Power battery with shell opening welding ring

Abstract

The utility model discloses a power battery with a shell opening welding ring, which comprises a shell, a collector plate and an anti-explosion valve plate, one end of the shell is provided with a shell opening, the shell opening welding ring comprises an annular main body, the inner side of the annular main body is sunken downwards to form a supporting step part, and the upper part of the outer side of the annular main body extends outwards to form a welding part; the collector plate comprises a middle portion and an edge portion arranged on the outer side of the middle portion, the bottom end face of the shell opening welding ring is connected with the edge portion of the collector plate in a welded mode, the welding portion is in lap joint with the shell opening and is connected with the shell in a welded mode, and the anti-explosion valve plate is arranged on the supporting step portion and is connected with the supporting step portion in a welded mode. According to the power battery, open circuit or short circuit caused by rotation torque of the naked battery core relative to the shell wall is effectively avoided; besides, the welding assembly of the shell opening welding ring and the current collecting plate is carried out outside a production line instead of welding in the shell, so that welding scraps can be cleaned, and the influence of the welding scraps generated by the welding assembly of the shell opening welding ring and the current collecting plate on the performance of the power battery is avoided.

Description

Technical Field

[0001] The utility model relates to the field of power batteries, in particular to a power battery with a shell opening welding ring. Background Art

[0002] Currently, lithium-ion or sodium-ion cylindrical batteries are becoming mainstream products in the new energy industry due to their high energy density and good capacity consistency. The full-tab collector plate structure is being increasingly adopted by manufacturers as the preferred cylindrical battery structure. However, common problems include:

[0003] 1. After the collector plate of a conventional cylindrical power battery is welded to the bare cell and placed in the shell, the edge of the collector plate is directly welded to the shell wall. In other words, the collector plate and the shell wall are laser welded. First, due to the thin shell wall, it is easy to weld through the shell wall or weld poorly, resulting in many welding defects. Second, when the collector plate is directly welded to the shell wall, metal chips fly inside the shell and cannot be effectively cleaned, posing a safety hazard to the battery.

[0004] 2. With existing large-size cylindrical power battery structures, long-term vibration during vehicle installation or roller testing can cause the bare battery cells to experience rotational torque relative to the shell wall, directly impacting the internal electrical connections of the battery, potentially leading to open circuits or short circuits, and shortening the battery life.

[0005] 3. In order to save the manufacturing cost of cylindrical power batteries, explosion-proof valves are generally stamped directly on the top cover or bottom. In order to ensure the shell opening welding strength, thicker plates are generally preferred. However, thicker plates will lead to a decrease in the sensitivity of the explosion-proof valve opening, and the battery structure cannot strike a balance between the two. Summary of the Invention

[0006] The purpose of the utility model is to provide a power battery with a shell opening welding ring to solve the problem in the prior art that when the collecting plate is directly welded to the shell wall, metal chips splash inside the shell and cannot be effectively cleaned, posing a safety hazard to the battery.

[0007] In order to achieve the above-mentioned purpose, the utility model provides a power battery with a shell opening welding ring, comprising a shell, a current collecting plate and an explosion-proof valve plate, wherein one end of the shell has a shell opening, and the shell opening welding ring comprises an annular main body, the inner side of the annular main body is recessed downward with a support step portion, and the upper outer side of the annular main body extends outward with a welding portion; the current collecting plate comprises a middle portion and an edge portion arranged outside the middle portion, the bottom end face of the shell opening welding ring is welded to the edge portion of the current collecting plate, the welding portion overlaps the shell opening and is welded to the shell, and the explosion-proof valve plate is arranged on the support step portion and the explosion-proof valve plate is welded to the support step portion.

[0008] Preferably, the thickness of the annular body is greater than the thickness of the shell.

[0009] Preferably, a downwardly recessed portion is provided on the middle portion of the current collecting plate, and the power battery further comprises a bare cell disposed inside the shell, and a full tab at one end of the bare cell is welded to the recessed portion.

[0010] Preferably, the recessed portions are multiple and evenly distributed, and each recessed portion is fan-shaped or rectangular.

[0011] Preferably, the outer edge of the bottom end surface of the shell opening welding ring is chamfered.

