Pole piece and battery cell
By designing a gradually increasing tab structure and optimizing the tab arrangement, the problem of incomplete tab welding in lithium batteries was solved, improving the cell's overcurrent capacity and reducing internal resistance and temperature rise.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGXI GANFENG BATTERY TECH
- Filing Date
- 2025-05-28
- Publication Date
- 2026-06-02
AI Technical Summary
The existing lithium battery tabs have problems with incomplete or impossible welding after increasing the number of layers, especially under high-rate fast charging conditions, which leads to insufficient overcurrent capacity and increased cell internal resistance.
Design an electrode structure in which the length of the electrode tabs gradually changes according to the arrangement order, the newly added electrode tabs are aligned with the original electrode tabs at the convergence point, the gradual height is achieved by laser die-cutting process to ensure complete electrode tab welding, and the arrangement of the electrode tab group is optimized by winding.
This achieves complete electrode tab welding, increases current carrying capacity, reduces cell internal resistance and temperature rise, and improves cell performance.
Smart Images
Figure CN224318466U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lithium-ion batteries, and in particular to an electrode and a battery cell. Background Technology
[0002] Fast charging has become a key demand in the automotive industry, and high-rate fast charging places higher demands on the current handling capacity of battery cells. The thickness of the tabs in a bare lithium-ion battery cell is typically only 5µm-12µm. To increase current handling capacity, the number of tab layers must be increased. However, if the added tabs are at the same height as the original tabs, the length of the added tabs after being gathered increases progressively with the step between them and the adjacent original tabs. Therefore, during welding, if the height of the added tabs does not cover the solder joint area after being gathered, the tabs may not be completely welded during ultrasonic welding, or even fail to weld at all.
[0003] To address this issue, we propose a new electrode and battery cell design to solve the welding problem of increasing the electrode tabs. Utility Model Content
[0004] The purpose of this utility model is to overcome the shortcomings of the existing technology. To achieve the above objective, this utility model adopts the following technical solution:
[0005] An electrode includes an electrode body. A plurality of monopole tabs and at least one booster tab are connected to one edge along the length direction of the electrode body. The monopole tabs are arranged at intervals, with each booster tab located between adjacent monopole tabs. The length from the connection end of each monopole tab to the free end away from the electrode body is the same. The lengths from the connection end of each booster tab to the free end away from the electrode body gradually increase or decrease according to the arrangement order.
[0006] More preferably, the single electrode tabs overlap and converge to form an electrode tab group after the electrode body is wound and formed. The electrode tab group is located on one side of the horizontal center line along the thickness direction of the electrode body after winding and forming. The electrode tab group overlaps with the electrode booster tab after winding and forming, and the electrode booster tab is located on the opposite side of the electrode tab group. After the electrode booster tab and the electrode tab group converge, the free ends of the electrode booster tab are flush.
[0007] More preferably, the free end of the augmented ear after convergence is flush with the free end of the adjacent monopole ear.
[0008] A battery cell, characterized in that it comprises an electrode and a separator as described above, wherein the electrode comprises a positive electrode and a negative electrode, the polarity of the positive electrode and the polarity of the negative electrode are opposite, the separator is disposed between the positive electrode and the negative electrode, and the positive electrode, the negative electrode and the separator are wound together.
[0009] More preferably, all the tabs on the positive or negative electrode sheet are located in the same longitudinal or transverse direction of the cell after the core is formed.
[0010] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0011] This invention uses a gradually increasing height tab to align the new tab with the original tab at its shortest point, thus enabling complete ultrasonic welding of the tab. Furthermore, by increasing the height of the tab, this invention not only increases the current carrying capacity but also effectively reduces the cell's internal resistance and temperature rise. Attached Figure Description
[0012] Figure 1 This is a planar view of the unfolded electrode sheet;
[0013] Figure 2 This is a schematic diagram of the electrode after winding;
[0014] Figure 3 This is a side view of the electrode after it has been wound.
[0015] Figure 4 This is a schematic diagram of the battery cell structure.
[0016] In the diagram: 1. Electrode body; 2. Monopolar tab; 3. Auger tab. Detailed Implementation
[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0018] Reference Figures 1-3 An electrode includes an electrode body 1. A plurality of monopole tabs 2 and at least one booster tab 3 are connected to one edge along the length direction of the electrode body 1. The monopole tabs are arranged at intervals, with each booster tab 3 located between adjacent monopole tabs 2. The length from the connection end of each monopole tab 2 to the free end away from the electrode body 1 is the same. The lengths of each booster tab 3 from the connection end to the free end away from the electrode body 1 gradually increase or decrease according to the arrangement order.
[0019] In the examples: such as Figure 1As shown, several monopole tabs 2 are arranged at intervals along the length of the electrode body 1. The spacing between adjacent monopole tabs 2 gradually increases or decreases according to the arrangement order. Newly added booster tabs 3 are arranged at intervals between adjacent monopole tabs 2. The length of booster tabs 3 gradually increases or decreases according to the arrangement order. The spacing between adjacent monopole tabs 2 is in the same direction as the increase or decrease of the length of booster tabs 3. For example, if the spacing between adjacent monopole tabs 2 gradually increases from left to right, the length of booster tabs 3 also gradually increases.
