallen onto it, effectively reducing the possibility of foreign matter entering the electric core 41, and the double-sided protective adhesive layer 42 covering the welding area 412 effectively prevents the welding area 412 from contacting the electrolyte after the secondary battery is injected, reducing the corrosion rate, and finally realizing the effective protection of the secondary battery by the double-sided protective adhesive layer 42.

[0122] Referring to FIG. 34, optionally, the double-sided protective adhesive layer 42 includes two adhesive layers 422 and a carbonate protective layer 423, the carbonate protective layer 423 being disposed between the two viscous layers 422.

[0123] This makes it possible for the carbonate protective layer 23 to release gas to suppress combustion in the event of unexpected thermal runaway of the secondary battery, thereby further improving the safety of the secondary battery.

[0124] Furthermore, the carbonate protective layer 423 is a sodium bicarbonate or sodium carbonate layer structure.

[0125] Alternatively, the adhesive layer 422 is a double-sided adhesive layer 422, and the carbonate protective layer 423 is a powder bed structure spread and adhered between two of the viscous layers 422.

[0126] This arrangement allows the carbonate protective layer 423 to be quickly and efficiently applied to the two protective adhesive layers, making the process less difficult and easier to carry out.

[0127] In some embodiments, the double-sided protective adhesive layer 42 is a full sheet structure, which simultaneously adheres and covers the welding areas 412 on the two adapter pieces 411. More specifically, Figures 35 and 36 exemplarily show two different implementations of the double-sided protective adhesive layer, with Figure 35 showing the same adapter piece configuration as Figure 33, i.e., having two double-sided protective adhesive layers 431 and 432 attached, respectively, while Figure 36 shows the entire double-sided protective adhesive layer 44 attached.

[0128] This allows multiple welding areas 412 to be covered simultaneously with a single double-sided protective adhesive layer 42, which speeds up the work and also increases the coverage area of ​​the double-sided protective adhesive layer 2 on the upper surface of the electric core 41, making the foreign matter adhesion effect more effective.

[0129] In some other embodiments, a plurality of the double-sided protective adhesive layers 42 are provided, and each of the double-sided protective adhesive layers 42 adheres to and covers one or more of the welding areas 412 on the two adapter sheets 411. Referring to FIG. 1, in this embodiment, specifically, two double-sided protective adhesive layers 42 corresponding to the two adapter pieces 411 are provided, and two double-sided protective adhesive layers 2 correspond to and cover the welding areas 412 on each adapter piece 411.

[0130] Optionally, the adapter piece 411 is provided with a transfer pad 4110 and an injection hole 4111, and the double-sided protective adhesive layer 42 is provided with a first hole position 420 corresponding to the transfer pad 4110 and a second hole position 421 corresponding to the injection hole 111.

[0131] Furthermore, the shape and size of the first hole 420 correspond to the shape and size of the transfer pad 4110 in the circumferential direction. The shape and size of the second hole 421 correspond to the shape and size of the injection hole 4111 in the circumferential direction.

[0132] By arranging it in this manner, the double-sided protective adhesive layer 42 can more fully cover the adapter sheet 411 while not affecting the normal use of the secondary battery, thereby protecting the adapter sheet 411 and preventing the welding slag from falling off.

[0133] In some preferred embodiments, a gasket 410 (also called an insulating gasket in other embodiments of the invention) is provided between the adapter piece 411 and the electrical core 41 to cover the top of the electrical core 41, and the tab is welded to the surface of the adapter piece 411 after penetrating the gasket 410 and the adapter piece 411.

[0134] Among them, the gasket 410 is provided with a vent hole 414 in the area between the two adapter pieces 411, and the heat dissipation of the electric core 41 is improved.

[0135] Furthermore, the double-sided protective adhesive layer 42 completely covers the adapter sheet 411, and both ends of the double-sided protective adhesive layer 42 protrude from both side edges of the gasket 410 and are adhered to the side walls of the electric core 41. Of course, it is necessary to ensure the necessary hole positions by referring to other members such as the injection holes 4111 while completely covering the adapter sheet 411, but in areas that do not collide with other members, the double-sided protective adhesive layer 42 is attached so as to completely cover the adapter sheet 4111.

