Cylindrical power battery

Abstract

The utility model discloses a cylindrical power battery, which comprises a pole and a collector plate, the collector plate comprises a disc-shaped body, the middle part of the disc-shaped body is provided with a lug boss, and the lug boss is connected with a welding piece; a through hole penetrating through the pole is formed in the middle of the pole, the through hole comprises an upper through hole and a lower through hole, and the upper through hole is connected with the lower through hole through a step part; the welding piece is embedded in the lower through hole, the outer side face of the welding piece is matched with the inner wall of the lower through hole to form a first matching gap, and the welding piece and the lower through hole are connected at the first matching gap in a laser welding mode so as to be connected with the collector plate and the pole. The lug boss is arranged in the middle of the collector plate, the welding piece is connected to the lug boss, and the outer side face of the welding piece is attached to the inner wall of the through hole in the lower part of the pole and is connected with the inner wall in a laser seam welding manner, so that a roll core is prevented from being damaged during welding, metal welding slag can be prevented from falling into the roll core of the power battery, and the design is ingenious.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of power battery, especially a cylindrical power battery. BACKGROUND

[0002] At present, lithium ion or sodium ion cylindrical battery gradually becomes the mainstream product of new energy industry because of high energy density, good capacity consistency, can support high rate charge and discharge and other advantages, more and more manufacturers continuously pursue the compactness optimization of cylindrical battery structure to improve energy density, and common problems are:

[0003] 1, cylindrical power battery current collector disc into shell and pole assembly, generally common in the pole face groove, take laser penetration welding and current collector disc connection, larger penetration welding power is easy to cause burn wound core, leading to battery direct scrap;

[0004] 2, cylindrical power battery current collector disc into shell and pole assembly, because current collector disc is thin and weak, and deformation is prone to appear when the clamp is pressed, leading to current collector disc and pole cannot be well attached, leading to insufficient flow area, and the demand of high rate charge and discharge overcurrent cannot be met;

[0005] 3, the welding power required in the assembly line welding pole is larger, metal welding slag splashes randomly and cannot be effectively cleaned, leading to safety risk to power battery. SUMMARY

[0006] The utility model discloses a cylindrical power battery to solve the problem that the larger penetration welding power in the welding process of the production of the existing power battery leads to the burn wound core.

[0007] In order to realize the above-mentioned purpose, the utility model provides a cylindrical power battery, including pole and current collector disc, the current collector disc includes disc body, the middle part of disc body is equipped with the convex part, and the welding piece is connected on the convex part, the middle part of pole is equipped with the through hole that passes through the pole, the through hole includes upper through hole and lower through hole, and the upper through hole is connected with the lower through hole through the step part, the welding piece is embedded in the lower through hole, and the outer side surface of the welding piece is matched with the inner wall of the lower through hole and forms the first cooperation gap, and the welding piece and the lower through hole are laser welded at the first cooperation gap to connect the current collector disc and the pole.

[0008] Preferably, the inner wall of the lower through hole includes the first inclined surface, the first inclined surface is inwardly tapered from bottom to top, the outer side surface of the welding piece includes the second inclined surface, and the second inclined surface is correspondingly tapered inwardly from bottom to top.

[0009] Preferably, the welded part is groove-shaped and includes a welding groove bottom and a welding groove wall connected to the welding groove bottom. The welding groove bottom includes a planar welding area. The upper surface of the protrusion is a plane to mate with and weld to the bottom surface of the planar welding area. The outer side of the welding groove wall mates with the inner wall of the lower through hole.

[0010] Preferably, the inner surface of the welding tank wall includes a third inclined surface, which is an outwardly expanding slope from bottom to top.

[0011] Preferably, the upper surface of the welding tank wall is an annular surface.

[0012] Preferably, the thickness of the planar welding area is greater than the thickness of the protrusion, the thickness of the planar welding area is greater than or equal to 0.4 mm and less than or equal to 0.8 mm, and the thickness of the protrusion is greater than or equal to 0.2 mm and less than or equal to 0.4 mm.

[0013] Preferably, it further includes a sealing pin, the outer side of which mates with the inner wall of the upper through hole to form a second mating gap, and the sealing pin and the upper through hole are laser welded together at the second mating gap.

[0014] Preferably, the inner wall of the upper through hole includes a fourth inclined surface, which is an inwardly contracting slope from top to bottom, and the outer side of the sealing nail includes a fifth inclined surface, which is an inwardly contracting slope from top to bottom.

[0015] Preferably, it further includes a housing and a cover that closes the opening end of the housing. The cover has the pole post in the middle. The housing also has a winding core. The disc-shaped body has several welding parts, and the welding parts are welded to the full pole lug at one end of the winding core.

