Lithium battery electrode plate, battery cell and cylindrical lithium battery
By setting the head, tail, and microporous structures on the electrode tab body, the electrode design is optimized, solving the problems of increased battery thickness, poor heat dissipation, and long immersion time, thereby improving battery safety and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-08
- Publication Date
- 2026-03-10
AI Technical Summary
The flat tab design of traditional cylindrical lithium batteries leads to increased thickness at both ends of the cell, poor heat dissipation, and poor gas expulsion, which affects battery safety and cycle life. At the same time, the longer immersion time affects the initial performance and efficiency of the battery.
A tab head and a tab tail are provided on the tab body of the electrode sheet, and multiple micropores are provided in between. A rounded corner is provided between the tab head and the tab tail to optimize the structural design of the electrode sheet.
The microporous structure improves the battery's permeability, reduces the risk of gas expansion during thermal runaway, enhances battery safety, accelerates electrolyte wetting efficiency, shortens the formation cycle, improves production efficiency, and reduces costs.
Smart Images
Figure CN223986572U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cylindrical lithium battery technology, specifically to a lithium battery electrode sheet, a battery cell, and a cylindrical lithium battery. Background Technology
[0002] Currently, large cylindrical battery cells generally adopt a full-tab structure design to improve rate performance, reduce internal resistance, and minimize heat generation. Traditional large cylindrical lithium batteries often use a flat tab design. During the flattening process, the stacking of multiple foils in this flat tab design can increase the thickness at both ends of the cell, increasing not only the battery's size and weight but also potentially affecting thermal management performance. Furthermore, flat tabs result in poor heat dissipation during charging and discharging and may hinder gas escape, thus affecting battery safety and cycle life. Additionally, the longer immersion time of flat tabs affects the battery's initial performance and efficiency. Utility Model Content
[0003] In view of the technical problem that poor heat dissipation in the cell structure of the prior art affects the safety and cycle life of the battery, this utility model provides a lithium battery electrode sheet, cell and cylindrical lithium battery, which improves the wetting efficiency and safety of the battery.
[0004] This utility model provides a lithium battery electrode sheet, with a tab body provided on one side along the width direction of the electrode sheet. The tab body is provided with a tab head, a tab portion and a tab tail in sequence along the length direction of the electrode sheet. The lengths of the tab head and the tab tail along the width direction of the electrode sheet are less than the lengths of the tab portion along the width direction of the electrode sheet. Multiple micropores are provided between the tab head and the tab tail, arranged along the length direction of the tab body.
[0005] Furthermore, a first rounded corner is provided between the head and the part of the electrode ear, and a second rounded corner is provided between the tail and the part of the electrode ear.
[0006] Furthermore, multiple micropores are evenly distributed between the end of the tab head facing the tab and the end of the tab tail facing the tab.
[0007] Furthermore, the first micropore facing the head of the electrode is located at the end of the head of the electrode facing the electrode, and the first micropore facing the tail of the electrode is located at the end of the tail of the electrode facing the electrode.
[0008] Furthermore, the diameter of the micropores is 0.02-2 mm; the gap between two adjacent micropores ranges from 1 to 5 mm.
[0009] Furthermore, the width of the tip of the electrode is equal to the width of the tail of the electrode.
[0010] Furthermore, the length of the electrode head is 200-500 mm; the length of the electrode tail is 300-500 mm; the width of the electrode head and electrode tail is 1-5 mm; and the distance between the electrode head and electrode tail is 4000-6000 mm.
[0011] Furthermore, the length of the tab head along the length of the electrode sheet is less than the length of the tab tail along the length of the electrode sheet.
[0012] This utility model also provides a battery cell, including a positive electrode and a negative electrode. The positive electrode and the negative electrode are lithium battery electrode plates as described above. The positive electrode, the negative electrode, and the separator between the positive electrode and the negative electrode are stacked and wound to form a core. The two ends of the core are flattened to form a flattened area.
[0013] This utility model also provides a cylindrical lithium battery, including a cell as described above.
