All-tab battery roll core and sodium ion battery

Abstract

The all-tab battery roll core comprises a main body and a tab extending from the main body, a tab distance is formed between the outer edge of the tab and a reference surface, the first flatness of the tab is smaller than 0.1 mm, and the first flatness is the difference between the maximum value of the tab distance and the average value of the tab distance.

Description

Technical Field

[0001] The utility model relates to a full-tab battery roll core and a sodium ion battery, and more specifically, to a full-tab battery roll core with improved welding quality between a tab and a current collecting plate. Background Art

[0002] Compared with traditional multi-electrode batteries, the full-electrode battery has a new full-electrode flattening process. After the core is wound, the pole ear is flattened and then welded to the collector plate. In existing full-electrode batteries, the welding between the pole ear and the collector plate may have problems with low welding quality (for example, cold welding, etc.).

[0003] To this end, it is desired to propose a full-tab battery coil and a sodium-ion battery to improve the welding quality between the tab and the current collecting plate. Utility Model Content

[0004] According to the first aspect of the utility model, a full-tab battery roll core is proposed, comprising a main body and tabs extending from the main body, wherein an outer edge of the tab has a tab distance from a reference plane, wherein a first flatness of the tab is less than 0.1 mm, and the first flatness is the difference between the maximum value of the tab distance and the average value of the tab distance.

[0005] According to this solution, by improving the first flatness of the electrode tab, the welding quality between the electrode tab and the current collecting plate can be improved.

[0006] In some embodiments, the tab distance may be the distance between the outer edge of the tab after flattening and the reference plane.

[0007] In some embodiments, a full-tab battery roll may include a positive electrode sheet, a negative electrode sheet and a separator between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet, the negative electrode sheet and the separator are wound to form a full-tab battery roll; the tabs include a positive electrode tab and a negative electrode tab, and the portion of the positive electrode sheet extending from the separator forms the positive electrode tab, and the portion of the negative electrode sheet extending from the separator forms the negative electrode tab.

[0008] In some embodiments, the first flatness of the positive electrode tab and / or the negative electrode tab may be less than 0.05 mm.

[0009] In some embodiments, the second flatness of the positive electrode tab and / or the negative electrode tab may be less than 0.2 mm, and the second flatness is the difference between the maximum value and the minimum value of the tab distance.

[0010] In some embodiments, the second flatness of the positive electrode tab and / or the negative electrode tab may be less than 0.1 mm.

[0011] In some embodiments, the positive electrode tab and the negative electrode tab may be formed at two opposite ends of the full-tab battery roll.

[0012] According to a second aspect of the present invention, a sodium ion battery is provided, comprising the full-tab battery roll core according to the first aspect of the present invention.

[0013] According to this solution, by improving the first flatness of the electrode tab, the welding quality between the electrode tab and the current collecting plate can be improved.

[0014] In some embodiments, the sodium ion battery may further include: a positive electrode current collector plate, welded and fixed to the positive electrode tab; and a negative electrode current collector plate, welded and fixed to the negative electrode tab.

[0015] In some embodiments, the residual welding area between the positive current collector and the positive electrode tab and / or the residual welding area between the negative current collector and the negative electrode tab may be greater than 70%, where the residual welding area is the ratio of the area of ​​the welding surface remaining after the current collector and the corresponding tab are pulled apart to the surface area of ​​the welding surface before the current collector and the corresponding tab are pulled apart. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a full-tab battery roll core according to an embodiment of the utility model is shown;

[0017] Figure 2 yes Figure 1 A partial enlarged view of . DETAILED DESCRIPTION

[0018] In order to make the purpose, scheme and advantages of the technical solution of the utility model clearer, the technical solution of the embodiment of the utility model will be clearly and completely described in conjunction with the drawings of the specific embodiments of the utility model. Unless otherwise specified, the terms used in this article have the usual meanings in the art. The same reference numerals in the drawings represent the same components.