[0020] The single electrode tabs 2 overlap and converge to form an electrode tab group after the electrode body 1 is wound and formed. The electrode tab group is located on one side of the horizontal center line along the thickness direction of the electrode body 1 after winding and forming. The electrode tab group overlaps with the electrode booster tab 3 after winding and forming, and the electrode booster tab 3 is located on the opposite side of the electrode tab group. After the electrode booster tab 3 and the electrode tab group converge, the free ends of the electrode booster tab 3 are flush. After convergence, the free ends of the electrode booster tab 3 are flush with the free ends of the adjacent single electrode tabs 2.
[0021] In this embodiment: When the electrode body 1 is wound, it is first wound from the end with the smaller spacing to the end with the larger spacing. After winding, the projections of the monopole tab 2 and the booster tab 3 in the horizontal direction coincide. The monopole tab 2 is located above the horizontal center line AA along the thickness direction of the electrode body 1, and the booster tab 3 is located below the horizontal center line AA along the thickness direction of the electrode body 1. Figure 2 As shown, all monopole ears 2 and booster ears 3 are overlapped and gathered together with the middle monopole ear 2 as the center, and the free end of the booster ear 3 after being gathered is flush with the free end of the adjacent monopole ear 2.
[0022] In this embodiment: By adding a new electrode booster 3 within the distance between the single electrodes 2, the purpose of creating a multi-electrode battery cell is achieved. The increasing or decreasing height of the electrode booster 3 is achieved through laser die-cutting, and the height of each electrode 4 is higher than the height H of the single electrode 2. The gradient height of the electrode booster 3 is H. n -H n-1 The gradient height is typically 0.1mm-1mm.
[0023] Based on the Pythagorean theorem for right triangles, calculate as follows: Figure 3 As shown:
[0024]
[0025] Where: a is the position of the electrode tab retracting; b is the distance between the tapered electrode tab and the retracting electrode piece; c1 is the length of the first tapered electrode tab from the retracting point; c2 is the length of the second tapered electrode tab from the retracting point; t is the spacing between adjacent electrode tabs.
[0026] A battery cell includes an electrode sheet and a separator as described above. The electrode sheet includes a positive electrode sheet and a negative electrode sheet, the polarity of the positive electrode sheet and the polarity of the negative electrode sheet being opposite. The separator is disposed between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the negative electrode sheet and the separator are wound together. All the tabs on the positive electrode sheet or the negative electrode sheet are located in the same longitudinal direction or the same transverse direction of the battery cell after the core is formed.
[0027] In the examples: such as Figure 4 As shown, the battery cell includes a separator, a positive electrode plate, and a negative electrode plate. The separator is located between the positive electrode plate and the negative electrode plate. The tabs on the positive electrode plate are called positive tabs, and the tabs on the negative electrode plate are called negative tabs. The positive electrode plate, the negative electrode plate, and the separator are wound together to form a battery cell. The positive tabs and the negative tabs are located on the same side of the battery cell.
[0028] In the embodiment: because the electrode plate has added a booster tab 3, the current near the booster tab 3 can be conducted through the booster tab 3, thereby shortening part of the current flow path, reducing the internal resistance of the cell, reducing the internal resistance, reducing the heat generation of the cell, and increasing the uniformity of the cell temperature rise.
[0029] The table below shows the test data for the battery cell before and after adding tab 3:
[0030]
[0031]
[0032] This invention uses a gradually increasing height tab to align the new tab with the original tab at its shortest point, thus enabling complete ultrasonic welding of the tab. Furthermore, by increasing the height of the tab, this invention not only increases the current carrying capacity but also effectively reduces the cell's internal resistance and temperature rise.
Claims
1. An electrode sheet, characterized in that, The electrode includes an electrode body, on one side edge of which are connected a plurality of monopole tabs and at least one booster tab. The monopole tabs are arranged at intervals, with each booster tab located between adjacent monopole tabs. The length from the connection end of each monopole tab to the free end away from the electrode body is the same. The lengths from the connection end of each booster tab to the free end away from the electrode body gradually increase or decrease according to the arrangement order.
2. The electrode sheet according to claim 1, characterized in that, The single electrode tabs overlap and converge to form an electrode tab group after the electrode body is wound and formed. The electrode tab group is located on one side of the horizontal center line along the thickness direction of the electrode body after winding and forming. The electrode tab group overlaps with the electrode booster tab after winding and forming, and the electrode booster tab is located on the opposite side of the electrode tab group. After the electrode booster tab and the electrode tab group converge, the free ends of the electrode booster tab are flush.
3. The electrode sheet according to claim 2, characterized in that, After being brought together, the free end of the augmented ear is flush with the free end of the adjacent monopole ear.
4. A battery cell, characterized in that, The device includes an electrode and a separator as described in any one of claims 1 to 3, wherein the electrode comprises a positive electrode and a negative electrode, the polarity of the positive electrode and the polarity of the negative electrode are opposite, the separator is disposed between the positive electrode and the negative electrode, and the positive electrode, the negative electrode and the separator are wound together.
5. A battery cell according to claim 4, characterized in that, All the tabs on the positive or negative electrode sheet are located in the same longitudinal or transverse direction of the cell after the core is formed.