Power battery with integrated liquid injection hole type collector plate

Abstract

The utility model discloses a power battery with an integrated liquid injection hole type current collecting disc, the middle part of the current collecting disc is provided with a convex part, the peripheral surface of the convex part is a first inclined surface which is inclined, and the middle part of the convex part is provided with a through liquid injection hole; the power battery further comprises a bottom shell, a matching hole corresponding to the protruding part is formed in the bottom shell, a second inclined face matched with the first inclined face is arranged on the inner wall of the matching hole, and the protruding part is embedded into the matching hole from the inner side of the bottom shell and enables the first inclined face and the second inclined face to be attached in an aligned mode and connected through laser seam welding. According to the utility model, the convex part is arranged in the middle of the collector plate, the peripheral surface of the convex part is arranged to be the first inclined surface, the matching hole is formed in the bottom shell, and the second inclined surface is arranged on the inner wall of the matching hole, so that the convex part and the matching hole can be accurately limited and can be sealed and fixed by adopting a laser seam welding process with relatively low power; and the welding yield of the collector plate and the bottom shell is effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of power batteries, in particular to a power battery with an integrated liquid injection hole type current collecting plate. Background Art

[0002] At present, lithium-ion / sodium-ion cylindrical batteries have gradually become the mainstream products in the new energy industry due to their high energy density, good capacity consistency, and support for high-rate charge and discharge. More and more manufacturers continue to pursue the optimization of the compactness of cylindrical battery structure to improve energy density. Common problems: 1. The current collector of the cylindrical power battery is assembled into the shell and the bottom of the shell. The common shell bottom has a liquid injection hole structure, which can only be connected to the current collector by laser penetration welding. The large penetration welding power can easily cause burns to the bare battery cell or breakdown of the shell bottom to leak liquid, resulting in direct battery scrapping; 2. The cylindrical power battery has a pole at one end, which is generally integrated with the top cover or shell bottom. The other end can only be fixed by resistance welding the bare battery cell to the shell bottom by center hole resistance welding. Resistance welding is prone to cold welding problems or the normal welding position may fall off during vehicle vibration. In addition, the small welding area of ​​resistance welding leads to poor overcurrent capacity, which cannot meet high-rate charge and discharge. Summary of the Invention

[0003] The purpose of the utility model is to provide a power battery with an integrated liquid injection hole collector plate, so as to solve the problem that the bare battery cells are burned or the bottom shell is penetrated and leaked when the existing collector plate is welded to the bottom shell by penetration welding, and the problem of cold welding when resistance welding is used.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a power battery with an integrated liquid injection hole type current collecting plate, wherein a protrusion is provided in the middle of the current collecting plate, the outer peripheral surface of the protrusion is an inclined first inclined surface, and the middle part of the protrusion is provided with the through liquid injection hole; the power battery also includes a bottom shell, a matching hole is provided on the bottom shell corresponding to the protrusion, and the inner wall of the matching hole is provided with a second inclined surface matching the first inclined surface, the protrusion is embedded in the matching hole from the inner side of the bottom shell and the first inclined surface and the second inclined surface are aligned and fit together and connected by laser seam welding.

[0005] Preferably, the current collecting disk is in a disk shape or a strip shape, and is further provided with a plurality of evenly arranged tab welding areas, wherein the tab welding areas are recessed in a direction away from the protruding portion.

[0006] Preferably, the current collecting plate is further provided with a plurality of through holes, and the plurality of through holes are arranged to avoid the tab welding area.

[0007] Preferably, the inclination angle between the first inclined surface and the vertical surface is greater than or equal to 22 degrees and less than or equal to 68 degrees, and the inclination angle between the second inclined surface and the vertical surface is greater than or equal to 22 degrees and less than or equal to 68 degrees.

[0008] Preferably, a countersunk hole is further provided on the outer side of the matching hole, and the cross-sectional dimension of the countersunk hole is larger than the cross-sectional dimension of the matching hole so that a platform surface is provided between the countersunk hole and the matching hole.

[0009] Preferably, a first sealing pin is provided in the liquid injection hole.

