Parallel winding core structure of cylindrical batteries and its manufacturing process

Abstract

The present invention provides a cylindrical battery parallel winding core structure and a manufacturing process thereof, wherein the cylindrical battery parallel winding core structure comprises a first winding core body and a second winding core body connected to each other, the first winding core body is provided with a first positive electrode ear and a first negative electrode ear located at different ends, the second winding core body is provided with a second positive electrode ear and a second negative electrode ear located at different ends, the first winding core body and the second winding core body both comprise a positive electrode sheet, a negative electrode sheet and a separation film separated between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet comprises a positive electrode collector and a positive electrode film sheet arranged on the positive electrode collector, the positive electrode collector comprises a coating portion provided with a positive electrode film sheet and a blank portion not provided with a positive electrode film sheet, the negative electrode sheet comprises a negative electrode collector and a negative electrode film sheet arranged on the negative electrode collector, the first winding core body and the second winding core body share the same positive electrode collector, and a portion of the blank portion of the positive electrode collector extends out of the first winding core body and simultaneously constitutes the first positive electrode ear and the second positive electrode ear.

Description

Technical Field

[0001] The present invention relates to the field of energy storage devices, in particular to a cylindrical battery, and more particularly to a cylindrical battery parallel winding core structure and a manufacturing process thereof. Background Art

[0002] Cylindrical batteries are a type of secondary battery that uses a metal shell or aluminum-plastic film soft packaging. They have the characteristics of good safety performance and high energy density, and are widely used in the market. The existing cylindrical battery cells mainly adopt a winding structure. The winding cell manufacturing process is simple, easy to automate, and has a high yield rate.

[0003] However, the wound cell is composed of a winding core. When the battery needs to be connected in parallel, it can generally only be achieved by welding the finished product externally. In this way, due to the poor performance consistency between different batteries, the rate and cycle life of the parallel battery pack formed after external parallel connection are poor. In addition, due to the large spacing between the parallel battery shells, the parallel battery pack occupies a large volume of battery compartment when used, which cannot meet the development needs of small-volume electrical products. Now there are parallel winding core structures of multiple cells, such as Chinese patent CN210744083U. Although it discloses a parallel dual-cell structure, this dual-cell structure is wound from both ends to the center on the basis of the same long diaphragm to form two parallel winding cores with the same height. It is not suitable for special-shaped batteries (different cell sizes, or irregular external shapes of the formed battery pack), and cannot meet the needs of the special-shaped battery market. In addition, this parallel winding core structure requires two windings, and in order to meet the consistency of the cell, the winding parameters need to be strictly controlled, so the production precision requirements are high, which greatly reduces the production efficiency. Summary of the invention

[0004] Based on the above problems, the present invention provides a parallel winding core structure of cylindrical batteries and its manufacturing process. The size of this parallel winding core structure is variable, and the shape of the battery pack composed of it is variable, which can meet the needs of the special-shaped battery market. At the same time, its manufacturing process is simple, the precision requirement is low, and the production efficiency is high.

[0005] To achieve the above-mentioned purpose, the present invention provides a parallel winding core structure of a cylindrical battery, comprising a first winding core body and a second winding core body connected to each other, the first winding core body is provided with a first positive electrode ear and a first negative electrode ear located at different ends, the second winding core body is provided with a second positive electrode ear and a second negative electrode ear located at different ends, the first winding core body and the second winding core body both comprise a positive electrode sheet, a negative electrode sheet and a separator separated between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet comprises a positive electrode collector and a positive electrode film sheet arranged on the positive electrode collector, the positive electrode collector comprises a coating portion provided with the positive electrode film sheet and a blank portion where the positive electrode film sheet is not arranged, the negative electrode sheet comprises a negative electrode collector and a negative electrode film sheet arranged on the negative electrode collector, the first winding core body and the second winding core body share the same positive electrode collector, and a portion of the blank portion of the positive electrode collector extends out of the first winding core body and simultaneously constitutes the first positive electrode ear and the second positive electrode ear.