[0016] Preferably, each of the welded portions is further provided with a seepage slit on its periphery.

[0017] Compared with the prior art, this utility model has a clever design by setting a protrusion in the middle of the current collector and connecting a welding part to the protrusion. The welding part is then attached to the inner wall of the lower through hole of the pole post and laser-welded together. This avoids damage to the core during welding and prevents metal welding slag from falling into the core of the power battery. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the cylindrical power battery according to an embodiment of the present invention.

[0019] Figure 2 This is a structural diagram of the collector disk in an embodiment of this utility model.

[0020] Figure 3This is a structural diagram of the welded component in an embodiment of this utility model.

[0021] Figure 4 This utility model embodiment shows the structure of the welded component after it has been welded to the manifold.

[0022] Figure 5 for Figure 4 Cross-sectional structural diagram.

[0023] Figure 6 This is a structural diagram of the core after the collector plate is welded onto it in this embodiment of the present invention.

[0024] Figure 7 A cross-sectional view of the pole in an embodiment of this utility model.

[0025] Figure 8 This is a cross-sectional view of the cylindrical power battery according to an embodiment of the present invention.

[0026] Figure 9 for Figure 8 Enlarged view of point A in the middle. Detailed Implementation

[0027] To explain in detail the technical content, structural features, and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0028] like Figures 1 to 9As shown, this utility model provides a cylindrical power battery 10, including a terminal post 5 and a current collector 3. The current collector 3 includes a disc-shaped body 31, with a protrusion 311 in the middle of the disc-shaped body 31, and a welding part 4 connected to the protrusion 311. The terminal post 5 has a through hole 51 in the middle of the terminal post 5, which includes an upper through hole 511 and a lower through hole 512. The upper through hole 511 and the lower through hole 512 are connected by a step portion 513. The welding part 4 is embedded in the lower through hole 512, and the outer side of the welding part 4 matches the inner wall of the lower through hole 512 to form a first mating gap 45. The welding part 4 and the lower through hole 512 are laser welded together at the first mating gap 45 to connect the current collector 3 and the terminal post 5. Specifically, the cylindrical power battery 10 also includes a housing 1 and a cover 7 that closes the opening of the housing 1. The cover 7 has a pole post 5 in the middle. The housing 1 also has a core 2. The disc-shaped body 31 has several welding parts 312. The welding parts 312 are welded to the full tabs at one end of the core 2. The core 2 has a central hole 21 in the middle. The current collector 3 can be a positive current collector. The welding parts 4 and the pole post 5 can be formed by cold extrusion or cold forging. In this embodiment of the cylindrical power battery 10, the welding parts 4 are set in the middle of the current collector 3 and embedded in the lower through hole 512 of the pole post 5. The outer side of the welding parts 4 is attached to the inner wall of the lower through hole 512 to form a first mating gap 45. When welding the weldment 4 to the inner wall of the lower through hole 512, laser seam welding can be performed from above the first mating gap 45. The welding position is far away from the core 2 to avoid damaging the core 2 during welding. In addition, the laser seam welding connection has low welding power, which can further avoid damaging the core 2 during welding. Moreover, since the laser seam welding connection can be performed from above the first mating gap 45, metal welding slag can be prevented from falling into the core 2 of the cylindrical power battery 10. The design is ingenious.

[0029] This utility model embodiment features a protrusion 311 in the middle of the collector plate 3, a welding component 4 connected to the protrusion 311, and a laser welded connection between the outer side of the welding component 4 and the inner wall of the lower through hole 512 of the pole post 5. This design avoids damage to the core 2 during welding and prevents metal welding slag from falling into the core 2 of the power battery.

[0030] In this embodiment of the utility model, such as Figures 3 to 9 As shown, the inner wall of the lower through hole 512 includes a first inclined surface 5121, which is an inwardly tapering slope from bottom to top. The outer surface of the welded part 4 includes a second inclined surface 421, which is also an inwardly tapering slope from bottom to top. Specifically, the arrangement of the first inclined surface 5121 and the second inclined surface 421 increases the contact area between the lower through hole 512 and the welded part 4, resulting in better laser welding performance and further preventing metal slag from falling into the core 2 of the cylindrical power battery 10.