[0136] Here, the double-sided protective adhesive layer 42 protruding from the peripheral portion of the gasket 410 is adhered to the side wall of the electric core 41. Specifically, in this embodiment, the double-sided protective adhesive layer 42 is provided as an entire sheet, and is simultaneously coated on two adapter pieces 411. The length of the long side of the gasket 410 is the same as that of the gasket, the length of the gasket in the width direction is 20 mm wider than the width of the gasket 410, and both ends in the length direction are further extended to the side wall of the electric core 41. The protective effect of the double-sided protective adhesive layer 42 on the electric core 41 can be further improved, and the safety of the secondary battery can be improved.

[0137] In the present specification, it should be explained that the orientation or positional relationship indicated by the terms "upper", "lower", etc., is based on the orientation or positional relationship shown in the drawings, and is merely for facilitating and simplifying the description of the present application, and does not indicate or imply that the device must have a specific orientation, be configured, or operate in a specific orientation, and therefore cannot be understood as limiting the present application. Unless otherwise clearly specified and limited, the terms "attached", "connected", and "connect" should be generally understood, for example, as a fixed connection, a removable connection, or an integral connection, as a mechanical connection, as an electrical connection, as a direct connection, or indirectly through an intermediate medium, or as an internal communication between two components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the context.

[0138] It should be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that such an actual relationship or sequence exists between these entities or operations. Furthermore, the terms "comprise", "include", or any other variation thereof are intended to cover a non-exclusive inclusion, whereby a process, method, article, or apparatus that includes a set of elements includes not only those elements, but also other elements not expressly listed or that are inherent to such process, method, article, or apparatus. In the absence of further limitations, an element qualified by the phrase "comprising a ..." does not exclude the presence of further identical elements in the process, method, article, or apparatus that includes the element.

[0139] The above are merely specific embodiments of the present application that enable those skilled in the art to understand or realize the present application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present application. Thus, the present application is not limited to these embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features described herein. [Explanation of symbols]

[0140] (The symbols in Figures 1 to 22 are as follows:) 1, top cover structure;2, positive adapter piece;3, negative adapter piece;4, insulating gasket;5, electric core;6, case;11, top cover plate;12, first upper pole;13, first upper plastic;14, first upper sealing ring;15, insulating plate;16, first lower sealing ring;17, first lower pole;18, second upper pole;19, second upper plastic;20, second upper sealing ring;21, second lower sealing ring;22, second lower pole;23, explosion-proof plate protective sheet;24, explosion-proof plate; 111, upper injection hole; 112, first upper through hole; 113, second upper through hole; 114, first upper sink hole; 115, second upper sink hole; 121, first upper pole through hole; 122, first upper bump; 151, first lower through hole; 152, second lower through hole; 153, first pad; 154, second pad; 155, first lower sink hole; 156, second lower sink hole; 157, lower injection hole; 158, undercut; 159, vent hole; 171, first lower pole through hole; 172, first lower bump; 181, second upper pole through hole; 182, second upper bump; 221, second lower pole through hole; 222, second lower bump. (The symbols in Figures 23A to 32 are as follows:) secondary battery 200, case 210, electric core assembly 220, insulating gasket 230, deflector 240, positive deflector 241, negative deflector 242, positive deflector pole 243a, negative deflector pole 243b, top cover structure 250; top cover sheet 310, upper sink platform 315a, lower sink platform 318a, top cover sheet through holes 311a, 311b, insulating part 320, insulating part through holes 321a, 321b, poles 330a, 330b, pole through holes 331a, upper plastic parts 340a, 340b, upper plastic through holes 341a, lower seal through holes 351a, lower seal parts 350a, 350b; anti-explosion valve 322, anti-explosion plate 324, anti-explosion hole 312, protection plate 314, injection holes 313, 323, first through hole 610, second through hole 620; upper sink platform 315a: upper sink platform surface 316a, upper sink platform wall 317a; Lower sink platform 318a: lower sink platform surface 3181, lower sink platform wall 3182; Pole 330a: outer wall 332a, lower surface 333a; Upper plastic part 340a: first bottom wall 342a, first side wall 343a; Lower seal part 350a: second bottom portion 352a, second protrusion portion 353a, first outer wall 3531, first top portion 3532, second outer wall 3521, second top portion 3522; Positive deflector pole 243a: pole main body 2431 and chassis 2432; Electric core assembly 22: single electric cores 221-224, tabs 221a, 221b, 222a, 222b, 223a, 223b, 224a, 224b, tab assembly parts 244a, 245a, 246a, 247a, 244b, 245b, 246b, 247b; (The symbols in Figures 33 to 36 are as follows:) 41, winding core; 410, gasket; 411, adapter piece; 4110, transfer pad; 4111, injection hole; 412, welding area; 414, ventilation hole; 42, 44, 431, 432, double-sided protective adhesive layer; 420, first hole position; 421, second hole position; 422, adhesive layer; 423, carbonate protective layer.