[0006] Compared with the prior art, the first core body and the second core body of the cylindrical battery parallel core structure of the present invention form the first positive electrode ear and the second positive electrode ear by extending out the blank part of the positive electrode collector of the first core body, that is, parallel connection is achieved only by connecting through the blank part of the positive electrode collector. The first core body and the second core body are independent individuals and do not affect each other. The sizes of the two can be the same or different. At the same time, the first core body and the second core body can also be combined into battery packs with different external shapes, thereby meeting the needs of the special-shaped battery market.

[0007] Preferably, the central axis of the first winding core body overlaps with the central axis of the second winding core body, the first negative electrode ear and the second negative electrode ear extend from the top of the first winding core body and the bottom of the second winding core body respectively, and the blank portion of the positive electrode collector between the first winding core body and the second winding core body constitutes the first positive electrode ear and the second positive electrode ear at the same time, and this structure can constitute a "one"-shaped parallel winding core structure. More preferably, the first positive electrode ear, the second positive electrode ear, the first negative electrode ear and the second negative electrode ear all overlap with the central axis of the first winding core body. The negative electrode collector includes a coating portion provided with the negative electrode film and a blank portion without the negative electrode film, and the upper end of the blank portion of the negative electrode collector is connected to the first negative electrode ear, and the lower end is connected to the second negative electrode ear.

[0008] Preferably, as another structure, the central axis of the first winding core body and the central axis of the second winding core body are arranged in parallel, the blank part of the positive electrode collector between the first winding core body and the second winding core body constitutes the first positive electrode ear and the second positive electrode ear, and the first winding core body and the second winding core body are respectively provided with the first negative electrode ear and the second negative electrode ear at the same end, and this structure can constitute a parallel winding core structure of a parallel structure. More preferably, the blank part of the positive electrode collector is bent in the middle and converged into a positive terminal, the first negative electrode ear and the second negative electrode ear are bent in the middle and converged into a negative terminal, and the positive terminal and the negative terminal extend out at different ends. Alternatively, in order to increase the length of the output terminal, the blank part of the positive electrode collector is bent in the middle and the positive terminal is welded, the first negative electrode ear and the second negative electrode ear are bent in the middle and converged into a negative terminal, and the positive terminal and the negative terminal extend out at different ends.

[0009] Preferably, the lengths of the first winding core body and the second winding core body are not equal, or the diameters of the first winding core body and the second winding core body are not equal. The first winding core body and the second winding core body have different sizes, and combined with the arrangement of the "I" shape and the parallel structure, a variety of heterogeneous structure battery packs can be formed.

[0010] Another aspect of the present invention provides a manufacturing process for a cylindrical battery parallel winding core structure, comprising:

[0011] (1) a blank portion is provided at the starting end of the positive electrode current collector along the longitudinal direction, and a first positive electrode film sheet and a second positive electrode film sheet are provided in parallel and adjacent to the blank portion in the transverse direction of the positive electrode current collector, and a gap is provided between the first positive electrode film sheet and the second positive electrode film sheet in the transverse direction;

[0012] (2) a blank portion is provided at the starting end of the negative electrode current collector along the longitudinal direction, and a first negative electrode film sheet and a second negative electrode film sheet are provided in parallel and adjacent to the blank portion in the transverse direction of the negative electrode current collector, and a gap is provided between the first negative electrode film sheet and the second negative electrode film sheet in the transverse direction;

[0013] (3) The first positive electrode film sheet and the first negative electrode film sheet, the second positive electrode film sheet and the second negative electrode film sheet are overlapped respectively and an isolation film is arranged between them for insulation, and the positive electrode collector and the negative electrode collector are wound from the starting ends to form a first core body and a second core body connected to each other, the first core body and the second core body are connected through the blank portion of the positive electrode collector located in the interval, and the blank portion of the positive electrode collector located in the interval simultaneously constitutes a first positive electrode ear of the first core body and a second positive electrode ear of the second core body.

