Cover body for power battery and power battery

Abstract

The utility model discloses a cover body for a power battery and the power battery. A liquid injection groove is formed in the cover body, a liquid injection hole penetrating downwards is formed in the middle of the bottom wall of the liquid injection groove, an annular protrusion is arranged on the edge of the liquid injection hole in an upward protruding mode to prolong the liquid injection hole, a partition groove is formed in at least one position of the annular protrusion in the circumferential direction of the annular protrusion, the inner side of the partition groove is communicated with the liquid injection hole, and the outer side of the partition groove is communicated with the liquid injection groove. And the partition groove is used for draining the electrolyte in the liquid injection groove to the liquid injection hole. When liquid injection is carried out, if electrolyte enters the liquid injection groove in the outer side of the annular protrusion, the electrolyte can be drained to the liquid injection hole through the partition groove, and liquid accumulation at the liquid injection groove and the problems caused by liquid accumulation are avoided. And meanwhile, the method that the edge of the liquid injection hole protrudes downwards and is thickened is not needed, so that the problems are avoided.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cover for a power battery and a power battery. Background Technology

[0002] Currently, lithium-ion / sodium-ion power batteries (including but not limited to cylindrical power batteries) are gradually becoming the mainstream products in the new energy industry due to their advantages such as high energy density, good capacity consistency, and support for high-rate charging and discharging. With the popularization of new energy vehicles, people have placed higher demands on fast-charging travel (i.e., high-rate fast charging of power batteries), and more and more manufacturers are beginning to explore bottom-through welding technology to address the needs of fast-charging travel. However, the following common problems still exist:

[0003] Power batteries typically have a thicker bottom casing, requiring high laser welding power to penetrate it. However, high penetration welding power can easily burn the core or puncture the bottom casing, causing leakage and rendering the battery unusable. Therefore, the thickness of the penetration welding point (where the electrolyte filling groove is located) needs to be reduced. Meanwhile, the edge of the electrolyte filling hole needs sufficient thickness to ensure the perpendicularity and airtightness of the sealing nail. If the edge of the filling hole bulges and thickens, it will cause electrolyte accumulation after filling, making cleaning difficult, severely impacting production cycle time, and also affecting the welding yield of the sealing aluminum nail.

[0004] To ensure sufficient thickness at the edge of the injection hole, some manufacturers use a downward convex thickening method. However, the downward convex position poses a risk of interference with the core, which can easily damage the core. Furthermore, it is difficult to ensure a good fit between the manifold and the bottom of the shell, and the problem of localized poor welding cannot be avoided. Utility Model Content

[0005] The purpose of this utility model is to provide a cover 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 utility model provides a cover for a power battery. The cover has an injection groove, and the bottom wall of the injection groove has a downward through injection hole. An annular protrusion protrudes upward at the edge of the injection hole to extend the injection hole. At least one position along the circumference of the annular protrusion forms a partition groove. The inner side of the partition groove communicates with the injection hole, and the outer side of the partition groove communicates with the injection groove. The partition groove is used to guide the electrolyte at the injection groove to the injection hole.

[0007] Optionally, the bottom surface of the partition groove is not higher than the bottom surface of the injection groove.

[0008] Optionally, the bottom surface of the partition groove and the bottom surface of the injection groove are located on the same horizontal plane.

[0009] Optionally, the top ends of the two opposite sidewalls of the partition groove are respectively formed with a first guide angle.

[0010] Optionally, the position where the bottom surface of the partition groove connects with the side wall of the injection hole forms a second guide angle.

[0011] Optionally, the annular protrusion is provided with at least two partition grooves evenly distributed along its circumference.

[0012] Optionally, the number of partition grooves is two, and the width of the partition grooves is 0.5mm to 1.0mm.

[0013] Optionally, a third guide angle is formed at the top of the sidewall of the injection hole.

[0014] Optionally, a boss is provided at the outer edge of the bottom wall of the injection groove, and the boss is used to support the sealing nail.

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

[0016] In this embodiment of the invention, the annular protrusion thickens the edge of the injection hole to provide sufficient thickness for the insertion of the rubber nail, improving the stability of the nail's vertical insertion and ensuring circumferential airtightness. Simultaneously, a partition groove is formed at at least one position along the circumference of the annular protrusion. The inner side of the partition groove communicates with the injection hole, and the outer side communicates with the injection groove. The partition groove guides the electrolyte from the injection groove to the injection hole. Therefore, during injection, if electrolyte enters the injection groove outside the annular protrusion, it can be guided to the injection hole through the partition groove, preventing liquid accumulation in the injection groove and related problems. This eliminates the need for a downward protrusion at the edge of the injection hole to avoid such problems. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the cover body according to an embodiment of the present utility model.

