Secondary battery top cover and secondary battery

Abstract

The invention discloses a secondary battery top cover. Comprising a cover plate, an inner insulating part, an outer insulating part, a connecting block and a connecting piece, wherein a pole hole is formed in the cover plate in a penetrating manner; the inner insulating part is attached to the lower surface of the cover plate; the outer insulating part is attached to the upper surface of the cover plate; the connecting block is connected with the connecting piece, the connecting column is connected with the connecting block and the connecting piece, the connecting column is sleeved with the sealing ring, a riveting hole is formed in the connecting block in a penetrating mode, and a first sunken groove is formed in the position, on the periphery of the riveting hole, of the surface of the connecting block in a sunken mode. The connecting column comprises a column body part, a lower protruding part and a flange edge, the bottom of the column body part protrudes downwards to form the lower protruding part, the top of the column body part protrudes in the radial direction to form the flange edge, the flange edge is supported in the first concave groove and welded to the connecting block, and the lower protruding part is contained in the fixing hole to be welded and fixed. The electric connection performance is stable, the product weight can be reduced, and the manufacturing cost is low.

Description

Technical Field

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

[0002] Secondary batteries are widely used in people's daily lives as energy storage carriers or to provide energy for electrical equipment, such as electric vehicles and energy storage projects. Secondary batteries generally include a metal shell, a battery cell encapsulated in the shell, an electrolyte, and a battery cover that seals the shell and leads out the electrodes. The battery cover has various structural forms, and its performance meets the requirements of sealing and explosion-proof. A battery cover structure that has been used for a long time is a riveted block method, which includes a cover plate with a pole hole formed through it, an outer insulating member located on the upper side of the cover plate, a riveted block located above the outer insulating member, an inner insulating member attached to the lower side of the cover plate, and a pole that passes through the cover plate and the riveted block from the bottom of the cover plate and is riveted to the riveted block. The top of the pole is fixed to the riveted block by riveting, and a sealing ring is clamped between the pole and the cover plate for sealing.

[0003] In battery connection technology, the positive electrode preferably uses aluminum as the current collector, while the negative electrode preferably uses copper as the current collector. The connecting piece connecting the current collector needs to be made of the same metal as the current collector. In the negative electrode scheme of the above scheme, the connecting piece and the pole are integrally formed, and the whole needs to use copper, resulting in a large amount of copper, resulting in increased weight and high material costs. To solve this problem, Chinese patent 201921041367.2 discloses a top cover, the negative top cover assembly of the top cover includes a negative electrode substrate, a negative electrode column, a negative electrode connection block, a negative electrode upper bracket, a negative electrode lower bracket and a negative electrode seal. The negative electrode column passes through the negative electrode seal, the negative electrode lower bracket, the negative electrode substrate, and the negative electrode upper bracket in sequence and is connected to the negative electrode connection block. The negative electrode column includes a negative electrode base (i.e., a connection piece), a negative electrode rivet and an auxiliary welding piece. The negative electrode connection block is riveted to the negative electrode rivet, and the auxiliary welding piece is laser welded to the negative electrode base. This solution uses aluminum for the negative electrode column, and uses an auxiliary welding piece of the same material to cover the bottom of the rivet and weld it to the negative electrode base. The rivet and the negative electrode base are limited by the flange edge, and there are certain problems with the stability of the electrical connection between the two. Summary of the Invention

[0004] In view of this, it is necessary to provide a secondary battery top cover and a secondary battery that have stable electrical connection, are lightweight and low-cost.

[0005] In order to solve the above technical problems, the present application provides a secondary battery top cover, comprising a cover plate with a pole hole formed therethrough, an inner insulating member attached to the lower surface of the cover plate, an outer insulating member attached to the upper surface of the cover plate, a connecting block supported on the outer insulating member, a connecting piece attached to the inner insulating member and having a fixing hole passed through, a connecting column connecting the connecting block and the connecting sheet, and a sealing ring sleeved outside the connecting column, the connecting block having a rivet hole formed therethrough, the surface of the connecting block having a first recessed groove formed in a recessed manner around the rivet hole, the connecting column comprising a column portion, a lower convex portion formed protruding downward from the bottom of the column portion, and a flange edge formed protruding radially from the top of the column portion, the flange edge being supported in the first recessed groove and welded to the connecting block, the lower convex portion being accommodated in the fixing hole and welded fixed, the connecting column comprising an aluminum layer welded to the connecting block and a copper layer wrapping the bottom of the aluminum layer and welded to the connecting piece.