[0014] Compared with the prior art, the manufacturing process of the parallel core structure of the present invention can be divided into an independent first core body and a second core body by setting intervals. Core bodies of different sizes can be manufactured by different sizes of membranes. The first core body and the second core body share the same positive electrode current collector and can be formed into a parallel core structure with consistent winding performance through one winding. Therefore, the production precision requirements are low and the production efficiency is high.

[0015] Furthermore, the upper and lower ends of the blank portion of the negative electrode current collector are respectively welded to a first negative electrode ear and a second negative electrode ear extending out at opposite ends. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the pole pieces before winding of the first embodiment of the cylindrical battery parallel winding core structure of the present invention. (a) is a schematic diagram of the positive pole piece before winding; (b) is a schematic diagram of the negative pole piece before winding.

[0017] Figure 2 FIG. 1 is a schematic diagram of a first embodiment of a cylindrical battery parallel winding core structure of the present invention.

[0018] Among them, (a) is a "one" shaped structure; (b) is a parallel structure.

[0019] Figure 3 Schematic diagram of the pole pieces before winding of the second embodiment of the cylindrical battery parallel winding core structure of the present invention. (a) is a schematic diagram of the positive pole piece before winding; (b) is a schematic diagram of the negative pole piece before winding.

[0020] Figure 4 FIG. 1 is a schematic diagram of a second embodiment of a parallel winding core structure of cylindrical batteries according to the present invention.

[0021] Among them, (a) is a "one" shaped structure; (b) is a parallel structure.

[0022] Component Symbols

[0023] 100-parallel winding core structure; 10a-first winding core body; 10b-second winding core body; 11-positive electrode current collector; 111-positive electrode blank part; 113-positive electrode coating part; 13-positive electrode sheet; 15-positive electrode terminal; 15a-first positive electrode ear; 15b-second positive electrode ear; 17-positive electrode film / first positive electrode film / second positive electrode film; 31-negative electrode current collector; 311-negative electrode blank part; 313-negative electrode coating part; 33-negative electrode sheet; 35-negative electrode terminal; 35a-first negative electrode ear; 35b-second negative electrode ear; 37-negative electrode film / first negative electrode film / second negative electrode film; 50-interval DETAILED DESCRIPTION

[0024] To better illustrate the purpose, technical solution, and beneficial effects of the present invention, the following describes the preferred embodiments of the present invention with reference to the accompanying drawings of the specification. It should be noted that the following described method is a further explanatory description of the present invention and should not be construed as a limitation of the present invention.

[0025] As Figures 1 to 4 shown, the cylindrical battery parallel winding core structure 100 includes a connected first winding core body 10a and a second winding core body 10b. The first winding core body 10a is provided with a first positive electrode tab 15a and a first negative electrode tab 35a at different ends. The second winding core body 10b is provided with a second positive electrode tab 15b and a second negative electrode tab 35b at different ends. Both the first winding core body 10a and the second winding core body 10b include a positive electrode plate 13, a negative electrode plate 33, and a separator (not shown in the figure) spaced between the positive electrode plate 13 and the negative electrode plate 33. The positive electrode plate 13 includes a positive electrode current collector 11 and a positive electrode film 17 provided on the positive electrode current collector 11. The positive electrode current collector 11 includes a positive electrode coating portion 113 provided with the positive electrode film and a positive electrode blank portion 111 not provided with the positive electrode film. The negative electrode plate 33 includes a negative electrode current collector 31 and a negative electrode film 37 provided on the negative electrode current collector 31. The first winding core body 10a and the second winding core body 10b share the same positive electrode current collector 11, and a part of the positive electrode blank portion 111 extends out of the first winding core body 10a and simultaneously forms the first positive electrode tab 15a and the second positive electrode tab 15b.

