Central tube structure and cylindrical lithium battery

Abstract

The utility model provides a central tube structure and a cylindrical lithium battery, the central tube structure comprises a hollow cylindrical tube body with two open ends, the outer wall of the tube body is provided with a guide groove along a spiral line, and the guide groove is used for guiding the flow of electrolyte and the discharge of gas in the battery. The spiral angle alpha of the spiral line is larger than 0 degree and smaller than 90 degrees, and the screw pitch L of the spiral line is larger than or equal to 1.5 mm and smaller than or equal to 21 mm. The central tube structure disclosed by the utility model can be used for guiding the flow of electrolyte and the discharge of gas in the battery, and is also beneficial to the diffusion and discharge of heat. And the mass of the central pipe can be reduced while enough strength is guaranteed, so that the central pipe has a good use effect.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a central tube structure. The utility model also relates to a cylindrical lithium battery provided with the central tube structure. Background Art

[0002] The center tube of a cylindrical lithium battery has the following functions: First, it supports the inside of the roll core to prevent the center hole of the roll core from collapsing during the charge and discharge cycle, which in turn causes the battery cell to fail; second, it conducts gas and heat, and exhausts gas and heat. Especially in extreme cases, after the battery cell explosion-proof valve is opened, the center tube can quickly discharge the gas and smoke inside the battery to prevent explosions caused by poor exhaust; third, it protects the roll core. High temperature will be generated when spot welding the negative electrode ear. Without the protection of the center tube, the diaphragm in the center of the roll core may be burned.

[0003] The existing center tubes have no gaps in their structure or the gaps are too narrow, which slows down the rate of lateral diffusion and penetration of the electrolyte from the inside of the winding core, making it difficult to add electrolyte. Alternatively, the gaps in the center tubes are too wide, which may cause the machine that inserts the center tubes to get stuck during the production process, because center tubes with too wide gaps are prone to being nested together, thus affecting production. Utility Model Content

[0004] In view of this, the utility model aims to provide a central tube structure to improve the capabilities of liquid conduction, exhaust and heat dissipation.

[0005] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0006] A central tube structure comprises a hollow cylindrical tube body with openings at both ends, wherein a guide groove is arranged on the outer wall of the tube body along a spiral line, wherein the guide groove is used to guide the flow of electrolyte and the discharge of gas inside the battery, and the spiral angle α of the spiral line satisfies: 0°<α<90°, and the pitch L of the spiral line satisfies: 1.5mm≤L≤21mm.

[0007] Furthermore, the cross section of the guide groove is rectangular, triangular, arc-shaped or trapezoidal.

[0008] Furthermore, the width of the guide groove is less than 1 mm; and / or the depth of the guide groove is less than 0.5 mm.

[0009] Furthermore, the tube body is made of high molecular polymer material.

[0010] Furthermore, the tube body has a first end and a second end; the tube body is provided with a plurality of through holes penetrating its own tube wall, and each of the through holes is arranged obliquely from the inner wall to the outer wall of the tube body along the direction from the first end to the second end.

[0011] Furthermore, in the longitudinal cross-sectional projection of the tube body, an angle β between the center line of the through hole and the horizontal line satisfies: 0°<β<90°.

[0012] Furthermore, the diameter of the through hole is less than 1 mm, and the number of the through holes is between 8 and 20.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] The central tube structure of the utility model is provided with a guide groove on the outer wall of the tube body, and the guide groove is provided along the direction of the spiral line, so that the flow of electrolyte and the discharge of gas inside the battery can be guided, and the injection efficiency can be improved. Moreover, the hollow tube body is conducive to the diffusion and discharge of heat. And while ensuring sufficient strength, the mass of the central tube can also be reduced, and a good use effect is achieved.

[0015] In addition, the cross section of the guide groove is set to be rectangular, triangular, arc or trapezoidal, which has the characteristics of simple structure and easy design and implementation. The setting of the width and depth of the guide groove can take into account the overall structural strength of the central tube and the function of guiding liquid and exhausting gas. The tube body is made of high molecular polymer material, which is widely used and has good insulation.

[0016] In addition, multiple through holes penetrating the tube wall are provided on the tube body to improve the lateral infiltration efficiency of the electrolyte, and the overall structure of the tube body can effectively avoid the situation where the central tubes are nested in pairs. At the same time, the mass of the central tube can be reduced to the greatest extent while ensuring the supporting capacity of the central tube.

[0017] Another object of the present invention is to provide a cylindrical lithium battery, wherein the cylindrical lithium battery is provided with the central tube structure as described above.

