Top cover assembly for power battery and power battery

Abstract

The invention discloses a top cover assembly for a power battery and the power battery, the top cover assembly comprises a top cover, a pole and an injection molding plastic body, the top cover forms a boss and a sinking groove located at the lower side of the boss through stamping, and the boss forms a pole mounting hole located at the middle part of the boss and a plurality of through holes surrounding the pole mounting hole; the polar columns are arranged at the polar column mounting holes and the sinking grooves, the upper sides of the polar columns and the side walls of the polar column mounting holes are arranged at intervals and upwards exceed the upper surface of the boss, the lower sides of the polar columns outwards protrude to form annular convex parts, and the annular convex parts outwards exceed the polar column mounting holes and are vertically arranged at intervals with the boss; the injection molding plastic body enters the gap between the filling pole and the boss from the plurality of through holes and the gap between the upper side of the pole and the side wall of the pole mounting hole; the injection molding plastic body also comprises a plastic body upper part which is formed on the upper surface of the boss, and the inner side of the plastic body upper part wraps the side wall of the pole. When the height of the pole is relatively high, targeted adjustment can be performed, so that the top cover assembly can be applied to the power battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a top cover assembly for a power battery and a power battery. Background Art

[0002] At present, lithium-ion / sodium-ion cylindrical power batteries have gradually become the mainstream products in the new energy industry due to their high energy density, good capacity consistency, and ability to support high-rate charge and discharge. However, there are the following technical problems with the top cover structure of cylindrical power batteries:

[0003] (1) For composite poles, such as those with copper on the top and aluminum on the bottom, the copper-aluminum interface needs to continuously bear the compressive elastic force of the sealing ring. If the strength of the copper-aluminum interface is not sufficient, the composite pole is at risk of breaking. This places higher requirements on the interface bonding strength of the copper-aluminum composite pole. The use of copper-aluminum friction welding poles, which are more expensive, will increase the manufacturing cost of the battery. Fig. 9 , which provides an example of a composite pole 71 assembled on a top cover 72, wherein the composite pole 71 is formed by an aluminum structure 711 located on the upper side and a copper structure 712 located on the lower side being fixed together. Among them, the aluminum structure 711 is located on the outer side of the top cover 72 and is wrapped and fixed by the PPS plastic 73 injection-molded on the top cover 71, and the lower part of the copper structure 712 is located on the inner side of the top cover 72 and protrudes outward to form an annular convex portion 7121, and a sealing ring 74 is provided between the annular convex portion 7121 and the inner wall of the top cover 72. The annular convex portion 7121 will continue to be subjected to the rebound force of the sealing ring 74, directly testing the bonding strength of the copper-aluminum interface, so that the composite pole 71 is at risk of breaking. In addition, the PPS plastic 73 on the outer side of the top cover 72 needs to withstand the shear force caused by the rebound force of the sealing ring 74, so the PPS plastic 73 needs to be relatively thick.

[0004] (2) Some top cover structures cannot be effectively adjusted when the pole height is too high, so they are not suitable for use in cylindrical power batteries. Summary of the invention

[0005] The purpose of the present application is to provide a top cover assembly for a power battery and a power battery, which can solve at least one technical problem in the above-mentioned background technology.

[0006] To achieve the above-mentioned objectives, the present application provides a top cover assembly for a power battery, the top cover assembly comprising a top cover, a pole and an injection molded plastic body, the top cover is formed by stamping a boss and a recessed groove located at the lower side of the boss, the boss is formed with a pole mounting hole located in the middle thereof and a plurality of through holes surrounding the pole mounting hole, the pole is placed at the pole mounting hole and the recessed groove, the upper side of the pole is spaced apart from the side wall of the pole mounting hole and upwardly exceeds the upper surface of the boss, the lower side of the pole protrudes outwardly with an annular convex portion, the annular convex portion outwardly exceeds the pole mounting hole and is spaced apart from the boss up and down, the injection molded plastic body enters from the gap between the plurality of through holes and the upper side of the pole and the side wall of the pole mounting hole to fill the gap between the pole and the boss, the injection molded plastic body also includes an upper part of the plastic body molded on the upper surface of the boss and wrapped inside the side wall of the pole.

[0007] Optionally, the side wall of the pole is inwardly recessed to form an annular groove, the annular groove faces the side wall of the pole mounting hole, and the injection-molded plastic fills the annular groove.

