A semi-pouch cylindrical battery

Abstract

The utility model discloses a kind of semi-full polar lug cylindrical batteries, comprising: negative plate and positive plate, negative plate and positive plate are wound into cylindrical battery;The side of negative plate has negative pole lug area, the negative pole lug area is divided into middle negative pole lug area and two-end negative pole lug area;Middle negative pole lug area is inclined interval negative pole lug. The side of positive plate has positive pole lug area, the positive pole lug area is divided into middle positive pole lug area and two-end positive pole lug area;Middle positive pole lug area is interval positive pole lug gradually increasing in distance from one end to the other end, and when the positive plate is wound into cylinder, each interval positive pole lug overlaps in same position.The utility model improves electrolyte wettability under the advantage of low internal resistance and can simplify assembly process by fusing semi-full polar lug design.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a semi-full-tab cylindrical battery. Background Technology

[0002] In the field of cylindrical battery technology, the all-tab design has become the mainstream solution for reducing internal resistance. However, existing processes still face a trade-off between electrolyte absorption efficiency and yield. Among current mainstream technologies, the flattening process achieves tab flatness through mechanical rolling, but this easily leads to metal debris causing short-circuit risks, and damage to the electrode's porous structure makes electrolyte wetting difficult. While the slicing and stacking process reduces flattening defects by laser-cutting the tab array, uneven interlayer spacing affects electrolyte distribution, and multiple laser welding steps increase process complexity and defect rate. The industry urgently needs an innovative manufacturing method that can balance low internal resistance, high electrolyte absorption, and high yield.

[0003] To address the aforementioned issues, the industry has attempted to improve the electrode structure, such as by step-shaped cutting, or by optimizing the current collector material, such as high-porosity composite electrodes. However, none of these efforts have been able to simultaneously improve both liquid absorption rate and yield. Summary of the Invention

[0004] This invention provides a semi-full-tab cylindrical battery that reduces internal resistance and increases electrode liquid absorption rate.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows: This utility model provides a semi-full-tab cylindrical battery, comprising: a negative electrode and a positive electrode, wherein the negative electrode and the positive electrode are wound into a cylindrical battery; The negative electrode sheet has a negative electrode tab area on its side, which is divided into a middle negative electrode tab area and two end negative electrode tab areas; the middle negative electrode tab area is a tilted and spaced negative electrode tab.

[0006] The positive electrode sheet has a positive electrode tab area on its side, which is divided into a middle positive electrode tab area and two end positive electrode tab areas. The middle positive electrode tab area consists of spaced positive electrodes that gradually increase in distance from one end to the other. When the positive electrode sheet is wound into a cylinder, each spaced positive electrode tab overlaps at the same position.

[0007] To optimize the above technical solution, the specific limitations also include: The negative electrode tabs at both ends are continuous metal foils with a height less than that of the inclined negative electrode tabs; the positive electrode tabs at both ends are continuous metal foils with a height less than that of the inclined positive electrode tabs.

[0008] Furthermore, the tilt angle of the tilted negative electrode tab is 65~75°.

[0009] Furthermore, the distance between adjacent tilted negative electrodes is the same, ranging from 0.4 to 0.6 mm.

[0010] Specifically, the height of the inclined negative electrode tab is 3~6mm, and the height of the negative electrode tab area at both ends is 0.5~1.5mm; the height of the inclined positive electrode tab is 3~6mm, and the height of the positive electrode tab area at both ends is 0.5~1.5mm.

[0011] Specifically, the number of positive electrode tabs is 6 to 30.

[0012] When the negative electrode sheet is wound into a cylinder, the inclined spaced negative electrode tabs in the middle negative electrode tab area are pressed inward in sequence and welded to the current collector.

[0013] When the positive electrode sheet is wound into a cylinder, the positive electrode tabs stacked at the same position are welded together, pressed inward, and welded to the cap tab of the battery.

[0014] It also includes a diaphragm, wherein at least one side of the diaphragm is coated with a ceramic layer, and the thickness of the ceramic layer on one side is 10~15μm.

[0015] Furthermore, when the negative electrode and positive electrode are wound into a cylindrical battery, the separator is first wound 1.4 to 1.6 turns, then the negative electrode is placed in and wound 1.1 to 1.3 turns, and then the positive electrode is placed in and wound. During the winding, there is only one positive electrode tab per turn.

[0016] Compared with the prior art, the beneficial effects of this utility model are: This invention, by integrating a semi-full tab design, improves electrolyte wettability while maintaining low internal resistance and simplifies the assembly process. The tilted negative tab and overlapping positive tab design significantly shorten the current path, maintain the low internal resistance characteristics of the full tab design, and reduce battery filling time and electrode liquid absorption time. This solution simplifies welding steps, eliminates multiple laser welding methods, reduces process complexity and defect rate, and lowers equipment costs. This invention provides a highly compatible solution for power tools, large-capacity energy storage, and other applications, driving the development of cylindrical batteries towards low cost and high performance. Attached Figure Description

[0017] Figure 1 : A schematic diagram of the negative electrode sheet of this utility model.