[0018] The cylindrical lithium battery of the present invention and the central tube structure as described above have the same beneficial effects as those of the prior art, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0020] Figure 1 This is a front view of the central tube structure described in an embodiment of the utility model;

[0021] Figure 2 This is a front view of the central tube structure described in an embodiment of the utility model;

[0022] Figure 3 Another structural schematic diagram of the central tube structure described in the embodiment of the utility model;

[0023] Figure 4 This is another structural schematic diagram of the central tube structure described in the embodiment of the utility model;

[0024] Description of reference numerals:

[0025] 1. Tube body; 101. First end; 102. Second end; 103. Guide groove; 104. Through hole. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0027] In the description of the present invention, it should be noted that if there are terms such as "upper", "lower", "inner", "outer" and the like indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, if there are terms such as "first" and "second", they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0028] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection" and "connector" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0030] Embodiment 1

[0031] The present embodiment relates to a central tube structure, which can improve the ability of conducting liquid, exhausting air and emitting heat, and at the same time, is also conducive to reducing the mass of the central tube.

[0032] In terms of overall structure, the central tube structure of this embodiment is as follows Figure 1 and Figure 2As shown, the central tube structure includes a hollow cylindrical tube body 1 with openings at both ends, and a guide groove 103 is arranged on the outer wall of the tube body 1 along the spiral line. The guide groove 103 is used to guide the flow of electrolyte and the discharge of gas inside the battery, and the spiral angle α of the spiral line satisfies: 0°<α<90°, and the pitch L of the spiral line satisfies: 1.5mm≤L≤21mm.

[0033] At this time, the guide groove 103 is arranged on the outer wall of the tube body 1, and the guide groove 103 is arranged along the direction of the spiral line, so that the flow of electrolyte and the discharge of gas inside the battery can be guided, and the injection efficiency can be improved. In addition, the hollow tube body 1 is conducive to the diffusion and discharge of heat. And while ensuring sufficient strength, it can also reduce the mass of the central tube, and has a good use effect.

[0034] For specific structure, continue to see Figure 1 and Figure 2 As shown, in this embodiment, the tube body 1 is in the shape of a hollow cylinder with two ends open. Figure 1 In the state shown, the upper end is the first end 101, and the lower end is the second end 102. A guide groove 103 is provided on the outer wall of the tube body 1 along the spiral line. The spiral guide groove 103 can improve the flow of electrolyte and the discharge of gas inside the battery, thereby improving the injection efficiency. While ensuring sufficient support strength, the mass of the central tube can be reduced, and the hollow tube body 1 structure is conducive to the diffusion and discharge of heat.

[0035] In specific implementation, the helical angle α can be set to, for example, 1°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or 89°. The pitch L of the helix can be set to, for example, 1.5 mm, 2 mm, 5 mm, 7 mm, 10 mm, 15 mm, 17 mm, 20 mm, or 21 mm. The setting of the helical angle α and the pitch L has the characteristics of simple structure and convenient design and implementation.

[0036] As a preferred implementation, in this embodiment, the cross-section of the guide groove 103 is rectangular, triangular, arc-shaped or trapezoidal. It has the characteristics of simple structure and easy design and implementation. Moreover, also as a preferred implementation, in this embodiment, the width of the guide groove 103 is less than 1 mm, and the depth of the guide groove 103 is less than 0.5 mm. The setting of the width and depth dimensions of the guide groove 103 can take into account the overall structural strength of the central tube and the function of guiding liquid and exhausting gas. In specific implementation, the width of the guide groove 103 can be set to 0.5 mm or 0.9 mm, for example, and the depth of the guide groove 103 can be set to 0.2 mm or 0.4 mm, for example.

[0037] In addition, in this embodiment, the tube body 1 is made of a polymer material, which is widely used and has good insulation properties. In specific implementation, for example, PP, PE, PC, ABS, PVC or PPS can be used.

[0038] As a preferred implementation, in this embodiment, Figure 1 As shown, the tube body 1 is provided with a plurality of through holes 104 penetrating the tube wall thereof, and each through hole 104 is arranged obliquely from the inner wall to the outer wall of the tube body 1 along the first end 101 to the second end 102. Specifically, in the longitudinal cross-sectional projection of the tube body 1, the angle β between the center line of the through hole 104 and the horizontal line satisfies: 0°<β<90°.

[0039] The multiple obliquely arranged through holes 104 provided on the tube body 1 can improve the lateral infiltration efficiency of the electrolyte, and cooperate with the guide grooves 103 formed on the outer side of the tube wall to effectively avoid the situation where the central tubes are nested in pairs. At the same time, under the premise of ensuring the supporting capacity of the central tube, the mass of the central tube can be reduced to the greatest extent.

