Connecting structure of collector plate and pole of cylindrical battery

Abstract

The utility model discloses a connecting structure of a collector plate and a pole of a cylindrical battery, the cylindrical battery comprises a shell with a hollow structure, the pole is arranged in the middle of one end face of the shell, the pole and the shell are coaxially arranged, a through hole is formed in the pole along the axial direction of the pole, and the through hole comprises an outer side hole and an inner side hole connected with the outer side hole; a naked battery cell is arranged in the shell, a first full tab is arranged on one side, corresponding to the pole column, of the naked battery cell, a current collecting plate is electrically connected to the first full tab, a lug boss is arranged on the current collecting plate corresponding to the inner side hole, and the lug boss is embedded in the inner side hole so as to realize limiting sealing connection. According to the utility model, the lug boss is embedded in the inner side hole, and the limiting and sealing connection is realized, so that the lug boss and the pole are accurately positioned, the connection consistency of the pole and the collector plate is improved, in addition, as the lug boss is arranged in the middle of the collector plate, the thickness of the middle of the collector plate can be increased, and the collector plate is not easy to deform when being jacked by a clamp; and the connecting surface of the lug boss and the inner side hole is larger, so that the overflowing area is ensured.

Description

Technical Field

[0001] The utility model relates to the field of cylindrical batteries, in particular to a connection structure between a current collecting plate and a pole of a cylindrical battery. Background Art

[0002] At present, lithium-ion / sodium-ion cylindrical batteries have gradually become 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 structures to improve energy density. Common problems: 1. When the cylindrical battery collector plate is assembled into the shell and the pole, it is common to dig grooves on the pole surface and use laser penetration welding to connect the collector plate. The large penetration welding power can easily cause burns to the bare battery cells, resulting in direct battery scrapping; 2. When the cylindrical battery collector plate is assembled into the shell and the pole, the collector plate is relatively weak and is prone to deformation when the clamp is supported, and the fit with the pole cannot be guaranteed, resulting in insufficient flow area and unable to meet the rate charge and discharge flow; 3. In order to ensure sufficient welding flow area, some manufacturers use Z-shaped bending welding pieces to connect, which reduces space utilization and cannot guarantee the compactness of the battery's internal structure. Summary of the invention

[0003] The purpose of the utility model is to provide a connection structure between a cylindrical battery collector and a pole, so as to solve the problem in the prior art that when the cylindrical battery collector is inserted into a shell and assembled with the pole, the collector is easily deformed when supported by a clamp and the fit with the pole cannot be guaranteed, resulting in insufficient flow area and failure to meet the rate charge and discharge flow.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a connection structure between a current collector and a pole of a cylindrical battery, wherein the cylindrical battery comprises a shell with a hollow structure, a pole is arranged in the middle of one end surface of the shell, the pole is coaxially arranged with the shell, a through hole is opened in the pole along its axial direction, the through hole comprises an outer hole and an inner hole connected to the outer hole; a bare battery cell is arranged in the shell, a first full-pole ear is arranged on one side of the bare battery cell corresponding to the pole, a current collector is electrically connected to the first full-pole ear, a protrusion is arranged on the current collector corresponding to the inner hole, and the protrusion is embedded in the inner hole to realize a limited sealing connection.

[0005] Preferably, a first step portion is provided on the inner wall of the inner hole, a second step portion is provided on the outer periphery of the protrusion, and the first step portion and the second step portion are snap-connected so that the protrusion is position-limitedly connected to the inner hole.

[0006] Preferably, the inner hole includes a cylindrical hole connected to the outer hole and a conical hole connected to the cylindrical hole, the inner diameter of one end of the conical hole connected to the cylindrical hole is larger than the inner diameter of the cylindrical hole so that a first step portion is formed between the conical hole and the cylindrical hole, and the raised portion is provided with a first portion matingly connected to the cylindrical hole and a second portion matingly connected to the conical hole, and the second step portion is formed between the first portion and the second portion.