[0006] Preferably, the connecting column is formed by stamping a copper-aluminum composite plate and a step portion is formed between the lower protrusion and the column portion, and the top surface of the connecting piece is abutted against the step portion; the copper-aluminum composite plate is formed by pressing softened or molten aluminum material onto a copper layer.

[0007] Preferably, the copper material layer is first punched to form a groove structure, and then softened or molten aluminum is filled into the groove structure and the upper surface of the copper material layer to form the copper-aluminum composite plate.

[0008] Preferably, a second recessed groove with an inner diameter larger than that of the first recessed groove is formed on the periphery of the rivet hole above the first recessed groove, and the bottom surface of the second recessed groove is flush with the top surface of the flange edge and welded at the junction of the two.

[0009] Preferably, the connecting sheet includes a sheet body, the fixing hole is formed through the sheet body, the bottom surface of the sheet body is located at the periphery of the fixing hole and is recessed upward to form a concave ring, the bottom surface of the lower convex portion is flush with the bottom surface of the concave ring, the lower convex portion is welded at the joint gap with the fixing hole, and the weld produced by the welding does not exceed the height of the concave ring downward, that is, does not exceed the lower surface of the sheet body.

[0010] Preferably, the outer insulating member includes an isolation plate body attached to the upper surface of the cover plate, an outer wall protruding upward from the periphery of the isolation plate body to partially surround the outer edge of the connecting block, and a through hole formed through the isolation plate body, the periphery of the through hole protrudes downward to form a lower edge ring body, the lower edge ring body is pressed into the inner side of the pole hole of the cover plate, there is a gap between the lower edge ring body and the column part, and the top end of the inner ring body of the sealing ring is inserted into the gap between the lower edge ring body and the column part.

[0011] Preferably, the inner insulating part includes a fitting body fitted on the lower surface of the cover plate, a through hole formed through the fitting body, and a receiving cavity formed on the bottom surface of the fitting body for accommodating the connecting piece, and a surrounding wall is formed on the outer periphery of the receiving cavity. The outer ring body of the sealing ring is located between the inner wall surface of the through hole and the outer surface of the columnar part in the radial direction, and the outer ring body is clamped between the connecting piece and the lower surface of the cover plate in the vertical direction.

[0012] Preferably, the cover plate is located on both sides of the pole hole and is stamped downward to form a first positioning structure, the first positioning structure includes a first positioning recessed portion recessed from the upper surface of the cover plate and a first positioning protrusion protruding from the lower surface of the cover plate, the inner insulating member is recessed downward corresponding to the first positioning protrusion to form a second positioning structure, the second positioning structure includes a second positioning recess for the first positioning protrusion to be snapped into and a second positioning protrusion protruding from the bottom surface of the inner insulating member, the outer insulating member is protruded on the first positioning recess to form a third positioning protrusion snapped into the first positioning recess, and the connecting piece is provided with a third positioning recess at the position corresponding to the second positioning protrusion.

[0013] Preferably, the secondary battery top cover is assembled according to the following steps: first, the connecting column is inserted into the rivet hole of the connecting block from top to bottom, and the flange edge of the connecting column is supported on the surface of the first recessed groove and welded to fix; then the outer insulating part is assembled on the outer surface of the cover plate; the inner insulating part is attached to the inner surface of the cover plate; the combination of the connecting block and the connecting column is positioned on the outer insulating part, and the connecting column passes through the outer insulating part, the cover plate, and the inner insulating part; the sealing ring is inserted into the outside of the column part from bottom to top; finally, the sheet body of the connecting piece is installed on the bottom surface of the inner insulating part, the lower protrusion is inserted into the fixing hole of the connecting piece and is welded to fix at the joint seam.

[0014] In order to solve the above technical problems, the present application also provides a secondary battery, comprising a shell, a battery cell unit encapsulated in the shell and the aforementioned secondary battery top cover, wherein the secondary battery top cover is used to seal the shell.