[0010] Preferably, the upper edge of the inner wall of the liquid injection hole is chamfered.

[0011] Preferably, the first sealing nail is a plastic nail.

[0012] Preferably, a second sealing pin is welded in the countersunk hole, the bottom of the second sealing pin is mounted on the platform surface, and the second sealing pin seals the countersunk hole.

[0013] Preferably, the inner wall of the countersunk hole is an inclined third slope, the outer wall of the second sealing pin is a fourth slope that cooperates with the third slope, the third slope is fitly connected to the fourth slope, and an avoidance groove is also provided on the side surface of the second sealing pin facing the first sealing pin.

[0014] Compared with the prior art, the present invention provides a raised portion in the middle of the collector plate and sets the outer peripheral surface of the raised portion as a first inclined surface. Meanwhile, a matching hole is provided on the bottom shell, and a second inclined surface is provided on the inner wall of the matching hole. This allows the raised portion and the matching hole to be precisely positioned and sealed using a low-power laser seam welding process, effectively improving the welding yield of the collector plate and the bottom shell. The provision of the first and second inclined surfaces also prevents the laser from damaging the bare battery cells inside the shell through the matching gap between the first and second inclined surfaces. Furthermore, the collector plate can be integrally formed by low-cost stamping or cold heading, ensuring the stability and penetration consistency of the laser seam welding, while also improving the production yield of cylindrical power batteries, improving their high-rate charge and discharge performance, and preventing the welding position from falling off due to vibration during battery loading. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a structural diagram of the power battery of this utility model.

[0016] Figure 2 This is a structural diagram of the current collecting plate in the power battery of the utility model.

[0017] Figure 3 This is a cross-sectional structural diagram of the current collecting plate in the power battery of the present utility model.

[0018] Figure 4 for Figure 3 Enlarged view of point A in the middle.

[0019] Figure 5This is a structural diagram of the shell of the power battery of this utility model.

[0020] Figure 6 This is a cross-sectional structural diagram of the shell of the power battery of the present utility model.

[0021] Figure 7 This is a cross-sectional structural diagram of the power battery of the present utility model.

[0022] Figure 8 for Figure 7 Enlarged view of point B in the middle. DETAILED DESCRIPTION

[0023] In order to explain the technical content, structural features and effects achieved by the present invention in detail, the following is a detailed description in conjunction with the embodiments and the accompanying drawings.

[0024] like Figures 1 to 8 As shown, the embodiment of the present invention provides a power battery with an integrated liquid injection hole type current collecting plate, a protrusion 21 is provided in the middle of the current collecting plate 2, the outer peripheral surface of the protrusion 21 is an inclined first slope 211, and a through liquid injection hole 22 is provided in the middle of the protrusion 21; the power battery 10 also includes a bottom shell 11, a matching hole 12 is provided on the bottom shell 11 corresponding to the protrusion 21, and the inner wall of the matching hole 12 is provided with a second slope 121 that matches the first slope 211, the protrusion 21 is embedded in the matching hole 12 from the inner side of the bottom shell 11, and the first slope 211 and the second slope 121 are aligned and fit together and connected by laser seam welding. Specifically, as Figure 1 、 Figure 7 and Figure 8 As shown, the power battery 10 is specifically a cylindrical power battery and includes a shell 1 and a bare cell 3 arranged in the shell 1. The bottom shell 11 is located at the bottom of the shell 1. The collecting plate 2 can be integrally formed by stamping or cold heading. The collecting plate 2 is arranged between the bare cell 3 and the bottom shell 11 to electrically connect the bare cell 3 and the shell 1.

[0025] The embodiment of the present invention provides a raised portion 21 in the middle of the current collecting plate 2 and configures the outer peripheral surface of the raised portion 21 as a first inclined surface 211. Furthermore, a mating hole 12 is provided on the bottom shell 11, and a second inclined surface 121 is provided on the inner wall of the mating hole 12. This allows the raised portion 21 and the mating hole 12 to be precisely positioned and sealed using a low-power laser seam welding process, effectively improving the welding yield between the current collecting plate 2 and the bottom shell 11. The provision of the first inclined surface 211 and the second inclined surface 121 also prevents the laser from damaging the bare battery cells 3 within the shell 1 through the mating gap between the first inclined surface 211 and the second inclined surface 121. Furthermore, the current collecting plate 2 is integrally formed using a low-cost stamping or cold heading method, which not only ensures the stability and penetration consistency of the laser seam welding, but also improves the production yield of the cylindrical power battery 10, improves its high-rate charge and discharge performance, and prevents the weld from falling off due to vibration during battery loading.

