Top cover assembly for power batteries and power batteries

Abstract

This application discloses a top cover assembly for a power battery and a power battery. The top cover assembly includes a top cover, terminals, and an injection-molded plastic body. The top cover is formed by stamping a boss and a recessed groove located on the lower side of the boss. The boss has a terminal mounting hole located in its center and multiple through holes surrounding the terminal mounting hole. The terminals are placed at the terminal mounting hole and the recessed groove. The upper side of the terminal is spaced apart from the sidewall of the terminal mounting hole and extends upward beyond the upper surface of the boss. The lower side of the terminal protrudes outward with an annular protrusion that extends outward beyond the terminal mounting hole and is spaced apart from the boss. The injection-molded plastic body enters from the multiple through holes and the gap between the upper side of the terminal and the sidewall of the terminal mounting hole to fill the gap between the terminal and the boss. The injection-molded plastic body also includes an upper part of plastic body formed on the upper surface of the boss and innerly wrapped around the sidewall of the terminal. This application allows for targeted adjustments when the terminal height is relatively high, so that the top cover assembly can be used in a power battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a top cover assembly for a power battery and the power battery itself. Background Technology

[0002] Currently, lithium-ion / sodium-ion cylindrical power batteries are gradually becoming the mainstream product in the new energy industry due to their advantages such as high energy density, good capacity consistency, and ability to support high-rate charge and discharge. However, the top cover structure of cylindrical power batteries presents the following technical challenges:

[0003] (1) For composite terminals, such as those with the same copper and aluminum at the top and aluminum at 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 insufficient, the composite terminal is at risk of breakage. This places higher demands on the interfacial bonding strength of copper-aluminum composite terminals. However, using copper-aluminum friction-welded terminals, which are more expensive, will increase the manufacturing cost of the battery. Please refer to... Figure 9 The invention provides an example of a composite electrode post 71 assembled on a top cover 72. The composite electrode post 71 is formed by bonding and fixing an upper aluminum structure 711 and a lower copper structure 712 together. The aluminum structure 711 is located on the outside of the top cover 72 and is wrapped and fixed by PPS plastic 73 injection-molded onto the top cover 71. The lower part of the copper structure 712 is located on the inside of the top cover 72 and protrudes outward to form an annular protrusion 7121. A sealing ring 74 is provided between the annular protrusion 7121 and the inner wall of the top cover 72. The annular protrusion 7121 is continuously subjected to the rebound force of the sealing ring 74, directly testing the bonding strength of the copper-aluminum interface, which poses a risk of breakage to the composite electrode post 71. Furthermore, the PPS plastic 73 on the outside of the top cover 72 needs to withstand the shear force from the rebound force of the sealing ring 74, therefore 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 this application is to provide a top cover assembly for a power battery and a power battery, which can solve at least one of the technical problems in the background art.

[0006] To achieve the above objectives, this application provides a top cover assembly for a power battery. The top cover assembly includes a top cover, a terminal post, and an injection-molded plastic body. The top cover is formed by stamping a boss and a recessed groove located on the lower side of the boss. The boss has a terminal post mounting hole located in its center and a plurality of through holes surrounding the terminal post mounting hole. The terminal post is placed at the terminal post mounting hole and the recessed groove. The upper side of the terminal post is spaced apart from the sidewall of the terminal post mounting hole and extends upward beyond the upper surface of the boss. The lower side of the terminal post protrudes outward with an annular protrusion. The annular protrusion extends outward beyond the terminal post mounting hole and is spaced vertically from the boss. The injection-molded plastic body enters from the plurality of through holes and the gap between the upper side of the terminal post and the sidewall of the terminal post mounting hole to fill the gap between the terminal post and the boss. The injection-molded plastic body also includes an upper part of plastic body formed on the upper surface of the boss and innerly wrapped around the sidewall of the terminal post.

[0007] Optionally, the sidewall of the electrode post is recessed inward to form an annular groove, the annular groove facing the sidewall of the electrode post mounting hole, and the injection-molded plastic fills the annular groove.

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

[0009] Optionally, the electrode post is a composite electrode post, including a first electrode post body and a second electrode post body, wherein the first electrode post body is fixed on the second electrode post body, and the annular protrusion is formed on the second electrode post body.

[0010] Optionally, the sidewall of the first electrode post is recessed inward to form an annular groove, the annular groove facing the sidewall of the electrode post 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 post; the top cover assembly further includes a sealing ring and a fixing ring, the sealing ring is disposed on the lower side of the annular protrusion, and the fixing ring includes a sealing ring platform located on its inner side. When the fixing ring is fixed on the inner side of the top cover, the sealing ring is pressed between the lower surface of the annular protrusion and the sealing ring platform.

