Cover body for power battery and power battery

Abstract

The utility model discloses a cover body for power battery and power battery, the cover body is provided with a liquid injection groove, the middle part of the bottom wall of the liquid injection groove is provided with a liquid injection hole penetrating downwards, the bottom wall of the liquid injection groove is provided with an annular sinking groove, the annular sinking groove surrounds the liquid injection hole, and the annular sinking groove is provided with a plurality of grooves. The position where the annular sinking groove is located is configured to conduct laser penetration welding. Due to the formation of the annular sinking groove 12, the position of laser penetration welding is thinned, so that the power of laser penetration welding can be reduced, and the risks of battery scrapping and the like caused by easy roll core burning or cover body breakdown liquid leakage due to relatively high power of laser penetration welding are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a cover body for a power battery and the power battery. Background Art

[0002] Currently, lithium-ion / sodium-ion cylindrical batteries are becoming 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. With the popularity of new energy vehicles, people have put forward higher requirements for fast charging (i.e., high-rate fast charging of power batteries). At the same time, more and more manufacturers are beginning to explore the shell bottom penetration welding process to meet the demand for fast charging. However, the following common problems still exist:

[0003] Cylindrical power batteries often have thicker shells at the bottom, requiring a larger laser welding power to penetrate. Larger penetration welding powers can easily burn the core or penetrate the shell bottom to leak liquid, causing the battery to be directly scrapped. Currently, effective quality monitoring of the core after welding is impossible.

[0004] After the cylindrical power battery core is flattened or patted, the end of the foil is uneven, or the current collecting plate is slightly deformed, which causes gaps to easily appear when the current collecting plate fits with the bottom of the shell. The laser penetration welding penetration depth consistency is poor, and the effective flow area cannot be guaranteed.

[0005] Cylindrical power batteries commonly use center-hole resistance welding to weld / fix the core and shell bottom. However, resistance welding is prone to problems such as cold welds or the normal welding positions falling off during vehicle vibration. In addition, the small welding area of ​​resistance welding results in poor current capacity, which cannot meet the requirements of high-rate charging and discharging.

[0006] The feature of the injection hole is stamped on the top cover or the bottom of the shell. Generally, due to the thin thickness of the injection hole (needing to adapt to the sealing nail), the stability / airtightness of the inserted glue nail is poor. Utility Model Content

[0007] The purpose of the present utility model is to provide a cover for a power battery and a power battery, which can solve at least one technical problem in the above-mentioned background technology.

[0008] To achieve the above-mentioned purpose, the present invention provides a cover body for a power battery, wherein the cover body is provided with a liquid injection groove, and a liquid injection hole is provided downwardly penetrating the middle part of the bottom wall of the liquid injection groove, and an annular groove is formed on the bottom wall of the liquid injection groove, and the annular groove surrounds the liquid injection hole, and the position of the annular groove is configured for laser penetration welding.

[0009] Optionally, the annular groove is formed by stamping and thinning.

[0010] Optionally, the thickness of the cover body at the location of the annular groove is 0.4 mm to 0.8 mm.

[0011] Optionally, the annular sink and the liquid injection hole are spaced apart.

[0012] Optionally, an annular protrusion is provided upwardly at the edge of the liquid injection hole.

[0013] Optionally, the outer side of the annular protrusion is connected to the annular groove.

[0014] Optionally, the cover body protrudes downward below the liquid injection groove to form a convex portion, and the convex portion is used for fitting and welding with the collecting plate.

[0015] Optionally, a boss is formed on the bottom wall of the liquid injection groove outside the annular sink, and the boss is used to support the sealing pin.

[0016] Optionally, the injection groove is formed by integral stamping / stretching.

[0017] To achieve the above-mentioned purpose, the present invention further provides a power battery, comprising the cover body for the power battery as described above.

[0018] In this embodiment of the present invention, the bottom wall of the injection groove is formed with an annular groove surrounding the injection hole. The location of the annular groove is configured for laser penetration welding. The formation of the annular groove 12 reduces the thickness of the laser penetration welding area, thereby reducing the power of the laser penetration welding and minimizing the risk of burning the winding core or penetrating the cover to leak liquid, thereby rendering the battery useless. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of the cover body of an embodiment of the present utility model.