[0012] Preferably, the distance between the upper surface of the step surface of the supporting step portion and the upper surface of the annular body is a first distance, and the first distance is greater than or equal to 0.5 mm and less than or equal to 1 mm.

[0013] Preferably, the thickness of the explosion-proof valve plate is less than or equal to the first distance.

[0014] Preferably, the welding portion is connected to the shell by laser welding, and the edge of the explosion-proof valve plate is connected to the supporting step portion by laser welding.

[0015] Preferably, the extended width of the welding portion is less than or equal to the thickness of the shell.

[0016] Preferably, the explosion-proof valve plate is provided with an annular explosion-proof engraved line.

[0017] Compared with the prior art, the collecting plate and the shell opening welding ring in the power battery of the utility model are welded to prevent rotation, the collecting plate and the bare battery cell are welded to prevent rotation, and the shell opening welding ring is welded and fixed to the shell opening, which effectively prevents the bare battery cell from having a rotational torque relative to the shell wall and directly impacting the internal electrical connection position of the power battery, causing an open circuit or a short circuit; in addition, the welding assembly of the shell opening welding ring and the collecting plate can be carried out outside the production line instead of welding inside the shell, and the welding chips can be cleaned, thereby avoiding the welding chips generated by the welding assembly of the shell opening welding ring and the collecting plate from affecting the performance of the power battery, thereby greatly increasing the service life of the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a three-dimensional structural diagram of a power battery with a shell opening welding ring according to the present invention.

[0019] Figure 2 This is a partial exploded view of the power battery with a shell opening welding ring of the present invention.

[0020] Figure 3 This is a structural diagram of a shell opening welding ring in a power battery having a shell opening welding ring from one angle of the present invention.

[0021] Figure 4This is a structural diagram of the shell opening welding ring in the power battery with a shell opening welding ring from another angle of the present invention.

[0022] Figure 5 This is a structural diagram of the shell opening welding ring and the current collecting plate in the power battery with the shell opening welding ring of the utility model after welding.

[0023] Figure 6 for Figure 5 sectional view of .

[0024] Figure 7 for Figure 6 Enlarged view of point A in the middle.

[0025] Figure 8 This is a cross-sectional structural diagram of a power battery with a shell opening welding ring according to the present invention. DETAILED DESCRIPTION

[0026] 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.

[0027] like Figures 1 to 8 As shown, an embodiment of the present utility model discloses a power battery with a shell opening welding ring, including a shell 1, a current collecting plate 3 and an explosion-proof valve plate 5. One end of the shell 1 has a shell opening 11, and the shell opening welding ring 4 includes an annular main body 41. The inner side of the annular main body 41 is recessed downward with a support step portion 42, and the upper outer side of the annular main body 41 extends outward with a welding portion 43; the current collecting plate 3 includes a middle portion 31 and an edge portion 32 provided on the outer side of the middle portion 31, the bottom end surface 44 of the shell opening welding ring 4 is welded to the edge portion 32 of the current collecting plate 3, the welding portion 43 overlaps the shell opening 11 and is welded to the shell 1, and the explosion-proof valve plate 5 is provided on the support step portion 42 and the explosion-proof valve plate 5 is welded to the support step portion 42. Specifically, the power battery 10 can be a cylindrical power battery, the shell 1 is columnar, and the material of the shell 1 can be aluminum or steel, etc. The shell 1 has an opening at one end and forms a shell opening 11. In actual application, the shell opening 11 can be the shell opening 11 of the negative end of the shell 1, and the positive end of the shell 1 is provided with a top cover and a pole. The shell opening welding ring 4 is an independent component, and the current collecting plate 3 is disc-shaped. The material of the current collecting plate 3 can be aluminum or copper-plated nickel material, etc. When the power battery 10 is assembled, the shell opening welding ring 4 and the current collecting plate 3 can be welded and assembled outside the production line first. After the shell opening welding ring 4 and the current collecting plate 3 are welded and assembled, the welding chips can be cleaned to avoid the welding chips in this step affecting the performance of the power battery 10.