[0012] Optionally, the outer edge of the settling tank is formed with an installation step, and the fixing ring further includes a fixing platform located on the outer side, the fixing platform being adapted to fit against the installation step and fixed by welding.

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

[0014] Optionally, the top cover assembly further includes a lower plastic component that is fitted and fixed to the inner side of the top cover, the inner side of the lower plastic component forming a shielding portion that covers the bottom of the fixing ring.

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

[0016] In this embodiment, the top cover is formed by stamping a boss and a recessed groove located on the lower side of the boss. The boss has a terminal mounting hole located in its center and multiple through holes surrounding the terminal mounting hole. The terminal is placed at the terminal mounting hole and the recessed groove. The lower side of the terminal protrudes outward beyond the terminal mounting hole and is spaced vertically from the boss by an annular protrusion. Injection-molded plastic enters from the multiple through holes and the gap between the upper side of the terminal and the sidewall of the terminal mounting hole, filling the gap between the terminal and the boss (including the gap between the annular protrusion and the boss). After the injection-molded plastic cools and solidifies, the terminal can be fixed to the top cover. Moreover, since the upper side of the terminal is spaced from the sidewall of the terminal mounting hole and extends upward beyond the upper surface of the boss, the injection-molded plastic also includes an upper part of plastic formed on the upper surface of the boss and innerly wrapped around the sidewall of the terminal, which helps to fix the terminal more reliably to the top cover. In addition, the top cover assembly of this application embodiment can stamp protrusions of different heights on the top cover for poles of different heights, thereby allowing for fine adjustment of the injection molding height to adapt to poles of different heights. When the pole height is relatively high, targeted adjustments can be made so that the top cover assembly can be used in power batteries. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the top cover assembly according to an embodiment of this application.

[0018] Figure 2 This is a cross-sectional structural diagram of the top cover assembly according to an embodiment of this application.

[0019] Figure 3 This is a cross-sectional structural schematic diagram of the top cover assembly from another perspective of an embodiment of this application.

[0020] Figure 4 This is a cross-sectional structural diagram of the top cover and the pole.

[0021] Figure 5 This is a three-dimensional structural diagram of the top cover according to an embodiment of this application.

[0022] Figure 6 This is a three-dimensional structural schematic diagram of the top cover from another perspective of an embodiment of this application.

[0023] Figure 7 This is a three-dimensional structural diagram of the pole in an embodiment of this application.

[0024] Figure 8 This is a three-dimensional structural diagram of the fixing ring according to an embodiment of this application.

[0025] Figure 9 This is a cross-sectional structural diagram of the top cover assembly in the prior art. Detailed Implementation

[0026] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0027] Please see Figures 1 to 8 This application discloses a top cover assembly for a power battery. The top cover assembly includes a top cover 1, a terminal post 2, and an injection-molded plastic body 3. The top cover 1 is formed by stamping a boss 10 and a recess 11 located on the lower side of the boss 10. The boss 10 has a terminal post mounting hole 12 located in its middle and a plurality of through holes 13 surrounding the terminal post mounting hole 12. The terminal post 2 is placed at the terminal post mounting hole 12 and the recess 11. The upper side of the terminal post 2 is spaced apart from the side wall of the terminal post mounting hole 12 and extends upward beyond the upper surface of the boss 10. On the lower side of the pole post 2, an annular protrusion 20 protrudes outward. The annular protrusion 20 extends outward beyond the pole post mounting hole 12 and is spaced vertically 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 upper side of the pole post 2 and the side wall of the pole post mounting hole 12 through the multiple through holes 13 and fills the gap between the pole post 2 and the boss 10. The injection-molded plastic body 3 also includes an upper plastic body 31 formed on the upper surface of the boss 10 and wrapped inside the side wall of the pole post 2.

