Anti-wrinkling winding type battery cell assembly pole piece
By creating consistent holes on both the anode and cathode electrodes, the problem of electrode wrinkling during the assembly of wound cells was solved, simplifying the production process, maintaining battery performance, and improving electrolyte wetting efficiency and production capacity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-14
- Publication Date
- 2026-03-06
AI Technical Summary
In the existing wound cell assembly method, the anode sheet is prone to wrinkling during charging and discharging, which leads to increased overall battery manufacturing costs, increased complexity of the production process, and affected battery performance.
Consistent holes are made on the anode and cathode electrodes to release stress and alleviate electrode wrinkling. The holes also improve the electrolyte wetting effect and prevent electrode wrinkling.
It effectively alleviates the problem of electrode wrinkling, simplifies the production process, maintains the overall performance of the battery, and improves electrolyte wetting efficiency and battery production capacity.
Smart Images
Figure CN223978051U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of new energy battery technology, specifically to a wrinkle-resistant wound-type cell assembly electrode sheet. Background Technology
[0002] Lithium / sodium-ion battery cells are rechargeable cells that can be repeatedly charged and discharged. They are mainly composed of anode and cathode electrodes, separators, electrolytes, and mechanical components. Currently, there are two main assembly methods for prismatic or large pouch cells: winding and stacking. Among them, the winding process has always been the mainstream process for major battery manufacturers due to its high efficiency and fewer burrs, but it also has its biggest drawback: severe wrinkling of the anode electrode.
[0003] Because the anode electrode experiences thickness rebound during charging and discharging, and the stress inside the bare cell cannot be released after winding, the electrode will wrinkle laterally (i.e., perpendicular to the winding direction). Currently, the mainstream solutions to the wrinkling problem are generally to use an adhesive-coated separator to ensure that the electrode and separator are tightly bonded together, preventing the electrode from wrinkling, or to use a low-elasticity adhesive in the anode formulation to reduce electrode rebound.
[0004] However, coated separators are generally more expensive than ordinary separators, increasing the overall manufacturing cost of the battery. The coating process is also cumbersome, increasing the complexity of the production process and the difficulty of quality control. The coating layer may also affect the separator's air permeability, electrolyte wettability, and other key properties, thereby affecting the overall performance of the battery. Using a low-elasticity adhesive may reduce the utilization rate of the active material in the anode, thus affecting the battery's capacity and energy density. Utility Model Content
[0005] The purpose of this invention is to provide a wrinkle-resistant wound cell assembly electrode to solve the problem that existing anti-wrinkle electrode methods increase the overall manufacturing cost of the battery, the complexity of the production process, and the difficulty of quality control, which can easily affect the overall performance of the battery.
[0006] A wrinkle-resistant wound battery cell assembly electrode includes an electrode group, which includes an anode electrode, a cathode electrode, and two separators. The electrode group has a tab on one side, and a negative tab and a positive tab are generated for each turn of winding. The anode electrode has multiple holes at the winding bend. The cathode electrode has corresponding holes at the positions of the anode electrode. The shape of the holes on the cathode electrode is consistent with that of the holes on the anode electrode.
[0007] Preferably, the shape of the hole is circular, elliptical, or spindle-shaped, or a combination of two or three of these shapes, and the total area of the hole is generally controlled between 1% and 5% of the entire electrode assembly.
[0008] Preferably, the hole is located at the bend of the electrode sheet when it is in the inner ring, and at the junction of the large surface of the bare cell and the rounded corner when it is in the outer ring.
[0009] Preferably, the pores allow electrolyte to permeate.
[0010] Preferably, the holes can be divided into single-row holes and double-row holes. The number of single-row holes is controlled within 20 turns, and the number of double-row holes is controlled after 20 turns. The diameter of the single-row holes is slightly larger than the diameter of the double-row holes.
[0011] The advantages of this utility model are as follows: The anti-wrinkle wound cell assembly electrode sheet of this utility model relieves the wrinkling of the electrode sheet by opening holes to release the stress in the anode electrode sheet, thereby avoiding the wrinkling phenomenon of the electrode sheet. It greatly improves the wrinkling situation of the cell electrode sheet, is easy to operate, does not incur additional manufacturing costs, does not increase the complexity of production and processing, and ensures good overall battery performance. Moreover, by utilizing the holes, the obstruction effect of the copper and aluminum thin sheets on the side of the cell is reduced, allowing electrolyte to be wetted on both sides of the cell. This increases the electrolyte wetting path on both sides of the bare cell, improves the electrolyte wetting effect, and greatly increases the electrolyte wetting efficiency. Attached Figure Description
[0012] Figure 1 This is a three-dimensional structural diagram of the present invention.
[0013] Figure 2 This is a schematic diagram of the structure of the electrode sheet in this utility model.
[0014] Figure 3 This is a schematic diagram of the structural shape of the hole in this utility model.
[0015] Among them, 100 is the electrode group; 101 is the negative electrode tab; 102 is the positive electrode tab; and 103 is the hole. Detailed Implementation
[0016] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.
