Top cover assembly for power battery and power battery

Abstract

The utility model discloses a top cover assembly for a power battery and the power battery, the top cover assembly comprises a top cover, a pole, a sealing ring and an injection molding plastic body, a pole mounting hole is formed in the top cover, the lower side of the pole mounting hole protrudes inwards to form an annular bearing platform, the pole comprises a first pole body and a second pole body, and the first pole body and the second pole body are arranged on the top cover. The first pole body is fixed on the second pole body, the upper side of the second pole body protrudes outwards to form an annular convex part, the pole is arranged at the pole mounting hole, a gap is formed between the pole and the side wall of the pole mounting hole, the annular convex part is pressed on the upper surface of the bearing platform through the sealing ring, and the gap is filled with the injection molding plastic body. The risk that the composite pole is broken due to long-term compression resilience force of the sealing ring is avoided, the manufacturing cost of the battery is favorably controlled, and the pole can be stably combined to the top cover.

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 8 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 aluminum structure 711 on the upper side and a copper structure 712 on the lower side. The aluminum structure 711 is located on the outside of the top cover 72 and is wrapped and fixed by PPS plastic 73 injected 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, which directly tests the bonding strength of the copper-aluminum interface, making the composite electrode post 71 susceptible to breakage.

[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. Utility Model Content

[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, terminals, a sealing ring, and an injection-molded plastic body. The top cover has a terminal mounting hole, and an annular support platform protrudes inward from the lower side of the terminal mounting hole. The terminal includes a first terminal body and a second terminal body. The first terminal body is fixed to the second terminal body, and an annular protrusion protrudes outward from the upper side of the second terminal body. The terminal is placed at the terminal mounting hole and forms a gap with the sidewall of the terminal mounting hole. The annular protrusion is pressed against the upper surface of the support platform by the sealing ring, and the injection-molded plastic body fills the gap.

[0007] Optionally, an upward protrusion is formed on the top cover, the pole mounting hole extends upward through the protrusion, the first pole body extends upward beyond the upper surface of the protrusion at least partially, and the injection-molded plastic body includes an upper part of plastic body formed on the upper surface of the protrusion and innerly wrapped around the outer wall of the first pole body.

[0008] Optionally, the top cover has a bent portion below the boss, the bent portion including a first annular portion and a second annular portion connected in a V-shape, the second annular portion being vertical and its inner wall forming the sidewall of the pole mounting hole, and the lower end of the second annular portion being bent inward to form the bearing platform.

[0009] Optionally, it also includes a lower plastic component that is attached and fixed to the inside of the top cover, the inner side of which forms a shielding portion that covers the bottom of the support platform.

[0010] Optionally, the sealing ring is fitted onto the lower side of the second pole piece.

[0011] Optionally, a plurality of injection-molded through holes are also formed on the top cover. The first end of the injection-molded through hole extends upward through the top cover, and the second end of the injection-molded through hole extends through the side wall of the pole mounting hole to face the outer side wall of the pole. The injection-molded plastic fills each of the injection-molded through holes.

[0012] Optionally, the injection through hole is located at the opening of the first end, which at least faces the outer wall of the annular protrusion.

[0013] Optionally, an upward-facing boss is formed on the top cover, the pole mounting hole extends upward through the boss, at least a portion of the first end of the injection through hole extends through the upper surface of the boss, at least a portion of the first pole extends upward beyond the upper surface of the boss, and the injection-molded plastic body includes an upper part of a plastic body formed on the upper surface of the boss and internally wrapped around the outer wall of the first pole.

[0014] Optionally, the injection through hole is an inclined through hole.

[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, an annular support platform protrudes inward from the lower side of the electrode mounting hole. The annular protrusion of the second electrode is pressed against the upper surface of the support platform by a sealing ring. That is, the sealing ring is pressed between the lower surface of the annular protrusion and the upper surface of the support platform. The annular protrusion of the second electrode bears the upward rebound force of the sealing ring. The interface between the first and second electrode does not need to bear tensile force, avoiding the risk of the composite electrode breaking due to long-term tension from the sealing ring. Since the interface between the two electrode bodies does not continuously bear the compressive rebound force of the sealing ring, the costly friction-welded electrode can be eliminated, which is beneficial for controlling battery manufacturing costs. In addition, since the injection-molded plastic fills the gap between the electrode and the electrode mounting hole, the electrode can be firmly bonded to the top cover. 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, pole, and sealing ring.

[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 cross-sectional structural diagram of the top cover 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 cross-sectional structural diagram of the top cover assembly in the prior art. Detailed Implementation

[0025] 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.