[0031] In this embodiment of the utility model, such as Figures 3 to 5 as well as Figures 8 to 9 As shown, the welded part 4 is groove-shaped and includes a welded groove bottom 41 and a welded groove wall 42 connected to the welded groove bottom 41. The welded groove bottom 41 includes a planar welded area 411. The upper surface of the protrusion 311 is a plane so as to mate with and weld to the bottom surface of the planar welded area 411. The outer side of the welded groove wall 42 mates with the inner wall of the lower through hole 512. Specifically, the current collector 3 can be integrally formed by stamping, that is, the protrusion 311 can be directly stamped in the middle of the current collector 3. By setting the upward protrusion 311 and the upper surface of the protrusion 311 being a plane, and the bottom surface of the planar welded area 411 also being a plane, the protrusion 311 and the planar welded area 411 can fit well together, with a large current flow area, effectively meeting the current flow requirements of rate charging and discharging.

[0032] In this embodiment of the utility model, such as Figure 3 As shown, the inner surface of the welding tank wall 42 includes a third inclined surface 423, which is an outwardly expanding inclined surface from bottom to top, ensuring the strength of the welded part 4 and saving the material cost of the welded part 4.

[0033] In this embodiment of the utility model, such as Figure 3 As shown, the upper surface of the welding tank wall 42 is a circular annular surface 422, which gives the welding tank wall 42 a certain thickness and ensures the laser seam welding effect.

[0034] In this embodiment of the utility model, such as Figure 5 As shown, the thickness of the planar welding area 411 is greater than the thickness of the protrusion 311. The thickness of the planar welding area 411 is greater than or equal to 0.4 mm and less than or equal to 0.8 mm, while the thickness of the protrusion 311 is greater than or equal to 0.2 mm and less than or equal to 0.4 mm. Specifically, when welding the welded part 4 to the protrusion 311 in the middle of the collector plate 3, it can be done outside the assembly line, effectively avoiding the impact of welding slag on the assembly line. In addition, by placing the thinner collector plate 3 above the thicker planar welding area 411 and using a laser to weld from the collector plate 3 to the planar welding area 411, a lower power laser can be used to ensure welding stability and less welding slag spatter, making the welding slag easy to clean.

[0035] In this embodiment of the utility model, such as Figures 7 to 9As shown, the cylindrical power battery 10 also includes a sealing pin 6. The outer side of the sealing pin 6 mates with the inner wall of the upper through hole 511 to form a second mating gap 56. The sealing pin 6 and the upper through hole 511 are laser welded together at the second mating gap 56. Specifically, the stepped portion 513 includes a first stepped surface 5131 connected to the upper through hole 511 and a second stepped surface 5132 connected to the lower through hole 512. The sealing pin 6 overlaps on the first stepped surface 5131 and its outer side mates with the inner wall of the upper through hole 511 for laser seam welding to further seal the through hole 51. Even if the lower through hole 512 and the welded part 4 have poor welding and leakage occurs, the sealing performance of the cylindrical power battery 10 can still be guaranteed. During welding, laser seam welding can be performed from above the second mating gap 56, with the welding position far away from the core 2 to avoid damage to the core 2 during welding. In addition, the laser seam welding connection has low welding power, which can further avoid damage to the core 2 during welding. Moreover, since the laser seam welding connection can be performed from above the second mating gap 56, it can prevent metal welding slag from falling into the core 2 of the power battery. The design is ingenious. In this embodiment of the utility model, the annular surface 422 of the welding groove wall 42 can be flush with the second step surface 5132.

[0036] In this embodiment of the utility model, such as Figures 7 to 9 As shown, the inner wall of the upper through hole 511 includes a fourth inclined surface 5111, which is an inwardly tapering slope from top to bottom. The outer surface of the sealing nail 6 includes a fifth inclined surface 61, which is also an inwardly tapering slope from top to bottom. The arrangement of the fourth inclined surface 5111 and the fifth inclined surface 61 increases the contact area between the upper through hole 511 and the sealing nail 6, resulting in better laser welding and further preventing metal slag from falling into the core 2 of the power battery.

[0037] In this embodiment of the utility model, such as Figure 2 As shown, each welded part 312 is also provided with a seepage slit 313 on its periphery to ensure smooth flow of liquid into the cylindrical power battery 10.

[0038] The assembly method of the cylindrical power battery 10 in this embodiment of the utility model is as follows: First, as... Figure 4 as well as Figure 5 As shown, outside the assembly line, the protruding part 311 in the middle of the manifold 3 is laser welded to the bottom 41 of the welding groove of the weldment 4; then the pole post 5 is riveted to the top cover; as shown Figure 6As shown, the full-pole tab at one end of the core 2 is laser-welded to the welding part 312 of the current collector 3, and the full-pole tab at the other end of the core 2 is laser-welded to the conventional negative current collector. Then, the core 2 with the current collector 3 welded on is placed into the housing 1, the welding part 4 is adapted to the lower through hole 512, and the core 2 is held in place by a clamp or the core 2 is held in place by a protrusion 311 through the center hole 21 of the core 2. The core 2 is then laser-welded to the first fitting gap 45. The sealing nail 6 is then adapted to the upper through hole 511 of the pole post 5 and laser-welded to the second fitting gap 56. Other processes are assembled and produced according to the normal process.