[0020] Figure 2 It is a three-dimensional structural diagram of the cover body of the embodiment of the utility model from another perspective.

[0021] Figure 3 It is a schematic cross-sectional structure diagram of the cover body of an embodiment of the present utility model.

[0022] Figure 4 yes Figure 3 Enlarged view of part A in the middle.

[0023] Figure 5 It is a schematic cross-sectional view of the local structure of the power battery after the glue nails and sealing nails are hidden in the embodiment of the utility model.

[0024] Figure 6 It is a schematic cross-sectional view of the local structure of the power battery behind the hidden sealing nails in an embodiment of the utility model.

[0025] Figure 7It is a schematic cross-sectional view of a partial structure of a power battery according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0026] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] See also Figures 1 to 7 The embodiment of the utility model discloses a cover body 1 for a power battery, wherein the cover body 1 is provided with a liquid injection groove 10, and a liquid injection hole 11 penetrating downward is opened in the middle of the bottom wall of the liquid injection groove 10, and an annular groove 12 is formed on the bottom wall of the liquid injection groove 10, which surrounds the liquid injection hole 11, and the position of the annular groove 12 is configured for laser penetration welding.

[0028] In this embodiment of the present invention, the bottom wall of the injection groove 10 is formed with an annular recess 12 surrounding the injection hole 11. The location of the recess 12 is configured for laser penetration welding. The formation of the recess 12 reduces the thickness of the laser penetration weld, thereby reducing the power of the laser penetration weld and minimizing the risk of burning the winding core or penetrating the cover 1 due to high laser penetration welding power, leading to leakage and battery failure.

[0029] It should be noted that the cover 1 in the embodiments of the present invention is not limited to a cover 1 in the narrow sense. Typically, a power battery comprises a housing and a top cover. The cover 1 can be either the top cover or the housing. When the cover 1 serves as the housing, the injection groove 10 and injection hole 11 are formed on the bottom of the housing. Alternatively, a power battery may comprise a housing with both ends open. In this case, the covers 1 mounted on either end of the housing can be the aforementioned covers 1.

[0030] Specifically, the annular groove 12 is formed by punching and thinning.

[0031] Specifically, the thickness T of the cover body 1 at the location of the annular recess 12 is 0.4 mm to 0.8 mm.

[0032] Specifically, the annular sink 12 is spaced apart from the liquid injection hole 11, but this is not limited thereto.

[0033] More specifically, an annular protrusion 13 is provided upwardly from the edge of the liquid injection hole 11. The upwardly protruding annular protrusion 13 thickens the edge of the liquid injection hole 11 as a whole, thereby ensuring that the edge of the liquid injection hole 11 has sufficient thickness to accommodate the plastic nail 2 inserted into the liquid injection hole 11. This improves the stability of the plastic nail 2 assembled in the liquid injection hole 11 and further enhances the airtightness of the liquid injection hole 11 after the plastic nail 2 is inserted.

[0034] Furthermore, the outer side of the annular protrusion 13 is connected to the annular groove 12. Of course, this is not limited to this. The outer side of the annular protrusion 13 may not be directly connected to the annular groove 12.

[0035] In some embodiments, the cover body 1 protrudes downward from the bottom of the liquid injection groove 10 to form a protrusion 14, which is used for fitting and welding with the collecting disc 3. Since the cover body 1 protrudes downward from the bottom of the liquid injection groove 10 to form the protrusion 14 for fitting and welding with the collecting disc 3, when the foil end is uneven or the collecting disc 3 is slightly deformed after the coil core is flattened or patted, it is beneficial to ensure that the laser penetration welding position of the cover body 1 is stably fitted with the collecting disc 3, avoid the formation of a gap between the collecting disc 3 and the cover body 1, improve the consistency of the laser penetration welding depth, avoid the occurrence of cold welds, and ensure the effective flow area.

[0036] In a specific example, the height dimension H of the protrusion 14 is preferably 0.2 mm to 0.4 mm.