[0019] Figure 1 A schematic diagram of a full-tab battery roll core 100 according to an embodiment of the utility model is shown, and the full-tab battery roll core 100 includes a main body and a tab extending from the main body. For example, the full-tab battery roll core 100 may include a positive electrode sheet, a negative electrode sheet, and a separator 110 between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet, the negative electrode sheet, and the separator 110 are wound to form the full-tab battery roll core 100; the tabs include a positive electrode tab 120 and a negative electrode tab 130, and the portion of the positive electrode sheet extending from the separator 110 forms the positive electrode tab 120, and the portion of the negative electrode sheet extending from the separator 110 forms the negative electrode tab 130. Preferably, the positive electrode tab 120 and the negative electrode tab 130 may be formed at two opposite ends of the full-tab battery roll core 100.

[0020] The full-tab battery roll core 100 of the utility model can be used to manufacture sodium-ion batteries. The positive tab 120 and the negative tab 130 are welded and fixed to the positive current collector and the negative current collector, respectively. The welding quality between the tab and the current collector is crucial to the performance of the sodium-ion battery, and an important factor affecting the welding quality between the tab and the current collector is the flatness of the outer edge 122 of the tab (i.e., the surface in contact with the current collector during welding). It should be understood that the welding of the positive tab 120 and the positive current collector and the welding of the negative tab 130 and the negative current collector are similar, so the positive tab 120 will be used as an example for explanation below. If there is no special explanation, the explanation about the positive tab 120 can also be applied to the negative tab 130 accordingly.

[0021] In order to improve the welding quality between the positive electrode tab 120 and the positive electrode current collector, the first flatness of the positive electrode tab 120 is designed to be less than 0.1 mm. The first flatness is the difference between the maximum value H2 of the tab distance H1 and the average value of the tab distance H1. The tab distance H1 is the distance between the outer edge 122 of the positive electrode tab 120 and the reference plane 140 (such as Figure 2 It should be understood that although Figure 2 The end surface of the diaphragm 110 is used as the reference plane 140, but the utility model is not intended to limit the specific position of the reference plane 140, and any other suitable plane may be used as the reference plane. By improving the first flatness of the positive electrode tab 120 (i.e., making the outer edge 122 of the positive electrode tab 120 smoother), the welding quality between the positive electrode tab 120 and the positive current collector can be improved.

[0022] Preferably, the first flatness of the positive electrode tab 120 and / or the negative electrode tab 130 may be less than 0.05 mm.

[0023] In addition, the second flatness of the positive electrode tab 120 and / or the negative electrode tab 130 may be less than 0.2 mm, and the second flatness is the difference between the maximum value of the tab distance H1 and the minimum value of the tab distance H1. Preferably, the second flatness of the positive electrode tab 120 and / or the negative electrode tab 130 may be less than 0.1 mm.

[0024] Performance tests were conducted on sodium ion batteries made with tabs having different tab flatnesses. The effect of the flatness of the positive tab 120 and / or the negative tab 130 on the welding quality is shown in Table 1.

[0025] Table 1 Effect of tab flatness on sodium ion battery performance

[0026]

[0027]

[0028] It can be seen from Table 1 that when the first flatness of the positive electrode tab 120 and / or the negative electrode tab 130 is less than 0.1 mm and / or the second flatness of the positive electrode tab 120 and / or the negative electrode tab 130 is less than 0.2 mm, the welding tension of the positive electrode is greater than 29 N (i.e., a force greater than 29 N is required to destroy the weld between the positive electrode tab 120 and the positive current collecting disk), and the welding tension of the negative electrode is greater than 14.5 N (i.e., a force greater than 14.5 N is required to destroy the weld between the negative electrode tab 130 and the negative current collecting disk). When the first flatness of the positive electrode tab 120 and / or the negative electrode tab 130 is less than 0.05 mm and / or the second flatness of the positive electrode tab 120 and / or the negative electrode tab 130 is less than 0.1 mm, the welding tension of the positive electrode is greater than 42.86 N (i.e., a force of more than 42.86 N is required to destroy the welding between the positive electrode tab 120 and the positive current collector), and the welding tension of the negative electrode is greater than 33.6 N (i.e., a force of more than 33.6 N is required to destroy the welding between the negative electrode tab 130 and the negative current collector). When the first flatness of the positive electrode tab 120 and / or the negative electrode tab 130 is too large (e.g., equal to 0.3 mm), the corresponding welding tension is small or even 0, which means that only a small tension is required to destroy the welding between the tab and the corresponding current collector, making the performance of the sodium ion battery very unstable.