[0026] The cylindrical battery parallel winding core structure 100 of the present invention can form a "one" - shaped structure as shown in Figure 2 and Figure 4 in (a), or can also form a juxtaposed structure as shown in Figure 2 and Figure 4 in (b).

[0027] First, explain the "one" - shaped structure as shown in Figure 2 and Figure 4 in (a). The central axis of the first winding core body 10a overlaps with the central axis of the second winding core body 10b. The first negative electrode tab 35a and the second negative electrode tab 35b extend out from above the first winding core body 10a and below the second winding core body 10b respectively. The positive electrode blank portion 111 between the first winding core body 10a and the second winding core body 10b simultaneously forms the first positive electrode tab 15a and the second positive electrode tab 15b. The first positive electrode tab 15a, the second positive electrode tab 15b, the first negative electrode tab 35a, and the second negative electrode tab 35b all overlap with the central axis of the first winding core body 10a. The negative electrode current collector 31 includes a negative electrode coating portion 313 provided with the negative electrode film 37 and a negative electrode blank portion 311 not provided with the negative electrode film 37. The upper end of the negative electrode blank portion 311 is connected to the first negative electrode tab 15a, and the lower end is connected to the second negative electrode tab 15b.

[0028] The above-mentioned “I”-shaped structure can be manufactured by the following manufacturing process, including:

[0029] (1) A positive electrode blank portion 111 is provided at the starting end of the positive electrode current collector 11 along the longitudinal direction, and a first positive electrode film 17 and a second positive electrode film 17 are provided in parallel in the transverse direction of the positive electrode current collector 11 next to the positive electrode blank portion 111, and a gap of 50 (eg, Figure 1 (as shown in Figure a);

[0030] (2) A negative electrode blank portion 311 is provided at the starting end of the negative electrode current collector 31 along the longitudinal direction, and a first negative electrode film 37 and a second negative electrode film 37 are provided in parallel in the transverse direction of the negative electrode current collector 31 next to the negative electrode blank portion 311, and a gap 50 (such as Figure 1 (as shown in Figure b);

[0031] (3) The first positive electrode film 17 and the first negative electrode film 37, the second positive electrode film 17 and the second negative electrode film 37 are overlapped and a separator is arranged between them for insulation, and the positive electrode collector 11 and the negative electrode collector 31 are wound from the starting end to form a first winding core body 10a and a second winding core body 10b which are arranged in parallel and have overlapping central axes, the first winding core body 10a and the second winding core body 10b are connected by a positive electrode blank portion 111 located at the interval 50, and the positive electrode blank portion 111 located at the interval 50 simultaneously constitutes a first positive electrode ear 15a and a second positive electrode ear 15b, the first negative electrode ear 15a is welded to the upper end of the negative electrode blank portion 311, and the second negative electrode ear 15b is welded to the lower end, the negative electrode blank portion 311 can be made of copper foil, and the first negative electrode ear 15a and the second negative electrode ear 15b are made of nickel foil.

[0032] Secondly, let’s explain how Figure 2 and Figure 4In the parallel structure shown in (b), the central axis of the first winding core body 10a and the central axis of the second winding core body 10b are arranged in parallel, the positive electrode blank portion 111 between the first winding core body 10a and the second winding core body 10b constitutes the first positive electrode ear 15a and the second positive electrode ear 15b, the negative electrode current collector 31 includes a negative electrode coating portion 313 provided with a negative electrode film 37 and a negative electrode blank portion 311 without a negative electrode film 37, and the first winding core body 10a and the second winding core body 10b are provided with a first negative electrode ear 35a and a second negative electrode ear 35b at the same end. The positive electrode blank portion 111 is bent in the middle and converged to form a positive terminal 15, and the first negative electrode ear 35a and the second negative electrode ear 35b are bent in the middle and converged to form a negative terminal 35, and the positive terminal 15 and the negative terminal 35 extend at different ends. Of course, in order to increase the length of the output terminal, the positive electrode blank portion 111 can be bent in the middle and welded to the positive electrode terminal 15 , and the first negative electrode tab 35 a and the second negative electrode tab 35 b are bent in the middle and converged into the negative electrode terminal 35 .

