Secondary battery top cover and secondary battery

Abstract

The utility model relates to a top cover of a secondary battery, which comprises a cover plate which is vertically penetrated to form a pole column hole, a pole column which is arranged in the pole column hole from top to bottom, a plastic body for isolating the pole column from the cover plate, a welding ring which is sleeved on the lower side of the pole column and is welded and fixed with the pole column, and a sealing ring, the pole comprises a fixed convex ring limited above the cover plate, an upper main body formed by protruding upwards from the fixed convex ring, and a lower main body formed by protruding downwards from the fixed convex ring; the lower main body comprises a first lower main body connected with the fixed convex ring and a second lower main body which is formed by protruding downwards from the first lower main body, the outer diameter of the second lower main body is smaller than that of the first lower main body, and the upper surface of the sealing ring is attached to at least part of the lower surface of the cover plate and the bottom surface of the second lower main body; and the lower surface of the sealing ring is extruded by the upper surface of the welding ring. The utility model also comprises a secondary battery.

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] A secondary battery includes a number of battery cells, a busbar assembly that connects the battery cells in parallel, and a pair of poles that electrically connect the busbar assembly and transmit electrical energy. Liquid substances such as electrolytes are injected into the secondary battery, and the sealing of the secondary battery needs to be maintained. To maintain the sealing, the secondary battery also includes a shell and a top cover that closes the shell. The pole is fixed to the top cover and requires a cover plate to maintain electrical isolation. Patent application No. 202311515865.7 of the People's Republic of China discloses a cover plate assembly, which includes a cover plate with a mounting hole, a pole installed in the mounting hole, a welding ring, an upper insulating member, a sealing ring, a connector, and a lower insulating member. The pole includes a first main body with an outer diameter larger than the inner diameter of the mounting hole and a second main body that is accommodated in the mounting hole and exposed downward. The welding ring is sleeved on the outer periphery of the second main body and welded to the second main body to limit the pole. The upper insulating member wraps around the outer periphery of the pole, and the sealing ring is clamped between the lower surface of the cover plate and the upper surface of the welding ring.

[0003] The above-mentioned prior art has the following technical problems: the sealing ring cannot cover the area between the outer periphery of the pole and the surface of the cover plate, and the sealing performance is seriously dependent on the welding effect between the welding ring and the pole. If the welding cannot achieve complete sealing, the above-mentioned top cover cannot achieve good sealing performance, and the electrolyte may overflow along the unwelded gap between the pole and the welding ring and the gap between the upper insulating part and the pole, causing safety risks. Utility Model Content

[0004] In view of this, it is necessary to provide a secondary battery top cover with stable sealing performance.

[0005] To solve the above technical problems, the present application provides a secondary battery top cover, comprising a cover plate with pole holes formed through the upper and lower parts, a pole inserted into the pole hole from top to bottom, a plastic body isolating the pole and the cover plate, a welding ring and a sealing ring sleeved on the lower side of the pole and welded and fixed to the pole, the pole comprising a fixing convex ring limited above the cover plate, an upper body protruding upward from the fixing convex ring, and a lower body protruding downward from the fixing convex ring, the lower body comprising a first lower body connected to the fixing convex ring and a second lower body protruding downward from the first lower body with an outer diameter smaller than the first lower body, the upper surface of the sealing ring is applied to at least a portion of the lower surface of the cover plate and the bottom surface of the second lower body, and the lower surface of the sealing ring is squeezed by the upper surface of the welding ring.

[0006] Preferably, the cover plate includes a plate body, the pole hole passes through the plate body from top to bottom, the lower surface of the plate body is located at the periphery of the pole hole and is pressed upward to form an annular groove, the annular groove is flush with the bottom surface of the second lower body of the pole, and the sealing ring is placed on the lower side of the annular groove and the bottom surface of the second lower body.

[0007] Preferably, the pole further includes a third lower body protruding downward from the second lower body and extending with an outer diameter smaller than that of the second lower body. The welding ring is sleeved on the outside of the third lower body. The welding ring extends in the radial direction and spans the bottom surface of the second lower body and at least a portion of the bottom surface of the annular groove.

