Cylindrical battery

Abstract

The present application provides a cylindrical battery, comprising a plurality of positive electrode sheets and a plurality of negative electrode sheets which are alternately stacked in the height direction of the cylindrical battery. Separators are arranged between every adjacent positive and negative electrode sheets; the cylindrical battery further comprises a positive current collector pole; the positive current collector pole passes through the plurality of positive electrode sheets, the plurality of negative electrode sheets, and the plurality of separators in the axial direction of the cylindrical battery; the positive electrode sheets are all electrically connected to the positive current collector pole; the positive current collector pole is electrically connected to a top cover; and the negative electrode sheets are electrically connected to a housing.

Description

Cylindrical batteries

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 27, 2023, with application number 2023236048493. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a cylindrical battery. Background Art

[0003] With the rapid development of new energy vehicles, the industry has increasingly higher requirements for battery energy density, safety and low cost.

[0004] In the related art, cylindrical batteries use positive electrode sheets, negative electrode sheets and separators that are stacked and then wound into a core using a winding device, which is then placed into a cylindrical shell. Technical issues

[0005] In the related art, due to the requirements of the starting space of the core, a large amount of space is wasted in the middle of the core, and the battery volume utilization rate is low. Technical Solutions

[0006] The present application provides a cylindrical battery, comprising a plurality of positive electrode sheets and a plurality of negative electrode sheets alternately stacked along the height direction of the cylindrical battery, with a separator provided between adjacent positive electrode sheets and negative electrode sheets;

[0007] The cylindrical battery also includes a positive current collecting column, which is arranged along the axial direction of the cylindrical battery through multiple positive electrode sheets, multiple negative electrode sheets and multiple separators. The positive electrode sheets are electrically connected to the positive current collecting column, the positive current collecting column is electrically connected to the top cover, and the negative electrode sheet is electrically connected to the outer shell. Beneficial effects

[0008] The beneficial effects of the cylindrical battery provided by the present application are: a battery cell is formed by stacking a positive electrode sheet, a separator, a negative electrode sheet and a separator in sequence, the positive current collecting post passes through the axis of the battery cell and is electrically connected to the positive electrode sheet, the positive current collecting post is electrically connected to the top cover, and the negative electrode sheet is electrically connected to the shell, so that the wasted space in the middle of the battery cell in the related art is filled with the positive current collecting post, and all the stacked positive electrode sheets are connected to the positive current collecting post, and are led out through the connection between the positive current collecting post and the top cover to form the positive electrode of the battery, and all the stacked negative electrode sheets are led out through the shell to form the negative electrode of the battery, thereby avoiding the waste of the middle space of the battery cell and greatly improving the utilization rate of the internal space of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is a schematic diagram of the overall structure of a cylindrical battery provided in this application;

[0010] FIG2 is a cross-sectional structural diagram along line BB in FIG1 ;

[0011] FIG3 is a schematic structural diagram of a cylindrical battery hidden housing and a top cover provided by the present application;

[0012] FIG4 is a schematic structural diagram of the positive electrode sheet provided in this application;

[0013] FIG5 is a schematic structural diagram of the negative electrode sheet provided in this application;

[0014] FIG6 is a schematic structural diagram of the positive electrode current collecting column provided in the present application.

[0015] In the picture:

[0016] 1. Battery 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;

[0017] 2. Shell; 21. Insulation pad;

[0018] 3. Positive electrode current collecting column; 31. Reinforcement rib;

[0019] 4. Top cover. Modes for Carrying Out the Invention

[0020] In the related art, cylindrical batteries use positive electrode sheets, negative electrode sheets and separators stacked together, which are then wound into a core using a winding device and then placed into a cylindrical shell. Due to the starting space requirements of the core, a large amount of space is wasted in the middle of the core, resulting in low battery volume utilization. At the same time, the positive electrode tabs and the current collector, as well as the negative electrode tabs and the current collector, are welded together, resulting in low assembly efficiency. In addition, there are welding debris and dust, which lead to large self-discharge and even safety accidents such as internal short circuits.