Claims

1. A top cover structure (1) for a secondary battery, comprising: The top cover structure (1) is An insulating plate (15) having a lower through hole extending vertically therethrough; a top cover plate (11) disposed on the top of the insulating plate (15) and having an upper through hole communicating with the lower through hole and penetrating vertically; a conductor (12, 17) fixedly connected to the top cover plate (11) and the insulating plate (15) through the upper through hole and the lower through hole, the conductor having a through hole formed therethrough; Equipped with The secondary battery is provided with an adapter piece (2, 3), The adapter pieces (2, 3) are provided with transfer pads, A top cover structure (1) for a secondary battery, characterized in that when the top cover structure (1) is connected to the adapter piece (2, 3), the transfer pad protrudes into the inside of a conductive through hole in the top cover structure (1).

2. The insulating plate (15) is provided with pads (153, 154) extending upward on the top thereof, the lower through hole is located in the pad, and a lower sink hole is provided at a bottom of the pad and communicates with the lower through hole, and a diameter of the lower sink hole is larger than a diameter of the lower through hole; The top cover structure of a secondary battery as described in claim 1, characterized in that an upper sink hole is provided at the bottom of the top cover plate (11) to accommodate the pad (153, 154) and communicate with the upper through hole, and the hole diameter of the upper sink hole is larger than the hole diameter of the upper through hole.

3. The conductors (12, 17) are a lower pole (17) located inside the lower sink hole and extending upward through the lower through hole; an upper pole (12) located on the top of the top cover plate (11) and extending downward through the upper through hole; Equipped with The lower pole and the upper pole are joined by welding, The through holes include an upper pole through hole penetrating both upper and lower ends of the upper pole (12) and a lower pole through hole penetrating both upper and lower ends of the lower pole (17), 3. The top cover structure for a secondary battery according to claim 2, wherein the upper pole through-hole and the lower pole through-hole are in communication with each other.

4. An upper plastic (13) is provided between the upper pole (12) and the top cover plate (11) to insulate the upper pole from the top cover plate (11); 4. The top cover structure of a secondary battery according to claim 3, characterized in that the upper plastic has a step hole having a larger diameter at the top and a smaller diameter at the bottom, the step hole communicates with the upper through hole, and the upper pole is located inside the step hole.

5. An upper bump is provided at the bottom of the upper pole (12) and is welded to the lower pole (17) through the step hole and the upper through hole. a cross section of the upper pole is larger than a cross section of the upper bump, and the upper pole and the upper bump are formed as an integrally molded structure; A lower bump is provided on the top of the lower pole (17) and is welded to the upper pole through the lower through hole.

5. The top cover structure of a secondary battery according to claim 4, wherein a cross section of the lower pole is larger than a cross section of the lower bump, and the lower pole and the lower bump are integrally molded.

6. Further comprising an upper seal ring (14) located within the upper through hole; An annular flange is provided on the top of the upper seal ring to seal between the upper pole (12) and the top cover plate (11), and the annular flange and the upper seal ring are integrally molded.

