Novel battery negative plate structure and cylindrical battery
By setting a parallel structure with blank copper foil in the negative electrode structure of lithium-ion batteries, the problems of high temperature rise and poor safety performance of lithium-ion batteries at high discharge rates are solved, and the battery performance of high energy density and high safety is improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2026-03-10
AI Technical Summary
Existing lithium-ion batteries exhibit high temperature rise and poor safety performance during high-rate discharge, failing to simultaneously meet the demands for high safety performance and high energy density.
A novel battery negative electrode structure is adopted, which separates the positive electrode material area and the negative electrode material area through a separator. Copper foil is coated and left blank in the width direction of the first and second tabs of the negative electrode to form a parallel structure, so as to achieve close contact with the bottom of the battery steel shell, avoid laser welding and flattening process, and reduce internal resistance.
It achieves a significant reduction in temperature rise during high-rate discharge, reduces battery resistance by at least 50%, improves safety performance and high energy density, and meets the endurance requirements of power tools.
Smart Images
Figure CN223986574U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a novel battery negative electrode structure and a cylindrical battery. Background Technology
[0002] With the development of lithium-ion batteries, they have become the most important component in the range requirements of power tools. Existing lithium-ion batteries have high temperature rise and poor safety performance when discharged at high rates. In order to solve the problem that existing lithium-ion battery materials cannot simultaneously meet the requirements of high safety performance, high energy density and high rate, this utility model is proposed. Utility Model Content
[0003] One objective of this invention is to provide a novel battery negative electrode structure.
[0004] To solve the above technical problems, the following technical solution is adopted:
[0005] A novel battery negative electrode structure includes a positive electrode material region and a negative electrode material region separated by a separator. The positive electrode material region is connected to a positive electrode tab one and a positive electrode tab two, and the negative electrode material region is connected to a negative electrode tab one and a negative electrode tab two. Copper foil is coated in the width direction of the negative electrode tab one and the negative electrode tab two, leaving a blank area.
[0006] Preferably, the ratio of the length A of the separator to the length B of the negative electrode material region is 1:1.
[0007] Furthermore, the ratio of the distance C from the upper end of the negative electrode material region to the upper edge of the separator to the width A of the separator is (0.5-1):66.
[0008] Preferably, the ratio of the distance D from the upper end of the positive electrode material area to the upper edge of the negative electrode material area to the width A of the separator is 1:66.
[0009] Furthermore, the ratio of the width E of the positive electrode material region to the width A of the separator is 62:66.
[0010] Preferably, the resistance-welded negative electrode tab one and negative electrode tab two are stacked with copper foil, leaving a gap for close contact with the bottom steel shell.
[0011] Another objective of this invention is to provide a cylindrical battery.
[0012] To solve the above technical problems, the following technical solution is adopted:
[0013] A cylindrical battery includes the aforementioned novel battery negative electrode structure.
[0014] Beneficial technical effects:
[0015] This invention features a negative electrode tab one and a negative electrode tab two with copper foil coated in the width direction, leaving a blank space inside. The internal structure is parallel, and the blank copper foil effectively contacts the bottom of the battery steel shell over a large area. This achieves the same internal resistance effect as the negative electrode tab structure without the need for flattening and laser welding processes. Compared with the traditional structure, it reduces the battery resistance by at least 50%, and greatly reduces the temperature rise during high-rate discharge. Attached Figure Description
[0016] The present invention will be further described below with reference to the accompanying drawings.
[0017] Figure 1 This is a schematic diagram of the winding and wrapping position of the negative electrode sheet structure of the battery of this utility model.
[0018] Figure 2 This is a schematic diagram of the core of the negative electrode structure of the battery of this utility model.
[0019] Figure 3 This is a schematic diagram comparing the internal resistance data in Example 2.
[0020] In the diagram, 1. Positive electrode tab one; 2. Positive electrode tab two; 3. Negative electrode tab one; 4. Negative electrode tab two; 5. Separator; 6. Negative electrode material area; 7. Positive electrode material area. Detailed Implementation
[0021] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.
[0022] Example 1
[0023] Reference Figure 1-2 As shown, a novel battery negative electrode structure includes a positive electrode region 7 and a negative electrode region 6 separated by a separator 5. The positive electrode region 7 is connected to a positive electrode tab 1 and a positive electrode tab 2, and the negative electrode region 6 is connected to a negative electrode tab 3 and a negative electrode tab 4. Copper foil is coated in the width direction of the negative electrode tabs 3 and 4, leaving a blank space 8.