[0037] In some embodiments, the bottom wall of the injection groove 10 is formed with a boss 15 outside the annular groove 12, and the boss 15 is used to support the sealing pin 4. Since the bottom wall of the injection groove 10 is formed with the boss 15 outside the annular groove 12 for supporting the sealing pin 4, the sealing pin 4 can be supported when it is required to be assembled, thereby ensuring the welding accuracy of the sealing pin 4.

[0038] In a specific example, the depth of the liquid injection groove 10 at the position of the boss 15 is h, and the height dimension of the annular protrusion 13 is L, and L is preferably greater than or equal to 0.8 mm.

[0039] In some embodiments, the injection groove 10 is formed by integral stamping / stretching.

[0040] In some embodiments, the cover 1 may be made of aluminum or steel.

[0041] Please combine Figures 1 to 7 The embodiment of the present utility model further discloses a power battery, comprising the cover body 1 as described above.

[0042] Specifically, the power battery includes a winding core 5, with a current collecting plate 3 welded to the end of the winding core 5. After the cover 1 is assembled, due to the presence of the protrusion 14, when the end of the foil is uneven after the winding core 5 is flattened or the current collecting plate 3 is slightly deformed, it is beneficial to ensure that the laser penetration welding position of the cover 1 is stably fitted with the current collecting plate 3, avoid the formation of a gap between the current collecting plate 3 and the cover 1, improve the consistency of the laser penetration welding depth, avoid the occurrence of cold welds, and ensure the effective flow area. When performing laser penetration welding, laser penetration welding is performed at the annular groove 12. Due to the formation of the annular groove 12, the position of the laser penetration welding is thinned, which can reduce the power of the laser penetration welding, thereby reducing the risk of burning the winding core 5 or breaking through the cover 1 due to the high power of the laser penetration welding, causing leakage and rendering the battery scrapped. When the glue nail 2 is inserted into the liquid injection hole 11, the edge of the liquid injection hole 11 is provided with an annular protrusion 13 protruding upward, so that the edge of the liquid injection hole 11 is thickened as a whole, which is conducive to the edge of the liquid injection hole 11 having sufficient thickness to adapt to the glue nail 2 inserted into the liquid injection hole 11, and can improve the stability of the glue nail 2 assembled in the liquid injection hole 11, thereby improving the airtightness of the liquid injection hole 11 after the glue nail 2 is inserted. When the sealing nail 4 is assembled and welded in the liquid injection groove 10, the bottom wall of the liquid injection groove 10 is formed with a boss 15 on the outside of the annular groove 12 for supporting the sealing nail 4. Therefore, when the sealing nail 4 needs to be assembled, the sealing nail 4 can be supported, thereby ensuring the welding accuracy of the sealing nail 4.

[0043] The above disclosure is only a preferred example of the present invention, and its role is to facilitate the understanding and implementation of those skilled in the art. It certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made within the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A cover for a power battery, characterized in that: The cover body is provided with a liquid injection groove, a liquid injection hole is provided in the middle of the bottom wall of the liquid injection groove, and an annular groove is formed on the bottom wall of the liquid injection groove. The annular groove surrounds the liquid injection hole, and the position of the annular groove is configured to perform laser penetration welding; An annular protrusion is provided at the edge of the liquid injection hole; The outer side of the annular protrusion is connected to the annular groove; The cover body protrudes downward below the liquid injection groove to form a convex portion, and the convex portion is used for welding with the collecting plate; The bottom wall of the liquid injection groove is formed with a boss on the outer side of the annular sink, and the boss is used to support the sealing pin.

2. The cover for a power battery according to claim 1, characterized in that: The annular groove is formed by punching and thinning.

3. The cover for a power battery according to claim 1, characterized in that: The thickness of the cover body at the location of the annular groove is 0.4 mm to 0.8 mm.

4. The cover for a power battery according to claim 1, characterized in that: The annular sink is spaced apart from the liquid injection hole.

5. The cover for a power battery according to claim 1, characterized in that: The injection groove is formed by integral stamping / stretching.

6. A power battery, characterized in that: The invention comprises a cover for a power battery according to any one of claims 1 to 5.

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