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, which was filed with the China National National Intellectual Patent Office on December 27, 2023, and the entire content disclosed in the above application is incorporated herein by reference. [Technical Field] This application relates to the technical field of batteries, 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. In related technologies, a cylindrical battery is formed by laminating a positive electrode sheet, a negative electrode sheet, and a separator, then winding them as a winding core by a winding machine, and 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 in the central part of the winding core is wasted, and the volume utilization rate of the battery is relatively low.

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 laminated 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 penetrates multiple positive electrode sheets, multiple negative electrode sheets, and multiple separators along the axial direction of the cylindrical battery, the positive electrode sheets being electrically connected to the positive electrode current collector pillar, the positive electrode current collector pillar being electrically connected to the head cover, and the negative electrode sheets being electrically connected to the housing. [Effects of the Invention]

[0006] The beneficial effects of the cylindrical battery provided by this invention are as follows: A positive electrode sheet, a separator, a negative electrode sheet, and a separator are stacked in order to form a cell, a 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. As a result, the space that would be wasted in the center of the cell in related technologies is filled by the positive electrode current collector pillar, and all stacked positive electrode sheets are connected to the positive electrode current collector pillar and pulled out by the connection between the positive electrode current collector pillar and the head cover to form the battery positive electrode, and all stacked negative electrode sheets are pulled out from the case to form the battery negative electrode, thereby avoiding wasted space in the center of the cell and greatly improving the utilization rate of the internal space of the battery. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of the overall structure of the cylindrical battery provided by this invention. [Figure 2] This is a cross-sectional structural diagram along line BB in Figure 1. [Figure 3] This is a schematic diagram of the structure of the concealed housing and head cover of the cylindrical battery provided by this application. [Figure 4] This is a schematic diagram of the structure of the positive electrode sheet provided by this application. [Figure 5] This is a schematic diagram of the structure of the negative electrode sheet provided by this application. [Figure 6] This is a schematic diagram of the structure of the positive electrode current collector pillar provided by this application.

BEST MODE FOR CARRYING OUT 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 it up as a winding core by a winding machine, 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 slag 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) that are 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 a receiving 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 receiving 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 housing groove 101 and reduce wasted space, the cylindrical battery further includes a negative electrode tab portion, a positive electrode current collector pillar 3, and a positive electrode tab portion, the negative electrode tab portion being provided on the outer circumference side of the negative electrode sheet 12 and bonded to the inner wall of the housing 2, the positive electrode current collector pillar 3 being provided in the housing groove 101, the positive electrode tab portion being provided on the inner circumferential wall of the positive electrode sheet 11 and bonded to the circumferential side of the positive electrode current collector pillar 3, and the head cover 4 being provided at the open end of the housing 2 and connected to the positive electrode current collector pillar 3.

[0012] First, the molding method of winding a core in related technologies is replaced with the laminated molding method of cell 1 of this application, the negative electrode tab portion is provided on the outer circumference side of the negative electrode sheet 12 and bonded to the inner wall of the housing 2, thereby forming the negative electrode of the battery with the housing 2, the positive electrode tab portion is provided on the inner circumference wall of the positive electrode sheet 11, and a positive electrode current collector pillar 3 is added to the housing groove 101 formed by the lamination of the through holes 10 of the positive electrode sheet 11, the through holes 10 of the negative electrode sheet 12, and the through holes 10 of the separator 13 in cell 1, and the positive electrode tab portion collects positive current The positive electrode tab is bonded to the pillar 3, connecting the positive electrode current collector pillar 3 and the head cover 4 to form the positive electrode of the battery. This allows for rational and sufficient use of the space in the housing groove 101, avoids wasted space inside the housing 2, improves the energy density of the battery, and during the assembly process, the negative electrode tab is bonded to the housing 2 while the positive electrode tab remains bonded to the positive electrode current collector pillar 3, resulting in higher assembly efficiency, eliminating the need for welding, and significantly improving the security of the cylindrical battery.