[0024] The ratio of the length A of the separator 5 to the length B of the negative electrode material region 6 is 1:1.
[0025] The ratio of the distance C from the upper end of the negative electrode material region 6 to the upper edge of the separator 5 to the width A of the separator 5 is (0.5-1):66.
[0026] The ratio of the distance D from the upper end of the positive electrode region 7 to the upper edge of the negative electrode region 6 to the width A of the separator 5 is 1:66.
[0027] The ratio of the width E of the positive electrode material region 7 to the width A of the separator 5 is 62:66.
[0028] Positive electrode tab 1, positive electrode tab 2, negative electrode tab 3, negative electrode tab 4, and the copper foil coating with blank space 8 serve to conduct electricity and guide current.
[0029] The entire internal area of the negative electrode tab 1 (3), negative electrode tab 2 (4), and the blank area of the copper foil (8) is connected in parallel, which is equivalent to the negative electrode full tab structure.
[0030] Resistance-welded negative electrode tab 1 3, negative electrode tab 2 4, copper foil stacked with blank space 8, in close contact with the bottom steel shell.
[0031] Example 2
[0032] A cylindrical battery includes the novel battery negative electrode structure described in Example 1, and the cylindrical battery is subjected to performance testing.
[0033] Comparative Example 1 is a negative full-tab battery, which refers to a battery with the negative copper foil left blank and the current collector laser-welded, and then resistively welded or laser-welded to the bottom of the steel shell.
[0034] Comparative Example 2 is a conventional structure battery, which refers to a battery with only negative electrode tabs at both ends of the negative electrode plate and a bottom steel shell resistively welded together. In Comparative Example 2, there is no copper foil left at the bottom of the negative electrode plate.
[0035] The internal resistance data of the negative omnipolar battery of Comparative Example 1, the conventional structure battery of Comparative Example 2, and the battery described in Example 1 were compared through performance testing. The test results are as follows: Figure 3 As shown, by Figure 3 It is evident that the high-energy-density cylindrical lithium battery of this invention possesses superior high-rate performance and high safety. By employing hot-melt adhesive bonding, rather than bottom-welding as in existing technologies, the negative electrode tabs of this invention achieve the same internal resistance as the original negative electrode tab structure without requiring flattening or laser welding processes. This reduces battery resistance by at least 50% compared to traditional structures, and significantly lowers the temperature rise during high-rate discharge. Furthermore, the battery described in Example 1 passed 100% of the safety tests for heavy object impact, short circuit, and overcharge.
[0036] The embodiment and comparative test method of this utility model compare the performance of lithium batteries. Through the improvement of the negative electrode structure, it can not only meet the requirements of high energy density performance, but also effectively reduce the temperature rise of the battery during high-rate discharge, ensuring the endurance requirements of power tools, and improve the advantages of high-rate operation and high safety, thus providing a new direction for the development of lithium-ion batteries.
[0037] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A novel battery negative electrode sheet structure, characterized by, The battery negative plate structure comprises a positive material area (7) and a negative material area (6) separated by a diaphragm (5), the positive material area (7) is connected with a positive tab (1) and a positive tab (2), the negative material area (6) is connected with a negative tab (3) and a negative tab (4), and the width direction of the negative tab (3) and the negative tab (4) is coated with a copper foil blank (8).
2. The novel battery negative electrode sheet structure according to claim 1, characterized by, The ratio of the length A of the diaphragm (5) to the length B of the negative material area (6) is 1:
1.
3. The novel battery negative electrode sheet structure according to claim 2, characterized by, The ratio of the distance C from the upper end of the negative material area (6) to the upper edge of the diaphragm (5) to the width A of the diaphragm (5) is (0.5-1):
66.
4. The novel battery negative electrode sheet structure according to claim 3, characterized by, The ratio of the distance D from the upper end of the positive material area (7) to the upper edge of the negative material area (6) to the width A of the diaphragm (5) is 1:
66.
5. The novel battery negative electrode sheet structure according to claim 1, characterized by, The ratio of the width E of the positive material area (7) to the width A of the diaphragm (5) is 62:
66.
6. A cylindrical battery, characterized by The battery negative plate structure comprises a positive material area (7) and a negative material area (6) separated by a diaphragm (5), the positive material area (7) is connected with a positive tab (1) and a positive tab (2), the negative material area (6) is connected with a negative tab (3) and a negative tab (4), and the width direction of the negative tab (3) and the negative tab (4) is coated with a copper foil blank (8).