[0017] like Figures 1 to 3 As shown, a wrinkle-resistant wound battery cell assembly electrode includes an electrode group 100. An electrode group 100 includes an anode electrode, a cathode electrode, and two separators. A tab is provided on one side of the electrode group 100. A negative electrode tab 101 and a positive electrode tab 102 are generated for each turn of winding. Multiple holes 103 are provided at the winding bend of the anode electrode. A corresponding hole 103 is provided on the cathode electrode at the position corresponding to the anode electrode. The shape of the hole 103 on the cathode electrode is consistent with that on the anode electrode.
[0018] Due to the winding tension and bending force of the coiled electrode, there is stress in the electrode that causes it to stretch outward. The bending of the electrode also causes stress that tends to return to straightness. However, under the constraint of the finishing adhesive, the electrodes can only be squeezed against each other in a fixed space, causing the electrodes to wrinkle. By opening holes 103, the stress in the anode electrode is released, which alleviates the wrinkling of the electrode and avoids the wrinkling phenomenon, greatly improving the wrinkling situation of the cell electrode.
[0019] In this embodiment, the shape of the hole 103 is preferably circular, elliptical, or spindle-shaped, or a combination of two or three of them. The total area of the hole 103 is generally controlled between 1% and 5% of the entire electrode group 100.
[0020] The shape, size, and number of holes 103 should be controlled to be relatively small and round, and the number should not be too large to avoid tape breakage.
[0021] In this embodiment, the hole 103 is located at the bend of the electrode sheet when it is in the inner ring, and at the junction of the large surface of the bare cell and the rounded corner when it is in the outer ring.
[0022] In this embodiment, the pore 103 allows electrolyte to permeate.
[0023] By setting holes 103, the obstruction effect of the thin copper and aluminum on the side of the cell is reduced, allowing electrolyte to be wetted on both sides of the cell. This increases the electrolyte wetting path on both sides of the bare cell, improves the electrolyte wetting effect, and increases production capacity.
[0024] In this embodiment, the hole 103 can be divided into a single row of holes and a double row of holes. The single row of holes is controlled within 20 turns, and the double row of holes is controlled after 20 turns. The diameter of the single row of holes is slightly larger than the diameter of the double row of holes.
[0025] Working process and principle: In use, this device creates multiple holes 103 at the winding and bending points of the electrode assembly 100. The shape of the holes 103 on the cathode electrode is consistent with that on the anode electrode, and is proportionally enlarged. The enlargement ratio needs to be consistent with the NP ratio of the actual cell design. The holes 103 release the stress in the electrode to alleviate wrinkling and prevent the electrode from wrinkling, greatly improving the wrinkling situation of the cell electrode. The shape, size, and number of holes 103 should be controlled to be relatively small and round, and the number should not be too large to avoid strip breakage. The operation is simple, does not incur additional manufacturing costs, does not increase the complexity of production and processing, and ensures good overall battery performance. At the same time, the holes 103 reduce the obstruction effect of the thin copper and aluminum on the side of the cell, allowing electrolyte to be wetted on both sides of the cell. This increases the electrolyte wetting path on both sides of the bare cell, improves the electrolyte wetting effect, and increases production capacity.
[0026] As is known from common technical knowledge, this utility model can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this utility model or its equivalents are included in this utility model.
Claims
1. A crease-resistant, wound cell assembly tab, characterized by: The application relates to a battery pole group (100) comprising a positive pole piece, a negative pole piece and two diaphragms, wherein one side of the pole group (100) is provided with a pole lug, one negative pole lug (101) and one positive pole lug (102) are generated per winding circle, a plurality of holes (103) are arranged at the winding bending position of the positive pole piece, and one corresponding hole (103) is arranged at the position corresponding to the positive pole piece on the negative pole piece, wherein the shape of the hole (103) on the negative pole piece is consistent with the shape of the hole (103) on the positive pole piece.
2. The anti-wrinkle winding type battery cell assembly tab according to claim 1, characterized in that: The shape of the hole (103) is one or more of a circle, an ellipse and a spindle, and the total area of the hole (103) is generally controlled to be between 1% and 5% of the whole pole group (100).
3. The anti-wrinkle jelly-roll type electrode assembly of claim 2, wherein: When the hole (103) is located at the inner circle, the position of the hole (103) is at the bending position of the pole piece, and when the hole (103) is located at the outer circle, the position of the hole (103) can be at the junction of the large surface of the bare battery core and the round corner.
4. The anti-wrinkle jelly-roll type electrode assembly of claim 3, wherein: The hole (103) can allow electrolyte to permeate.
5. The anti-wrinkle jelly-roll type electrode assembly of claim 4, wherein: The hole (103) can be divided into single-row holes and double-row holes, the single-row holes are controlled to be within 20 circles, the double-row holes are controlled to be after 20 circles, and the diameter of the single-row holes is slightly larger than the diameter of the double-row holes.