Jelly roll center pin and battery

Abstract

The present application discloses a jelly roll center pin and a battery. The jelly roll center pin comprises a cylindrical supporting rod and a plurality of supporting ribs. The plurality of supporting ribs are arranged on the outer side wall of the supporting rod at equal angles in the circumferential direction, the supporting ribs abut against the inner side wall of a center hole of the jelly roll, and a relief space is formed between two adjacent supporting ribs.

Description

A core center needle and battery

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 20, 2023, with application number 2023225615137. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of battery manufacturing, and in particular to a winding core center needle and a battery. Background Art

[0003] Cylindrical batteries typically consist of an outer shell and a winding core mounted within it. The core is composed of a wound positive electrode sheet, a separator, and a negative electrode sheet. However, this wound core has a hollow structure within it. During battery cycling, this hollow structure can cause the core to expand and collapse inward, deforming or even breaking, shortening the battery's lifespan. Technical issues

[0004] Currently, a cylindrical center pin is typically installed within the hollow core structure to support the core and prevent it from collapsing and deforming. This related technology has the following drawbacks: the cylindrical center pin fits against the inner wall of the hollow core structure, which can easily block the flow of electrolyte and affect the core's absorption of electrolyte. Technical Solutions

[0005] In the first aspect, the present application provides a winding core center needle, comprising a support rod and a plurality of support ribs. The support rod is cylindrical, and the outer wall of the support rod is provided with a plurality of support ribs at equal angles along its own circumference. The support ribs are resting on the inner wall of the center hole of the winding core, and an escape space for electrolyte flow is formed between two adjacent support ribs.

[0006] In a second aspect, a battery is provided, comprising a shell, a winding core disposed in the shell, and the above-mentioned winding core center needle, wherein the winding core center needle is inserted into the center hole of the winding core. Beneficial effects

[0007] The beneficial effects of a core center needle and battery provided in the present application are as follows: when the center needle is inserted into the center hole of the core, all support ribs can be evenly pressed against the inner side wall of the center hole of the core along the circumferential direction, and two adjacent support ribs and the inner wall of the center hole of the core form a fan-shaped structure that is approximately triangular, so as to stably support the core; at the same time, the avoidance space formed between the two adjacent support ribs can allow electrolyte to flow, so as to reduce the obstruction of electrolyte flow, and help the core to infiltrate and absorb electrolyte, and the contact area between the support ribs and the inner side wall of the center hole of the core is smaller, which can increase the contact area between the inner side wall of the center hole of the core and the electrolyte, so as to minimize the impact of the center needle on the core's absorption of electrolyte, thereby ensuring the performance of the core. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG1 is a three-dimensional view of the center needle of the winding core provided in the present application.

[0009] FIG2 is a cross-sectional view of the winding core provided in the present application when supported by a central needle.

[0010] FIG3 is a cross-sectional view of the winding core provided by the present application when the central needle is retracted.

[0011] FIG4 is an enlarged view of point A in FIG2 .

[0012] In the picture:

[0013] 100, winding core; 101, center hole;

[0014] 1. Support rod; 11. Mounting cavity; 12. Opening; 2. Support rib; 3. Avoidance space; 4. Telescopic structure; 41. Connecting rod; 42. Elastic member; 5. Limiting member; 51. Support portion; 511. Limiting groove; 6. First limiting portion; 7. Second limiting portion; 8. Air guide groove; 9. Through hole. Modes for Carrying Out the Invention

[0015] As shown in Figures 1 to 3, the present application provides a core center needle, which includes a support rod 1 and multiple support ribs 2. The support rod 1 is cylindrical, and the outer wall of the support rod 1 is provided with multiple support ribs 2 at equal angles along its own circumference. The support ribs 2 are against the inner wall of the center hole 101 of the core 100 to support the core 100 and prevent the core 100 from collapsing and deforming inward. An escape space 3 for the flow of electrolyte is formed between two adjacent support ribs 2.

[0016] When the center needle of the core is inserted into the center hole 101 of the core 100, all the supporting ribs 2 can be evenly pressed against the inner wall of the center hole 101 of the core 100 along the circumferential direction. Two adjacent supporting ribs 2 and the inner wall of the center hole 101 of the core 100 form a fan-shaped structure that is approximately triangular, which can stably support the core 100. At the same time, the avoidance space 3 formed between the two adjacent supporting ribs 2 can allow electrolyte to flow, so as to reduce the obstruction of electrolyte flow, and help the core 100 to soak and absorb electrolyte. At the same time, it can also provide gas discharge when the battery has an abnormality and needs to release pressure. Moreover, the contact area between the supporting ribs 2 and the inner wall of the center hole 101 of the core 100 is smaller, which can increase the contact area between the inner wall of the center hole 101 of the core 100 and the electrolyte, so as to minimize the influence of the center needle of the core on the core 100 absorbing electrolyte, thereby ensuring the performance of the core 100.