4. The top cover structure of a secondary battery according to claim 3, wherein a lower seal ring (21) is provided within the lower through hole, and the lower seal ring seals between the lower pole (17) and the top cover plate (11).

7. The lower through-holes (321a, 321b) of the insulating plate (320) correspond one-to-one to the upper through-holes (311a, 311b) of the top cover plate (310) and communicate with each other to form a first through-hole (610), The conductor comprises poles (330a, 330b); The top cover structure further includes an upper plastic part (340a, 340b) and a lower sealing part (350a, 350b); The pole, the upper plastic part, and the lower seal part are arranged in this order from top to bottom, the pole and the upper plastic part are disposed above the top cover plate, the upper plastic part is disposed between the pole and the top cover plate, and the lower seal part is provided penetrating through a lower through-hole of the insulating plate and an upper through-hole of the top cover plate, 2. The top cover structure of a secondary battery as described in claim 1, characterized in that the conductor through hole has a pole through hole, the upper plastic part has an upper plastic through hole, and the lower seal part has a lower seal through hole, the pole through hole, the upper plastic through hole, and the lower seal through hole are connected to each other to form a second through hole (620), and a second projection along the vertical direction of the second through hole is located inside a first projection along the vertical direction of the first through hole.

8. The top cover plate includes an upper sink platform (315a); 8. The top cover structure of a secondary battery as claimed in claim 7, wherein the upper sink platform is recessed with respect to the upper surface of the top cover plate, the upper through hole of the top cover plate is located on the upper sink platform, and the upper plastic part is located on the upper sink platform.

9. The upper plastic part comprises a first bottom wall (342a) and a first side wall (343a) connected to each other, The upper sink platform has an upper sink platform surface (316a) and an upper sink platform wall (317a); 9. The top cover structure of a secondary battery as described in claim 8, characterized in that the pole has an outer wall (332a) and a lower surface (333a), the first bottom wall is sandwiched between the upper sink platform surface and the lower surface, and the first side wall is sandwiched between the upper sink platform wall and the outer wall.

10. The lower seal part includes a second bottom portion (352a) and a second protrusion portion (353a) connected to each other, the second projection includes a first outer wall (3531) and a first apex (3532); The top cover structure of a secondary battery as described in claim 7, characterized in that the pole has a lower surface, the first top abuts the lower surface, and the second bottom and the first outer wall both abut against the hole wall of the first through hole.

11. The top cover structure of a secondary battery according to claim 10 , wherein the first outer wall also abuts against a wall of the upper plastic through-hole.

12. The top cover plate further comprises a lower sink platform (318a); the lower sink platform is recessed relative to a lower surface of the top cover plate; The lower sink platform has a lower sink platform surface (3181) and a lower sink platform wall (3182); 11. The top cover structure of a secondary battery as described in claim 10, wherein the second bottom has a second outer wall and a second apex, the second outer wall abutting the lower sink platform wall, and the second apex abutting the lower sink platform surface.

13. The insulating plate (15) is provided with a lower injection hole (157) and a vent hole (159), and a blowout prevention plate is provided at the bottom of the lower injection hole (157). The top cover plate (11) is provided with an upper injection hole (111) communicating with the lower injection hole (157) and an explosion prevention valve hole communicating with the vent hole (159), 2. The top cover structure of a secondary battery as described in claim 1, characterized in that an explosion-proof plate (24) that blocks the explosion-proof valve hole is provided at the bottom of the top cover plate (11), and an explosion-proof plate protective sheet (23) that blocks the explosion-proof valve hole is provided at the top of the top cover plate (11).

14. The top cover structure of a secondary battery as described in claim 1, characterized in that a plurality of undercuts (158) are provided on both sides of the insulating plate (15) and arranged in sequence at intervals in the longitudinal direction of the insulating plate (15), and the plurality of undercuts (158) are an injection-molded structure integral with the insulating plate (15).

15. A top cover structure (1) according to any one of claims 1 to 14, the adapter piece (2) for connecting the conductors (12, 17) in the top cover structure (1); An insulating gasket (4) provided at the bottom of the adapter piece (2); the adapter piece (2) is provided with a transfer pad that protrudes into a through hole in the conductor (12, 17), and the transfer part is joined to the conductor (12, 17) by welding.