[0028] In this embodiment, the top cover 1 is formed by stamping a boss 10 and a recess 11 located on the lower side of the boss 10. The boss 10 has a pole mounting hole 12 located in its middle 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 recess 11. The lower side of the pole 2 protrudes outward beyond the pole mounting hole 12 and is spaced vertically from the boss 10 by an annular protrusion 20. The injection-molded plastic 3 enters from the gap A between the multiple 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). After the injection-molded plastic 3 cools and solidifies, the pole 2 can be fixed on the top cover 1. Furthermore, since the upper side of the terminal post 2 is spaced apart from the sidewall of the terminal post mounting hole 12 and extends upward beyond the upper surface of the boss 10, the injection-molded plastic body 3 also includes an upper plastic body 31 formed on the upper surface of the boss 10 and internally wrapped around the sidewall of the terminal post 2. Combined with the portion filling the gap, this facilitates a more reliable fixation of the terminal post 2 to the top cover 1. In addition, the top cover assembly of this application embodiment can stamp bosses 10 of different heights on the top cover 1 for terminal posts 2 of different heights, thereby allowing for fine adjustment of the injection height to adapt to terminal posts 2 of different heights. Furthermore, when the height of the terminal post 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 to this.

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

[0031] In some embodiments, the boss 10 after forming the pole mounting hole 12 is annular, and a plurality of through holes 13 are distributed circumferentially along the boss 10. However, this is not a limitation.

[0032] In some embodiments, the sidewall of the electrode post 2 is recessed inward to form an annular groove 21, the annular groove 21 facing the sidewall of the electrode post mounting hole 12, and the injection-molded plastic body 3 fills the annular groove 21. By forming an annular groove 21 facing the electrode post mounting hole 12 on the sidewall of the electrode post 2, the injection-molded plastic body 3 fills the annular groove 21, which helps to fix the electrode post 2 more securely to the top cover 1. Of course, the sidewall of the electrode post 2 is not limited to being recessed to form an annular groove 21. For example, the sidewall of the electrode post 2 can also be recessed to form multiple spaced grooves for the injection-molded plastic body 3 to fill. In addition, the sidewall of the electrode post 2 may not have grooves.

[0033] In some embodiments, the upper surface of the annular protrusion 20 has a plurality of outwardly penetrating notches 22, and the injection-molded plastic body 3 fills each notch 22. By having a plurality of outwardly penetrating notches 22 distributed on the upper surface of the annular protrusion 20, and filling each notch 22 with the injection-molded plastic body 3, it is beneficial to fix the pole post 2 to the top cover 1 more securely.

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

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

[0036] Specifically, the sidewall of the first electrode post 23 is recessed inward to form an annular groove 21, which faces the sidewall of the electrode post mounting hole 12. The injection-molded plastic body 3 fills the annular groove 21. By forming an annular groove 21 facing the electrode post mounting hole 12 on the sidewall of the first electrode post 23, the injection-molded plastic body 3 fills the annular groove 21, which helps to more securely fix the electrode post 2 to the top cover 1. Of course, the sidewall of the first electrode post 23 is not limited to being recessed to form an annular groove 21. For example, the sidewall of the first electrode post 23 can also be recessed to form multiple spaced grooves for the injection-molded plastic body 3 to fill. Alternatively, the sidewall of the first electrode post 23 may not have grooves.

[0037] In some embodiments, the lower surface of the annular protrusion 20 is higher than the lower surface of the electrode post 2. The top cover assembly also includes a sealing ring 4 and a retaining ring 5. The sealing ring 4 is disposed on the lower side of the annular protrusion 20, and the retaining ring 5 includes a sealing ring platform 51 located inside it. When the retaining ring 5 is fixed inside 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, thereby locking the compression ratio. Since the sealing ring 4 is pressed between the annular protrusion 20 and the sealing ring platform 51, the annular protrusion 10 of the second electrode post 24 bears the upward rebound force of the sealing ring 4. The interface between the first electrode post 23 and the second electrode post 24 does not need to bear the tensile force, avoiding the risk of the composite electrode post 2 breaking due to long-term tension from the sealing ring 4. Since the interface between the two electrode posts does not continuously bear the tension of the sealing ring 4, the costly friction-welded electrode post 2 can be eliminated, which is beneficial for controlling battery manufacturing costs. In addition, since the boss 10 can withstand the upward rebound force of the sealing ring 4, the upper part 31 of the plastic body mainly bears the stress of the pole post 2 relative to the top cover 1, and basically does not bear the shear force brought by the rebound force of the sealing ring 4. Therefore, the upper part 31 of the plastic body does not need to be thick.

[0038] When assembling the sealing ring 4, the sealing ring 4 can be fitted onto the lower part of the second pole post 24. When the fixing ring 5 is fixed inside 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 retaining ring 5 can be made of high-hardness aluminum alloy, but it is not limited to this.

[0040] Specifically, the material of the sealing ring 4 can be fluororubber, etc.

[0041] Specifically, the outer edge of the settling tank 11 forms an installation step 111, and the fixing ring 5 also includes a fixing platform 52 located on the outer side. The fixing platform 52 is adapted to fit against the installation step 111 and is fixed by welding. When the fixing platform 52 is welded and fixed to the installation step 111, the compression ratio of the sealing ring 4 is simultaneously locked.