[0017] It should be noted that the number of the supporting ribs 2 can be two or more, and the number of the supporting ribs 2 is not limited here.

[0018] Referring to Figure 1 , multiple through-holes 9 are provided through the outer wall of the support rod 1 and any one or a combination of the two support ribs 2. In this embodiment, multiple through-holes 9 are provided through both the outer wall of the support rod 1 and the support ribs 2. These through-holes 9 connect all of the escape spaces 3, allowing electrolyte to flow through them and promoting electrolyte absorption by the winding core 100.

[0019] The diameter of the through hole 9 is 1 mm to 3 mm. For example, the diameter of the through hole 9 can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc. If the diameter of the through hole 9 is too large, the strength of the core center pin will be reduced, and an excessive diameter of the through hole 9 will affect the flow efficiency of the electrolyte. This design can maximize the flow efficiency of the electrolyte while minimizing the impact on the strength of the core center pin.

[0020] Referring to Figure 1 , the outer walls of both the support rod 1 and the support rib 2 are provided with air guide grooves 8 , which extend along the length of the center pin. This means that the support rod 1 and the support rib 2 have the same length. The air guide grooves 8 on the support rod 1 extend along the length of the support rod 1 and pass through both ends of the lengthwise direction of the support rod 1. The air guide grooves 8 on the support rib 2 extend along the length of the support rib 2 and pass through both ends of the lengthwise direction of the support rod 1. When the battery requires venting and pressure relief, the air guide grooves 8 can quickly direct the gas to the exterior of the winding core 100, improving venting and pressure relief efficiency.

[0021] All the supporting ribs 2 can be telescopically arranged on the supporting rod 1 along the radial direction of the supporting rod 1 to adjust the supporting outer diameter of the winding core center needle so that the winding core center needle is suitable for the center hole 101 of the winding core 100 with different diameters.

[0022] For example, as shown in Figures 2 and 3, a mounting cavity 11 is provided inside the support rod 1, and the center needle of the winding core further includes a telescopic structure 4, which is provided in the mounting cavity 11. The telescopic structure 4 includes a cylindrical connecting rod 41, the central axis of the connecting rod 41 coincides with the central axis of the support rod 1, and the connecting rod 41 is provided with a plurality of elastic members 42 at equal angles along its own circumference. A plurality of openings 12 are provided on the outer wall of the support rod 1 corresponding to the positions of the support ribs 2. The number of the elastic members 42, the openings 12 and the support ribs 2 is the same. One end of all the support ribs 2 is located inside the support rod 1 and is connected one by one to the elastic members 42, and the other end can respectively pass through the openings 12 and extend to the outside of the support rod 1. The elastic members 42 drive the support ribs 2 to have a movement tendency against the inner wall of the center hole 101 of the winding core 100, so as to realize that the support ribs 2 can be telescopically provided on the support rod 1.

[0023] When it is necessary to insert the core center needle into the center hole 101 of the core 100, the compressible support rib 2 can be moved toward the installation cavity 11 to reduce the support outer diameter of the core center needle, so as to facilitate the insertion of the core center needle into the center hole 101 as a whole. After being inserted into the center hole 101, the support rib 2 can automatically move toward the outside of the support rod 1 under the action of the elastic member 42 to rest against the inner wall of the center hole 101 of the core 100, thereby realizing the installation of the core center needle.

[0024] A limiting member 5 is also provided in the mounting cavity 11. The limiting member 5 includes a plurality of support portions 51 arranged at equal angles along the circumference of the support rod 1. The number of the support portions 51 is the same as the number of the openings 12. Each support portion 51 is provided with a limiting slot 511 communicating with the opening 12. The length of the limiting slot 511 extends along the movement direction of the support rib 2. The support rib 2 is slidably provided in the limiting slot 511. At least a portion of the elastic member 42 is located in the limiting slot 511 and is connected to one end of the support rib 2. The elastic member 42 can drive the support rib 2 to move in the limiting slot so that the other end of the support rib 2 slides out of the limiting through-hole 9 and passes through the opening 12 to the outside of the support rod 1. By providing the limiting slot 511, the limiting member 5 can guide the movement of the support rib 2 to prevent the support rib 2 from deviating and getting stuck inside the support rod 1, thereby ensuring that the support rib 2 can smoothly extend to the outside of the support rod 1.

[0025] Each support portion 51 has a first end and a second end that are opposite each other. The length direction of the limiting slot 511 is the same as the relative direction of the first and second ends. The limiting slot 511 extends through the first and second ends. The first ends of all support portions 51 are connected, and the second ends of all support portions 51 are connected to the inner side wall of the support rod 1 and communicate with the openings 12. This design connects the first ends of all support portions 51 to form an integrated limiting member 5, enabling the support portions 51 to interact with each other to support the inner side wall of the support rod 1, thereby increasing the strength of the support rod 1. Moreover, the limiting slots 511 of all support portions 51 are connected, forming an installation space within the limiting member 5. The telescopic structure 4 is disposed within the installation space and connected to the support rib 2.