[0008] Preferably, a gap is formed between the outer periphery of the first lower body of the pole and the inner wall surface of the pole hole, and the sealing ring includes a ring body and a vertical portion protruding upward from the middle of the ring body and extending into the gap, and the ring body includes an outer ring body located outside the vertical portion and an inner ring body located inside the vertical portion.

[0009] Preferably, the inner ring body is applied to the bottom surface of the second lower body, the outer ring body is applied to the bottom surface of the annular groove, the sealing ring is squeezed by the welding ring so that the ring body extends in the radial direction, and the vertical part extends upward and fills the gap.

[0010] Preferably, the plastic body is integrally formed with the pole, and the plastic body includes a plastic ring body that wraps the outer side surface and upper and lower surfaces of the fixed convex ring and a plurality of positioning posts protruding downward from the bottom surface of the plastic ring body. The upper surface of the plate body is provided with a plurality of positioning blind holes located around the pole hole for inserting the positioning posts.

[0011] Preferably, the plastic body is molded separately, and the pole is assembled on the plastic body from top to bottom. The plastic body includes a plastic ring body surrounding the outer side surface and lower surface of the fixed convex ring and a plurality of positioning posts protruding downward from the bottom surface of the plastic ring body. The upper surface of the plate body is provided with a plurality of positioning blind holes for inserting the positioning posts at the periphery of the pole hole.

[0012] Preferably, the inner wall surface of the plastic ring body close to the first lower body is set as an inclined surface, and the vertical portion of the sealing ring is squeezed and extended upward into the inclined surface to completely isolate the first lower body from the inner wall surface of the pole hole.

[0013] Preferably, the pole further includes a fourth lower body protruding downwardly from the third lower body and extending, the outer diameter of which is smaller than that of the third lower body; a welding groove is formed on the bottom surface of the third lower body and the outer side surface of the fourth lower body; the welding ring includes an annular body, the inner bottom surface of the annular body is thinned to form a welding groove which is on the same horizontal plane as the bottom surface of the third lower body; the welding groove of the welding ring is welded and fixed to the welding groove of the pole at the junction.

[0014] To solve the above technical problems, the present application also provides a secondary battery, including the aforementioned secondary battery top cover, a battery shell, and a battery cell encapsulated in the battery shell through the secondary battery top cover, wherein the battery cell is electrically connected to the pole and conducts electrical energy through the pole.

[0015] The secondary battery top cover of the present application achieves good sealing performance between the pole and the cover plate by clamping the sealing ring between the pole, the lower surface of the plate and the upper surface of the welding ring; at the same time, the sealing ring protrudes upward in the middle and extends to the vertical part between the outer surface of the pole and the inner side surface of the pole hole of the plate, further improving the sealing performance of the battery top cover. 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] Figure 1 A three-dimensional assembly diagram of the secondary battery top cover of this application;

[0018] Figure 2 This is a three-dimensional exploded view of the secondary battery top cover of this application;

[0019] Figure 3 This is a three-dimensional exploded view of the secondary battery top cover from another angle of the present application;

[0020] Figure 4 For the Figure 1 A cross-sectional view taken along the dashed line AA is shown;

[0021] Figure 5 for Figure 4 Exploded view of the section view shown.

[0022] Description of Reference Numerals

[0023] Inner shell-10; inner shell body-11; through hole-12; hot melt column-13; cover plate-20; plate body-21; outer surface-211; inner surface-212; hot melt hole-213; pole column hole-22; positioning blind hole-221; annular groove-222; explosion-proof port-23; liquid injection hole-24; pole column-30; fixed convex ring-31; upper body-32; upper wrapping step-321; lower body-33; first lower body-34; lower wrapping step-341; second lower body-35; sealing step-351; third lower body-36; welding step-361; fourth lower body-37; welding groove-371, 53; sealing ring-40; ring body-41; outer ring body-411; inner ring body-412; vertical part-42; sleeve hole-43; welding ring-50; annular body-51; through hole-52; plastic body-60; plastic ring body-61; embedded ring groove-62; positioning column-64. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in conjunction with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0025] The present application is described below in conjunction with the drawings. Figure 1 The X direction shown in the drawings is the transverse direction, the Y direction is the longitudinal direction, and the Z direction is the upward vertical direction.