[0015] The secondary battery top cover and secondary battery of the present application are realized by adding a connecting column provided with an aluminum layer and a copper layer, and connecting connecting blocks and connecting plates of different metal materials through the connecting column to complete welding between the same metal materials; at the same time, the upper and lower sides of the connecting column are fixed by welding to ensure the stability of the electrical connection; the use of the copper-aluminum composite plate greatly reduces the use of copper material, reduces weight and reduces material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Example 1

[0018] Figure 1 This is a three-dimensional diagram of the secondary battery top cover of Example 1 of the present application;

[0019] Figure 2 This is a three-dimensional exploded view of the secondary battery top cover of Example 1 of the present application;

[0020] Figure 3 For the Figure 2 A cross-sectional view taken along the dashed line AA is shown;

[0021] Figure 4 A three-dimensional diagram of the outer insulating member of the secondary battery top cover according to the first embodiment of the present application;

[0022] Figure 5 A three-dimensional view of the inner insulating member of the secondary battery top cover of the first embodiment of the present application

[0023] Figure 6 For the Figure 1 A cross-sectional view taken along the dashed line BB shown;

[0024] Example 2

[0025] Figure 7 This is a diagram showing the assembly of the electrode and the connecting piece of the secondary battery top cover according to the second embodiment of the present application;

[0026] Figure 8 This is a cross-sectional view of the secondary battery top cover before riveting in Example 2 of the present application;

[0027] Figure 9 This is a cross-sectional view of the secondary battery top cover after riveting in Example 2 of the present application;

[0028] Example 3

[0029] Figure 10 This is a cross-sectional view of the secondary battery top cover of Example 3 of the present application.

[0030] Description of Reference Numerals

[0031] Cover plate 10; Pole hole 11; First positioning structure 12; First positioning recess 121; First positioning protrusion 122; Connecting block 20; Riveting hole 21; Second recessed groove 211; First recessed groove 212; Outer insulator 30; Isolating plate 31; Outer wall 32; Accommodating cavity 33; Through hole 34; Lower ring 35; Third positioning protrusion 36; Connecting plate 40; Plate 41; Fixing hole 42; Third positioning recess 4 3; concave ring-44; inner insulating member-50; fitting body-51; through hole-52; second positioning structure-53; second positioning recess-531; second positioning protrusion-532; surrounding wall-54; receiving cavity-55; sealing ring-60; inner ring body-61; sealing hole-62; outer ring body-63; connecting column-90; aluminum layer-901; copper layer-902; column portion-91; lower protrusion-92; step portion-93; flange edge-94; rivet groove-95. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions and advantages of this application more clear, the technical solutions of this application will be described clearly and completely below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this application, not all of them.

[0033] This application is based on Figure 1 The X direction is the lateral direction, the Y direction is the longitudinal direction, and the Z direction is the vertical direction upward.

[0034] Example 1

[0035] See also Figures 1 to 6 As shown, the secondary battery top cover of this embodiment includes a cover plate 10, an inner insulating member 50 attached to the lower surface of the cover plate 10, an outer insulating member 30 attached to the upper surface of the cover plate 10, a connecting block 20 mounted on the outer insulating member 30, a connecting piece 40 placed on the inner insulating member 50, a connecting column 90 that fixes the connecting block 20 and the connecting piece 40 together, and a sealing ring 60 clamped between the cover plate 10, the connecting column 90 and the connecting piece 40.

[0036] Please refer to Figure 2 、 Figure 3As shown, the cover plate 10 is made of one of aluminum alloy, stainless steel, or titanium alloy. If stainless steel or titanium alloy is used, the cover plate 10 is thinner, while aluminum alloy allows for a thicker cover plate. Stainless steel and titanium alloy have higher melting points, offering improved safety. However, stainless steel is more difficult to process than aluminum alloy, making it difficult to fabricate complex structures on the cover plate 10, which would otherwise increase manufacturing costs. Titanium alloy, on the other hand, is more difficult to process and has higher material costs, and is generally used in the aviation field. Aluminum alloy is currently widely used in automotive power batteries and energy storage batteries. However, due to its low melting point, it can easily burn through and destroy the entire battery pack in a short period of time if a fire occurs, resulting in a short explosion time and insufficient escape time for vehicle occupants. Stainless steel, on the other hand, not only reduces material costs and improves space utilization, but also improves product safety, extending the duration of a large-scale fire or explosion, providing more time for occupants to escape.

