A type of battery cell and battery
By using an alternating arrangement of electrodes and separators in a winding structure, the space occupied by the pre-wound separator in lithium-ion battery cores is solved, thereby increasing volumetric energy density and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 惠州赣锋锂电科技有限公司
- Filing Date
- 2025-06-26
- Publication Date
- 2026-06-30
AI Technical Summary
The existing lithium-ion battery winding structure, with the pre-wound separator film at the innermost layer of the core, leads to increased space occupation, material waste, and increased costs, affecting volumetric energy density.
The first and second electrodes are arranged alternately, with the diaphragm distributed on both sides of the electrodes. By controlling the alignment and distance between the diaphragm and the electrodes, the pre-wound diaphragm is reduced, forming a second unit structure.
This reduces the amount of separator used, decreases the cell thickness, increases volumetric energy density, and reduces material and cost costs.
Smart Images
Figure CN224437641U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to a battery cell and a battery. Background Technology
[0002] Lithium-ion batteries have advantages such as high energy density, long cycle life, environmental friendliness, and no memory effect, and are widely used in mobile communication or digital products such as mobile phones, portable computers, digital cameras, and portable music playback devices.
[0003] Existing lithium-ion batteries typically use wound or stacked structures as bare cells, with aluminum-plastic film or hard shells for protection. Wound structures are the preferred choice in the consumer lithium battery field due to their ease of processing and fast changeover speed. Conventional wound structures use a one-and-a-half-turn pre-wound separator clamped by the innermost winding needle to achieve fully automatic winding, avoiding folds in the separator and wrinkles on the electrode at the head, which would affect cell performance. However, the pre-wound separator not only takes up space and increases battery thickness, resulting in a decrease in volumetric energy density, but also causes material waste and increased costs. Utility Model Content
[0004] The main purpose of this utility model is to provide a battery cell and battery to solve the above-mentioned problems.
[0005] To achieve the above objectives, this utility model provides a battery cell, including a first electrode, a second electrode, a first separator, and a second separator; both the first electrode and the second electrode are wound structures composed of multiple straight segments and multiple bent segments, and the first electrode and the second electrode are staggered; the inner side of the first bent segment inside the first electrode is a first corner; the inner side of the first bent segment inside the second electrode is a second corner; the winding start end of the first electrode faces the second corner; the winding start end of the second electrode faces the first corner; the first separator and the second separator are distributed on both sides of the second electrode; the winding start ends of the first separator and the second separator are aligned with the winding start end of the second electrode; the distance between the first separator and the first corner is ≥1mm, and the distance between the winding start end of the second electrode and the first corner is ≥1mm.
[0006] Furthermore, the alignment between the winding start ends of the first diaphragm and the winding start end of the second electrode is ±1mm.
[0007] Furthermore, the distance between the starting end of the first electrode winding and the second corner is ≥1mm.
[0008] Furthermore, the first diaphragm, the second electrode, and the second diaphragm together form the second unit.
[0009] Furthermore, both the first and second electrode plates are welded with tabs.
[0010] Furthermore, a protective adhesive layer is provided on the first electrode sheet; the protective adhesive layer is located at the first corner.
[0011] This utility model also provides a battery, including the above-mentioned battery cell.
[0012] This utility model has the following beneficial effects:
[0013] This invention employs a method where the second electrode and the separator are wound simultaneously, resulting in an innermost ring consisting of only one anode sheet, two separator layers, and one cathode sheet. This reduces the amount of separator pre-wound by one and a half turns, thereby reducing the amount of separator used per cell. Furthermore, this structure reduces the separator thickness by one and a half turns, thus increasing the volumetric energy density. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of a battery cell and battery proposed in this utility model;
[0015] Figure 2 This is another schematic diagram of a battery cell and battery proposed in this utility model.
[0016] In the diagram: 1-First electrode; 2-Second electrode; 3-First diaphragm; 4-Second diaphragm; 5-Protective adhesive layer; 6-First corner; 7-Second corner. Detailed Implementation
[0017] To achieve the above objectives and effects, the technical means and structure adopted by this utility model are described in detail with reference to the accompanying drawings, focusing on the features and functions of the preferred embodiments of this utility model.