[0026] In the embodiment of the present invention, the collecting plate 2 is in the shape of a plate or a strip, and is provided with a plurality of evenly arranged tab welding areas 23, which are recessed in a direction away from the raised portion 21. Specifically, Figure 2 As shown, the current collecting tray 2 is disk-shaped, and three tab welding areas 23 are evenly arranged around the raised portion 21 on the current collecting tray 2. The tab welding areas 23 fit over the entire tab of the bare cell 3 and are welded to the entire tab of the bare cell 3. In some other embodiments, the current collecting tray 2 can be strip-shaped. Of course, the specific structure of the current collecting tray 2 can be set according to actual needs.

[0027] In the embodiment of the present invention, the collecting plate 2 is further provided with a plurality of through holes 24, and the plurality of through holes 24 are arranged to avoid the tab welding area 23. Figure 2 As shown, three through holes 24 are evenly arranged on the current collecting plate 2 . The provision of the through holes 24 further accelerates the injection speed of the power battery 10 , thereby saving the production and processing time of the power battery 10 .

[0028] In the embodiment of the present invention, the inclination angle between the first inclined surface 211 and the vertical surface is greater than or equal to 22 degrees and less than or equal to 68 degrees, and the inclination angle between the second inclined surface 121 and the vertical surface is greater than or equal to 22 degrees and less than or equal to 68 degrees. Figure 4 and Figure 6 As shown, the inclination angle between the first bevel 211 and the vertical plane is the first inclination angle a, and the inclination angle between the second bevel 121 and the vertical plane is the second inclination angle b. By setting the first inclination angle a and the second inclination angle b, the processing of the first bevel 211 and the second bevel 121 as well as the installation and welding of the first bevel 211 and the second bevel 121 are facilitated. The difference between the outermost second diameter D of the matching hole 12 and the first diameter d of the outer end face of the protrusion 21 is greater than or equal to 0 and less than or equal to 0.1 mm, and the difference between the depth H of the matching hole 12 and the height h of the protrusion 21 is greater than or equal to 0 and less than or equal to 0.05 mm.

[0029] In the embodiment of the present invention, a countersunk hole 13 is further provided on the outside of the mating hole 12. The cross-sectional dimension of the countersunk hole 13 is larger than the cross-sectional dimension of the mating hole 12 so that a platform surface 14 is provided between the countersunk hole 13 and the mating hole 12. Specifically, Figures 5 and 6 As shown, the countersunk hole 13 is connected to the matching hole 12 , the matching hole 12 is arranged on the inner side close to the bare battery core 3 , and the countersunk hole 13 is arranged on the outer side away from the bare battery core 3 .

[0030] In the embodiment of the present utility model, Figures 7 and 8As shown, a first sealing nail 4 is provided in the injection hole 22. Specifically, a chamfer 221 is provided on the upper edge of the inner wall of the injection hole 22 to facilitate the embedding of the first sealing nail 4, which can be a plastic nail.

[0031] In the embodiment of the present invention, a second sealing pin 5 is welded within the countersunk hole 13. The bottom of the second sealing pin 5 is mounted on the platform surface 14, thereby sealing the countersunk hole 13. The provision of the platform surface 14 ensures that the second sealing pin 5 can be supported on the platform surface 14, resulting in a good installation effect and a clever design. In addition, the provision of the first sealing pin 4 and the second sealing pin 5 further ensures the sealing effect of the liquid injection hole 22 of the power battery 10, thereby ensuring the service life of the power battery 10.

