Lithium ion battery with double-middle winding type structure
Through a dual-center winding structure design, the positive and negative electrode foils of the lithium-ion battery are stacked with electrolytic paper, bent, and wound. The tabs are welded to the center of the electrode sheet, which solves the problem of high internal resistance of lithium-ion batteries, achieves low internal resistance, superior rate and cycle performance, and reduces the thermal effect during high-rate discharge.
Patent Information
- Application Number
- CN202520301668.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-02-25
AI Technical Summary
Existing lithium-ion batteries have high internal resistance, which leads to problems with energy density, cycle life and thermal effects, and makes it difficult to maintain stable performance under different temperatures and operating conditions.
The design adopts a double-center winding structure. The positive and negative electrode foils are stacked with electrolytic paper and then bent and wound in the middle. The electrode tab welding position is designed in the middle of the electrode sheet to shorten the current flow path. Electrolytic paper is stacked on the surface of the positive and negative electrode foils to reduce internal resistance.
It significantly reduces the internal resistance of the battery cell by 45-55%, improves rate performance and power performance, reduces the thermal effect during high-rate discharge, and enhances the cycle life and thermal stability of the battery cell.
Smart Images
Figure CN223941805U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lithium-ion battery manufacturing technology, and in particular to a dual-center-mounted wound lithium-ion battery. Background Technology
[0002] The impact of cell internal resistance on battery performance is mainly reflected in the following aspects:
[0003] Discharge efficiency:
[0004] Lower internal resistance helps reduce energy loss during charging and discharging, thereby improving battery output power and efficiency. For example, by optimizing battery materials and structural design, internal resistance can be significantly reduced, enabling the battery to provide higher current and longer usage time during discharge.
[0005] Energy density:
[0006] Batteries with high internal resistance may have higher energy density, but this is usually accompanied by greater internal resistance, which may lead to increased energy loss during charging and discharging. Therefore, balancing internal resistance and energy density is key to designing high-performance batteries.
[0007] Cycle life:
[0008] An increase in battery internal resistance is usually closely linked to the battery aging process, which can lead to a decline in battery performance over time. Monitoring changes in battery internal resistance can help predict battery life and maintain battery health.
[0009] Temperature effect:
[0010] Temperature is a key environmental parameter affecting battery internal resistance. At low temperatures, the ionic conductivity of the electrolyte decreases, leading to an increase in battery internal resistance. Conversely, at suitable temperatures, the battery internal resistance remains relatively stable.
[0011] Usage conditions:
[0012] Usage conditions such as charge / discharge state, usage duration, and load current also affect internal resistance. For example, frequent charge / discharge cycles may cause changes in the battery's internal structure, increasing internal resistance. Summary of the Invention
[0013] The purpose of this invention is to overcome the shortcomings of the prior art and provide a dual-center-wound lithium-ion battery with a reasonable structure that can effectively improve the rate performance, power performance, DCR and thermal effect of the battery cell during high-rate discharge, so that the wound-type battery cell of the same capacity has superior rate performance, cycle life, low internal resistance and small thermal effect during charging and discharging.
[0014] To achieve the above objectives, the technical solution provided by this utility model is as follows: a dual-center-mounted wound lithium-ion battery, the battery comprising a shell and a cell located within the inner shell, the shell having a positive electrode foot and a negative electrode foot connected to the cell, wherein the cell is formed by winding positive and negative electrode foils, the positive electrode foot being connected to the middle of the positive electrode foil along its length, and the negative electrode foot being connected to the middle of the negative electrode foil along its length, and electrolytic paper being stacked on the surfaces of the positive and negative electrode foils on both sides of the welding surfaces of the positive and negative electrode feet; the positive electrode foil, negative electrode foil, and electrolytic paper are stacked and then wound to form the cell.
[0015] The positive electrode foil, negative electrode foil, and electrolytic paper are stacked, bent, and then wound to form a battery cell.
[0016] The positive electrode foil, negative electrode foil, and electrolytic paper are stacked and then wound from one end to form a battery cell.
[0017] Electrolytic paper is laminated on the surface and bottom of both the positive and negative electrode foils.
[0018] The technical advantages of this solution are:
[0019] First, the structure provided by this solution is simple and reasonable, can be directly used in solid-state and liquid batteries, and is easy to operate.