[0018] Figure 2 : A schematic diagram of the structure of the positive electrode sheet of this utility model.

[0019] In the diagram: 1-Negative electrode, 2-Positive electrode, 3-Middle negative electrode tab area, 4-Both negative electrode tab areas, 5-Slanted spaced negative electrode tabs, 6-Middle positive electrode tab area, 7-Both positive electrode tab areas, 8-Spaced positive electrode tabs, 9-Diagram spacing. Detailed Implementation

[0020] The present invention will be further described in detail below through specific embodiments. However, it should not be construed as the scope of the present invention being limited to the following embodiments. All technologies implemented based on the present invention fall within the scope of the present invention.

[0021] In the description of this utility model, it should also be noted that: The technical solution of this utility model will be further described in detail below with reference to specific embodiments: This utility model provides a semi-full-tab cylindrical battery, comprising: a negative electrode 1 and a positive electrode 2, wherein the negative electrode 1 and the positive electrode 2 are wound into a cylindrical battery; like Figure 1 As shown, the negative electrode plate 1 has a negative electrode tab area on its side, which is divided into a middle negative electrode tab area 3 and two negative electrode tab areas 4 at both ends; the middle negative electrode tab area 3 is a tilted and spaced negative electrode tab 5.

[0022] like Figure 2 As shown, the positive electrode plate 2 has a positive electrode tab region on its side. The positive electrode tab region is divided into a middle positive electrode tab region 6 and two end positive electrode tab regions 7. The middle positive electrode tab region 6 consists of spaced positive electrodes 8 that gradually increase in distance from one end to the other end. When the positive electrode plate 2 is wound into a cylinder, each spaced positive electrode tab 8 overlaps at the same position.

[0023] When the positive electrode is wound, it starts from the end with the smaller spacing and moves towards the end with the larger spacing. The spacing gradually increases from one end to the other so that the positive electrode tabs of the inner and outer rings can overlap.

[0024] The negative electrode tabs at both ends are continuous metal foils with a height less than that of the inclined negative electrode tabs; the positive electrode tabs at both ends are continuous metal foils with a height less than that of the inclined positive electrode tabs.

[0025] The negative electrode tabs at both ends 4 are continuous metal foils with a height less than the inclined negative electrode tabs 5; the positive electrode tabs at both ends 7 are continuous metal foils with a height less than the inclined positive electrode tabs 8.

[0026] The tilt angle of the tilted negative electrode tab 5 is 65~75°; preferably 70°.

[0027] The tab spacing 9 between adjacent inclined negative tabs 5 is the same, ranging from 0.4 to 0.6 mm. The spacing between the negative tabs has a certain impact on the electrolyte absorption of the electrode. If the tab spacing 9 is too small, the electrolyte penetration will be poor, affecting the battery cycle performance.

[0028] The height of the inclined negative electrode tab 5 is 3~6mm, and the height of the negative electrode tab area 4 at both ends is 0.5~1.5mm; the height of the inclined positive electrode tab 8 is 3~6mm, and the height of the positive electrode tab area 7 at both ends is 0.5~1.5mm.

[0029] The number of positive electrode tabs 8 is 6 to 30.

[0030] The tilted negative electrode tab 5 and the tilted positive electrode tab 8 can be formed by laser cutting.

[0031] When the negative electrode sheet 1 is wound into a cylinder, the inclined interval negative electrode tabs 5 in the central negative electrode tab area 3 are pressed inward in sequence and welded to the current collector plate by laser welding, and the current collector plate and the bottom of the steel shell are welded together by ultrasonic welding.

[0032] When the positive electrode sheet 2 is wound into a cylinder, the positive electrode tabs 8 stacked at the same position are welded together, pressed inward, and welded to the cap tab of the battery. After roller grooving, short circuit testing, baking, liquid injection, and sealing, the battery is completed.

[0033] It also includes a diaphragm, which has a ceramic layer coated on at least one side, with a thickness of 10~15μm on one side; the ceramic diaphragm synergistically promotes uniform wetting of the electrolyte.

[0034] When the negative electrode 1 and the positive electrode 2 are wound into a cylindrical battery, the separator is wound 1.4 to 1.6 turns first, then the negative electrode 1 is placed in and wound 1.1 to 1.3 turns, and then the positive electrode 2 is placed in and wound. During the winding, there is only one positive electrode tab 8 in each turn.

[0035] Example 1 The above scheme is adopted, wherein the tilt angle of the tilted negative electrode tab 5 is 70°; the electrode tab spacing 9 between adjacent tilted negative electrode tabs 5 is 0.5mm; the height of the tilted negative electrode tab 5 is 4.5mm, and the height of the negative electrode tab area 4 at both ends is 1mm; the height of the interval positive electrode tab 8 is 4.5mm, and the height of the positive electrode tab area 7 at both ends is 1mm, and a total of 7 positive electrodes are provided.