[0008] Optionally, a plurality of outwardly penetrating notches are distributed on the upper surface of the annular protrusion, and the injection-molded plastic fills each of the notches.

[0009] Optionally, the pole is a composite pole, comprising a first pole body and a second pole body, the first pole body is fixed on the second pole body, and the annular protrusion is formed on the second pole body.

[0010] Optionally, the side wall of the first pole body is inwardly recessed to form an annular groove, the annular groove faces the side wall of the pole mounting hole, and the injection-molded plastic fills the annular groove.

[0011] Optionally, the lower surface of the annular protrusion is higher than the lower surface of the pole; the top cover assembly also includes a sealing ring and a fixing ring, the sealing ring is arranged on the lower side of the annular protrusion, the fixing ring includes a sealing ring platform located on the inner side thereof, and when the fixing ring is fixed on the inner side of the top cover, the sealing ring is crimped between the lower surface of the annular protrusion and the sealing ring platform.

[0012] Optionally, an installation step is formed on the outer edge of the sink, and the fixing ring further includes a fixing platform located on the outside, and the fixing platform is adapted to fit on the installation step and fixed by welding.

[0013] Optionally, a plastic platform surface that is flush with the upper platform surface of the mounting step and a wrapping portion that wraps around the outer wall of the annular protrusion are formed on the lower side of the injection-molded plastic body, and the upper end of the outer wall of the wrapping portion is connected to the plastic platform surface, and the fixed platform is attached to the mounting step and the plastic platform surface.

[0014] Optionally, the top cover assembly further comprises a lower plastic piece which is fitted and fixed to the inner side of the top cover, and the inner side of the lower plastic piece forms a shielding portion which shields the bottom of the fixing ring.

[0015] To achieve the above-mentioned objectives, the present application also provides a power battery, including the top cover assembly for the power battery as described above.

[0016] In the embodiment of the present application, the top cover is formed by stamping a boss and a recessed groove located at the lower side of the boss, the boss is formed with a pole mounting hole located in the middle thereof and a plurality of through holes surrounding the pole mounting hole, the pole is placed at the pole mounting hole and the recessed groove, the lower side of the pole protrudes outwardly beyond the pole mounting hole and an annular protrusion spaced apart from the boss, the injection molded plastic enters from the gap between the plurality of through holes and the upper side of the pole and the side wall of the pole mounting hole to fill the gap between the pole and the boss (including the gap between the annular protrusion and the boss), and then the pole can be fixed on the top cover after the injection molded plastic is cooled and solidified. Moreover, since the upper side of the pole is spaced apart from the side wall of the pole mounting hole and exceeds the upper surface of the boss upward, the injection molded plastic also includes an upper part of the plastic formed on the upper surface of the boss and wrapped around the side wall of the pole on the inner side, which is conducive to more reliably fixing the pole on the top cover. In addition, the top cover assembly of the embodiment of the present application can stamp out bosses of different heights on the top cover for poles of different heights, and then fine-tune the injection molding height to adapt to poles of different heights. When the height of the pole is relatively high, targeted adjustments can be made so that the top cover assembly can be used in power batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the top cover assembly of the embodiment of the present application.

[0018] Figure 2 It is a schematic diagram of the cross-sectional structure of the top cover assembly of the embodiment of the present application.

[0019] Figure 3 It is a schematic diagram of the cross-sectional structure of the top cover assembly of the embodiment of the present application from another perspective.

[0020] Figure 4 It is a schematic diagram of the cross-sectional structure of the top cover and the pole.

[0021] Figure 5 It is a schematic diagram of the three-dimensional structure of the top cover of the embodiment of the present application.

[0022] Figure 6 It is a schematic diagram of the three-dimensional structure of the top cover of the embodiment of the present application from another perspective.

[0023] Figure 7 It is a schematic diagram of the three-dimensional structure of the pole according to the embodiment of the present application.

[0024] Figure 8 It is a schematic diagram of the three-dimensional structure of the fixing ring of the embodiment of the present application.