[0020] Secondly, this solution can significantly reduce the internal resistance of the battery cell, with actual measurements showing a reduction of approximately 45-55%.
[0021] Third, this solution can significantly reduce the ohmic internal resistance of the battery cell, improve the rate performance, power performance, DCR and thermal effect of the battery cell during high-rate discharge, and enable the wound structure battery cell of the same capacity to have superior rate performance, cycle life, low internal resistance and low thermal effect during charging and discharging.
[0022] Fourth, through comparative experiments, the cycle and rate performance of this scheme are very significant. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the positive electrode foot structure of this utility model.
[0024] Figure 2 This is a schematic diagram of the negative electrode foot structure of this utility model. Detailed Implementation
[0025] The present invention will be further described below with reference to all the accompanying drawings. A preferred embodiment of the present invention is shown in the accompanying drawings. Figure 1 and appendix Figure 2This embodiment describes a dual-center wound lithium-ion battery, which includes a casing and a battery cell located inside the inner casing. The casing has a positive electrode 3 and a negative electrode 4 connected to the battery cell. The battery cell is formed by winding a positive electrode foil 1 and a negative electrode foil 2. The positive electrode 3 is connected to the middle of the positive electrode foil 1 along its length, and the negative electrode 4 is connected to the middle of the negative electrode foil 2 along its length. Electrolytic paper 5 is stacked on the surfaces of the positive electrode foil 1 and the negative electrode foil 2 on both sides of the welding surfaces of the positive electrode 3 and the negative electrode 4. The positive electrode foil 1, the negative electrode foil 2, and the electrolytic paper 5 are stacked and wound to form the battery cell.
[0026] Positive electrode foil 1, negative electrode foil 2, and electrolytic paper 5 are stacked, bent in the middle, and then wound to form a battery cell. Positive electrode foil 1, negative electrode foil 2, and electrolytic paper 5 are stacked and wound from one end to form a battery cell. Electrolytic paper 5 is stacked on both the surface and bottom of positive electrode foil 1 and negative electrode foil 2.
[0027] After adopting the above scheme, the electrode tab welding position is designed in the middle of the electrode sheet, so that the current flows from both ends of the electrode sheet to the electrode tab, which greatly shortens the current flow path. In addition, the empty foil area is not wound and folded, which avoids uneven stress during pressure formation caused by uneven thickness of the cell. At the same time, the structure after adopting this scheme is reasonable and can effectively improve the cell rate performance, power performance, DCR and thermal effect during high-rate discharge. This makes the wound structure cell of the same capacity have superior rate performance, cycle life, low internal resistance and low thermal effect during charging and discharging.
[0028] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all changes made in accordance with the shape and principle of this utility model should be covered within the protection scope of this utility model.
Claims
1. A dual-center-mounted wound lithium-ion battery, the battery comprising a casing and a cell located within an inner casing, the casing having a positive electrode (3) and a negative electrode (4) connected to the cell, characterized in that: The battery cell is formed by winding positive electrode foil (1) and negative electrode foil (2). The positive electrode foot (3) is connected to the middle of the positive electrode foil (1) along its length, and the negative electrode foot (4) is connected to the middle of the negative electrode foil (2) along its length. Electrolytic paper (5) is stacked on the surfaces of the positive electrode foil (1) and negative electrode foil (2) on both sides of the welding surface of the positive electrode foot (3) and negative electrode foot (4). The positive electrode foil (1), negative electrode foil (2), and electrolytic paper (5) are stacked and then wound to form the battery cell.
2. The lithium-ion battery with a dual-center-mounted wound structure according to claim 1, characterized in that: The positive electrode foil (1), negative electrode foil (2), and electrolytic paper (5) are stacked, bent in the middle, and then wound to form a battery cell.
3. A dual-center-mounted wound lithium-ion battery according to claim 1, characterized in that: The positive electrode foil (1), negative electrode foil (2), and electrolytic paper (5) are stacked and then wound from one end to form a battery cell.
4. A dual-center-mounted wound lithium-ion battery according to claim 1, characterized in that: Electrolytic paper (5) is laminated on the surface and bottom of both the positive electrode foil (1) and the negative electrode foil (2).