[0007] Preferably, the inner diameter of one end of the truncated cone hole connected to the cylindrical hole is smaller than the inner diameter of the other end of the truncated cone hole.

[0008] Preferably, the hole depth of the cylindrical hole is greater than 0 mm and less than or equal to 0.7 mm, the sum of the hole depths of the cylindrical hole and the truncated cone hole is greater than or equal to 0.5 mm, the first step portion has a first step surface, the second step portion has a second step surface, the radial width of the first step surface and the second step surface is greater than 0 mm and less than or equal to 1.0 mm, and the angle between the inner surface of the truncated cone hole and its axis is greater than or equal to 15 degrees and less than or equal to 50 degrees.

[0009] Preferably, the protrusion is connected to the inner hole by laser seam welding.

[0010] Preferably, the outer hole is arranged in a V-shape, and the angle between the inner side surface of the outer hole and its axis is greater than or equal to 30 degrees and less than or equal to 60 degrees.

[0011] Preferably, the through hole also includes a first hole arranged outside the outer hole, the diameter of the first hole is larger than the inner diameter of an end of the truncated cone hole connected to the first hole, and the hole depth of the first hole is greater than 0 mm and less than or equal to 0.7 mm.

[0012] Preferably, the current collecting plate comprises a disc-shaped body and the raised portion arranged in the middle of the disc-shaped body, and the disc-shaped body is further provided with a hollow groove.

[0013] Preferably, the protrusion is connected to the disc-shaped body by laser welding or ultrasonic welding, or the protrusion is integrally formed with the disc-shaped body, and the diameter of the end face of the protrusion is greater than or equal to 4 mm and less than or equal to 8 mm.

[0014] Compared with the prior art, the utility model provides a through hole on the pole, and a protrusion is provided on the inner hole corresponding to the through hole on the current collecting disk, and the protrusion is embedded in the inner hole and realizes a limited sealing connection to accurately position the protrusion and the pole, so as to improve the consistency of the connection between the pole and the current collecting disk. In addition, since the protrusion is arranged in the middle of the current collecting disk, the thickness of the middle part of the current collecting disk can be increased, and the current collecting disk is not easy to deform when the clamp is supported. Moreover, since the protrusion is limitedly connected with the inner hole, the protrusion and the inner hole are better positioned and installed and the fitting effect is good. The connection surface between the protrusion and the inner hole is larger, which ensures the flow area and meets the rate charge and discharge flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a structural diagram of a cylindrical battery according to an embodiment of the present utility model.

[0016] Figure 2 It is a cross-sectional structural diagram of a cylindrical battery according to an embodiment of the utility model.

[0017] Figure 3 It is a structural diagram of a pole according to an embodiment of the utility model.

[0018] Figure 4 It is a cross-sectional structural diagram of a pole according to an embodiment of the utility model.

[0019] Figure 5 for Figure 4 Front view of .

[0020] Figure 6 for Figure 5 Enlarged view of point A in the middle.

[0021] Figure 7 This is a structural diagram of the current collecting plate of an embodiment of the utility model.

[0022] Figure 8 It is a cross-sectional structural diagram of the current collecting plate according to an embodiment of the utility model.

[0023] Fig. 9 for Figure 8 Enlarged view of point B in the middle. DETAILED DESCRIPTION

[0024] 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 implementation modes and the accompanying drawings.

[0025] like Figures 1 to 9As shown, an embodiment of the utility model provides a connection structure between a current collector and a pole of a cylindrical battery. The cylindrical battery comprises a shell 1 with a hollow structure. A pole 2 is arranged in the middle of one end surface of the shell 1. The pole 2 is coaxially arranged with the shell 1. A through hole 3 is opened along the axial direction of the pole 2. The through hole 3 comprises an outer hole 31 and an inner hole 32 connected to the outer hole 31. A bare cell 4 is arranged in the shell 1. A first full-pole ear is arranged on one side of the bare cell 4 corresponding to the pole 2. A current collector 5 is electrically connected to the first full-pole ear. A protrusion 52 is arranged on the current collector 5 corresponding to the inner hole 32. The protrusion 52 is embedded in the inner hole 32 to achieve a limited sealing connection.