[0028] The collecting plate 3 and the shell opening welding ring 4 in the power battery 10 of the present invention are welded to prevent rotation, the collecting plate 3 and the bare battery cell 2 are welded to prevent rotation, and the shell opening welding ring 4 is welded and fixed to the shell opening 11, which effectively prevents the bare battery cell 2 from having a rotational torque relative to the shell wall and directly impacting the internal electrical connection position of the power battery 10, causing an open circuit or a short circuit. In addition, the welding assembly of the shell opening welding ring 4 and the collecting plate 3 can be carried out outside the production line instead of welding inside the shell 1, and the welding chips can be cleaned, thereby avoiding the welding chips generated by the welding assembly of the shell opening welding ring 4 and the collecting plate 3 from affecting the performance of the power battery 10, thereby greatly increasing the service life of the power battery 10.

[0029] In the embodiment of the present utility model, Figure 7 As shown, the thickness H of the annular body 41 is greater than the thickness of the housing 1. By setting the thickness H of the annular body 41 greater than the thickness of the housing 1, the weld between the collecting plate 3 and the annular body 41 is more secure, avoiding the problems of welding through the shell wall or cold welds that are prone to frequent weld defects caused by the thin shell wall of the housing 1 and the collecting plate 3 in the prior art. Furthermore, the thicker annular body 41 provides better support performance, making this a very clever design.

[0030] In the embodiment of the present utility model, Figure 2 As shown, a recessed portion 34 is provided on the middle portion 31 of the current collecting plate 3. The power battery 10 further includes a bare cell 2 provided inside the housing 1. The full tab at one end of the bare cell 2 is welded to the recessed portion 34. Specifically, the recessed portions 34 are evenly distributed, such as Figure 2 As shown, there are three recessed portions 34 , each recessed portion 34 is fan-shaped. In some other embodiments, the recessed portion 34 may also be rectangular, and the specific design may be based on actual needs.

[0031] In the embodiment of the present invention, the bare cell 2 has a central hole 21 in the middle, and the current collecting plate 3 has a central through hole 33 corresponding to the central hole 21 .

[0032] In the embodiment of the present utility model, Figure 7 As shown, the outer edge of the lower end surface of the shell opening welding ring 4 is provided with a chamfer 45 , and the chamfer 45 has a guiding function, which facilitates the shell opening welding ring 4 to smoothly adapt to the shell opening 11 .

[0033] In the embodiment of the present utility model, Figure 7 As shown, the distance between the upper surface of the step surface of the supporting step portion 42 and the upper surface of the annular body 41 is a first distance h, and the first distance h is greater than or equal to 0.5 mm and less than or equal to 1 mm.

[0034] In the embodiment of the present invention, the thickness of the explosion-proof valve disc 5 is less than or equal to the first distance h. Specifically, the explosion-proof valve disc 5 is provided with an annular explosion-proof scoreline 51. The shell opening welding ring 4 is relatively thick, and the shell opening welding ring 4 can be used to support the power battery 10. Therefore, the explosion-proof valve disc 5 can be set to be relatively thin, effectively improving the valve opening sensitivity of the explosion-proof valve disc 5 and enhancing the safety of the power battery 10.

[0035] In the embodiment of the present invention, the welding portion 43 is laser welded to the housing 1, and the edge of the explosion-proof valve disc 5 is laser welded to the support step 42. Specifically, laser welding is more convenient and effectively ensures the sealing and fixation of the shell opening welding ring 4 and the housing 1, as well as the sealing and fixation of the explosion-proof valve disc 5 and the shell opening welding ring 4.

[0036] In the embodiment of the present utility model, Figures 7 and 8 As shown, the extension width w of the welding portion 43 is less than or equal to the thickness of the shell 1 . Preferably, the extension width w of the welding portion 43 is equal to the thickness of the shell 1 , so that the outer surface of the power battery 10 is smoother.

[0037] The assembly method of the power battery 10 of the embodiment of the present invention is as follows: first, the bare battery cell 2 is wound, and the positive electrode full tab on the inner side of one end and the negative electrode full tab on the other end are flattened or patted; then, the edge portion 32 of the collecting plate 3 is welded to the bottom of the shell opening welding ring 4 outside the production line, and metal chips are cleaned; then, the bottom surface of the fan-shaped or rectangular recessed portion 34 of the collecting plate 3 is fitted with the full tab of the bare battery cell 2, and laser welding is performed to fix it; then, the bare battery cell 2 is placed in the shell 1, and the shell opening welding ring 4 is overlapped on the shell opening 11, and sealed and fixed by laser welding; then the power battery 10 is injected with liquid for production; finally, the explosion-proof valve plate 5 is overlapped on the supporting step portion 42, and laser welding is performed to seal and fix it.