[0014] The beneficial effects of this utility model are as follows:
[0015] In this invention, micropores are provided in the electrode tab body of the electrode sheet, and electrode tab head and electrode tab tail structures are provided at the front and rear ends of the electrode sheet respectively. The two structures work together, which not only greatly beautifies the appearance of the battery after it is flattened, but also substantially optimizes the internal structural layout of the battery.
[0016] In this invention, the microporous structure can effectively increase the permeability at both ends of the battery cell, which can effectively reduce the gas expansion problem that may occur when the battery experiences thermal runaway, reduce the risk caused by overheating, and thus improve the safety of the battery.
[0017] In this invention, the microporous structure allows the electrolyte to penetrate the electrode surface more easily, improving the battery's wetting efficiency and thus accelerating the formation process. The faster wetting time can reduce the overall formation cycle, thereby improving production efficiency and reducing production costs. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the structure of one embodiment of the present utility model;
[0020] Figure 2 This table compares the pressure relief capacity and wetting time of Examples 1-3 and Comparative Example 1.
[0021] Figure 3 This is a comparison table of the pressure relief capacity and wetting time of Examples 1, 4-6, and Comparative Example 1;
[0022] Explanation of main reference numerals in the attached drawings: 11-Electrode body, 12-Electrode plate body, 2-Micropore, 3-Electrode head, 4-Electrode tail, 5-Electrode part, 61-First rounded corner, 62-Second rounded corner. Detailed Implementation
[0023] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort should fall within the protection scope of this utility model.
[0024] like Figure 1 As shown, one embodiment of this utility model provides a lithium battery electrode sheet. An electrode body 11 is provided on one side along the width direction of the electrode sheet, and the part of the electrode body 11 facing the other side of the electrode sheet is an electrode body 12. The side of the electrode body 12 facing the electrode body 11 is parallel to the length direction of the electrode body 12. The electrode body 11 is provided with a tab head 3, a tab portion 5 and a tab tail 4 in sequence along the length direction of the electrode sheet. The lengths of the tab head 3 and the tab tail 4 along the width direction of the electrode sheet are less than the lengths of the tab portion 5 along the width direction of the electrode sheet. A plurality of micropores 2 are arranged along the length direction of the electrode body 11 between the tab head 3 and the tab tail 4. The plurality of micropores 2 are evenly arranged between the end of the tab head 3 facing the tab portion 5 and the end of the tab tail 4 facing the tab portion 5. The first micropore 2 facing the tab head 3 is located at the end of the tab head 3 facing the tab portion 5, and the first micropore 2 facing the tab tail 4 is located at the end of the tab tail 4 facing the tab portion 5.
[0025] A first rounded corner 61 is provided between the electrode head 3 and the electrode portion 5, and a second rounded corner 62 is provided between the electrode tail 4 and the electrode portion 5. The fabrication of the micropore 2, the electrode head 3, the electrode tail 4, and the first rounded corner 61 and the second rounded corner 62 includes the following steps:
[0026] Step S1: Produce the positive and negative electrode sheets after rolling. The production methods of the negative and positive electrode sheets are basically the same.
[0027] In step S2, the positive and negative electrode sheets are cut from one edge towards the center to form the tab head 3. Then, the bottom micro-hole 2 of the tab 5 is cut into the positive electrode sheet, and the tab tail 4 is cut into the positive and negative electrode sheets. The heights of the tab head 3 and the tab tail 4 are the same, and the micro-hole 2 is positioned at the tail end of the tab head 3 and the front end of the tab tail 4.
[0028] Step S3: After the positive electrode sheet, negative electrode sheet and separator are cut, they are stacked and wound to form a core. Then, the two ends of the core are flattened to form a flattened area.