[0021] To this end, in conjunction with Figures 1 to 6 , an embodiment of the present application provides a cylindrical battery, which includes a battery cell 1, a housing 2, and a top cover 4. The battery cell 1 of this embodiment is stacked. Specifically, the battery cell 1 includes a plurality of positive electrode sheets 11 (see Figure 4 ) and a plurality of negative electrode sheets 12 (see Figure 5 ) alternately stacked along the height direction of the cylindrical battery. A separator 13 is provided between adjacent positive electrode sheets 11 and negative electrode sheets 12. Through holes 10 are provided along the axial direction of the positive electrode sheets 11, the axial direction of the negative electrode sheets 12, and the axial direction of the separator 13. After stacking, all the positive electrode sheets 11, the negative electrode sheets 12, and the separator 13 form a receiving groove 101 (see Figure 3) through the through holes 10. Among them, the outer diameter of the cylindrical battery in this embodiment is r, and the height of the cylindrical battery is h, satisfying 52mm<r<84mm, 120mm<h<200mm. For example, the outer diameter r of the outer shell 2 can be 54mm, 58mm, 60mm, 64mm, 68mm, 70mm, 74mm, 78mm, 80mm, etc., and the height of the cylindrical battery can be 140mm, 160mm, 180mm, etc.

[0022] It should be noted that the accommodating groove 101 of this embodiment is similar to the wasted space in the middle of the winding core in the related art.

[0023] In one embodiment, in order to rationally utilize the space of the accommodating tank 101 and reduce space waste, the cylindrical battery further includes a negative electrode ear, a positive electrode current collecting post 3, and a positive electrode ear. The negative electrode ear is arranged on the outer peripheral side of the negative electrode sheet 12 and is in contact with the inner wall of the shell 2. The positive electrode current collecting post 3 is arranged in the accommodating tank 101. The positive electrode ear is arranged on the inner peripheral wall of the positive electrode sheet 11 and is in contact with the peripheral side of the positive electrode current collecting post 3. The top cover 4 is arranged at the open end of the shell 2 and is connected to the positive electrode current collecting post 3.

[0024] First, the winding forming core method in the related art is replaced by the stacking forming battery cell 1 method of the present application, and then, the negative electrode ear is set on the outer peripheral side of the negative electrode sheet 12 and is attached to the inner wall of the shell 2, so as to form the negative electrode of the battery through the shell 2, and the positive electrode ear is set on the inner peripheral wall of the positive electrode sheet 11, and a positive electrode ear is added to the battery cell 1 by 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 diaphragm 13. The positive electrode current collecting column 3 and the positive electrode ear are fitted with the positive electrode current collecting column 3, and the positive electrode current collecting column 3 is connected to the top cover 4 to form the positive electrode of the battery, so as to reasonably and fully utilize the space of the accommodating groove 101, avoid wasting the internal space of the shell 2, and improve the energy density of the battery; during the assembly process, the negative electrode ear is kept in fit with the shell 2, and the positive electrode ear is kept in fit with the positive electrode current collecting column 3, which has higher assembly efficiency and does not require welding connection, thereby greatly improving the safety of the cylindrical battery.

[0025] Specifically, as shown in FIG5 , the negative electrode tab portion includes a negative tab 121 , of which a plurality is provided. The plurality of negative tabs 121 are arranged on the outer peripheral side of the negative electrode sheet 12 along the circumference of the negative electrode sheet 12 , and the negative tabs 121 and the negative electrode sheet 12 are in the same plane, with the end of the negative tab 121 facing away from the negative electrode sheet 12 being in contact with the outer shell 2 . The negative tabs 121 of this embodiment are arranged in a fan-shaped manner so that the outer arc surface of the negative tab 121 matches and fits tightly with the inner circumferential wall of the cylindrical outer shell 2 , thereby ensuring a tight connection between the two without welding, and having good reliability. The spacing between adjacent negative tabs 121 is equal, which ensures stable output of the cylindrical battery. The negative electrode tab portion is integrally formed with the negative electrode sheet 12 , and has good integrity.

[0026] As shown in FIG6 , the positive electrode tab portion includes a positive tab 111. A plurality of positive tabs 111 are provided. The plurality of positive tabs 111 are arranged on the inner circumferential wall of the positive electrode sheet 11 along the circumference of the positive electrode sheet 11. The positive tabs 111 are bent to fit the positive electrode current collector 3. In this embodiment, the positive tab 111 is arc-shaped. The inner arc surface of the bent positive tab 111 is coplanar with the through-hole 10 of the positive electrode sheet 11. The inner arc surface of the positive tab 111 matches and fits tightly against the circumference of the positive electrode current collector 3, ensuring a tight connection without welding. This ensures that the stacked positive electrode sheet 11, negative electrode sheet 12, and separator 13 are all aligned on the same axis, reducing deviations in the insertion of the battery cell 1 into the shell and facilitating subsequent shell insertion operations. The spacing between adjacent positive tabs 111 is equal, making the output of the cylindrical battery more stable. The positive tab portion is integrally formed with the positive electrode sheet 11, providing improved integrity.