[0038] The embodiment of the utility model sets a shell opening welding ring 4 at the position of the shell opening 11 of the power battery 10, has a welding portion 43 at the upper position of the outer edge of the shell opening welding ring 4, has a supporting step portion 42 at the inner edge of the shell opening welding ring 4, welds the edge of the collecting plate 3 to the bottom end surface 44 of the shell opening welding ring 4, fixes the collecting plate 3 to the full-pole ear of the bare battery cell 2 by laser welding, seals and fixes the welding portion 43 of the shell opening welding ring 4 to the shell opening 11 by laser welding, and overlaps the explosion-proof valve plate 5 on the supporting step portion 42 on the shell opening welding ring 4 and seals and fixes it by laser welding; finally, the utility model realizes : The collecting plate 3 and the shell opening welding ring 4 are welded to prevent rotation, the collecting plate 3 and the bare battery cell 2 are welded to prevent rotation, and the shell opening welding ring 4 is welded and fixed to the shell opening 11; the thickness of the explosion-proof valve plate 5 is fine-tuned by presetting the depth of the first distance h to improve the sensitivity of the explosion-proof valve plate 5; the bare battery cell 2 can be completely limited and prevented from rotating relative to the shell 1, and the edge of the collecting plate 3 and the bottom of the shell opening welding ring 4 are welded outside the production line to avoid the problem of metal chips in the welding of the collecting plate 3. At the same time, the sensitivity of the explosion-proof valve plate 5 and the welding strength of the shell opening 11 can be flexibly taken into account, and the design is ingenious.

[0039] 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 a shell welding ring, characterized in that: The shell comprises a shell, a collecting plate and an explosion-proof valve plate. One end of the shell has a shell opening. The shell opening welding ring comprises an annular body. The inner side of the annular body is recessed downward to form a support step portion. The outer upper part of the annular body extends outward to form a welding portion. The collecting plate includes a middle portion and an edge portion arranged outside the middle portion, the bottom end surface of the shell opening welding ring is welded to the edge portion of the collecting plate, the welding portion overlaps the shell opening and is welded to the shell, and the explosion-proof valve plate is arranged on the support step portion and the explosion-proof valve plate is welded to the support step portion.

2. The power battery with a shell opening welding ring according to claim 1, characterized in that: The thickness of the annular body is greater than the thickness of the shell.

3. The power battery with a shell opening welding ring according to claim 1, characterized in that: A downwardly recessed portion is provided on the middle portion of the current collecting plate. The power battery further comprises a bare cell disposed inside the shell. A full tab at one end of the bare cell is welded to the recessed portion.

4. The power battery with a shell opening welding ring according to claim 3, characterized in that: There are multiple evenly distributed concave portions, and each concave portion is fan-shaped or rectangular.

5. The power battery with a shell opening welding ring according to claim 3, characterized in that: The outer edge of the lower end surface of the shell opening welding ring is provided with a chamfer.

6. The power battery with a shell opening welding ring according to claim 1, characterized in that: A distance between an upper surface of the step surface of the supporting step portion and an upper surface of the annular body is a first distance, and the first distance is greater than or equal to 0.5 mm and less than or equal to 1 mm.

7. The power battery with a shell opening welding ring according to claim 6, characterized in that: The thickness of the explosion-proof valve plate is less than or equal to the first distance.

8. The power battery with a shell opening welding ring according to claim 1, characterized in that: The welding portion is connected to the shell by laser welding, and the edge of the explosion-proof valve plate is connected to the supporting step portion by laser welding.

9. The power battery with a shell opening welding ring according to claim 1, characterized in that: An extension width of the welding portion is less than or equal to a thickness of the shell.

10. The power battery with a shell opening welding ring according to claim 1, characterized in that: The explosion-proof valve plate is provided with an annular explosion-proof engraved line.

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