[0039] This embodiment of the utility model achieves welding and fixing of the protrusion 311 in the middle of the current collector 3 of the cylindrical power battery 10 and the bottom 41 of the welding groove of the welding component 4 to the protrusion 311 outside the assembly line by setting a protrusion 311 in the middle of the current collector 3 and welding a groove-shaped welding component 4 to the protrusion 311. The outer side of the welding component 4 is adapted to the lower through hole 512 of the pole 5 and laser welding is performed at the first mating gap 45 to prevent metal welding slag from falling into the interior of the power battery. The sealing nail 6 is adapted to the upper through hole 511 of the pole 5 and laser welding is performed. Sealing and fixing prevents metal welding slag from falling into the battery and avoids leakage at the step welding position. Ultimately, it enables the protrusion 311 in the middle of the current collector 3 to be welded to the bottom of the welding tank 41 outside the assembly line, which avoids the risk of metal welding slag and the risk of burning the core 2 caused by conventional high-power penetration welding. The welding part 4 and the pole post 5 are sealed and fixed by laser welding in the first mating gap 45, and the sealing nail 6 is sealed and fixed by laser welding in the upper through hole 511 of the pole post 5. This also completely avoids the risk of metal welding slag falling into the battery, widens the assembly process window of the cylindrical power battery 10, improves the production yield, and improves the safety of the cylindrical power battery 10.

[0040] The above-disclosed examples are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the scope of the present utility model application shall still fall within the scope of the present utility model.

Claims

1. A cylindrical power battery, characterized in that, It includes an electrode post and a current collector. The current collector includes a disc-shaped body with a protrusion in the middle and a welded part connected to the protrusion. The electrode post has a through hole in the middle, which includes an upper through hole and a lower through hole. The upper through hole and the lower through hole are connected by a stepped part. The welded component is embedded in the lower through hole, and the outer side of the welded component matches the inner wall of the lower through hole to form a first fitting gap. The welded component and the lower through hole are laser welded together at the first fitting gap to connect the collector plate and the pole.

2. The cylindrical power battery as described in claim 1, characterized in that, The inner wall of the lower through hole includes a first inclined surface, which is an inwardly tapering slope from bottom to top. The outer side of the welded part includes a second inclined surface, which is a corresponding inwardly tapering slope from bottom to top.

3. The cylindrical power battery as described in claim 2, characterized in that, The welded part is groove-shaped and includes a welding groove bottom and a welding groove wall connected to the welding groove bottom. The welding groove bottom includes a planar welding area. The upper surface of the protrusion is a plane to mate with and weld to the bottom surface of the planar welding area. The outer side of the welding groove wall mates with the inner wall of the lower through hole.

4. The cylindrical power battery as described in claim 3, characterized in that, The inner surface of the welding tank wall includes a third inclined surface, which is an outwardly expanding slope from bottom to top.

5. The cylindrical power battery as described in claim 3, characterized in that, The upper surface of the welding groove wall is an annular surface.

6. The cylindrical power battery as described in claim 3, characterized in that, The thickness of the planar welding area is greater than the thickness of the protrusion. The thickness of the planar welding area is greater than or equal to 0.4 mm and less than or equal to 0.8 mm, and the thickness of the protrusion is greater than or equal to 0.2 mm and less than or equal to 0.4 mm.

7. The cylindrical power battery as described in claim 1, characterized in that, It also includes a sealing pin, the outer side of which mates with the inner wall of the upper through hole to form a second mating gap, and the sealing pin and the upper through hole are laser welded together at the second mating gap.

8. The cylindrical power battery as described in claim 7, characterized in that, The inner wall of the upper through hole includes a fourth inclined surface, which is an inwardly contracting slope from top to bottom. The outer side of the sealing nail includes a fifth inclined surface, which is an inwardly contracting slope from top to bottom.

9. The cylindrical power battery as described in claim 1, characterized in that, It also includes a housing and a cover that closes the opening of the housing. The pole post is provided in the middle of the cover. The housing also contains a winding core. The disc-shaped body is provided with several welding parts. The welding parts are welded to the full pole lug at one end of the winding core.

10. The cylindrical power battery as described in claim 9, characterized in that, Each of the welded parts is also provided with a seepage slit on its periphery.

Images