[0029] Preferably, the residual welding area between the positive current collector and the positive electrode tab 120 and / or the residual welding area between the negative current collector and the negative electrode tab 130 may be greater than 70%, and the residual welding area is the ratio of the area of ​​the welding surface remaining after the current collector and the corresponding tab are pulled apart to the surface area of ​​the welding surface before the current collector and the corresponding tab are pulled apart. The larger the residual welding area, the better the welding quality between the tab and the current collector.

[0030] This document describes in detail several exemplary embodiments of the present invention with reference to preferred embodiments. However, it will be understood by those skilled in the art that, without departing from the concept of the present invention, various modifications and variations may be made to the above-mentioned specific embodiments, and various technical features and structures proposed in the present invention may be combined without exceeding the protection scope of the present invention, which is determined by the appended claims.

Claims

1. A full-tab battery roll core, characterized in that: The invention comprises a main body and a pole ear extending from the main body, wherein a pole ear distance is provided between an outer edge of the pole ear and a reference plane. The first flatness of the tab is less than 0.1 mm, and the first flatness is the difference between the maximum value of the tab distance and the average value of the tab distance.

2. The full-tab battery roll core according to claim 1, characterized in that: The tab distance is the distance between the outer edge of the tab after flattening and the reference plane.

3. The full-tab battery roll core according to claim 2, characterized in that: It includes a positive electrode sheet, a negative electrode sheet and a separator between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode sheet, the negative electrode sheet and the separator are wound to form the full-tab battery roll core; the tabs include a positive electrode tab and a negative electrode tab, wherein the portion of the positive electrode sheet extending from the separator forms the positive electrode tab, and the portion of the negative electrode sheet extending from the separator forms the negative electrode tab.

4. The full-tab battery roll core according to claim 3, characterized in that: The first flatness of the positive electrode tab and / or the negative electrode tab is less than 0.05 mm.

5. The full-tab battery roll core according to claim 3, characterized in that: The second flatness of the positive electrode tab and / or the negative electrode tab is less than 0.2 mm, and the second flatness is the difference between the maximum value of the tab distance and the minimum value of the tab distance.

6. The full-tab battery roll core according to claim 3, characterized in that: The second flatness of the positive electrode tab and / or the negative electrode tab is less than 0.1 mm.

7. The full-tab battery roll core according to claim 3, characterized in that: The positive electrode tab and the negative electrode tab are formed at two opposite ends of the full-tab battery roll core.

8. A sodium ion battery, characterized in that: It comprises a full-tab battery pole piece roll core according to any one of claims 1 to 7.

9. The sodium ion battery according to claim 8, characterized in that: Also includes: A positive electrode current collector, welded and fixed to the positive electrode tab; The negative electrode current collector is welded and fixed to the negative electrode tab.

10. The sodium ion battery according to claim 9, characterized in that: The residual welding area between the positive electrode current collector and the positive electrode tab and / or the residual welding area between the negative electrode current collector and the negative electrode tab is greater than 70%, and the residual welding area is the ratio of the area of ​​the welding surface remaining after the current collector and the corresponding tab are pulled apart to the surface area of ​​the welding surface before the current collector and the corresponding tab are pulled apart.

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