[0036] The separator is coated with 12μm thick ceramic on one side; the separator is first rolled 1.5 times, then the negative electrode sheet is rolled 1.2 times, and the positive electrode sheet is rolled 2 times. The negative electrode is then laser-welded to the current collector, and ultrasonic welding is used to weld the current collector to the bottom of the steel shell. The positive electrode tabs are welded together using ultrasonic welding, and then the cap tabs are welded together with the cell tabs. After rolling, short-circuit testing, baking, liquid injection, and sealing, the battery is completed.

[0037] Comparative Example 1 The scheme of this comparative example is basically the same as that of Example 1, except that the distance 9 between adjacent inclined negative electrode tabs 5 is 0.1 mm.

[0038] Comparative Example 2 The scheme of this comparative example is basically the same as that of Example 1, except that the distance 9 between adjacent inclined negative electrode tabs 5 is 1 mm.

[0039] Comparative Example 3 The scheme of this comparative example is basically the same as that of Example 1, except that there are a total of 4 positive electrode tabs.

[0040] Comparative Example 4 We tested existing batteries with flattened positive and negative electrodes using a full-tab process.

[0041] Comparative Example 5 We tested existing batteries with lap-cut positive and negative electrodes using a full tab process.

[0042] The test results are shown in Table 1.

[0043] Table 1

[0044] The above examples show that the spacing between the negative electrode tabs has a certain impact on the electrolyte absorption of the electrode. If the tab spacing is too small, the electrolyte penetration will be poor, which will affect the battery cycle performance. However, the tab spacing should not be too large, as it will significantly increase the DCR and weaken the advantage of low internal resistance. The fewer the positive electrode tabs, the greater the battery's internal resistance, and the higher the temperature that the tabs will withstand. Although a large number of positive electrode tabs has little impact on product performance, it will affect welding and subsequent processes, thus affecting production efficiency.

[0045] The solution of this utility model can achieve lower internal resistance, shorter electrode liquid injection time, better liquid absorption, and better battery cycle performance.

[0046] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the present utility model's technical solution and based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model's technical solution.

Claims

1. A semi-full-tab cylindrical battery, characterized in that, include: A negative electrode and a positive electrode, wherein the negative electrode and the positive electrode are wound into a cylindrical battery; The negative electrode sheet has a negative electrode tab area on its side, which is divided into a middle negative electrode tab area and two end negative electrode tab areas; the middle negative electrode tab area is an inclined spaced negative electrode tab. The positive electrode sheet has a positive electrode tab area on its side, which is divided into a middle positive electrode tab area and two end positive electrode tab areas. The middle positive electrode tab area consists of spaced positive electrodes that gradually increase in distance from one end to the other. When the positive electrode sheet is wound into a cylinder, each spaced positive electrode tab overlaps at the same position.

2. A semi-full-tab cylindrical battery according to claim 1, characterized in that: The negative electrode tabs at both ends are continuous metal foils with a height less than that of the inclined negative electrode tabs; the positive electrode tabs at both ends are continuous metal foils with a height less than that of the inclined positive electrode tabs.

3. A semi-full-tab cylindrical battery according to claim 1, characterized in that: The tilt angle of the tilted negative electrode tab is 65~75°.

4. A semi-full-tab cylindrical battery according to claim 1, characterized in that: The distance between adjacent tilted negative electrodes is the same, ranging from 0.4 to 0.6 mm.

5. A semi-full-tab cylindrical battery according to claim 1, characterized in that: The height of the inclined negative electrode tab is 3~6mm, and the height of the negative electrode tab area at both ends is 0.5~1.5mm; the height of the inclined positive electrode tab is 3~6mm, and the height of the positive electrode tab area at both ends is 0.5~1.5mm.

6. A semi-full-tab cylindrical battery according to claim 1, characterized in that: The number of positive electrode loops is 6 to 30.

7. A semi-full-tab cylindrical battery according to claim 1, characterized in that: When the negative electrode sheet is wound into a cylinder, the inclined spaced negative electrode tabs in the middle negative electrode tab area are pressed inward in sequence and welded to the current collector.

8. A semi-full-tab cylindrical battery according to claim 1, characterized in that: When the positive electrode sheet is wound into a cylinder, the positive electrode tabs stacked at the same position are welded together, pressed inward, and welded to the cap tab of the battery.

9. A semi-full-tab cylindrical battery according to claim 1, characterized in that: It also includes a diaphragm, wherein at least one side of the diaphragm is coated with a ceramic layer, and the thickness of the ceramic layer on one side is 10~15μm.

10. A semi-full-tab cylindrical battery according to claim 9, characterized in that: When the negative electrode and positive electrode are wound into a cylindrical battery, the separator is first wound 1.4 to 1.6 turns, then the negative electrode is placed in and wound 1.1 to 1.3 turns, and then the positive electrode is placed in and wound. During the winding, there is only one positive electrode tab per turn.

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