[0029] The length of the tab head 3 is shorter than the length of the tab tail 4. The micropores 2 are cut starting from the rear end of the tab head 3, and there is a distance between the micropores 2 and the bottom of the tab 5. The edges of the tab 5 and the tab head 3 are chamfered, and the edges of the tab 5 and the tab tail 4 are also chamfered. Multiple micropores 2 are arranged along the length of the electrode body 11 between the tab head 3 and the tab tail 4. The multiple micropores 2 are evenly distributed between the end of the tab head 3 facing the tab 5 and the end of the tab tail 4 facing the tab 5. The positive electrode, negative electrode, and the separator between the positive and negative electrode are stacked and wound to form a core. The two ends of the core are flattened to form a flattened area, forming a battery cell, which is then made into a lithium battery. After flattening, the thickness at both ends of the battery cell is reduced, which fundamentally solves the problem of high pressure relief and excessive electrolyte wetting time caused by the thickness at both ends of the battery cell.
[0030] The diameter of the micropore 2 is 0.02-2 mm; the gap between the micropores 2 is 1-5 mm; the length of the tab head 3 is 200-500 mm; the length of the tab tail 4 is 300-500 mm; the width of the tab head 3 and the tab tail 4 is 1-5 mm; the distance between the tab head 3 and the tab tail 4 is 4000-6000 mm; and the length of the tab head 3 along the length of the electrode sheet is less than the length of the tab tail 4 along the length of the electrode sheet.
[0031] In other embodiments of this utility model, the micropores 2 are not uniformly arranged between the end of the tab head 3 facing the tab 5 and the end of the tab tail 4 facing the tab 5. For example, along the direction from the tab head 3 to the tab tail 4, the distance between the micropores 2 gradually increases or gradually decreases.
[0032] In Example 1, after rolling, the electrode sheet is laser-diced to cut circular micro-holes 2 at the bottom of the tab. The size of the micro-holes 2 is 0.05 mm, and the gap between the micro-holes 2 is 1 mm. The length of the tab head 3 is 300 mm, and the height is 3 mm; the length of the tab tail 4 is 400 mm, and the distance between the tab head 3 and the tab tail 4 is set to 4500 mm. After winding and flattening, the thickness at both ends of the cell is controlled to be 0.8 mm. Then, the battery is manufactured according to the battery manufacturing process, and the battery pressure relief capacity and electrolyte wetting time are tested.
[0033] In Example 2, after rolling, the electrode sheet is laser-divided to cut circular micro-holes 2 at the bottom of the electrode tab. The size of the micro-holes 2 is 1 mm, and the gap between the micro-holes 2 is 1 mm. The length of the electrode tab head 3 is 300 mm and the height is 3 mm; the length of the electrode tab tail 4 is 400 mm, and the distance between the electrode tab head 3 and the electrode tab tail 4 is set to 4500 mm. After winding and flattening, the thickness at both ends of the cell is controlled to be 0.8 mm. Then, the battery is manufactured according to the battery manufacturing process, and the battery pressure relief capacity and electrolyte wetting time are tested.
[0034] In Example 3, after rolling, the electrode sheet is laser-divided to cut circular micro-holes 2 at the bottom of the tab. The size of the micro-holes 2 is 1.5 mm, and the gap between the micro-holes 2 is 1 mm. The length of the tab head 3 is 300 mm and the height is 3 mm; the length of the tab tail 4 is 400 mm, and the distance between the tab head 3 and the tab tail 4 is set to 4500 mm. After winding and flattening, the thickness at both ends of the cell is controlled to be 0.8 mm. Then, the battery is manufactured according to the battery manufacturing process, and the battery pressure relief capacity and electrolyte wetting time are tested.
[0035] In Example 4, after rolling, the electrode sheet is laser-diced to cut circular micro-holes 2 at the bottom of the electrode tab. The size of the micro-holes 2 is 1 mm, and the gap between the micro-holes 2 is 1.5 mm. The length of the electrode tab head 3 is 300 mm and the height is 3 mm; the length of the electrode tab tail 4 is 400 mm, and the distance between the electrode tab head 3 and the electrode tab tail 4 is set to 4500 mm. After winding and flattening, the thickness at both ends of the cell is controlled to be 0.8 mm. Then, the battery is manufactured according to the battery manufacturing process, and the battery pressure relief capacity and electrolyte wetting time are tested.