[0025] Fig. 9 It is a schematic diagram of the cross-sectional structure of a top cover assembly in the prior art. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0027] See also Figures 1 to 8 The embodiment of the present application discloses a top cover assembly for a power battery, the top cover assembly includes a top cover 1, a pole 2 and an injection-molded plastic body 3, the top cover 1 is formed by stamping a boss 10 and a sink 11 located at the lower side of the boss 10, the boss 10 is formed with a pole mounting hole 12 located in the middle thereof and a plurality of through holes 13 surrounding the pole mounting hole 12, the pole 2 is placed at the pole mounting hole 12 and the sink 11, the upper side of the pole 2 is spaced from the side wall of the pole mounting hole 12 and upwardly exceeds the upper surface of the boss 10 The lower side of the pole 2 protrudes outwardly to form an annular protrusion 20, which protrudes outwardly beyond the pole mounting hole 12 and is spaced apart from the boss 10 (the annular protrusion 20 is located on the lower side of the boss 10). The injection-molded plastic body 3 enters from the gap A between the plurality of through holes 13 and the upper side of the pole 2 and the side wall of the pole mounting hole 12 to fill the gap between the pole 2 and the boss 10. The injection-molded plastic body 3 also includes a plastic upper part 31 formed on the upper surface of the boss 10 and wrapped around the side wall of the pole 2 on the inner side.

[0028] In the embodiment of the present application, the top cover 1 is formed by stamping a boss 10 and a recessed groove 11 located at the lower side of the boss 10, the boss 10 is formed with a pole mounting hole 12 located in the middle thereof and a plurality of through holes 13 surrounding the pole mounting hole 12, the pole 2 is placed at the pole mounting hole 12 and the recessed groove 11, the lower side of the pole 2 protrudes outwardly beyond the pole mounting hole 12 and extends outwardly beyond the pole mounting hole 12 and is spaced apart from the boss 10 by an annular protrusion 20, the injection molded plastic body 3 enters from the gap A between the plurality of through holes 13 and the upper side of the pole 2 and the side wall of the pole mounting hole 12 to fill the gap between the pole 2 and the boss 10 (including the gap between the annular protrusion 20 and the boss 10), and then the pole 2 can be fixed on the top cover 1 after the injection molded plastic body 3 is cooled and solidified. Moreover, since the upper side of the pole 2 is spaced apart from the side wall of the pole mounting hole 12 and extends upwardly beyond the upper surface of the boss 10, the injection-molded plastic body 3 also includes an upper portion 31 of the plastic body formed on the upper surface of the boss 10 and wrapped around the side wall of the pole 2 on the inner side, which, combined with the portion filled in the gap, is conducive to more reliably fixing the pole 2 on the top cover 1. In addition, the top cover assembly of the embodiment of the present application can punch out bosses 10 of different heights on the top cover 1 for poles 2 of different heights, and then fine-tune the injection molding height to adapt to poles 2 of different heights, and then when the height of the pole 2 is relatively high, targeted adjustments can be made so that the top cover assembly can be used in power batteries.

[0029] In some embodiments, the injection-molded plastic body 3 is made of PPS material, but is not limited thereto.

[0030] In some embodiments, the upper portion 31 of the plastic body is slightly lower than the upper surface of the pole 2 , but this is not limited thereto.

[0031] In some embodiments, the boss 10 after the pole mounting hole 12 is formed is annular, and the plurality of through holes 13 are distributed along the circumference of the boss 10. However, this is not limited thereto.

[0032] In some embodiments, the side wall of the pole 2 is recessed inward to form an annular groove 21, the annular groove 21 faces the side wall of the pole mounting hole 12, and the injection molded plastic body 3 fills the annular groove 21. By forming the annular groove 21 facing the pole mounting hole 12 on the side wall of the pole 2, the injection molded plastic body 3 is filled in the annular groove 21, which is conducive to more firmly fixing the pole 2 on the top cover 1. Of course, the side wall of the pole 2 is not limited to being recessed to form the annular groove 21. For example, the side wall of the pole 2 can also be recessed to form a plurality of grooves arranged at intervals for the injection molded plastic body 3 to fill. In addition, the side wall of the pole 2 can also be provided with no grooves.

[0033] In some embodiments, the upper surface of the annular protrusion 20 is provided with a plurality of outwardly penetrating notches 22, and the injection-molded plastic body 3 fills each notch 22. By distributing a plurality of outwardly penetrating notches 22 on the upper surface of the annular protrusion 20 and filling each notch 22 with the injection-molded plastic body 3, the pole 2 is more firmly fixed on the top cover 1.