[0026] Specifically, the pole 2 has opposite polarity to that of the shell 1. The shell 1 includes a top cover 11 located on the upper part of the shell 1. The pole 2 is arranged on the top cover 11 of the shell 1. A sealing ring 6 is arranged between the pole 2 and the top cover 11, and an insulating gasket 7 is arranged between the top cover 11 and the current collecting plate 5. The first full-pole ear is a positive full-pole ear. The utility model provides a through hole 3 on the pole 2, and provides a protrusion 52 on the inner hole 32 corresponding to the through hole 3 on the current collecting plate 5, and the protrusion 52 is embedded in the inner hole 32 and realizes limiting. The protrusion 52 is sealed and connected in place to accurately position the protrusion and the pole 2, so as to improve the consistency of the connection between the pole 2 and the current collecting disk 5. In addition, since the protrusion 52 is arranged in the middle of the current collecting disk 5, the thickness of the middle of the current collecting disk 5 can be increased, and the current collecting disk is not easy to deform when the clamp is supported. Moreover, since the protrusion 52 and the inner hole 32 are limitedly connected, the protrusion 52 and the inner hole 32 are better positioned and installed and the fitting effect is good. The connection surface between the protrusion 52 and the inner hole 32 is larger, which ensures the flow area and meets the rate charge and discharge flow.

[0027] Of course, in some other embodiments, the shell 1 includes a shell bottom located at the lower part of the shell 1, and the pole 2 can also be arranged on the shell bottom. In this case, the first full pole lug can be a negative pole full pole lug.

[0028] In the embodiment of the utility model, Figures 2 to 9 As shown, a first step portion is provided on the inner wall of the inner hole 32 , and a second step portion is provided on the outer periphery of the protrusion 52 . The first step portion and the second step portion are snap-connected so that the protrusion 52 is positionally connected to the inner hole 32 .

[0029] Specifically, Figures 2 to 9 As shown, the inner hole 32 includes a cylindrical hole 321 connected to the outer hole 31 and a truncated cone hole 322 connected to the cylindrical hole 321. The inner diameter of one end of the truncated cone hole 322 connected to the cylindrical hole 321 is larger than the inner diameter of the cylindrical hole 321 so that a first step portion is formed between the truncated cone hole 322 and the cylindrical hole 321. The protrusion 52 is provided with a first portion 521 matched with the cylindrical hole 321 and a second portion 522 matched with the truncated cone hole 322. A second step portion is formed between the first portion 521 and the second portion 522. Figure 5 As shown, the protrusion 52 is embedded in the inner hole 32 along the direction of arrow c so that the outer periphery of the first part 521 fits with the inner wall of the cylindrical hole 321, the outer periphery of the second part 522 fits with the inner wall of the conical hole 322, and the first step part is clamped with the second step part. In addition, the inner diameter of one end of the conical hole 322 connected to the cylindrical hole 321 is smaller than the inner diameter of the other end of the conical hole 322, so that the conical hole 322 can play a guiding role during the embedding process of the protrusion 52.

[0030] It should be noted that, in some other embodiments, the inner hole 32 may also be threadedly connected to the protrusion 52 to achieve a limited sealing connection.

