Cylindrical battery

Abstract

The utility model discloses a cylindrical battery which comprises a shell with a hollow structure, the shell comprises a bottom soldering lug arranged at the bottom of the shell, a liquid injection hole is formed in the middle of the bottom soldering lug, a naked battery cell is arranged in the shell, a first full tab is arranged at one end, corresponding to the bottom soldering lug, of the naked battery cell, and a collector plate is electrically connected to the first full tab; a limiting hole corresponding to the liquid injection hole is formed in the middle of the flow collecting disc, a protruding limiting ring is arranged on the flow collecting disc around the limiting hole, the protruding limiting ring is coaxially arranged on the side, facing the bottom soldering lug, of the limiting hole, the hole diameter of the limiting hole is the same as the inner diameter of the protruding limiting ring, and the protruding limiting ring is coaxially arranged on the inner side of the liquid injection hole. The protruding limiting ring is provided with an outer side face and an inner side face opposite to the outer side face, and the outer side face is attached to the inner wall of the liquid injection hole and connected with the inner wall through laser seam welding. According to the laser seam welding device, a laser seam welding process with relatively low power can be realized, and the stability and the penetration consistency of laser seam welding can be ensured, so that the production yield of cylindrical batteries is improved, and the like.

Description

Technical Field

[0001] The utility model relates to the field of batteries, in particular to a cylindrical battery. 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 structures to improve energy density. Common problems: 1. The cylindrical battery collector plate is assembled into the shell and the shell bottom. Some manufacturers use laser penetration welding to connect the collector plate. The large penetration welding power can easily cause the core to burn or penetrate the shell bottom to leak, resulting in direct battery scrapping; 2. The cylindrical battery has one end of the pole, which is generally integrated with the top cover or the shell bottom, and the other end can only use the bare cell center hole resistance welding method to fix the bare cell and the shell bottom by welding, etc., and resistance welding is prone to cold welding problems or the normal welding position falls off during loading vibration, and the small welding area of ​​resistance welding leads to its poor current capacity and cannot meet high-rate charge and discharge. Summary of the invention

[0003] The utility model aims to provide a cylindrical battery to solve the problem that the existing laser penetration welding between the current collecting plate and the bottom welding piece easily causes burning of the bare battery core or breakdown of the bottom welding piece to leak liquid, resulting in direct battery scrapping.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a cylindrical battery, including a shell with a hollow structure, the shell including a bottom welding piece arranged at the bottom of the shell, a liquid injection hole is arranged in the middle of the bottom welding piece, a bare battery cell is arranged in the shell, and a first full-pole ear is arranged at one end of the bare battery cell corresponding to the bottom welding piece, a current collecting plate is electrically connected to the first full-pole ear, a limiting hole is opened in the middle of the current collecting plate corresponding to the liquid injection hole, a raised limiting ring is arranged around the limiting hole on the current collecting plate, the raised limiting ring is coaxially arranged on the side of the limiting hole facing the bottom welding piece, and the aperture of the limiting hole is the same as the inner diameter of the raised limiting ring, the raised limiting ring is coaxially arranged on the inner side of the liquid injection hole, the raised limiting ring has an outer side surface and an inner side surface opposite to the outer side surface, and the outer side surface is adhered to the inner wall of the liquid injection hole and connected by laser seam welding.

[0005] Preferably, the raised limiting ring is a continuous circular ring structure or a discontinuous circular ring structure.

[0006] Preferably, a sinker surrounding the injection hole is further provided on the bottom welding sheet, the sinker having a sinker bottom surface, and the sinker bottom surface is connected to the inner wall of the injection hole through a chamfer.

[0007] Preferably, the radial width of the raised limiting ring is greater than or equal to 1 mm.

[0008] Preferably, the current collecting plate comprises a disc-shaped body and the raised limiting ring arranged in the middle of the disc-shaped body, and the disc-shaped body is further provided with a hollow groove.

[0009] Preferably, the raised limiting ring is connected to the disc-shaped body by laser welding or ultrasonic welding.

[0010] Preferably, the raised limiting ring is integrally provided with the disc-shaped body.

[0011] Preferably, the cylindrical battery further comprises a sealing steel nail having a head and a rod, wherein the rod is passed through the raised limiting ring, and the outer periphery of the head is adhered to the side wall of the sink and connected by laser seam welding.

[0012] Preferably, the bottom welding sheet is provided with a sunken groove from the outer side to the inner side thereof, and the sinking platform is provided at the middle part of the bottom of the sunken groove.