[0037] The cover plate 10 includes a through-hole 11 and first positioning structures 12 stamped downwardly on both sides of the hole 11 in the transverse direction. The first positioning structure 12 includes a first positioning recess 121 recessed inward from the upper surface of the cover plate 10 and a first positioning protrusion 122 protruding from the lower surface of the cover plate 10. The first positioning recess 121 and the first positioning protrusion 122 are stamped simultaneously on the outer and inner sides of the first positioning structure 12.

[0038] The connecting piece 40 is stamped from a copper alloy sheet and includes a sheet body 41, a fixing hole 42 formed vertically through the sheet body 41, and third positioning recesses 43 stamped laterally on either side of the fixing hole 42. The third positioning recesses 43 are formed on the upper surface of the sheet body 41. The lower surface of the sheet body 41 is flat and has no protrusions. The third positioning recesses 43 are open laterally to form a notched circular shape. The lower surface of the sheet body 41 is recessed upward to form a concave ring 44 around the fixing hole 42. The bottom surface of the concave ring 44 is higher than the bottom surface of the sheet body 41.

[0039] Key References Figure 2 、 Figure 3 、 Figure 5As shown, the inner insulating member 50 includes a fitting body 51 fitted to the lower surface of the cover plate 10, a through hole 52 formed through the fitting body 51, second positioning structures 53 formed on both sides of the through hole 52, and a receiving cavity 55 formed on the lower surface of the fitting body 51 and enclosing the through hole 52. The second positioning structure 53 includes a second positioning recess 531 formed downwardly from the upper surface of the fitting body 51 and a second positioning protrusion 532 protruding from the lower surface of the fitting body 51. The second positioning protrusion 532 is also enclosed within the receiving cavity 55. The receiving cavity 55 is formed by a surrounding wall 54 protruding from the lower surface of the fitting body 51, and the lower surface of the second positioning protrusion 532 does not extend beyond the bottom surface of the surrounding wall 54. The connecting piece 40 is pressed into the receiving cavity 55. The periphery of the connecting piece 40 is restrained by the surrounding wall 54. The third positioning recess 43 of the connecting piece 40 is correspondingly engaged with the second positioning protrusion 532 to prevent rotation. The second positioning protrusion 532 is integrally connected to the surrounding wall 54 to enhance the strength of the second positioning protrusion 532.

[0040] Please continue reading Figures 2 to 4 As shown, the outer insulating member 30 includes an isolation plate 31, an outer peripheral wall 32 protruding upward from the upper surface of the isolation plate 31, a receiving cavity 33 enclosed by the isolation plate 31 and the outer peripheral wall 32, and a through hole 34 formed through the isolation plate 31. A third positioning protrusion 36 protrudes downward from the bottom surface of the isolation plate 31, and a lower edge ring 35 extends downward from the edge of the through hole 34.

[0041] The sealing ring 60 includes an inner ring body 61, an outer ring body 63 extending radially outward from the lower side of the inner ring body 61, and a sealing hole 62 formed through the inner ring body 61. The outer diameter of the outer ring body 63 is larger than the outer diameter of the inner ring body 61, and the inner ring body 61 is formed by protruding upward from the upper surface of the outer ring body 63.

[0042] A rivet hole 21 is formed through the middle of the connection block 20. A second recessed groove 211 and a first recessed groove 212 are formed on the surface of the connection block 20, recessed downward from the periphery of the rivet hole 21. The bottom surface of the second recessed groove 211 is higher than the bottom surface of the first recessed groove 212, and the inner diameter of the second recessed groove 211 is larger than the inner diameter of the first recessed groove 212. The inner diameter of the first recessed groove 212 is also larger than the inner diameter of the rivet hole 21.

[0043] The connecting post 90 includes a body 91, a lower convex portion 92 extending downward from the bottom of the body 91, a flange 94 extending radially from the top outer edge of the body 91, and a stepped portion 94 formed on the lower surface of the body 91 and radially outward of the lower convex portion 92. If the connecting post 90 is used as the positive electrode material, it is made entirely of aluminum. If the connecting post 90 is used as the negative electrode, it includes an aluminum layer 901 and a copper layer 902 covering the bottom surface of the aluminum layer 901. The copper layer 902 wraps around the bottom surfaces of the lower convex portion 92 and the stepped portion 93.