[0034] In some embodiments, the pole 2 is a composite pole, including a first pole body 23 and a second pole body 24 , the first pole body 23 is fixed on the second pole body 24 , and the annular protrusion 20 is formed on the second pole body 24 .

[0035] Specifically, the first pole body 23 is an aluminum pole body, and the second pole body 24 is a copper pole body.

[0036] Specifically, the side wall of the first pole body 23 is recessed inward to form an annular groove 21, the annular groove 21 faces the side wall of the pole mounting hole 12, and the injection molded plastic body 3 fills the annular groove 21. By forming the annular groove 21 facing the pole mounting hole 12 on the side wall of the first pole body 23, the injection molded plastic body 3 is filled in the annular groove 21, which is conducive to more firmly fixing the pole 2 on the top cover 1. Of course, the side wall of the first pole body 23 is not limited to being recessed to form the annular groove 21. For example, the side wall of the first pole body 23 can also be recessed to form a plurality of grooves arranged at intervals for the injection molded plastic body 3 to fill. In addition, the side wall of the first pole body 23 may also be provided with no grooves.

[0037] In some embodiments, the lower surface of the annular protrusion 20 is higher than the lower surface of the pole 2; the top cover assembly also includes a sealing ring 4 and a fixing ring 5, the sealing ring 4 is arranged on the lower side of the annular protrusion 20, and the fixing ring 5 includes a sealing ring platform 51 located on the inner side thereof. When the fixing ring 5 is fixed on the inner side of the top cover 1, the sealing ring 4 is crimped between the lower surface of the annular protrusion 20 and the sealing ring platform 51, so as to achieve the locking of the compression rate. Since the sealing ring 4 is crimped between the annular protrusion 20 and the sealing ring platform 51, the annular boss 10 of the second pole body 24 bears the upward rebound force of the sealing ring 4, and the interface between the first pole body 23 and the second pole body 24 does not need to bear the pulling force, thereby avoiding the risk of the composite pole 2 being pulled by the sealing ring 4 for a long time and breaking. Since the interface between the two poles will not continuously bear the pulling of the sealing ring 4, it is not necessary to use the friction welding pole 2 with high cost, which is conducive to controlling the manufacturing cost of the battery. In addition, since the boss 10 bears the upward rebound force of the sealing ring 4, the plastic upper part 31 mainly bears the stress of the position of the pole 2 relative to the top cover 1, and basically does not bear the shear force caused by the rebound force of the sealing ring 4, so the plastic upper part 31 does not need to be thicker.

[0038] When assembling the sealing ring 4 , the sealing ring 4 can be sleeved on the lower part of the second pole body 24 . When the fixing ring 5 is fixed on the inner side of the top cover 1 , the sealing ring 4 is pressed between the lower surface of the annular protrusion 20 and the sealing ring platform 51 .

[0039] Specifically, the material of the fixing ring 5 can be a high-hardness aluminum alloy, but it is not limited thereto.

[0040] Specifically, the sealing ring 4 may be made of fluororubber or the like.

[0041] Specifically, the outer edge of the sink 11 is formed with a mounting step 111, and the fixing ring 5 further includes a fixing platform 52 located on the outside, which is adapted to fit on the mounting step 111 and fixed by welding. When the fixing platform 52 is welded and fixed on the mounting step 111, the compression rate of the sealing ring 4 is locked at the same time.

[0042] More specifically, the fixing platform 52 is fixed to the mounting step 111 by laser welding.

[0043] More specifically, the fixing ring 5 further comprises a connecting portion 53 in the middle, the outer side of the connecting portion 53 is connected to the fixing platform 52 , the inner side of the connecting portion 53 is connected to the sealing ring platform 51 , and the sealing ring platform 51 is lower than the fixing platform 52 .

[0044] More specifically, the lower side of the injection-molded plastic body 3 is formed with a plastic platform surface 32 that is flush with the upper platform surface 112 of the mounting step 111 and a wrapping portion 33 that wraps around the outer side wall of the annular protrusion 20, the upper end of the outer side wall of the wrapping portion 33 is connected to the plastic platform surface 32, and the fixed platform 52 is attached to the mounting step 111 and the plastic platform surface 32. Since the lower side of the injection-molded plastic body 3 is formed with a plastic platform surface 32 that is flush with the upper platform surface 112 of the mounting step 111, it can objectively extend the upper platform surface 112 of the mounting step 111, thereby facilitating a more stable assembly of the fixing ring 5 through the fixing platform 52. Since the lower side of the injection-molded plastic body 3 is formed with a wrapping portion 33 that wraps around the outer side wall of the annular protrusion 20, it is beneficial for the pole 2 to be more reliably fixed to the top cover 1.