[0026] Please continue to refer to Figures 1 to 5 The secondary battery top cover of the present application includes a cover plate 20 provided with a pole column hole 22, a pole column 30 loaded into the pole column hole 22, a plastic body 60 wrapping the pole column 30, a welding ring 50 sleeved on the lower side of the pole column 30 and fixedly welded with the pole column 30, and a sealing ring 40 clamped between the welding ring 50 and the pole column 30, cover plate 20.

[0027] The cover plate 20 includes a plate body 21, a pole column hole 22 formed through the plate body 21, an explosion-proof port 23, and a liquid injection hole 24. A plurality of positioning blind holes 221 are punched downward on the upper surface of the periphery of the pole column hole 22, and an annular groove 222 is punched upward on the lower surface of the outer periphery of the pole column hole 22. The plate body 21 includes an outer surface 211, an inner surface 212, a plurality of hot melt holes 213 punched on the lower surface 212, and the hot melt holes 213 are blind hole structures. The upper surface 211 of the plate body 21 is a planar structure, the upper surface of the periphery of the pole column hole 22 has no arch structure, the wall thickness of the annular groove 222 of the periphery of the pole column hole 22 is smaller than the wall thickness of the rest of the plate body 21, and the annular groove 222 is used to accommodate the welding ring 50.

[0028] The terminal 30 includes a fixed protruding ring 31, an upper body 32 protruding upward from the center of the fixed protruding ring 31, and a lower body 33 protruding downward from the center of the fixed protruding ring 31. The outer diameter of the fixed protruding ring 31 is larger than the inner diameter of the terminal hole 22, and also larger than the outer diameters of the upper and lower bodies 32, 33. The outer diameter of the lower body 33 is smaller than the inner diameter of the terminal hole 22. An upper wrapping step 321 is formed on the upper side of the fixed protruding ring 31, located outside the upper body 32. The lower body 33 includes a first lower body 34, a second lower body 35, a third lower body 36, and a fourth lower body 37, each with a gradually decreasing outer diameter from top to bottom. A lower wrapping step 341 is formed on the outer side of the first lower body 34, a sealing step 351 is formed on the outer side of the second lower body 35, a welding step 361 is formed on the outer side of the third lower body 36, and a welding groove 371 is formed on the outer side of the fourth lower body 37.

[0029] The plastic body 60 is integrally formed around the pole 30 and partially encapsulates the pole 30. The plastic body 60 comprises a plastic ring 61, an embedded annular groove 62 formed inside the plastic ring, and a positioning post 64 protruding downward from the lower surface of the plastic ring 61. The fixed protrusion 31 of the pole 30 is encased in the embedded annular groove 62. The inner edge of the bottom of the plastic ring 61 is designed as an inclined surface.

[0030] In other embodiments, the plastic body 60 may be formed separately, and then the pole 30 may be installed in the plastic body 60. This solution can reduce manufacturing costs to a certain extent.

[0031] The sealing ring 40 includes a ring body 41, a vertical portion 42 protruding upward from the center of the ring body 41, and a sleeve hole 43 extending vertically therethrough. The ring body 41 includes an outer ring body 411 located outside the vertical portion 42 and an inner ring body 412 located inside the vertical portion 42. The sleeve hole 43 is formed in the inner ring body 412.

[0032] The welding ring 50 includes an annular body 51 and a through-hole 52 extending vertically through the annular body 51. A welding groove 53 is formed on the lower surface of the annular body 51, formed by thinning the periphery of the through-hole 52. The welding groove 53 of the welding ring 50 is coplanar with the welding groove 371 on the outer side of the fourth lower body 37 of the terminal 30.