[0026] Please see Figures 1 to 7This application discloses a top cover assembly for a power battery. The top cover assembly includes a top cover 10, a terminal post 20, a sealing ring 30, and an injection-molded plastic body 40. The top cover 10 has a terminal post mounting hole 11. An annular support platform 12 protrudes inward from the lower side of the terminal post mounting hole 11. The terminal post 20 includes a first terminal post 21 and a second terminal post 22. The first terminal post 21 is fixed on the second terminal post 22. An annular protrusion 221 protrudes outward from the upper side of the second terminal post 22. The terminal post 20 is placed at the terminal post mounting hole 11 and forms a gap 111 between it and the side wall of the terminal post mounting hole 11. The annular protrusion 221 is pressed against the upper surface of the support platform 12 by the sealing ring 30. The injection-molded plastic body 40 fills the gap 111.

[0027] In this embodiment, an annular support platform 12 protrudes inward from the lower side of the terminal mounting hole 11. The annular protrusion 221 of the second terminal body 22 is pressed against the upper surface of the support platform 12 by a sealing ring 30. That is, the sealing ring 30 is pressed between the lower surface of the annular protrusion 221 and the upper surface of the support platform 12. The annular protrusion 221 of the second terminal body 22 bears the upward rebound force of the sealing ring 30. The interface between the first terminal body 21 and the second terminal body 22 does not need to bear the tensile force, thus avoiding the risk of the composite terminal body 20 breaking due to long-term tension from the sealing ring 30. Since the interface between the two terminal bodies does not continuously bear the compressive rebound force of the sealing ring 30, the costly friction-welded terminal body 20 can be eliminated, which is beneficial for controlling battery manufacturing costs. In addition, since the injection-molded plastic body 40 fills the gap 111 between the terminal body 20 and the terminal mounting hole 11, the terminal body 20 can be firmly bonded to the top cover 10.

[0028] In some embodiments, the top cover 10 is made of aluminum and can be integrally formed using a stretching or cold extrusion process. However, this is not a limitation.

[0029] In some embodiments, the first electrode post 21 is an aluminum electrode post, and the second electrode post 22 is a copper electrode post. However, this is not a limitation.

[0030] In some embodiments, the injection-molded plastic body 40 is made of PPS material. However, this is not a limitation.

[0031] In some embodiments, an upwardly extending boss 13 is formed on the top cover 10, and the terminal mounting hole 11 extends upward through the boss 13. The first terminal body 21 extends upward beyond the upper surface of the boss 13 at least partially. The injection-molded plastic body 40 includes an upper portion 41 of plastic body formed on the upper surface of the boss 13 and internally wrapped around the outer wall of the first terminal body 20. Because the top cover 10 has a boss 13 and the injection-molded plastic body 40 includes an upper portion 41 of plastic body formed on the upper surface of the boss 13 and internally wrapped around the outer wall of the first terminal body 20, it is more conducive to more reliably fixing the terminal body 20 to the top cover 10. In addition, the top cover assembly of the present application embodiment can produce bosses 13 of different heights on the top cover 10 for terminal bodies 20 of different heights, thereby allowing for fine adjustment of the injection height to adapt to terminal bodies 20 of different heights. Furthermore, when the height of the terminal body 20 is relatively high, targeted adjustments can be made so that the top cover assembly can be used in a power battery.

[0032] Specifically, the upper part 41 of the plastic body is slightly lower than the upper surface of the pole 20. However, this is not a limitation.

[0033] Specifically, the boss 13 after forming the pole mounting hole 11 is annular in shape. However, it is not limited to this.

[0034] Specifically, the top cover 10 has a bent portion 14 formed below the boss 13. The bent portion 14 includes a first annular portion 141 and a second annular portion 142 connected in a V-shape. The second annular portion 142 is vertical and its inner wall forms the sidewall of the pole mounting hole 11. The lower end of the second annular portion 142 is bent inward to form a supporting platform 12. Of course, in this embodiment of the present invention, it is not limited to having a bent portion 14, and the formation of the supporting platform 12 is not limited to this method.

[0035] In some embodiments, the top cover assembly further includes a lower insulating member 50 that is fitted and fixed to the inside of the top cover 10, and the inner side of the lower insulating member 50 forms a shielding portion 51 that shields the bottom of the support platform 12.

[0036] Specifically, the lower insulating component 50 can be fixed to the inside of the top cover 10 by means of heat fusion or snap fasteners.

[0037] In some embodiments, the sealing ring 30 is fitted onto the lower side of the second pole post 22. That is, in addition to being pressed between the lower surface of the annular protrusion 221 and the upper surface of the bearing platform 12, the sealing ring 30 is also fitted onto the lower side of the second pole post 22, which facilitates better sealing.

[0038] Specifically, the sealing ring 30 can be made of fluororubber, etc.

[0039] In some embodiments, a plurality of injection-molded through holes 15 are also formed on the top cover 10. The first end of the injection-molded through hole 15 extends upward through the top cover 10, and the second end of the injection-molded through hole 15 extends through the sidewall of the electrode mounting hole 11 to face the outer sidewall of the electrode 20. The injection-molded plastic body 40 fills each injection-molded through hole 15. By forming a plurality of injection-molded through holes 15 and filling each injection-molded through hole 15 with the injection-molded plastic body 40, it is beneficial to more reliably bond the electrode 20 to the top cover 10 by injection molding.