[0044] This embodiment uses the connecting post 90 as the negative electrode. These connecting posts 90 are formed by stamping, that is, a plurality of them are punched out of a metal sheet. The metal sheet is formed by first selecting a copper material of a certain thickness, then pressing softened or molten aluminum onto the surface of the copper material to form a copper-aluminum composite plate. The copper-aluminum composite plate is then stamped into the connecting posts 90. This design results in the copper layer 902 on the outer side of the lower protrusion 92 becoming thinner or missing, but the copper layer 902 on the bottom surface of the lower protrusion 92 remains intact, achieving the required performance.

[0045] Alternatively, the copper plate is pre-punched to form a groove structure, and then softened or molten aluminum is pressed on the groove structure and the surface of the copper material to form a copper-aluminum composite plate with a lower protrusion 92 and a step portion 93, and then the copper-aluminum composite plate is cut into a plurality of connecting columns 90.

[0046] Key References Figure 6 As shown, the following will focus on the assembly method of the secondary battery top cover of this embodiment:

[0047] First, the connecting column 90 is installed from top to bottom into the rivet hole 21 of the connecting block 20, the flange edge 94 of the connecting column 90 is supported on the surface of the first recessed groove 212 and the upper surface of the flange edge 94 is flush with the bottom surface of the second recessed groove 211, the connecting column 90 and the connecting block 20 are welded and fixed along the junction of the flange edge 94 and the edge of the second recessed groove 211 and sealed; then, the outer insulating member 30 is assembled on the outer surface of the cover plate 10, the third positioning protrusion 36 of the outer insulating member 30 enters the first positioning recessed portion 121 on the outer surface of the cover plate 10, and the lower edge ring body 35 is snapped into the edge of the pole hole 11; the inner insulating member 50 is attached to the inner surface of the cover plate 10, and is fixed to the inner surface of the cover plate 10 by snapping or bonding, and the first positioning protrusion 122 enters the second positioning recessed portion 531 on the surface of the inner insulating member 50 for position limiting. The inner diameter of the through hole 52 of the inner insulating member 50 is much larger than the pole hole 11 of the cover plate 10 so that at least part of the inner surface of the cover plate 10 within the range of the through hole 52 is exposed outside the inner insulating member 50; the combination of the connecting block 20 and the connecting column 90 is positioned on the outer insulating member 20, the connecting block 20 is at least partially surrounded by the accommodating cavity 33, and the lower part of the connecting column 90 passes through the through hole 34, the pole hole 11 and the through hole 52; the sealing ring 60 is inserted into the outside of the column part 91 from bottom to top, the top of the inner ring body 61 is against the bottom surface of the connecting block 20 and wraps the outer periphery of the column part 91, the outer ring body 63 is located within the range of the through hole 52 of the inner insulating member 50 and the upper surface of the outer ring body 63 is in contact with the lower surface of the cover plate 10; finally, The sheet body of the connecting piece 40 is installed in the receiving cavity 55 on the bottom surface of the inner insulating part 50, and the second positioning protrusion 532 of the inner insulating part 50 is inserted into the third positioning recess 43 of the connecting piece 40. The bottom surface of the outer ring body 63 of the sealing ring 60 is supported on the upper surface of the connecting piece 40, and the lower protrusion 92 is inserted into the fixing hole 42 of the connecting piece 40, and the upper surface of the connecting piece 40 is limited to the step portion 93. The connecting piece 40 and the connecting block 20 are pressed tightly so that the bottom surface of the concave ring 44 of the connecting piece 40 is flush with the bottom surface of the lower protrusion 92. At this time, the inner ring body 61 of the sealing ring 60 is squeezed and clamped by the connecting piece 40 and the bottom surface of the connecting block 20, and the outer ring body 63 is squeezed and clamped by the inner surface of the cover plate 10 and the connecting piece 40. The outer contour of the connecting piece 40 is consistent with the receiving cavity 55 of the inner insulating member 50, so that the connecting piece 40 is confined within the receiving cavity 55. After the connecting block 20 and the connecting piece 40 are pressed together, continuous welding is performed at the joint between the connecting piece 40 and the lower protrusion 92 to fix the connecting column 90 and the connecting piece 40 together and form a welding ring S.