[0040] In addition, as a preferred implementation, in this embodiment, the diameter of the through hole 104 is less than 1 mm, and the number of the through holes 104 is between 8 and 20.

[0041] Preferably, the diameter of the through hole 104 is set to 1 mm-2 mm, and the number of the through holes 104 is between 6 and 12. In specific implementation, the diameter of the through hole 104 can be set to 1 mm, 1.3 mm, 1.5 mm, 1.7 mm or 2 mm, for example. The number of the through holes 104 can be set to 6, 8, 10 or 12, for example.

[0042] In addition, the Figure 3 and Figure 4 A central tube structure different from the above structure is also exemplified. Figure 3 Compared with the central tube structure in the above-mentioned embodiment, the central tube structure shown in the figure has only a guide groove 103 arranged on the outer wall of the tube body 1, and the guide groove 103 is arranged along the spiral line. Compared with the above-mentioned central tube structure, the central tube structure is weaker in the effect of lateral infiltration of electrolyte and exhaust and heat dissipation, and is mainly used in the case where the central tube support strength is higher.

[0043] Figure 4 Compared with the central tube structure in the above-mentioned embodiment, the central tube structure shown in the figure only has a plurality of through holes 104 arranged on the tube body 1. It should be noted that the diameter of the through holes 104 and the number of the through holes 104 are different. Figure 4In the central tube structure, the aperture of the through hole 104 is preferably set to 1 mm-2 mm, and the number of the through holes 104 is between 6 and 12. In specific implementation, the aperture of the through hole 104 can be set to 1 mm, 1.3 mm, 1.5 mm, 1.7 mm or 2 mm, for example. The number of the through holes 104 can be set to 6, 8, 10 or 12, for example.

[0044] Compared with the above-mentioned central tube structure, the central tube structure is weaker in terms of the effect of lateral electrolyte infiltration and exhaust and heat dissipation, and is mainly used to reduce the manufacturing cost of the central hole.

[0045] The central tube structure of this embodiment can not only improve the ability of liquid conduction, exhaust and heat dissipation, but also improve the lateral infiltration effect of the electrolyte. While ensuring sufficient supporting strength of the central tube, it can also reduce the mass of the central tube, and has a good use effect.

[0046] Embodiment 2

[0047] This embodiment relates to a cylindrical lithium battery, which is provided with the central tube structure described in Embodiment 1. Specifically, the negative electrode sheet, the separator and the positive electrode sheet in the cylindrical lithium battery are wound on the tube body 1 of the central tube of Embodiment 1 in sequence.

[0048] The cylindrical lithium battery of this embodiment, by adopting the central tube structure of the first embodiment, can not only guide the flow of electrolyte and improve the injection efficiency, but also facilitate the discharge of gas inside the battery and the diffusion and discharge of heat, thereby improving the quality of the cylindrical lithium battery.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A central tube structure, characterized in that: It comprises a hollow cylindrical tube body with openings at both ends, wherein a guide groove is arranged on the outer wall of the tube body along a spiral line, wherein the guide groove is used to guide the flow of electrolyte and the discharge of gas inside the battery, and the spiral angle α of the spiral line satisfies: 0°<α<90°, and the pitch L of the spiral line satisfies: 1.5mm≤L≤21mm.

2. The central tube structure according to claim 1, characterized in that: The cross section of the guide groove is rectangular, triangular, arc-shaped or trapezoidal.

3. The central tube structure according to claim 1, characterized in that: The width of the guide groove is less than 1 mm; and / or the depth of the guide groove is less than 0.5 mm.

4. The central tube structure according to claim 1, characterized in that: The tube body is made of high molecular polymer material.

5. The central tube structure according to any one of claims 1 to 4, characterized in that: The tube body has a first end and a second end; The tube body is provided with a plurality of through holes penetrating the tube wall thereof, and each of the through holes is arranged obliquely from the inner wall to the outer wall of the tube body along the direction from the first end to the second end.

6. The central tube structure according to claim 5, characterized in that: In the longitudinal cross-sectional projection of the tube body, an angle β between the center line of the through hole and the horizontal line satisfies: 0°<β<90°.

7. The central tube structure according to claim 5, characterized in that: The diameter of the through holes is less than 1 mm, and the number of the through holes is between 8 and 20.

8. A cylindrical lithium battery, characterized in that: The cylindrical lithium battery is provided with a central tube structure as claimed in any one of claims 1 to 7.

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