[0013] Specifically, as shown in Figure 5, the negative electrode tab section includes a negative electrode tab 121, and a plurality of negative electrode tabs 121 are provided. The plurality of negative electrode tabs 121 are provided on the outer circumference 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, and one end of the negative electrode tab 121 away from the negative electrode sheet 12 is bonded to the housing 2. In this embodiment, the negative electrode tabs 121 are provided in a fan shape so that the outer arc surface of the negative electrode tab 121 is tightly bonded to the inner circumferential wall of the cylindrical housing 2, thereby ensuring a tight connection between the two without welding, resulting in high reliability. The pitch between adjacent negative electrode tabs 121 is equal, stabilizing the output of the cylindrical battery, and the negative electrode tab section is integrally molded with the negative electrode sheet 12, resulting in good integration.

[0014] As shown in Figure 6, the positive electrode tab portion includes a positive electrode tab 111, and a plurality of positive electrode tabs 111 are provided. The plurality of positive electrode tabs 111 are 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 tabs 111 are bent and bonded to the positive electrode current collector pillar 3. In this embodiment, the positive electrode tab 111 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 aligning the inner arc surface of the positive electrode tab 111 with the circumferential side of the positive electrode current collector pillar 3 and tightly bonding them together, a tight connection between the two can be guaranteed without welding. This ensures that the laminated positive electrode sheet 11, negative electrode sheet 12, and separator 13 are all on the same axis, reducing misalignment when inserting the cell 1 into the housing, thereby facilitating the subsequent process 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 molded with the positive electrode sheet 11, resulting in better integration.

[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 of the positive electrode sheet 11 is made smaller than the diameter of the through-hole 10 of the negative electrode sheet 12, and further, the diameter of the through-hole 10 of the positive electrode sheet 11 is made smaller than the diameter of the through-hole 10 of the separator 13, so that the folded positive electrode tab 111 can smoothly pass through the through-hole 10 of the negative electrode sheet 12 and the through-hole 10 of the separator 13 during stacking, facilitating assembly. At the same time, a gap between the through-hole 10 of the negative electrode sheet 12 and the positive electrode current collector 3 avoids interference between the two, ensuring the stability of the cylindrical battery.

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

Explanation of Reference Numerals

[0017] 1 Cell 10 Through-hole 101 Accommodation 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 collector pillar 31 Reinforcing rib 4 Head cover

Claims

1. It is a cylindrical battery, The cylindrical battery includes a plurality of positive electrode sheets (11) and a plurality of negative electrode sheets (12) stacked alternately along the height direction, with a separator (13) provided between adjacent positive electrode sheets (11) and negative electrode sheets (12), the cylindrical battery further includes a positive electrode current collector pillar (3), the positive electrode current collector pillar (3) is penetrated through the plurality of positive electrode sheets (11), the plurality of negative electrode sheets (12), and the plurality of separators (13) along the axial direction of the cylindrical battery, the positive electrode sheets (11) are electrically connected to the positive electrode current collector pillar (3), and the positive electrode current collector pillar (3) is electrically connected to a head cover (4), The negative electrode sheet (12) is electrically connected to the housing (2), Multiple positive electrode tabs (111) are provided on the inner circumference of the positive electrode sheet (11), and the multiple positive electrode tabs (111) are 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 tabs (111) are bent and bonded to the positive electrode current collector pillar (3). Cylindrical battery.

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

3. The diameter of the through hole (10) in the negative electrode sheet (12) is larger than the diameter of the through hole (10) in the positive electrode sheet (11). The cylindrical battery according to claim 2.

4. The positive electrode tab (111) is integrally molded with the positive electrode sheet (11), The negative electrode tab (121) is integrally molded with the negative electrode sheet (12). The cylindrical battery according to claim 2.

5. 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 2.

6. The positive electrode current collector pillar (3) is provided as a hollow structure with open ends. The cylindrical battery according to claim 1.

7. The inner wall of the positive electrode current collector pillar (3) is provided with a plurality of reinforcing ribs (31) along its circumferential direction, and the reinforcing ribs (31) extend along the axial direction of the positive electrode current collector pillar (3). The cylindrical battery according to claim 6.

8. The head cover (4) and the positive electrode current collector pillar (3) are welded together. The cylindrical battery according to claim 1.

9. 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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