[0013] Compared with the prior art, the outer side surface of the raised limiting ring of the current collecting plate of the utility model fits closely with the inner wall of the liquid injection hole, and at the same time, the height of the raised limiting ring is precisely limited by the inner wall of the liquid injection hole, which can optimize the high-power laser penetration welding to the low-power laser seam welding process, and ensure the stability and consistency of the laser seam welding, so as to improve the production yield of cylindrical batteries and improve their high-rate charging and discharging performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a structural diagram of a cylindrical battery in an embodiment of the utility model, in which the bottom welding piece faces upward.

[0015] Figure 2 It is a cross-sectional structural diagram of a cylindrical battery according to an embodiment of the utility model.

[0016] Figure 3 for Figure 2 Front view of .

[0017] Figure 4 This is a structural diagram of the bottom welding piece of a cylindrical battery in an embodiment of the utility model.

[0018] Figure 5 This is a structural diagram of the current collecting plate of the cylindrical battery in the embodiment of the utility model.

[0019] Figure 6 It is a cross-sectional structural diagram of the current collecting plate of the cylindrical battery according to an embodiment of the utility model.

[0020] Figure 7 for Figure 6 Front view of .

[0021] Figure 8This is a structural diagram of an implementation scheme of a raised limiting ring of a cylindrical battery in an embodiment of the utility model.

[0022] Fig. 9 This is a structural diagram of another implementation of the raised limiting ring of the cylindrical battery in an embodiment of the utility model. DETAILED DESCRIPTION

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

[0024] like Figures 1 to 8 As shown, an embodiment of the utility model provides a cylindrical battery, comprising a shell 1 with a hollow structure, the shell 1 comprising a bottom welding piece 2 arranged at the bottom of the shell 1, a liquid injection hole 21 being arranged in the middle of the bottom welding piece 2, a bare battery cell 5 being arranged in the shell 1, a first full-pole ear being arranged at one end of the bare battery cell 5 corresponding to the bottom welding piece 2, a current collecting plate 3 being electrically connected to the first full-pole ear, a limiting hole 32 being opened in the middle of the current collecting plate 3 corresponding to the liquid injection hole 21, a raised limiting ring 4 being arranged around the limiting hole 32 on the current collecting plate 3, the raised limiting ring 4 being coaxially arranged on the side of the limiting hole 32 facing the bottom welding piece 2, and the aperture of the limiting hole 32 is the same as the inner diameter of the raised limiting ring 4, the raised limiting ring 4 being coaxially arranged on the inner side of the liquid injection hole 21, the raised limiting ring 4 having an outer side surface 41 and an inner side surface 42 opposite to the outer side surface 41, the outer side surface 41 is attached to the inner wall of the liquid injection hole 21 and connected by laser seam welding.

[0025] In the embodiment of the utility model, the outer side surface 41 of the raised limiting ring 4 of the current collecting plate 3 fits snugly with the inner wall of the liquid injection hole 21, and at the same time, the height of the raised limiting ring 4 is precisely limited by the inner wall of the liquid injection hole 21, so that the high-power laser penetration welding can be optimized to a low-power laser seam welding process, and the stability and consistency of the laser seam welding can be ensured, so as to improve the production yield of the cylindrical battery 10 and improve its high-rate charge and discharge performance.

[0026] In the embodiment of the utility model, the raised limiting ring 4 is a continuous circular ring structure, as shown in FIG. Figure 8 In some other embodiments, the raised limiting ring 4 may also be a discontinuous circular ring structure, as shown in FIG. Fig. 9 As shown, the raised limiting ring 4a is in a discontinuous state, and includes a first ring 41a and a second ring 42a. A gap is provided between the first ring 41a and the second ring 42a to facilitate the raised limiting ring 4a to be embedded in the injection hole 21.

[0027] In the embodiment of the utility model, Figure 3 to Figure 4As shown, a sink 22 surrounding the injection hole 21 is also provided on the bottom welding sheet 2, and the sink 22 has a sink bottom surface 221, and the sink bottom surface 221 is connected to the inner wall of the injection hole 21 through a chamfer 23. Specifically, the injection hole 21 is provided at the bottom center of the sink 22, and the sink bottom surface 221 is connected to the inner wall of the injection hole 21 through a chamfer 23 of a C-shaped or R-shaped structure. The chamfer 23 is provided to facilitate the protruding limit ring 4 to be embedded in the injection hole 21 to avoid interference with the injection hole 21.

[0028] In the embodiment of the utility model, Figure 3 As shown, the radial width W of the raised stop ring 4 is greater than or equal to 1 mm. By setting the raised stop ring 4 to have a certain width, the strength of the raised stop ring 4 is increased and laser welding is facilitated.

