Cylindrical battery

Abstract

To provide a cylindrical battery with reduced waste of space in a center part of a cell to achieve high utilization of an internal space.SOLUTION: A cylindrical battery includes a plurality of positive electrode sheets 11 and a plurality of negative electrode sheets that are alternatively laminated along a height direction of the cylindrical battery, and separators 13 are provided in every space between the positive electrode sheet 11 and the negative electrode sheet adjacent to each other. The cylindrical battery further includes a positive-electrode current collecting pillar 3. The positive-electrode current collecting pillar 3 is provided to penetrate the plurality of positive electrode sheets 11, the plurality of negative electrode sheets, and the plurality of separators 13 along an axial direction of the cylindrical battery. The positive electrode sheets 11 are each electrically connected to the positive-electrode current collecting pillar 3. The positive-electrode current collecting pillar 3 is electrically connected to a head cover. The negative electrode sheets are electrically connected to a housing 2.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the priority of a Chinese patent application with the application number 2023236048493, filed with the China National Intellectual Property Administration on December 27, 2023, and the entire content disclosed in the above - mentioned application is incorporated herein by reference in its entirety. [Technical Field] This application relates to the technical field of batteries, and more specifically, to cylindrical batteries.

Background Art

[0002] With the rapid development of new energy vehicles, the industry's requirements for the energy density, security, and low cost of batteries are increasing more and more. In related technologies, a cylindrical battery is formed by stacking a positive electrode sheet, a negative electrode sheet, and a separator, then winding it as a winding core by a winding machine, and then incorporating the winding core into a cylindrical housing.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In related technologies, due to the requirements for the starting space of the winding core, a lot of space is wasted in the central part of the winding core, resulting in a relatively low volume utilization rate of the battery.

Means for Solving the Problems

[0004] This application provides a cylindrical battery, which includes a plurality of positive electrode sheets and a plurality of negative electrode sheets alternately stacked along the height direction of the cylindrical battery, and a separator is provided between adjacent positive electrode sheets and negative electrode sheets.

[0005] The cylindrical battery further includes a positive electrode current collector pillar, which is penetrated through a plurality of positive electrode sheets, a plurality of negative electrode sheets, and a plurality of separators along the axial direction of the cylindrical battery. The positive electrode sheet is electrically connected to the positive electrode current collector pillar, the positive electrode current collector pillar is electrically connected to the head cover, and the negative electrode sheet is electrically connected to the housing.

Advantages of the Invention

[0006] The beneficial effects of the cylindrical battery provided by the present application are as follows. The positive electrode sheet, the separator, the negative electrode sheet, and the separator are stacked in sequence to form a cell. The positive electrode current collector pillar penetrates along the axis of the cell and is electrically connected to the positive electrode sheet. The positive electrode current collector pillar is electrically connected to the head cover, and the negative electrode sheet is electrically connected to the housing. Thereby, in the related art, the space wasted at the central part of the cell is filled by the positive electrode current collector pillar, and all the stacked positive electrode sheets are connected on the positive electrode current collector pillar, and are drawn out by the connection between the positive electrode current collector pillar and the head cover to form the battery positive electrode. All the stacked negative electrode sheets are drawn out from the case to form the battery negative electrode, avoiding the waste of space at the central part of the cell and greatly improving the utilization rate of the internal space of the battery.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0008] In the related art, a cylindrical battery is formed by laminating a positive electrode sheet, a negative electrode sheet, and a separator, and then winding them up as a winding core by a winder, and incorporating the winding core into a cylindrical housing. Due to the requirement for the starting space of the winding core, a lot of space is wasted in the central part of the winding core, resulting in a relatively low volume utilization rate of the battery. At the same time, the positive electrode tab and the current collector, and the negative electrode tab and the current collector are welded and connected, resulting in low assembly efficiency. In addition, due to the presence of welding burrs and dust, it causes an increase in self-discharge and even safety accidents such as internal short circuits.

[0009] Therefore, as shown in FIGS. 1 to 6, the embodiment of the present application provides a cylindrical battery, which includes a cell 1, a housing 2, and a head cover 4. The cell 1 according to this embodiment adopts a method of laminating sheets. Specifically, the cell 1 includes a plurality of positive electrode sheets 11 (see FIG. 4) and a plurality of negative electrode sheets 12 (see FIG. 5) alternately laminated along the height direction of the cylindrical battery. A separator 13 is provided between adjacent positive electrode sheets 11 and negative electrode sheets 12. In addition, through holes 10 are provided through each of the positive electrode sheet 11, the negative electrode sheet 12, and the separator 13 along the axial direction. After lamination, all the positive electrode sheets 11, negative electrode sheets 12, and separators 13 form an accommodation groove 101 through the through holes 10 (see FIG. 3). Here, the outer diameter of the cylindrical battery according to this embodiment is r, and the height of the cylindrical battery is h, satisfying 52 mm < r < 84 mm and 120 mm < h < 200 mm. Exemplarily, the outer diameter r of the housing 2 may be 54 mm, 58 mm, 60 mm, 64 mm, 68 mm, 70 mm, 74 mm, 78 mm, 80 mm, etc., and the height of the cylindrical battery may be 140 mm, 160 mm, 180 mm, etc.