[0031] In the embodiment of the utility model, Figure 5 , Figure 6 and Fig. 9 As shown, the hole depth of the cylindrical hole 321 is greater than 0 mm and less than or equal to 0.7 mm, the sum of the hole depths H1 of the cylindrical hole 321 and the truncated cone hole 322 is greater than or equal to 0.5 mm, the first step portion has a first step surface 323, the second step portion has a second step surface 523, the width W1 of the first step surface 323 along the radial direction of the inner hole 32 is greater than 0 mm and less than or equal to 1.0 mm, the width W2 of the second step surface 523 along the radial direction of the protrusion 52 is greater than 0 mm and less than or equal to 1.0 mm, the angle between the inner side surface of the truncated cone hole 322 and its axis is greater than or equal to 15 degrees and less than or equal to 50 degrees, the thickness of the first part 521 is the same as the hole depth of the cylindrical hole 321, the sum of the hole depths H1 of the cylindrical hole 321 and the truncated cone hole 322 is the same as the sum of the thickness of the first part 521 and the thickness of the second part 522 H2.

[0032] In the embodiment of the utility model, the raised portion 52 is connected to the inner hole 32 by laser seam welding. Figure 2 As shown by the middle arrow, laser seam welding is performed on the fitting portion of the raised portion 52 and the inner hole 32 by laser, thereby optimizing the high-power laser penetration welding to a low-power laser seam welding process to improve the energy density and production yield of the cylindrical power battery, improve its high-rate charge and discharge performance, etc., and solve the problem that when laser penetration welding is used to connect the collector plate 5, the large penetration welding power is likely to cause burns to the bare battery cell 4, resulting in direct scrapping of the battery; in addition, the precise positioning of the raised portion 52 and the pole 2 ensures the stability and consistency of the laser seam welding.

[0033] In the embodiment of the utility model, Figure 5As shown, the outer hole 31 is arranged in a V shape, and the angle a between the inner side surface of the outer hole 31 and its axis is greater than or equal to 30 degrees and less than or equal to 60 degrees. Since the laser forms a V-shaped focus through the focusing lens, the outer hole 31 is arranged in a V shape with a large outer inner diameter and a small inner inner diameter to avoid partial shielding of the laser light by the outer hole 31, thereby improving the utilization rate of the laser.

[0034] In the embodiment of the utility model, Figure 5 As shown, the through hole 3 also includes a first hole 33 arranged outside the outer hole 31, the diameter of the first hole 33 is larger than the inner diameter of one end of the truncated cone hole 322 connected to the first hole 33, the hole depth h of the first hole 33 is greater than 0 mm and less than or equal to 0.7 mm, and the first hole 33 is used to reserve a position for optional welding sealing aluminum nails.

[0035] In the embodiment of the utility model, Figures 7 to 9 As shown, the current collecting plate 5 includes a disc-shaped body 51 and a protrusion 52 arranged in the middle of the disc-shaped body 51, and a hollow groove 55 is also arranged on the disc-shaped body 51. Specifically, the edge of the disc-shaped body 51 is evenly distributed with alignment grooves 53 that are recessed toward the center of the disc-shaped body 51, and the hollow groove 55 is used for electrolyte infiltration. The hollow groove 55 includes three evenly distributed ones, each of which is a slit arranged around the welding area 54, and the welding area 54 is used for welding and connecting with the first full-electrode tab.

[0036] In the embodiment of the utility model, Fig. 9 As shown, the protrusion 52 is connected to the disc-shaped body 51 by laser welding, and the diameter D of the end surface of the protrusion 52 is greater than or equal to 4 mm and less than or equal to 8 mm. In some other embodiments, the protrusion 52 is connected to the disc-shaped body 51 by ultrasonic welding or the protrusion 52 and the disc-shaped body 51 are integrally formed.

[0037] The assembly method of the connection structure between the current collector 5 and the pole 2 of the cylindrical battery in the embodiment of the utility model is: first, the pole 2 is integrated into the top cover 11 or the bottom of the shell, and then the first full pole ear of the bare battery cell 4 is fixed to the welding area 54 of the current collector 5 by laser welding, and then the raised portion 52 of the current collector 5 is guided by the truncated cone hole 322 to adapt to the lower part of the pole 2, and finally, the first part 521 of the raised portion 52 is adapted to the inner wall of the cylindrical hole 321 of the pole 2, and at the same time, the first step portion of the pole 2 is limitedly adapted to the second step portion of the current collector 5, and then laser seam welding is performed to fix and seal.