[0040] Specifically, the opening of the injection through hole 15 at the first end faces at least the outer wall of the annular protrusion 221.

[0041] Specifically, an upward-facing boss 13 is formed on the top cover 10, and the pole mounting hole 11 extends upward through the boss 13. At least a portion of the first end of the injection molding through hole 15 extends through the upper surface of the boss 13, and at least a portion of the first pole body 21 extends upward beyond the upper surface of the boss 13. The injection-molded plastic body 40 includes an upper portion 41 of plastic body formed on the upper surface of the boss 13 and internally wrapped around the outer wall of the first pole body 20. Since the injection molding through hole 15 is formed on the boss 13, it is convenient to form the injection molding through hole 15. Of course, in this embodiment of the present invention, the injection molding through hole 15 is not limited to being formed on the boss 13, nor is it limited to having a boss 13.

[0042] Specifically, the boss 13 after forming the pole mounting hole 11 is annular, and multiple injection through holes 15 are distributed around the boss 13. However, this is not a limitation.

[0043] Specifically, the injection through-hole 15 is an inclined through-hole. Of course, the injection through-hole 15 is not limited to being an inclined through-hole.

[0044] In some embodiments, the upper surface of the annular protrusion 221 is provided with a plurality of anti-rotation grooves 222, and the injection-molded plastic body 40 fills each anti-rotation groove 222. Of course, the upper surface of the annular protrusion 221 may also be provided with anti-rotation protrusions instead of anti-rotation grooves 222, or both anti-rotation grooves 222 and anti-rotation protrusions that are combined with the injection-molded plastic body 40 may be provided simultaneously. By providing a plurality of anti-rotation grooves 222 or anti-rotation protrusions on the upper surface of the annular protrusion 221, rotation of the electrode post 20 can be prevented, which is beneficial for more securely fixing the electrode post 20 to the top cover 10.

[0045] Please combine Figures 1 to 7 This application also discloses a power battery, including the top cover assembly as described above.

[0046] Specifically, the power battery can be a cylindrical power battery or other types of power batteries, and this application does not limit this.

[0047] 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, a pole, a sealing ring, and an injection-molded plastic body. The top cover has a pole mounting hole, and an annular support platform protrudes inward from the lower side of the pole mounting hole. The pole includes a first pole body and a second pole body. The first pole body is fixed to the second pole body, and an annular protrusion protrudes outward from the upper side of the second pole body. The pole is placed at the pole mounting hole and forms a gap with the sidewall of the pole mounting hole. The annular protrusion is pressed against the upper surface of the support platform by the sealing ring, and the injection-molded plastic body fills the gap.

2. The top cover assembly for a power battery according to claim 1, characterized in that, An upward-facing boss is formed on the top cover, and the pole mounting hole extends upward through the boss. The first pole body extends upward beyond the upper surface of the boss at least partially. The injection-molded plastic body includes an upper part of a plastic body formed on the upper surface of the boss and internally wrapped around the outer wall of the first pole body.

3. The top cover assembly for a power battery according to claim 2, characterized in that, The top cover has a bent portion below the boss. The bent portion includes a first annular portion and a second annular portion connected in a V-shape. The second annular portion is vertical and its inner wall forms the side wall of the pole mounting hole. The lower end of the second annular portion is bent inward to form the bearing platform.

4. The top cover assembly for a power battery according to any one of claims 1 to 3, 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 support platform.

5. The top cover assembly for a power battery according to claim 1, characterized in that, The sealing ring is fitted onto the lower side of the second pole piece.

6. The top cover assembly for a power battery according to claim 1, characterized in that, The top cover also has a plurality of injection through holes, the first end of the injection through hole penetrating the top cover upward, the second end of the injection through hole penetrating the side wall of the pole mounting hole to face the outer side wall of the pole, and the injection-molded plastic fills each of the injection through holes.

7. The top cover assembly for a power battery according to claim 6, characterized in that, The injection through hole is located at the opening of the first end, which faces at least the outer wall of the annular protrusion.

8. The top cover assembly for a power battery according to claim 6, characterized in that, An upward-facing boss is formed on the top cover, the pole mounting hole extends upward through the boss, at least a portion of the first end of the injection through hole extends through the upper surface of the boss, at least a portion of the first pole extends upward beyond the upper surface of the boss, and the injection-molded plastic body includes an upper part of a plastic body formed on the upper surface of the boss and internally wrapped around the outer wall of the first pole.

9. The top cover assembly for a power battery according to any one of claims 6 to 8, characterized in that, The injection molding through hole is an inclined through hole.

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

Images