[0029] In the embodiment of the utility model, Figures 5 to 7 As shown, the collecting plate 3 includes a disc-shaped body 31 and a raised limiting ring 4 arranged in the middle of the disc-shaped body 31. A hollow groove 35 is also arranged on the disc-shaped body 31. Specifically, the edge of the disc-shaped body 31 is evenly distributed with alignment grooves 33 recessed toward the center of the disc-shaped body 31. The hollow groove 35 is used for electrolyte infiltration. The hollow groove 35 includes three evenly distributed ones. Each hollow groove 35 is a slit arranged around the welding area 34. The welding area 34 is used to be welded to the first full-pole ear to achieve electrical connection.

[0030] In the embodiment of the utility model, the raised stop ring 4 is integrally arranged with the disc-shaped body 31. Specifically, a center hole can be opened in the center of the disc-shaped body 31, the diameter of the center hole is smaller than the inner diameter of the raised stop ring 4, and then the center hole is integrally punched into a U-shaped flange and then flattened to form the raised stop ring 4. The raised stop ring 4 is integrally arranged with the disc-shaped body 31, and the connection effect is better. Of course, in some other embodiments, the raised stop ring 4 and the disc-shaped body 31 can also be connected by laser welding or ultrasonic welding.

[0031] In the embodiment of the utility model, the cylindrical battery 10 also includes a sealing steel nail (not shown in the figure), which has a head and a rod. The rod is inserted into the raised limiting ring 4, and the outer periphery of the head is attached to the side wall of the sink 22 and connected by laser seam welding.

[0032] In the embodiment of the utility model, Figure 1 , Figure 3 and Figure 4 As shown, the bottom welding plate 2 is provided with a sunken groove 24 from its outer side to the inner side, and the sinking platform 22 is provided in the middle of the bottom of the sunken groove 24. The sunken groove 24 is provided to facilitate the implementation of the raised limiting ring 4 being embedded in the injection hole 21.

[0033] 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 cylindrical battery, characterized in that: The invention comprises a shell with a hollow structure, wherein the shell comprises a bottom welding piece arranged at the bottom of the shell, a liquid injection hole is arranged in the middle of the bottom welding piece, a bare battery cell is arranged in the shell, a first full-pole ear is arranged at one end of the bare battery cell corresponding to the bottom welding piece, a current collecting plate is electrically connected to the first full-pole ear, a limiting hole is opened in the middle of the current collecting plate corresponding to the liquid injection hole, a raised limiting ring is arranged around the limiting hole on the current collecting plate, the raised limiting ring is coaxially arranged on the side of the limiting hole facing the bottom welding piece, and the aperture of the limiting hole is the same as the inner diameter of the raised limiting ring, the raised limiting ring is coaxially arranged on the inner side of the liquid injection hole, the raised limiting ring has an outer side surface and an inner side surface opposite to the outer side surface, and the outer side surface is attached to the inner wall of the liquid injection hole and connected by laser seam welding.

2. The cylindrical battery according to claim 1, characterized in that: The raised limiting ring is a continuous circular ring structure or a discontinuous circular ring structure.

3. The cylindrical battery according to claim 1, characterized in that: A sinking platform surrounding the injection hole is also arranged on the bottom welding sheet, and the sinking platform has a sinking platform bottom surface, and the sinking platform bottom surface is connected to the inner wall of the injection hole through chamfering.

4. The cylindrical battery according to claim 1, characterized in that: The radial width of the raised limiting ring is greater than or equal to 1 mm.

5. The cylindrical battery according to claim 1, characterized in that: The current collecting plate comprises a disc-shaped body and the raised limiting ring arranged in the middle of the disc-shaped body, and a hollow groove is also arranged on the disc-shaped body.

6. The cylindrical battery according to claim 5, characterized in that: The raised limiting ring is connected to the disc-shaped body by laser welding or ultrasonic welding.

7. The cylindrical battery according to claim 5, characterized in that: The raised limiting ring is integrally arranged with the disc-shaped body.

8. The cylindrical battery according to claim 3, characterized in that: The cylindrical battery also includes a sealing steel nail, which has a head and a rod. The rod is inserted into the raised limiting ring, and the outer periphery of the head is attached to the side wall of the sink and connected by laser seam welding.

9. The cylindrical battery according to claim 3, characterized in that: The bottom welding sheet is provided with a sinking groove from the outer side to the inner side thereof, and the sinking platform is provided at the middle part of the bottom of the sinking groove.

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