[0032] In the embodiment of the present invention, the inner wall of the countersunk hole 13 is an inclined third slope 131, and the outer wall of the second sealing pin 5 is a fourth slope 51 that matches the third slope 131. The third slope 131 and the fourth slope 51 are closely connected. An avoidance groove 52 is also provided on the side of the second sealing pin 5 facing the first sealing pin 4. Specifically, Figure 8 As shown, the third bevel 131 and the fourth bevel 51 are connected by laser seam welding. Due to the provision of the second sealing nail 5, the welding of the first bevel 211 and the second bevel 121 can allow for poor welding airtightness. The second sealing nail 5 can ensure the airtightness of the battery, which is a clever design.

[0033] The assembly method of the power battery 10 of the embodiment of the present utility model is as follows: the full tabs of the bare battery cell 3 are fixed to the tab welding area 23 on the surface of the current collecting plate 2 by laser welding, and then the bare battery cell 3 is placed in the shell 1 and the first inclined surface 211 of the current collecting plate 2 is overlapped and limited with the second inclined surface 121 of the bottom shell 11, and then a clamp is used to support the current collecting plate 2 through the center hole 31 in the middle of the bare battery cell 3 and the current collecting plate 2 and the bottom shell 11 are sealed and fixed by laser seam welding. The other processes are produced and assembled in a normal manner. Finally, a plastic nail is inserted into the liquid injection hole 22, and then the second sealing nail 5 is welded.

[0034] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A power battery with an integrated liquid injection hole collector plate, characterized in that: A convex portion is provided in the middle of the collecting plate, the outer peripheral surface of the convex portion is an inclined first slope, and a through injection hole is opened in the middle of the convex portion; The power battery also includes a bottom shell, a matching hole is opened on the bottom shell corresponding to the raised portion, and the inner wall of the matching hole is provided with a second inclined surface matching the first inclined surface. The raised portion is embedded in the matching hole from the inner side of the bottom shell, and the first inclined surface and the second inclined surface are aligned and fit together and connected by laser seam welding.

2. The power battery with an integrated liquid injection hole type current collecting plate according to claim 1, characterized in that: The current collecting disk is in a disk shape or a strip shape, and is further provided with a plurality of evenly arranged tab welding areas. The tab welding areas are recessed in a direction away from the raised portion.

3. The power battery with an integrated liquid injection hole type current collecting plate according to claim 2, characterized in that: The current collecting plate is further provided with a plurality of through holes, and the plurality of through holes are arranged to avoid the tab welding area.

4. The power battery with an integrated liquid injection hole type current collecting plate according to claim 1, characterized in that: An inclination angle between the first inclined surface and the vertical surface is greater than or equal to 22 degrees and less than or equal to 68 degrees, and an inclination angle between the second inclined surface and the vertical surface is greater than or equal to 22 degrees and less than or equal to 68 degrees.

5. The power battery with an integrated liquid injection hole type current collecting plate according to claim 1, characterized in that: A countersunk hole is further provided on the outside of the matching hole, and the cross-sectional dimension of the countersunk hole is larger than the cross-sectional dimension of the matching hole so that a platform surface is provided between the countersunk hole and the matching hole.

6. The power battery with an integrated liquid injection hole type current collecting plate according to claim 5, characterized in that: A first sealing pin is provided in the liquid injection hole.

7. The power battery with an integrated liquid injection hole type current collecting plate according to claim 6, characterized in that: The upper edge of the inner wall of the liquid injection hole is chamfered.

8. The power battery with an integrated liquid injection hole type current collecting plate according to claim 6, characterized in that: The first sealing nail is a plastic nail.

9. The power battery with an integrated liquid injection hole type current collecting plate according to claim 6, characterized in that: A second sealing pin is welded in the countersunk hole, and the bottom of the second sealing pin is installed on the platform surface. The second sealing pin seals the countersunk hole.

10. The power battery with an integrated liquid injection hole type current collecting plate according to claim 9, characterized in that: The inner wall of the countersunk hole is an inclined third slope, the outer wall of the second sealing pin is a fourth slope that cooperates with the third slope, the third slope is fitly connected to the fourth slope, and an avoidance groove is also provided on the side surface of the second sealing pin facing the first sealing pin.

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