[0045] Specifically, the top cover assembly further includes a lower plastic part 6 fixed to the inner side of the top cover 1, and the inner side of the lower plastic part 6 forms a shielding portion 61 shielding the bottom of the fixing ring 5. Further, the lower plastic part 6 can be fixed to the inner side of the top cover 1 by hot melting. Of course, it is not limited to this.

[0046] Please combine Figures 1 to 8 , an embodiment of the present application also discloses a power battery, including the top cover assembly as described above.

[0047] Specifically, the power battery may be a cylindrical power battery or other types of power batteries, which is not limited in the present application.

[0048] The above disclosure is only a preferred example of the present application, and its role is to facilitate the technical personnel in this field to understand and implement it. Of course, it cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the scope of the patent application of the present application still fall within the scope covered by the present application.

Claims

1. A top cover assembly for a power battery, characterized in that: The top cover assembly comprises a top cover, a pole and an injection-molded plastic body, wherein the top cover is formed by stamping to form a boss and a recessed groove located at the lower side of the boss, the boss is formed with a pole mounting hole located in the middle thereof and a plurality of through holes surrounding the pole mounting hole, the pole is placed at the pole mounting hole and the recessed groove, the upper side of the pole is spaced apart from the side wall of the pole mounting hole and upwardly exceeds the upper surface of the boss, the lower side of the pole protrudes outwardly with an annular convex portion, the annular convex portion outwardly exceeds the pole mounting hole and is spaced apart from the boss up and down, the injection-molded plastic body enters from the gap between the plurality of through holes and the upper side of the pole and the side wall of the pole mounting hole to fill the gap between the pole and the boss, and the injection-molded plastic body also includes an upper part of the plastic body molded on the upper surface of the boss and wrapped inside the side wall of the pole.

2. The top cover assembly for a power battery according to claim 1, characterized in that: The side wall of the pole is inwardly recessed to form an annular groove, the annular groove faces the side wall of the pole mounting hole, and the injection-molded plastic fills the annular groove.

3. The top cover assembly for a power battery according to claim 1, characterized in that: A plurality of notches extending outward are distributed on the upper surface of the annular protrusion, and the injection-molded plastic fills each of the notches.

4. The top cover assembly for a power battery according to claim 1, characterized in that: The pole is a composite pole, comprising a first pole body and a second pole body, the first pole body is fixed on the second pole body, and the annular protrusion is formed on the second pole body.

5. The top cover assembly for a power battery according to claim 4, characterized in that: The side wall of the first pole body is inwardly recessed to form an annular groove, the annular groove faces the side wall of the pole mounting hole, and the injection-molded plastic fills the annular groove.

6. The top cover assembly for a power battery according to claim 4, characterized in that: The lower surface of the annular protrusion is higher than the lower surface of the pole; the top cover assembly also includes a sealing ring and a fixing ring, the sealing ring is arranged on the lower side of the annular protrusion, the fixing ring includes a sealing ring platform located on the inner side thereof, and when the fixing ring is fixed on the inner side of the top cover, the sealing ring is crimped between the lower surface of the annular protrusion and the sealing ring platform.

7. The top cover assembly for a power battery according to claim 6, characterized in that: The outer edge of the sink is formed with a mounting step, and the fixing ring further comprises a fixing platform located on the outside, and the fixing platform is adapted to fit on the mounting step and fixed by welding.

8. The top cover assembly for a power battery according to claim 7, characterized in that: A plastic platform surface flush with the upper platform surface of the mounting step and a wrapping portion wrapped around the outer wall of the annular protrusion are formed on the lower side of the injection-molded plastic body, and the upper end of the outer wall of the wrapping portion is connected to the plastic platform surface, and the fixed platform is attached to the mounting step and the plastic platform surface.

9. The top cover assembly for a power battery according to claim 6, characterized in that: It also includes a lower plastic part which is fitted and fixed to the inner side of the top cover, and the inner side of the lower plastic part forms a shielding portion which shields the bottom of the fixing ring.

10. A power battery, characterized in that: It comprises a top cover assembly for a power battery as described in any one of claims 1 to 9.

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