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

[0043] More specifically, the fixing ring 5 also includes a connecting part 53 located in the middle, the outer side of the connecting part 53 is connected to the fixing platform 52, the inner side of the connecting part 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 has a plastic platform surface 32 that is flush with and connected to 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 fixing 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 has a plastic platform surface 32 that is flush with and connected to the upper platform surface 112 of the mounting step 111, it can objectively extend the upper platform surface 112 of the mounting step 111, which is conducive to the more stable assembly of the fixing ring 5 through the fixing platform 52. Since the lower side of the injection-molded plastic body 3 has a wrapping portion 33 that wraps around the outer side wall of the annular protrusion 20, it is conducive to the more reliable fixing of the pole post 2 to the top cover 1.

[0045] Specifically, the top cover assembly also includes a lower plastic part 6 that is fitted and fixed to the inside of the top cover 1, and the inner side of the lower plastic part 6 forms a blocking portion 61 that blocks the bottom of the fixing ring 5. Further, the lower plastic part 6 can be fixed to the inside of the top cover 1 by heat fusion. Of course, this is not a limitation.

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

[0047] Specifically, the power battery can be a cylindrical power battery or other types of power batteries, and this application does not limit this.

[0048] The above-disclosed examples are merely preferred embodiments of this application, intended to facilitate understanding and implementation by those skilled in the art. They should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the scope of this application are still within the scope of this application.

Claims

1. A top cover assembly for a power battery, characterized in that, The top cover assembly includes a top cover, an electrode post, and an injection-molded plastic body. The top cover is formed by stamping a boss and a recessed groove located on the lower side of the boss. The boss has an electrode post mounting hole located in its center and a plurality of through holes surrounding the electrode post mounting hole. The electrode post is placed at the electrode post mounting hole and the recessed groove. The upper side of the electrode post is spaced apart from the sidewall of the electrode post mounting hole and extends upward beyond the upper surface of the boss. The lower side of the electrode post protrudes outward with an annular protrusion. The annular protrusion extends outward beyond the electrode post mounting hole and is spaced apart vertically from the boss. The injection-molded plastic body enters from the plurality of through holes and the gap between the upper side of the electrode post and the sidewall of the electrode post mounting hole to fill the gap between the electrode post and the boss. The injection-molded plastic body also includes an upper part of plastic body formed on the upper surface of the boss and innerly wrapped around the sidewall of the electrode post. The upper surface of the annular protrusion has multiple outwardly penetrating notches, and the injection-molded plastic fills each of the notches; The electrode post is a composite electrode post, including a first electrode post body and a second electrode post body, wherein the first electrode post body is fixed on the second electrode post body, and the annular protrusion is formed on the second electrode post body; The lower surface of the annular protrusion is higher than the lower surface of the pole post; the top cover assembly also includes a sealing ring and a fixing ring, the sealing ring is disposed on the lower side of the annular protrusion, and the fixing ring includes a sealing ring platform located on its inner side. When the fixing ring is fixed to the inner side of the top cover, the sealing ring is pressed between the lower surface of the annular protrusion and the sealing ring platform. The outer edge of the settling tank is formed with an installation step, and the fixing ring also includes a fixing platform located on the outer side. The fixing platform is adapted to fit into the installation step and is fixed by welding.

2. The top cover assembly for a power battery according to claim 1, characterized in that, The sidewall of the electrode post is recessed inward to form an annular groove, the annular groove facing the sidewall of the electrode post 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, The sidewall of the first electrode post is recessed inward to form an annular groove, the annular groove facing the sidewall of the electrode post mounting hole, and the injection-molded plastic fills the annular groove.

4. The top cover assembly for a power battery according to claim 1, characterized in that, The lower side of the injection-molded plastic body has a plastic platform surface that is flush with and connected to the upper platform surface of the mounting step, and a wrapping part that wraps around the outer side wall of the annular protrusion. The upper end of the outer side wall of the wrapping part is connected to the plastic platform surface, and the fixing platform is attached to the mounting step and the plastic platform surface.

5. The top cover assembly for a power battery according to claim 1, characterized in that, It also includes a lower plastic component that is attached and fixed to the inside of the top cover, and the inner side of the lower plastic component forms a shielding part that covers the bottom of the fixing ring.

6. A power battery, characterized in that, Includes the top cover assembly for a power battery as described in any one of claims 1 to 5.

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