[0018] Figure 2 This is a cross-sectional structural diagram of the cover body according to an embodiment of the present utility model.

[0019] Figure 3 This is another structural schematic diagram of the cover body in an embodiment of this utility model.

[0020] Figure 4 This is a cross-sectional schematic diagram of a portion of the structure behind the concealed adhesive nails and sealing nails in an embodiment of this utility model.

[0021] Figure 5This is a cross-sectional structural diagram of a partial structure of the power battery according to an embodiment of the present invention. Detailed Implementation

[0022] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model 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 utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0023] Please see Figures 1 to 5 This utility model discloses a cover 1 for a power battery. The cover 1 is provided with an injection groove 11 (laser penetration welding is performed at the location of the injection groove 11). An injection hole 12 extending downward is opened in the middle of the bottom wall of the injection groove 11. An annular protrusion 13 protrudes upward at the edge of the injection hole 12 to extend the injection hole 12. At least one position of the annular protrusion 13 along its circumference is formed with a partition groove 131 (that is, the annular protrusion 13 is broken to make it discontinuous). The inner side of the partition groove 131 communicates with the injection hole 12, and the outer side of the partition groove 131 communicates with the injection groove 11. The partition groove 131 is used to guide the electrolyte at the injection groove 11 to the injection hole 12.

[0024] In this embodiment of the invention, the annular protrusion 13 thickens the edge of the injection hole 12 to provide sufficient thickness for the insertion of the adhesive nail 4 into the injection hole 12, improving the stability of the adhesive nail 4 when vertically inserted into the injection hole 12 and ensuring circumferential airtightness after the adhesive nail 4 is inserted into the injection hole 12. Simultaneously, since at least one partition groove 131 is formed at a position along the circumference of the annular protrusion 13, the inner side of the partition groove 131 communicates with the injection hole 12, and the outer side of the partition groove 131 communicates with the injection groove 11, the partition groove 131 guides the electrolyte from the injection groove 11 to the injection hole 12. Therefore, during injection, if electrolyte enters the injection groove 11 outside the annular protrusion 13, it can be guided to the injection hole 12 through the partition groove 131, avoiding liquid accumulation in the injection groove 11 and the problems caused therefrom. This also eliminates the need for the downward protrusion thickening method at the edge of the injection hole 12 to avoid such problems.

[0025] It should be noted that the cover 1 in this embodiment of the present invention is not limited to the cover 1 in the narrow sense. Typically, a power battery includes a casing and a top cover. The cover 1 can be either a top cover or a casing. When the cover 1 is a casing, the liquid injection groove 11 and the liquid injection hole 12 are formed on the bottom of the casing. Alternatively, the power battery may also include a casing with openings at both ends; in this case, the covers fitted to both ends of the casing can be the aforementioned cover 1.

[0026] Specifically, the bottom surface of the partition groove 131 is not higher than the bottom surface of the injection groove 11. Since the bottom surface of the partition groove 131 is not higher than the bottom surface of the injection groove 11, it is beneficial to smoothly guide the liquid in the injection groove 11 to the injection hole 12 through the partition groove 131.

[0027] More specifically, the bottom surface of the partition groove 131 and the bottom surface of the liquid injection groove 11 are located on the same horizontal plane.

[0028] Specifically, the top ends of the two opposite sidewalls of the partition groove 131 are respectively formed with a first guide angle R1. Further, the radius of the first guide angle R1 is preferably 0.1mm to 0.2mm.

[0029] Specifically, the position where the bottom surface of the partition groove 131 connects with the side wall of the injection hole 12 forms a second guide angle R2. Further, the radius of the second guide angle R2 is preferably 0.1 mm to 0.2 mm.

[0030] In some embodiments, the annular protrusion 13 is provided with at least two partition grooves 131 evenly distributed along its circumference.

[0031] In the specific example, there are two partition grooves 131, which are formed opposite to each other on the annular protrusion 13. Of course, the number of partition grooves 131 is not limited.

[0032] In a specific example, the width of the partition groove 131 is 0.5mm to 1.0mm.

[0033] In some embodiments, a third guide angle R3 is formed at the top of the sidewall of the injection hole 12. Further, the radius of the third guide angle R3 is preferably 0.2 mm to 0.3 mm.

[0034] In the specific example, the third guide angle R3 is greater than the first guide angle R1 and the second guide angle R2.