[0027] In order to facilitate the stacking of 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 smaller than the diameter of the through hole 10 of the negative electrode sheet 12, and the diameter of the through hole 10 of the positive electrode sheet 11 is also smaller than the diameter of the through hole 10 of the separator 13, so as to ensure that the bent positive electrode ear 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 the stacking process, so as to facilitate assembly. At the same time, there is a gap between the through hole 10 of the negative electrode sheet 12 and the positive electrode current collector 3 to avoid interference between the two, thereby ensuring the stability of the cylindrical battery.

[0028] In this embodiment, as shown in Figure 6, the positive electrode current collector 3 is hollow and open at both ends. The inner wall of the positive electrode current collector 3 is provided with multiple reinforcing ribs 31 along its circumference. The reinforcing ribs 31 extend in the axial direction of the positive electrode current collector 3. The provision of the reinforcing ribs 31 enhances the overall strength of the positive electrode current collector 3, the battery cell 1, and even the cylindrical battery. Before the battery cell 1 is placed in the outer shell 2, an insulating gasket 21 is provided on the inner bottom wall of the outer shell 2. The battery cell 1 is then placed in the shell. The insulating gasket 21 can isolate the positive electrode current collector 3 from the outer shell 2 to prevent interference between them and prevent short circuits. Finally, the top cover 4 is welded to the edges of the positive electrode current collector 3 and the open end of the outer shell 2 to achieve a tight seal for the battery cell 1.

Claims

1. A cylindrical battery, comprising a plurality of positive electrode sheets (11) and a plurality of negative electrode sheets (12) alternately stacked in a height direction of the cylindrical battery, wherein a separator (13) is disposed between adjacent positive electrode sheets (11) and negative electrode sheets (12); the cylindrical battery further comprises a positive electrode current collecting column (3), wherein the positive electrode current collecting column (3) penetrates through the plurality of positive electrode sheets (11), the plurality of negative electrode sheets (12) and the plurality of separators (13) in an axial direction of the cylindrical battery, the positive electrode sheets (11) are electrically connected to the positive electrode current collecting column (3), the positive electrode current collecting column (3) is electrically connected to a top cover (4), and the negative electrode sheets (12) are electrically connected to a housing (2).

2. The cylindrical battery according to claim 1, wherein, A plurality of negative electrode ears (121) are arranged on the circumferential side of the negative electrode sheet (12); the plurality of negative electrode ears (121) are arranged 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 ear (121) facing away from the negative electrode sheet (12) is in contact with the outer shell (2).

3. The cylindrical battery according to claim 2, wherein, A plurality of positive electrode ears (111) are arranged on the inner circumference of the positive electrode sheet (11); the plurality of positive electrode ears (111) are arranged 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 ears (111) are fitted with the positive electrode current collecting column (3) after being bent.

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

5. The cylindrical battery according to claim 3, wherein, The positive electrode ear (111) is integrally formed on the positive electrode sheet (11); The negative electrode ear (121) is integrally formed on the negative electrode sheet (12).

6. The cylindrical battery according to claim 3, wherein, The spacing between adjacent positive electrode ears (111) is equal; The spacing between adjacent negative electrode ears (121) is equal.

7. The cylindrical battery according to any one of claims 1-6, wherein, The positive electrode current collecting column (3) is hollow and has two open ends.

8. The cylindrical battery according to claim 7, wherein, The inner wall of the positive electrode current collecting column (3) is provided with a plurality of reinforcing ribs (31) along its circumference, and the reinforcing ribs (31) extend along the axial direction of the positive electrode current collecting column (3).

9. The cylindrical battery according to any one of claims 1-6, wherein, The top cover (4) is welded to the positive electrode current collecting column (3).

10. The cylindrical battery according to any one of claims 1-6, wherein, An insulating pad (21) is provided on the inner bottom wall of the outer shell (2).

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