[0033] The inner housing 10 includes an inner housing 11 attached to the inner surface 212 of the plate body 21 of the cover plate 20, a through hole 12 corresponding to the position of the pole hole 22, and a heat-seal post 13 protruding upward from the upper surface of the inner housing 11. The heat-seal post 13 on the inner housing 11 is inserted upward into the heat-seal hole 213 on the lower surface of the plate body 21 of the cover plate 20 and is fixed by heat-seal.

[0034] The assembly method of the secondary battery top cover of this embodiment is as follows:

[0035] First, the pole 30 is integrally molded to form the plastic body 60 or the plastic body 60 is molded separately, and then the pole 30 is installed in the plastic body 60; then, the plastic body 60 and the pole 30 therein are installed from top to bottom into the pole hole 22 of the cover plate 20, at this time, the positioning column 64 on the lower surface of the plastic ring body 61 of the plastic body 60 is inserted into the positioning blind hole 221 on the upper surface of the plate body 21 of the cover plate 20; then, the sealing ring 40 is inserted into the outside of the pole 30 from bottom to top, at this time, the vertical portion 42 of the sealing ring 40 is inserted upward between the outer side surface of the lower wrapping step 341 and the inner side surface of the pole hole 22, the outer ring body 411 is attached to the lower surface of the annular groove 222 of the plate body 21, and the inner ring body 412 is attached to the lower surface of the sealing step 351 on the outer side of the second lower main body 35 of the pole 30; finally, the welding The ring 50 is sleeved on the welding step 361 on the outer side surface of the third lower body 36 of the pole 30 and is welded to the pole 30. At this time, the upper surface of the ring body 50 of the welding ring 50 squeezes the ring body 41 of the sealing ring 40, that is, squeezes the outer ring body 411 and the inner ring body 412 at the same time. The top surface of the sealing step portion 361 is on the same horizontal plane as the top surface of the annular groove 222 of the plate body 21. In the initial state of the sealing ring 40, the thickness of the ring body 41 is relatively large. When the ring body 41 is squeezed by the welding ring 50, it extends, causing the ring body 41 to expand in the radial direction. The vertical portion 42 is squeezed upward into the inclined surface of the bottom surface of the plastic body 60 to increase the contact between the sealing ring 40 and the outer surface of the pole 30, increase the sealing area, and achieve better sealing performance. The outer ring body 411 extends outward to the edge of the annular groove 222 and fits in place. The welding groove 53 of the welding ring 50 and the welding groove 371 on the outer side of the fourth lower body 37 of the pole 30 are on the same horizontal plane. The weld joint is the gap between the welding groove 53 of the welding ring 50 and the welding groove 371 of the pole 30. This gap corresponds to the welding step 361 and is offset from the sealing ring 40 to avoid damage to the sealing ring during welding. The inner shell 10 is finally installed on the inner surface 212 of the plate body 21 and fixed by heat-melting the heat-melting post 13 to the heat-melting hole 213. In other embodiments, the heat-melting post 13 can be replaced with a conventional plastic post, which is inserted into the heat-melting hole 213 through an interference fit and fixed.

[0036] The secondary battery of the present application includes the battery top cover, the battery shell, and the battery cell encapsulated in the battery shell by the battery top cover. The battery cell is electrically connected to the pole 30 and conducts electrical energy through the pole 30.

[0037] The secondary battery top cover of the present application achieves good sealing performance between the pole 30 and the cover plate 20 by clamping the sealing ring 40 between the pole 30, the lower surface of the plate 21 and the upper surface of the welding ring 50; at the same time, the sealing ring 40 protrudes upward in the middle and extends to the vertical portion 42 between the outer surface of the pole 30 and the inner side surface of the pole hole 222 of the plate 21, further improving the sealing performance of the battery top cover.

[0038] 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.