[0026] Among them, the central axis of the connection point of the first end of all the support parts 51 is the central axis of the limiter 5, the connecting rod 41 is arranged at the central axis of the limiter 5, and the central axis of the connecting rod 41 coincides with the central axis of the limiter 5, all the elastic parts 42 are arranged at equal angles along the circumference of the connecting rod 41, and one end of each elastic part 42 away from the connecting rod 41 extends into a limiting groove 511 and is connected to the support rib 2.

[0027] Referring to Figure 4 , a first limiting portion 6 is provided on the groove wall of the limiting groove 511 adjacent to the second end, and a second limiting portion 7 is provided on the support rib 2 to engage with the first limiting portion 6. For example, the first limiting portion 6 is a first protrusion that protrudes toward the center of the limiting groove 511, and the second limiting portion 7 is a second protrusion that protrudes from the outer side wall of the end of the support rib 2 connected to the elastic member 42. When the support rib 2 moves to the extreme position, the second protrusion can abut against the first protrusion to limit the movement of the support rib 2 and prevent the support rib 2 from falling out of the limiting groove 511.

[0028] For example, the limiter 5 divides the interior of the support rod 1 into multiple flow spaces, and drainage holes are provided through the limiter 5. All flow spaces are connected through the drainage holes, and the flow spaces can also flow with the avoidance space 3 through the through hole 9 on the support rod 1, so that the electrolyte can flow inside and outside the center needle of the core to infiltrate the core 100.

[0029] For example, both the inner and outer walls of the support rod 1 are provided with air guide grooves 8 , and the outer wall of the limiting member 5 may also be provided with air guide grooves 8 to improve the air guide effect.

[0030] The present application also provides a battery comprising a housing, a cylindrical core 100 disposed within the housing, and a core center pin provided herein, which is inserted into a central hole 101 of the core 100. The battery of the present application utilizes the core center pin to prevent the core 100 from collapsing and deforming inward. The core center pin also minimizes the effect of the core 100 on electrolyte absorption, thereby improving the battery's performance and service life.

Claims

1. A winding core center needle, comprising a support rod and a plurality of supporting ribs, wherein the support rod is cylindrical, and the outer wall of the support rod is provided with a plurality of supporting ribs at equal angles along its own circumference, the supporting ribs are against the inner wall of the center hole of the winding core, and an escape space for electrolyte flow is formed between two adjacent supporting ribs.

2. The winding core center needle according to claim 1, wherein: All the supporting ribs can be telescopically arranged on the support rod along the radial direction of the support rod.

3. The center needle of the winding core according to claim 2, wherein an installation cavity is provided inside the support rod, and the center needle of the winding core also includes a telescopic structure, and the telescopic structure is arranged in the installation cavity; the telescopic structure includes a connecting rod, and the connecting rod has a plurality of elastic members arranged at equal intervals along its circumference, and the outer wall of the support rod is provided with a plurality of openings corresponding to the position of the support rib, one end of the support rib is connected one by one with the elastic member, and the other end passes through the opening and extends to the outside of the support rod, and the elastic member drives the support rib to have a movement tendency against the inner wall of the center hole of the winding core.

4. The winding core center needle according to claim 3, wherein: A limiting member is arranged in the installation cavity, and the limiting member includes a plurality of supporting parts arranged at equal angles along the circumference of the connecting rod, and the supporting part is provided with a limiting groove connected to the opening, and the length of the limiting groove extends along the moving direction of the supporting rib plate, and at least a part of the supporting rib plate is slidably arranged in the limiting groove.

5. The winding core center needle according to claim 4, wherein: The support portion has a first end and a second end opposite to each other, the limiting groove runs through the first end and the second end, the first ends of all the support portions are connected to form an installation space inside the limiting member, the second ends of all the support portions are against the inner side wall of the support rod and are connected to the opening, and the telescopic structure is arranged in the installation space and connected to the supporting rib.

6. The winding core center needle according to claim 5, wherein: A first limiting portion is disposed on the groove wall of the limiting groove adjacent to the second end, and a second limiting portion cooperating with the first limiting portion is disposed on the support rib plate to prevent the support rib plate from escaping from the limiting groove.

7. The winding core center needle according to any one of claims 1 to 6, wherein: A plurality of air guide grooves are arranged on the outer side wall of the support rod and the outer side wall of the support rib, and the air guide grooves extend along the length direction of the central needle of the winding core.

8. The winding core center needle according to any one of claims 1 to 6, wherein: A plurality of through holes are provided through the outer side wall of the support rod and any one or a combination of two of the support ribs, and all the avoidance spaces are connected through the through holes to allow the electrolyte to flow.

9. The winding core center needle according to claim 8, wherein: The through hole has a diameter of 1 mm to 3 mm.

10. A battery, comprising a shell and a winding core arranged in the shell, and further comprising a winding core center needle according to any one of claims 1 to 9, wherein the winding core center needle is inserted into a center hole of the winding core.

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