[0048] In this embodiment, the inner ring body 61 of the sealing ring 60 realizes the sealing between the bottom surface of the connecting block 20, the outer peripheral surface of the connecting column 90 and the surface of the connecting piece 40, and the outer ring body 63 realizes the sealing between the inner surface of the cover plate 10 and the surface of the connecting piece 40, thereby achieving double waterproofing, and waterproofing no longer depends on the welding sealing of the welding ring S.

[0049] This embodiment adds a connecting column 90 having an aluminum layer 901 and a copper layer 902, and connects the connecting block 20 and the connecting plate 40 made of different metal materials through the connecting column 90 to complete welding between the same metal materials; at the same time, the upper and lower sides of the connecting column 90 are fixed by welding to ensure the stability of the electrical connection.

[0050] Example 2

[0051] See also Figures 7 to 9 As shown, the difference between this embodiment and the first embodiment is that the flange edge 94 of the connecting column 90 is eliminated, so that the outer diameter of the column portion 91 remains the same. The following differences occur during assembly: the connecting piece 40 and the connecting column 90 are first welded together and fixed; the sealing ring 60 is then inserted from top to bottom onto the outer side of the column portion 91; the outer insulating member 30 and the inner insulating member 50 are then installed on the outer and inner surfaces of the cover plate 10, respectively; the combination of the connecting piece 40 and the connecting column 90 is inserted from bottom to top, so that the column portion 91 passes through the through hole 52, the pole hole 11, the through hole 34, and the rivet hole 21; finally, the top of the column portion 91 is riveted so that the outer diameter of the column portion 91 is expanded to support the bottom surface of the first recessed groove 212, and the column portion 91 and the second recessed groove 211 are simultaneously welded together. A rivet groove 95 is formed when the top of the connecting column 90 is riveted.

[0052] The remaining structures of Example 2 are basically the same as those of Example 1. The design of the concave ring 44 of the connecting piece 40 in Examples 1 and 2 is used to ensure that the welding joint between the connecting piece 40 and the second column 202 is performed within the concave ring 44, and to ensure that the weld point formed during welding does not protrude beyond the bottom surface of the sheet body 41 of the connecting piece 40, so that the bottom surface of the sheet body 41 remains smooth and flat.

[0053] In the second embodiment, a riveting process is added between the connecting column 90 and the connecting block 20 during welding, so that the connection between the connecting column 90 and the connecting block 20 is more stable and reliable.

[0054] Example 3

[0055] See also Figure 7 、 Figure 10As shown, the difference between this embodiment and the first embodiment is that: the structure of the flange edge 94 of the connecting column 90 is cancelled, so that the outer diameter of the column part 91 remains the same; the first recessed groove 212 of the connecting block 20 is cancelled, and only the said is retained; there are the following differences during assembly: first, the connecting piece 40 and the connecting column 90 are combined and welded and fixed; then the sealing ring 60 is inserted from top to bottom into the outside of the column part 91; then the outer insulating member 30 and the inner insulating member 50 are respectively installed on the outer surface and inner surface of the cover plate 10; the combination of the connecting piece 40 and the connecting column 90 is installed from bottom to top, so that the column part 91 passes through the through hole 52, the pole hole 11 and the through hole 34 and the rivet hole 21; at this time, the top surface of the column part 91 is flush with the bottom surface of the second recessed groove 211, and the column part 91 and the second recessed groove 211 are combined and welded.

[0056] The present application also includes a secondary battery, which includes a shell, a battery cell unit encapsulated in the shell, and a secondary battery top cover that closes the shell and is electrically connected to the battery cell unit.

[0057] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above embodiments merely represent preferred embodiments of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A secondary battery top cover, comprising a cover plate with a terminal hole formed therethrough, an inner insulating member attached to the lower surface of the cover plate, an outer insulating member attached to the upper surface of the cover plate, a connecting block supported on the outer insulating member, a connecting piece attached to the inner insulating member and having a fixing hole therethrough, a connecting post connecting the connecting block and the connecting piece, and a sealing ring sleeved over the connecting post, characterized in that: A rivet hole is formed through the connecting block, and a first recessed groove is formed on the surface of the connecting block around the rivet hole. The connecting column includes a column portion, a lower convex portion protruding downward from the bottom of the column portion, and a flange edge protruding radially from the top of the column portion. The flange edge is supported in the first recessed groove and welded to the connecting block, and the lower convex portion is accommodated in the fixing hole and welded fixed. The connecting column includes an aluminum layer welded to the connecting block and a copper layer wrapping the bottom of the aluminum layer and welded to the connecting piece.