[0035] In a specific example, the thickness T after the injection groove 11 is preferably 0.4mm to 0.7mm to facilitate laser penetration welding with the manifold. After extending (thickening) the injection hole 12 by providing an upwardly protruding annular protrusion 13, the depth H of the injection hole 12 is preferably greater than or equal to 0.8mm.

[0036] In some embodiments, a boss 14 protrudes upward from the outer edge of the bottom wall of the injection groove 11, and the boss 14 is used to support the sealing nail 5. Because the boss 14 protrudes upward from the outer edge of the bottom wall of the injection groove 11 to support the sealing nail 5, the sealing nail 5 can be supported when it needs to be assembled, thereby ensuring the welding accuracy of the sealing nail 5. Since the injection groove 11 is lower than the boss 14, the area where the laser penetration weld is applied is thinned, which reduces the power of the laser penetration weld and decreases the risk of burning the core or puncturing the cover 1 due to the high power of the laser penetration weld, thus preventing battery failure.

[0037] Specifically, the injection groove 11 and the boss 14 can be formed by thinning through stamping.

[0038] In some embodiments, the injection groove 11, the annular protrusion 13, etc., can be formed by integral stamping / stretching.

[0039] In some embodiments, the cover 1 can be made of aluminum or steel, etc.

[0040] Please combine Figures 1 to 5 This utility model embodiment also discloses a power battery, including the cover 1 as described above.

[0041] Specifically, the power battery includes a core 2, with a current collector 3 welded to the end of the core 2. During laser penetration welding, the laser penetration welding is performed at the injection groove 11. The formation of the injection groove 11 thins the area where the laser penetration welding is performed, thus reducing the power of the laser penetration welding and mitigating the risk of burning the core 2 or puncturing the cover 1 due to high power, leading to battery failure. During electrolyte injection (including secondary replenishment), if electrolyte enters the injection groove 11 outside the annular protrusion 13, it can be diverted to the injection hole 12 through the partition groove 131, avoiding electrolyte accumulation in the injection groove 11 and the associated problems. This also eliminates the need for thickening the edge of the injection hole 12 to prevent such problems. After injection, a period of time can be allowed for the electrolyte in the injection groove 11 to be fully diverted to the injection hole 12. When the adhesive nail 4 is inserted into the injection hole 12, the annular protrusion 13 protrudes upward at the edge of the injection hole 12, thickening the edge of the injection hole 12. This ensures sufficient thickness at the edge of the injection hole 12 to accommodate the inserted adhesive nail 4, improving the stability of the adhesive nail 4 when inserted vertically into the injection hole 12 and thus enhancing the circumferential airtightness of the injection hole 12 after the adhesive nail 4 is inserted. When assembling the sealing nail 5, the bottom wall of the injection groove 11 has a protrusion 14 for supporting the sealing nail 5, ensuring the welding accuracy of the sealing nail 5.

[0042] The above-disclosed examples are merely preferred embodiments of the present utility model, intended to facilitate understanding and implementation by those skilled in the art. They should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model are still within the scope of the present utility model.

Claims

1. A cover for a power battery, characterized in that, The cover is provided with a liquid injection groove, and a downward through-hole is opened in the middle of the bottom wall of the liquid injection groove. An annular protrusion is provided at the edge of the liquid injection hole to extend the liquid injection hole. At least one position of the annular protrusion along its circumference forms a partition groove. The inner side of the partition groove communicates with the liquid injection hole, and the outer side of the partition groove communicates with the liquid injection groove. The partition groove is used to guide the electrolyte at the liquid injection groove to the liquid injection hole.

2. The cover for a power battery according to claim 1, characterized in that, The bottom surface of the partition groove is not higher than the bottom surface of the injection groove.

3. The cover for a power battery according to claim 2, characterized in that, The bottom surface of the partition groove and the bottom surface of the injection groove are on the same horizontal plane.

4. The cover for a power battery according to claim 1, characterized in that, The top ends of the two opposite sidewalls of the partition groove are respectively formed with a first guide angle.

5. The cover for a power battery according to claim 1, characterized in that, The position where the bottom surface of the partition groove connects with the side wall of the injection hole forms a second guide angle.

6. The cover for a power battery according to claim 1, characterized in that, The annular protrusion has at least two partition grooves evenly arranged along its circumference.

7. The cover for a power battery according to claim 6, characterized in that, The number of partition grooves is two, and the width of the partition grooves is 0.5mm to 1.0mm.

8. The cover for a power battery according to claim 1, characterized in that, The top of the sidewall of the injection hole has a third guide angle.

9. The cover for a power battery according to claim 1, characterized in that, A boss is provided at the outer edge of the bottom wall of the injection groove, and the boss is used to support the sealing nail.

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

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