[0033] The above-mentioned parallel structure can be manufactured by the following manufacturing process, including:

[0034] (1) A positive electrode blank portion 111 is provided at the starting end of the positive electrode current collector 11 along the longitudinal direction, and a first positive electrode film 17 and a second positive electrode film 17 are provided in parallel in the transverse direction of the positive electrode current collector 11 next to the positive electrode blank portion 111, and a gap of 50 (eg, Figure 1 (as shown in Figure a);

[0035] (2) A negative electrode blank portion 311 is provided at the starting end of the negative electrode current collector 31 along the longitudinal direction, and a first negative electrode film 37 and a second negative electrode film 37 are provided in parallel in the transverse direction of the negative electrode current collector 31 next to the negative electrode blank portion 311, and a gap 50 (such as Figure 1 (as shown in Figure b);

[0036] (3) The first positive electrode film 17 and the first negative electrode film 37, the second positive electrode film 17 and the second negative electrode film 37 are overlapped and a separator is arranged between them for insulation, and the positive electrode collector 11 and the negative electrode collector 31 are wound from the starting ends into a first winding core body 10a and a second winding core body 10b which are arranged in parallel and whose central axes overlap, the first winding core body 10a and the second winding core body 10b are connected through a positive electrode blank portion 111 located at the interval 50, and the positive electrode blank portion 111 located at the interval 50 simultaneously constitutes a first positive electrode ear 15a and a second positive electrode ear 15b, the first negative electrode ear 15a is welded to the upper end of the negative electrode blank portion 311, and the second negative electrode ear 15b is welded to the lower end, the negative electrode blank portion 311 can be made of copper foil, and the first negative electrode ear 15a and the second negative electrode ear 15b are made of nickel foil;

[0037] (4) The first winding core body 10a and the second winding core body 10b are folded in half relative to the positive electrode blank portion 111 located at the interval 50, and then the first positive electrode ear 15a and the second positive electrode ear 15b are bent, that is, the positive electrode blank portion 111 located at the interval 50 is bent in the middle and then gathered to form the positive terminal 15, and the first negative electrode ear 35a and the second negative electrode ear 35b are bent in the middle and gathered to form the negative terminal 35.

[0038] It should be noted that the length and diameter of the first winding core body 10a and the second winding core body 10b may be the same. Figures 1-2 As shown, in addition, the lengths and diameters of the first winding core body 10a and the second winding core body 10b may also be different, such as Figures 3-4 As shown, the length of the first winding core body 10a is smaller than that of the second winding core body 10b, which can be achieved by setting membranes of different widths (such as Figure 3 Similarly, the first winding core body 10a and the second winding core body 10b can be formed by using membranes of different lengths to form the first winding core body 10a and the second winding core body 10b of different diameters.

[0039] The first winding core body 10a and the second winding core body 10b of the present invention have different sizes, and combined with the arrangement of the "I" shape and the parallel structure, a variety of heterogeneous structure battery packs can be formed, thereby meeting the needs of the special-shaped battery market.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A cylindrical battery parallel winding core structure, characterized in that: It includes a first winding core body and a second winding core body connected to each other, the first winding core body is provided with a first positive electrode ear and a first negative electrode ear located at different ends, the second winding core body is provided with a second positive electrode ear and a second negative electrode ear located at different ends, the first winding core body and the second winding core body both include a positive electrode sheet, a negative electrode sheet and a separator separated between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet includes a positive electrode collector and a positive electrode film sheet arranged on the positive electrode collector, the positive electrode collector includes a coating portion provided with the positive electrode film sheet and a blank portion where the positive electrode film sheet is not arranged, the negative electrode sheet includes a negative electrode collector and a negative electrode film sheet arranged on the negative electrode collector, the first winding core body and the second winding core body share the same positive electrode collector, and part of the blank portion of the positive electrode collector extends out of the first winding core body and simultaneously constitutes the first positive electrode ear and the second positive electrode ear.