[0036] In Example 5, after rolling, circular micro-holes 2, each 1 mm in size, are cut into the bottom of the electrode tab using laser die-cutting, with a gap of 2 mm between the micro-holes 2. The head 3 of the electrode tab is 300 mm long and 3 mm high; the tail 4 of the electrode tab is 400 mm long, and the distance between the head 3 and the tail 4 is set to 4500 mm. After winding and flattening, the thickness at both ends of the cell is controlled to be 0.8 mm. Then, the battery is manufactured according to the battery manufacturing process, and the battery's pressure relief capacity and electrolyte wetting time are tested.
[0037] In Example 6, after rolling, circular micro-holes 2 are cut into the bottom of the electrode tab using laser die-cutting. The size of the micro-holes 2 is 1 mm, and the gap between the micro-holes 2 is 2.5 mm. The length of the electrode head 3 is 300 mm and the height is 3 mm; the length of the electrode tail 4 is 400 mm, and the distance between the electrode head 3 and the electrode tail 4 is set to 4500 mm. After winding and flattening, the thickness at both ends of the cell is controlled to be 0.8 mm. Then, the battery is manufactured according to the battery manufacturing process, and the battery pressure relief capacity and electrolyte wetting time are tested.
[0038] Comparative Example 1: The electrode sheet after roll forming is cut into a common full tab shape by laser die cutting. The tab size is the same as in the example. After winding and flattening, the thickness at both ends of the cell is controlled to be 0.8 mm. The cell is made into a complete battery according to the battery manufacturing process. The pressure relief capacity at both ends of the battery and the electrolyte wetting time are tested.
[0039] Test data for the examples and comparative examples are as follows: Figure 2 and Figure 3 As shown, from Figure 2 It can be seen that as the diameter of the circular micropores increases, the battery's pressure relief decreases and the electrolyte wetting time shortens; from Figure 3 It can be seen that as the gap between the micropores 2 increases, the battery pressure relief strength increases and the electrolyte wetting time increases. However, the embodiment with the largest gap between the micropores 2 has a lower pressure relief strength and electrolyte wetting time than the battery without micropores 2.
[0040] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the present invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be included within the protection scope of the present invention.
Claims
1. A lithium battery electrode sheet, characterized by, The tab head and the tab tail are provided with a first round corner between the tab head and the tab, and a second round corner between the tab and the tab tail.
2. A lithium battery electrode sheet as claimed in claim 1, wherein, The plurality of micro-holes are evenly arranged between the end of the tab head facing the tab and the end of the tab tail facing the tab.
3. A lithium battery electrode sheet as claimed in claim 1, wherein, The first micro-hole in the direction of the tab head is arranged at the end of the tab head facing the tab, and the first micro-hole in the direction of the tab tail is arranged at the end of the tab tail facing the tab.
4. A lithium battery electrode sheet as claimed in claim 3, wherein the lithium battery electrode sheet is a lithium battery cathode sheet. The diameter of the micro-hole is 0.02-2mm, and the gap between the adjacent two micro-holes is 1-5mm.
5. A lithium battery electrode sheet as claimed in claim 1, wherein the lithium battery electrode sheet is a lithium battery cathode sheet. The width of the tab head is equal to the width of the tab tail.
6. A lithium battery electrode sheet as claimed in claim 1, wherein, The length of the tab head is 200-500mm, the length of the tab tail is 300-500mm, the width of the tab head and the tab tail is 1-5mm, and the distance between the tab head and the tab tail is 4000-6000mm.
7. A lithium battery electrode sheet as claimed in claim 1, wherein, The length of the tab head along the length direction of the tab is less than the length of the tab tail along the length direction of the tab.
8. A lithium battery electrode sheet as claimed in claim 1, wherein, The positive electrode tab and the negative electrode tab are a lithium battery electrode tab as claimed in any one of claims 1-8, and the positive electrode tab, the negative electrode tab, and the separator between the positive electrode tab and the negative electrode tab are stacked and wound to form a roll core, and the ends of the roll core are flattened to form a flattened area.
9. An electric cell characterized by The electric core comprises the electric core as claimed in claim 9.
10. A cylindrical lithium battery, characterized by,