[0010] It should be noted that the accommodation groove 101 according to this embodiment is similar to the wasted space in the central part of the winding core in the related art.

[0011] In one embodiment, in order to rationally utilize the space of the accommodation groove 101 and reduce space waste, the cylindrical battery further includes a negative electrode tab portion, a positive electrode current collecting pillar 3, and a positive electrode tab portion. The negative electrode tab portion is provided on the outer peripheral side of the negative electrode sheet 12 and is attached to the inner wall of the housing 2. The positive electrode current collecting pillar 3 is provided in the accommodation groove 101. The positive electrode tab portion is provided on the inner peripheral wall of the positive electrode sheet 11 and is attached to the peripheral side of the positive electrode current collecting pillar 3. The head cover 4 is provided at the open end of the housing 2 and is connected to the positive electrode current collecting pillar 3.

[0012] First, replace the forming method by winding the winding core in the related art with the lamination forming method of the cell 1 of the present application. Provide the negative electrode tab portion on the outer peripheral side of the negative electrode sheet 12 and attach it to the inner wall of the housing 2. Thereby, the battery negative electrode is formed by the housing 2. Provide the positive electrode tab portion on the inner peripheral wall of the positive electrode sheet 11. In the accommodation groove 101 formed by laminating the through hole 10 of the positive electrode sheet 11, the through hole 10 of the negative electrode sheet 12, and the through hole 10 of the separator 13 in the cell 1, add the positive electrode current collecting pillar 3. The positive electrode tab portion is attached to the positive electrode current collecting pillar 3, and the positive electrode current collecting pillar 3 and the head cover 4 are connected to form the battery positive electrode. Thereby, the space of the accommodation groove 101 is rationally and sufficiently utilized, the waste of the internal space of the housing 2 is avoided, the energy density of the battery is improved. In the assembly process, the negative electrode tab portion may just be attached to the housing 2, and the positive electrode tab portion may just be attached to the positive electrode current collecting pillar 3. The assembly efficiency is higher, there is no need for welding connection, and the security of the cylindrical battery is greatly improved.

[0013] Specifically, as shown in FIG. 5, the negative electrode tab portion includes negative electrode tabs 121, and a plurality of negative electrode tabs 121 are provided. The plurality of negative electrode tabs 121 are provided on the outer peripheral side of the negative electrode sheet 12 along the circumferential direction of the negative electrode sheet 12, and the negative electrode tabs 121 and the negative electrode sheet 12 are on the same plane. One end of the negative electrode tab 121 away from the negative electrode sheet 12 is bonded to the housing 2. The negative electrode tab 121 according to this embodiment is provided in a fan shape so that the outer arc surface of the negative electrode tab 121 is closely bonded to the inner peripheral wall of the cylindrical housing 2. In this way, a tight connection between the two can be ensured without welding, with high reliability. The pitch between adjacent negative electrode tabs 121 is equal, which stabilizes the output of the cylindrical battery. The negative electrode tab portion is integrally formed with the negative electrode sheet 12, having good integrity.

[0014] As shown in FIG. 6, the positive electrode tab portion includes positive electrode tabs 111, and a plurality of positive electrode tabs 111 are provided. The plurality of positive electrode tabs 111 are provided on the inner peripheral wall of the positive electrode sheet 11 along the circumferential direction of the positive electrode sheet 11, and the positive electrode tabs 111 are bent and bonded to the positive electrode current collector pillar 3. The positive electrode tab 111 according to this embodiment is provided in an arc shape, and the inner arc surface of the bent positive electrode tab 111 is on the same plane as the through hole 10 of the positive electrode sheet 11. By closely bonding the inner arc surface of the positive electrode tab 111 to the circumferential side of the positive electrode current collector pillar 3, a tight connection between the two can be ensured without welding, ensuring that the stacked positive electrode sheet 11, negative electrode sheet 12, and separator 13 are all on the same axis, reducing the deviation when the cell 1 is inserted into the housing, thereby facilitating the subsequent operation of inserting it into the housing. The pitch between adjacent positive electrode tabs 111 is equal, further stabilizing the output of the cylindrical battery. The positive electrode tab portion is integrally formed with the positive electrode sheet 11, having better integrity.