2. The secondary battery top cover according to claim 1, wherein: The connecting column is formed by stamping a copper-aluminum composite plate and a step portion is formed between the lower convex portion and the column portion, and the top surface of the connecting piece is abutted against the step portion; the copper-aluminum composite plate is formed by pressing softened or molten aluminum material onto a copper material layer.

3. The secondary battery top cover according to claim 2, wherein: The copper material layer is first punched to form a groove structure, and then softened or molten aluminum is filled into the groove structure and the upper surface of the copper material layer to form the copper-aluminum composite plate.

4. The secondary battery top cover according to claim 2, wherein: A second recessed groove with an inner diameter larger than that of the first recessed groove is formed on the periphery of the rivet hole and located above the first recessed groove. The bottom surface of the second recessed groove is flush with the top surface of the flange edge and the two are welded at their junction.

5. The secondary battery top cover according to claim 2, wherein: The connecting sheet includes a sheet body, the fixing hole is formed through the sheet body, the bottom surface of the sheet body is located at the periphery of the fixing hole and is recessed upward to form a concave ring, the bottom surface of the lower convex portion is flush with the bottom surface of the concave ring, the lower convex portion is welded at the joint gap with the fixing hole, and the welding point produced by the welding does not exceed the height of the concave ring downward, that is, does not exceed the lower surface of the sheet body.

6. The secondary battery top cover according to claim 5, wherein: The outer insulating member includes an isolation plate body attached to the upper surface of the cover plate, an outer wall protruding upward from the periphery of the isolation plate body to partially surround the outer edge of the connecting block, and a through hole formed through the isolation plate body, the periphery of the through hole protrudes downward to form a lower edge ring body, the lower edge ring body is pressed into the inner side of the pole hole of the cover plate, there is a gap between the lower edge ring body and the column part, and the top end of the inner ring body of the sealing ring is inserted into the gap between the lower edge ring body and the column part.

7. The secondary battery top cover according to claim 6, wherein: The inner insulating part includes a fitting body fitted on the lower surface of the cover plate, a through hole formed through the fitting body, and a receiving cavity formed on the bottom surface of the fitting body for receiving the connecting piece, a surrounding wall is formed on the outer periphery of the receiving cavity, the outer ring body of the sealing ring is located between the inner wall surface of the through hole and the outer surface of the columnar part in the radial direction, and the outer ring body is clamped between the connecting piece and the lower surface of the cover plate in the vertical direction.

8. The secondary battery top cover according to claim 7, wherein: The cover plate is located on both sides of the pole hole and is stamped downward to form a first positioning structure. The first positioning structure includes a first positioning recessed portion recessed from the upper surface of the cover plate and a first positioning protrusion protruding from the lower surface of the cover plate. The inner insulating member is recessed downward corresponding to the first positioning protrusion to form a second positioning structure. The second positioning structure includes a second positioning recess for the first positioning protrusion to be snapped into and a second positioning protrusion protruding from the bottom surface of the inner insulating member. The outer insulating member is protruded on the first positioning recess to form a third positioning protrusion that is snapped into the first positioning recess. The connecting piece is provided with a third positioning recess at a position corresponding to the second positioning protrusion.

9. The secondary battery top cover according to claim 2, wherein: The secondary battery top cover is assembled according to the following steps: first, the connecting column is inserted into the rivet hole of the connecting block from top to bottom, and the flange edge of the connecting column is supported on the surface of the first recessed groove and welded to fix; then the outer insulating part is assembled on the outer surface of the cover plate; the inner insulating part is attached to the inner surface of the cover plate; the combination of the connecting block and the connecting column is positioned on the outer insulating part, and the connecting column passes through the outer insulating part, the cover plate, and the inner insulating part; the sealing ring is inserted into the outside of the column part from bottom to top; finally, the sheet body of the connecting piece is installed on the bottom surface of the inner insulating part, the lower protrusion is inserted into the fixing hole of the connecting piece and is welded to fix at the joint seam.

10. A secondary battery, characterized in that: The battery comprises a shell, a battery cell unit encapsulated in the shell, and the secondary battery top cover as claimed in claim 1, wherein the secondary battery top cover is used to seal the shell.

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