2. The cylindrical battery parallel winding core structure according to claim 1, characterized in that: The central axis of the first core body overlaps with the central axis of the second core body, the first negative electrode ear and the second negative electrode ear extend from the top of the first core body and the bottom of the second core body respectively, and the blank portion of the positive electrode collector between the first core body and the second core body simultaneously constitutes the first positive electrode ear and the second positive electrode ear.

3. The cylindrical battery parallel winding core structure according to claim 2, characterized in that: The first positive electrode tab, the second positive electrode tab, the first negative electrode tab, and the second negative electrode tab all overlap with the central axis of the first winding core body.

4. The cylindrical battery parallel winding core structure according to claim 2, characterized in that: The negative electrode current collector includes a coating portion provided with the negative electrode film and a blank portion not provided with the negative electrode film. The upper end of the blank portion of the negative electrode current collector is connected to the first negative electrode tab, and the lower end is connected to the second negative electrode tab.

5. The cylindrical battery parallel winding core structure according to claim 1, characterized in that: The central axis of the first winding core body and the central axis of the second winding core body are arranged in parallel, the blank portion of the positive electrode collector between the first winding core body and the second winding core body constitutes the first positive electrode ear and the second positive electrode ear, and the first winding core body and the second winding core body are respectively provided with the first negative electrode ear and the second negative electrode ear at the same end.

6. The cylindrical battery parallel winding core structure according to claim 5, characterized in that: The blank portion of the positive electrode current collector is bent in the middle and converged into a positive terminal, the first negative electrode ear and the second negative electrode ear are bent in the middle and converged into a negative terminal, and the positive terminal and the negative terminal extend out at different ends.

7. The cylindrical battery parallel winding core structure according to claim 5, characterized in that: The blank portion of the positive electrode current collector is bent in the middle and welded to a positive terminal, the first negative electrode ear and the second negative electrode ear are bent in the middle and converged into a negative terminal, and the positive terminal and the negative terminal extend out at different ends.

8. The cylindrical battery parallel winding core structure according to any one of claims 1 to 7, characterized in that: The lengths of the first winding core body and the second winding core body are not equal, or the diameters of the first winding core body and the second winding core body are not equal.

9. A manufacturing process for a cylindrical battery parallel winding core structure, characterized in that: include: (1) a blank portion is provided at the starting end of the positive electrode current collector along the longitudinal direction, and a first positive electrode film sheet and a second positive electrode film sheet are provided in parallel in the transverse direction of the positive electrode current collector next to the blank portion, and a gap is provided between the first positive electrode film sheet and the second positive electrode film sheet in the transverse direction; (2) a blank portion is provided at the starting end of the negative electrode current collector along the longitudinal direction, and a first negative electrode film sheet and a second negative electrode film sheet are provided in parallel and adjacent to the blank portion in the transverse direction of the negative electrode current collector, and a gap is provided between the first negative electrode film sheet and the second negative electrode film sheet in the transverse direction; (3) The first positive electrode film sheet and the first negative electrode film sheet, the second positive electrode film sheet and the second negative electrode film sheet are overlapped respectively and a separator is provided between them for insulation, and the positive electrode collector and the negative electrode collector are wound from the starting ends thereof into a first winding core body and a second winding core body connected to each other, the first winding core body and the second winding core body are connected through a blank portion of the positive electrode collector located in the interval, and the blank portion of the positive electrode collector located in the interval simultaneously constitutes a first positive electrode ear of the first winding core body and a second positive electrode ear of the second winding core body.

10. The manufacturing process of the cylindrical battery parallel winding core structure according to claim 9, characterized in that: The upper and lower ends of the blank portion of the negative electrode current collector are respectively welded to a first negative electrode ear and a second negative electrode ear extending out at opposite ends.

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