[0015] In order to easily stack the positive electrode sheet 11, the separator 13, and the negative electrode sheet 12, the diameter of the through hole 10 in the positive electrode sheet 11 is made smaller than the diameter of the through hole 10 in the negative electrode sheet 12, and further, the diameter of the through hole 10 in the positive electrode sheet 11 is made smaller than the diameter of the through hole 10 in the separator 13, so that the bent positive electrode tab 111 can smoothly pass through the through hole 10 in the negative electrode sheet 12 and the through hole 10 in the separator 13 during stacking, facilitating assembly. At the same time, there is a gap between the through hole 10 in the negative electrode sheet 12 and the positive electrode current collector 3, avoiding interference between the two and ensuring the stability of the cylindrical battery.

[0016] In this embodiment, as shown in FIG. 6, the positive electrode current collecting pillar 3 is provided with a hollow structure with both ends open, and a plurality of reinforcing ribs 31 are provided along the circumferential direction on the inner wall of the positive electrode current collecting pillar 3. The reinforcing ribs 31 extend along the axial direction of the positive electrode current collecting pillar 3. By providing the reinforcing ribs 31, the overall strength of the positive electrode current collecting pillar 3 and thus the cylindrical battery is enhanced. Before installing the entire cell 1 in the housing 2, an insulating pad 21 is provided on the inner bottom wall of the housing 2. Then, the cell 1 is placed in the housing, and the insulating pad 21 isolates the positive electrode current collecting pillar 3 from the housing 2, avoiding mutual interference and short circuits. Finally, the head cover 4 is welded and connected to the edges of the open ends of the positive electrode current collecting pillar 3 and the housing 2 to tightly seal the cell 1.

Explanation of Reference Numerals

[0017] 1 Cell 10 Through hole 101 Receiving groove 11 Positive electrode sheet 111 Positive electrode tab 12 Negative electrode sheet 121 Negative electrode tab 13 Separator 2 Housing 21 Insulating pad 3 Positive electrode current collecting pillar 31 Reinforcing rib 4 Head cover

Claims

1. A cylindrical battery, comprising: a plurality of positive electrode sheets (11) and a plurality of negative electrode sheets (12) alternately stacked along the height direction of the cylindrical battery, with a separator (13) provided between each adjacent positive electrode sheet (11) and negative electrode sheet (12); the cylindrical battery further includes a positive electrode current collector pillar (3), the positive electrode current collector pillar (3) being provided to penetrate through a plurality of the positive electrode sheets (11), a plurality of the negative electrode sheets (12), and a plurality of the separators (13) along the axial direction of the cylindrical battery, the positive electrode sheet (11) being electrically connected to the positive electrode current collector pillar (3), the positive electrode current collector pillar (3) being electrically connected to a head cover (4), and the negative electrode sheet (12) being electrically connected to a housing (2). A cylindrical battery.

2. A plurality of negative electrode tabs (121) are provided on the circumferential side of the negative electrode sheet (12), the plurality of negative electrode tabs (121) being provided on the outer peripheral side of the negative electrode sheet (12) along the circumferential direction of the negative electrode sheet (12), and one end of the negative electrode tab (121) away from the negative electrode sheet (12) being bonded to the housing (2). The cylindrical battery according to Claim 1.

3. A plurality of positive electrode tabs (111) are provided on the inner circumference of the positive electrode sheet (11), the plurality of positive electrode tabs (111) being provided on the inner circumferential wall of the positive electrode sheet (11) along the circumferential direction of the positive electrode sheet (11), and the positive electrode tab (111) being bent and bonded to the positive electrode current collector pillar (3). The cylindrical battery according to Claim 2.

4. The diameter of the through hole (10) of the negative electrode sheet (12) is larger than the diameter of the through hole (10) of the positive electrode sheet (11). The cylindrical battery according to Claim 3.

5. The positive electrode tab (111) is integrally formed with the positive electrode sheet (11). The negative electrode tab (121) is integrally formed with the negative electrode sheet (12). The cylindrical battery according to Claim 3.

6. The pitch between adjacent positive electrode tabs (111) is equal. The pitch between adjacent negative electrode tabs (121) is equal. The cylindrical battery according to Claim 3.

7. The positive electrode current collector pillar (3) is provided with a hollow structure with both ends open. The cylindrical battery according to Claim 1.

8. On the inner wall of the positive electrode current collector pillar (3), a plurality of reinforcing ribs (31) are provided along the circumferential direction thereof, and the reinforcing ribs (31) extend along the axial direction of the positive electrode current collector pillar (3). The cylindrical battery according to claim 7.

9. The head cover (4) and the positive electrode current collector pillar (3) are connected by welding. The cylindrical battery according to claim 1.

10. An insulating pad (21) is provided on the inner bottom wall of the housing (2). The cylindrical battery according to claim 1.

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