[0038] The above disclosure is only a preferred example 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 connection structure between a cylindrical battery collector and a pole, characterized in that: The cylindrical battery comprises a shell with a hollow structure, a pole is arranged in the middle of one end surface of the shell, the pole is coaxially arranged with the shell, a through hole is opened along the axial direction of the pole, and the through hole comprises an outer hole and an inner hole connected to the outer hole; A bare battery cell is arranged in the shell, and a first full-pole ear is arranged on one side of the bare battery cell corresponding to the pole, a current collecting disk is electrically connected to the first full-pole ear, a protrusion is arranged on the current collecting disk corresponding to the inner hole, and the protrusion is embedded in the inner hole to realize a limited sealing connection.

2. The connection structure of the cylindrical battery collector and the pole according to claim 1, characterized in that: A first step portion is provided on the inner wall of the inner hole, and a second step portion is provided on the outer periphery of the protruding portion. The first step portion and the second step portion are snap-connected so that the protruding portion is position-limitedly connected to the inner hole.

3. The connection structure of the cylindrical battery collector and the pole according to claim 2, characterized in that: The inner hole includes a cylindrical hole connected to the outer hole and a truncated cone hole connected to the cylindrical hole. The inner diameter of one end of the truncated cone hole connected to the cylindrical hole is larger than the inner diameter of the cylindrical hole so that a first step portion is formed between the truncated cone hole and the cylindrical hole. The raised portion is provided with a first portion matingly connected to the cylindrical hole and a second portion matingly connected to the truncated cone hole, and the second step portion is formed between the first portion and the second portion.

4. The connection structure of the cylindrical battery collector and the pole according to claim 3, characterized in that: The inner diameter of one end of the truncated cone hole connected to the cylindrical hole is smaller than the inner diameter of the other end of the truncated cone hole.

5. The connection structure of the cylindrical battery collector and the pole according to claim 3, characterized in that: The hole depth of the cylindrical hole is greater than 0 mm and less than or equal to 0.7 mm, the sum of the hole depths of the cylindrical hole and the truncated cone hole is greater than or equal to 0.5 mm, the first step portion has a first step surface, the second step portion has a second step surface, the radial width of the first step surface and the second step surface is greater than 0 mm and less than or equal to 1.0 mm, and the angle between the inner surface of the truncated cone hole and its axis is greater than or equal to 15 degrees and less than or equal to 50 degrees.

6. The connection structure of the cylindrical battery collector and the pole according to claim 1, characterized in that: The protrusion is connected to the inner hole by laser seam welding.

7. The connection structure of the cylindrical battery collector and the pole according to claim 3, characterized in that: The outer hole is arranged in a V shape, and the angle between the inner side surface of the outer hole and its axis is greater than or equal to 30 degrees and less than or equal to 60 degrees.

8. The connection structure of the cylindrical battery collector and the pole according to claim 3, characterized in that: The through hole also includes a first hole arranged outside the outer hole, the diameter of the first hole is larger than the inner diameter of an end portion of the truncated cone hole connected to the first hole, and the hole depth of the first hole is greater than 0 mm and less than or equal to 0.7 mm.

9. The connection structure of the cylindrical battery collector and the pole according to claim 1, characterized in that: The current collecting plate comprises a plate-shaped body and the protruding portion arranged in the middle of the plate-shaped body, and a hollow groove is also arranged on the plate-shaped body.

10. The connection structure of the cylindrical battery collector and the pole according to claim 9, characterized in that: The protrusion is connected to the disc-shaped body by laser welding or ultrasonic welding, or the protrusion is integrally formed with the disc-shaped body, and the diameter of the end face of the protrusion is greater than or equal to 4 mm and less than or equal to 8 mm.

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