[0018] like Figures 1-2 As shown, this utility model provides a battery cell, including a first electrode 1, a second electrode 2, a first separator 3, and a second separator 4; both the first electrode 1 and the second electrode 2 are wound structures composed of multiple straight segments and multiple bent segments, and the first electrode 1 and the second electrode 2 are arranged alternately; the inner side of the first bent segment inside the first electrode 1 is a first corner 6; the inner side of the first bent segment inside the second electrode 2 is a second corner 7; the winding start end of the first electrode 1 faces the second corner 7; the winding start end of the second electrode 2 faces the second corner 7. The first electrode 2 is positioned facing the first corner 6; the first diaphragm 3 and the second diaphragm 4 are distributed on both sides of the second electrode 2; the winding start ends of the first diaphragm 3 and the second diaphragm 4 are aligned with the winding start end of the second electrode 2, with an alignment degree of ±1mm; the distance L2 between the first diaphragm 3 and the first corner 6 should satisfy L2≥1mm, and the distance between the winding start end of the second electrode 2 and the first corner 6 should satisfy ≥1mm; the distance L3 between the winding start end of the first electrode 2 and the second corner should satisfy L3≥1mm; to prevent the diaphragm from wrinkling during the core pressing process.
[0019] In another embodiment, the first diaphragm 3, the second electrode 2, and the second diaphragm 4 together form the second unit.
[0020] In another embodiment, both the first electrode 1 and the second electrode 2 are welded with tabs.
[0021] In another embodiment, a protective adhesive layer 5 is provided on the first electrode 1; the protective adhesive layer 5 is located at the first corner. This protective adhesive layer 5 can prevent the battery cell from having a safety risk because when the distance between the second electrode 2 and the corner L2 is ≥ 1 mm, there is no effective active material of the second electrode 2 in the vertical projection of the first electrode 1 at that position.
[0022] The battery cell manufacturing process is as follows:
[0023] The first step is to weld the tabs and apply protective adhesive to the corresponding positions of the first electrode 1 and the second electrode 2 respectively;
[0024] The second step is to assemble the second electrode 2, the first diaphragm 3, and the second diaphragm 4 into a second unit, which can be done by clamping with a special coiling needle or by heating and bonding.
[0025] The third step is to insert the second unit and the first electrode 1 into the winding needle, and wind them clockwise or counterclockwise according to the winding direction of the electrode.
[0026] The fourth step is to loosen the winding needle, pull out the battery cell to complete the winding, and obtain the battery cell.
[0027] This utility model also provides a battery, including the above-mentioned battery cell.
[0028] The above description is only a preferred embodiment of the present utility model and not all embodiments. Anyone should know that structural changes made under the guidance of the present utility model are protected by the present utility model. All technical solutions that are the same as or similar to the present utility model are within the scope of protection of the present utility model.
Claims
1. A battery cell, characterized in that, The device includes a first electrode, a second electrode, a first diaphragm, and a second diaphragm. Both the first and second electrode are wound structures composed of multiple straight segments and multiple bent segments, with the first and second electrode interleaved. The inner side of the first bent segment inside the first electrode is a first corner; the inner side of the first bent segment inside the second electrode is a second corner; the starting end of the winding of the first electrode faces the second corner; the starting end of the winding of the second electrode faces the first corner; the first and second diaphragms are distributed on both sides of the second electrode; the starting ends of the winding of both the first and second diaphragms are aligned with the starting end of the winding of the second electrode; the distance between the first diaphragm and the first corner is ≥1mm, and the distance between the starting end of the winding of the second electrode and the first corner is ≥1mm.
2. A battery cell as described in claim 1, characterized in that, The alignment between the winding start ends of the first diaphragm and the winding start end of the second electrode is ±1mm.
3. A battery cell as described in claim 2, characterized in that, The distance between the starting end of the first electrode winding and the second corner is ≥1mm.
4. A battery cell as described in claim 3, characterized in that, The first diaphragm, the second electrode, and the second diaphragm together form the second unit.
5. A battery cell as described in any one of claims 1-4, characterized in that, Both the first and second electrodes are welded with tabs.
6. A battery cell as described in claim 5, characterized in that, A protective adhesive layer is provided on the first electrode; the protective adhesive layer is located at the first corner.
7. A battery, characterized in that, Includes a battery cell as described in any one of claims 1-6.