16. The secondary battery comprises an electric core (5), The electric core (5) is provided with a number of tabs on its top, The number of the adapter pieces (2, 3) is two, and the two adapter pieces are provided on the top of the electric core (5); The tabs are welded to the surfaces of the two adapter pieces (2, 3) to form welded areas, At least one double-sided protective adhesive layer (42) is attached to the upper portion of the two adapter pieces (2, 3), and both sides of the double-sided protective adhesive layer are adhesive surfaces; The top cover assembly of a secondary battery according to claim 15, characterized in that the double-sided protective adhesive layer covers at least the welding area (412) when applied over the adapter pieces (2, 3).

17. The secondary battery is A top cover structure (250) according to any one of claims 7 to 12; A deflector; Equipped with the deflector is disposed below an insulating plate in the top cover structure, A deflector pole is provided on an upper surface of the deflector, The deflector pole includes a pole main body and a chassis, A top cover assembly for a secondary battery, characterized in that the pole main body is located on the chassis, suitable for passing through a first through hole and a second through hole in the top cover structure, and abuts against a hole wall of the second through hole.

18. The top cover assembly for a secondary battery according to claim 17 , wherein the chassis abuts against a wall of the through hole of the insulating plate in the first through hole.

19. Further comprising an electric core assembly and a case; the electrical core assembly is disposed within the case and includes at least one unitary electrical core, the unitary electrical core having an upwardly projecting tab; the deflector is positioned above the electric core assembly; The deflector is provided with a tab assembly part, 20. The top cover assembly of claim 17, wherein the tab assembly part is for passing a corresponding tab through and bending the tab so as to electrically connect the tab to the upper surface of the deflector in intimate contact therewith.

20. A top cover assembly as claimed in claim 15; A case (6) for housing an electric core (5), The case (6) has a plurality of electric cores (5) provided therein, and tabs of the electric cores (5) are welded to the adapter pieces (2, 3) via an insulating gasket (4) in the top cover assembly.

21. The electric core (5) is provided with a number of tabs on its top, The number of the adapter pieces is two, and the two adapter pieces are provided on the top of the electric core (5); The tabs are welded to the surfaces of the two adapter pieces (2, 3) to form welded areas (412); The secondary battery comprises at least one double-sided protective adhesive layer (42); Both sides of the double-sided protective adhesive layer are adhesive surfaces, 21. The secondary battery according to claim 20, characterized in that the double-sided protective adhesive layer is applied onto the adapter pieces (2, 3) and covers at least the welding areas.

22. The double-sided protective adhesive layer (42) is Two adhesive layers (422); a carbonate protective layer (423) disposed between the two viscous layers; The secondary battery according to claim 21 ,

23. 23. The secondary battery according to claim 22, wherein the carbonate protective layer has a sodium bicarbonate or sodium carbonate layer structure.

24. The secondary battery according to claim 22 , wherein the two adhesive layers are double-sided adhesive layers, and the carbonate protection layer has a powder layer structure that is spread and adhered between the two viscous layers.

25. said double-sided protective adhesive layer is an overall sheet structure, bonding and covering said welding areas on both said adapter pieces (2, 3) simultaneously; The adapter pieces (2, 3) are provided with an injection hole (4111), 22. The secondary battery of claim 21, wherein the double-sided protective adhesive layer has a first hole position (420) corresponding to a transfer pad (111) of the top cover assembly and a second hole position (421) corresponding to the injection hole.

26. The secondary battery according to claim 21, characterized in that a plurality of the double-sided protective adhesive layers are provided, each of which adheres and covers one or more of the welding areas on the two adapter sheets (2, 3).

27. The secondary battery according to claim 21, characterized in that the double-sided protective adhesive layer completely covers the adapter sheets (2, 3), and both ends of the double-sided protective adhesive layer protrude from both side edges of the insulating gasket and are adhered to the side walls of the electric core (5).

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