[0039] The above embodiments merely represent preferred implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model 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 concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A secondary battery top cover, comprising a cover plate with a terminal hole formed therethrough, a terminal inserted into the terminal hole from top to bottom, a plastic body separating the terminal from the cover plate, a welding ring and a sealing ring sleeved on the underside of the terminal and welded to the terminal, characterized in that: The pole includes a fixed protruding ring limited above the cover plate, an upper body formed by protruding upward from the fixed protruding ring, and a lower body formed by protruding downward from the fixed protruding ring. The lower body includes a first lower body connected to the fixed protruding ring and a second lower body formed by protruding downward from the first lower body and having an outer diameter smaller than that of the first lower body. The upper surface of the sealing ring is applied to at least a portion of the lower surface of the cover plate and the bottom surface of the second lower body, and the lower surface of the sealing ring is squeezed by the upper surface of the welding ring.

2. The secondary battery top cover according to claim 1, wherein: The cover plate includes a plate body, the pole hole passes through the plate body from top to bottom, the lower surface of the plate body is located at the periphery of the pole hole and is pressed upward to form an annular groove, the annular groove is flush with the bottom surface of the second lower body of the pole, and the sealing ring is placed under the annular groove and the bottom surface of the second lower body.

3. The secondary battery top cover according to claim 2, wherein: The pole also includes a third lower body that protrudes downward from the second lower body and has an outer diameter smaller than that of the second lower body. The welding ring is sleeved on the outside of the third lower body. The welding ring extends in the radial direction and spans the bottom surface of the second lower body and at least a portion of the bottom surface of the annular groove.

4. The secondary battery top cover according to claim 3, wherein: A gap is formed between the outer periphery of the first lower body of the pole and the inner wall surface of the pole hole. The sealing ring includes a ring body and a vertical portion protruding upward from the middle of the ring body and extending into the gap. The ring body includes an outer ring body located outside the vertical portion and an inner ring body located inside the vertical portion.

5. The secondary battery top cover according to claim 4, wherein: The inner ring body is applied to the bottom surface of the second lower body, and the outer ring body is applied to the bottom surface of the annular groove. The sealing ring is squeezed by the welding ring so that the ring body extends in the radial direction, and the vertical part extends upward and fills the gap.

6. The secondary battery top cover according to claim 5, wherein: The plastic body is integrally formed with the pole, and includes a plastic ring body that wraps the outer side surface and upper and lower surfaces of the fixed convex ring and a plurality of positioning posts protruding downward from the bottom surface of the plastic ring body. The upper surface of the plate body is provided with a plurality of positioning blind holes located around the pole hole for inserting the positioning posts.

7. The secondary battery top cover according to claim 5, wherein: The plastic body is molded separately, and the pole is assembled on the plastic body from top to bottom. The plastic body includes a plastic ring body surrounding the outer side and lower surface of the fixed convex ring and a plurality of positioning posts protruding downward from the bottom surface of the plastic ring body. The upper surface of the plate body is provided with a plurality of positioning blind holes for inserting the positioning posts at the periphery of the pole hole.

8. The secondary battery top cover according to claim 6 or 7, wherein: The inner wall surface of the plastic ring body close to the first lower body is set as an inclined surface, and the vertical portion of the sealing ring is squeezed and extended upward into the inclined surface to completely isolate the first lower body from the inner wall surface of the pole hole.

9. The secondary battery top cover according to claim 3, wherein: The pole also includes a fourth lower body that protrudes downward from the third lower body and has an outer diameter smaller than that of the third lower body. A welding groove is formed on the bottom surface of the third lower body and the outer side surface of the fourth lower body. The welding ring includes an annular body, and the inner bottom surface of the annular body is thinned to form a welding groove that is on the same horizontal plane as the bottom surface of the third lower body. The welding groove of the welding ring is welded and fixed to the welding groove of the pole at the junction.

10. A secondary battery, characterized in that: The battery comprises a secondary battery top cover as described in any one of claims 1-7 and 9, a battery shell, and a battery cell encapsulated in the battery shell through the secondary battery top cover, wherein the battery cell is electrically connected to the pole and conducts electrical energy through the pole.

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