Electrode structure, wound cell and battery
By extending the foil layer to form the first empty foil portion and connecting it with the tab body, the dust risk of intermediate welding tabs and the complex and expensive laser equipment problems are solved, achieving low-cost and high-efficiency battery production and high-quality safety performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- EVE ENERGY CO LTD
- Filing Date
- 2025-06-17
- Publication Date
- 2026-07-03
AI Technical Summary
Existing technologies using intermediate welding tabs in pouch lithium-ion batteries present risks of dust introduction and complex and expensive laser equipment, while also leading to capacity loss in the active material layer and affecting the battery's volumetric energy density.
The electrode structure design avoids laser removal of the active material layer by extending the foil layer to form the first empty foil part and connecting it with the electrode body, thereby reducing process complexity and increasing connection strength, and ensuring battery quality and safety performance.
This technology eliminates the need for laser removal of the active material layer, reducing production costs, preventing dust introduction, improving battery capacity and connection strength, and ensuring battery quality and safety.
Smart Images
Figure CN224458106U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to an electrode structure, a wound cell, and a battery. Background Technology
[0002] Pouch lithium-ion batteries used in mobile phones, tablets, and other electronic devices require both high-rate charging capability and extremely high volumetric energy density. To shorten the electron transport path, a wound structure is currently widely used, with tabs welded in the middle of long electrode sheets to achieve high-rate charging capability while minimizing the loss of volumetric energy density. However, current methods of welding tabs in the middle require first using lasers to remove dust from the tab area. This introduces dust and the laser equipment is complex and expensive. Furthermore, the removal of effective active material reduces the battery's capacity, resulting in a loss of overall volumetric energy density. Utility Model Content
[0003] The purpose of this invention is to provide an electrode structure, a wound cell, and a battery, which have a simple structure, low production cost, and can avoid the loss of electrode capacity caused by removing the active material layer, as well as avoid the risk of introducing dust during the removal of the active material layer.
[0004] To achieve this objective, the present invention adopts the following technical solution:
[0005] On one hand, an electrode structure is provided, including an electrode body and an electrode tab body. The electrode body includes a foil layer and an active material layer disposed on at least one side of the foil layer in the thickness direction. One end of the foil layer along a first direction is flush with the active material layer, and the other end of the foil layer along the first direction extends outside the active material layer to form a first empty foil portion. The width of the first empty foil portion along a second direction is L1. The first direction is the direction of the central axis of the wound battery cell formed after the electrode structure is wound, and the second direction is perpendicular to the first direction.
[0006] The electrode body includes a connecting part and an external part. The connecting part is connected to the first empty foil part, and the external part is located on the side of the connecting part away from the first empty foil part. The width of the external part along the second direction is L2, where L1 > L2.
[0007] In one embodiment, the connecting portion is welded to the first empty foil portion, and the connecting portion and the first empty foil portion are connected by a plurality of welding points, all of which are spaced apart along the second direction.
[0008] In one embodiment, the side surfaces of the connecting portion and the first empty foil portion that are connected to each other have the same area and overlap.
[0009] In one embodiment, the first empty foil portion has a dimension L3 along the first direction, where L3 is 2.5-5 mm.
[0010] In one embodiment, L1 = nL2, where n is 2-3.
[0011] In one embodiment, the foil layer further extends along the first direction with a second empty foil portion, the second empty foil portion being disposed on at least one side of the first empty foil portion along the second direction, the first empty foil portion having a dimension of L3 along the first direction, and the second empty foil portion having a dimension of L4 along the first direction, where L3 > L4.
[0012] In one embodiment, L4 is 0.5-2 mm.
[0013] In one embodiment, the first empty foil portion is located at the middle of the electrode body along the second direction.
[0014] In one embodiment, the electrode body is further provided with electrode adhesive, the electrode adhesive is connected to the external part, and the dimension of the electrode adhesive along the second direction is L5, where L5 > L2.
[0015] In one embodiment, the side of the connecting portion along the thickness direction is set at an angle to the side of the foil layer along the thickness direction, and the side of the connecting portion along the thickness direction is set at an angle to the side of the external portion along the thickness direction.
[0016] In one embodiment, the side of the connecting portion along the thickness direction is set at a 90° angle to the side of the foil layer along the thickness direction, and the side of the connecting portion along the thickness direction is set at a 90° angle to the side of the external portion along the thickness direction.
[0017] On the other hand, a wound battery cell is also provided, including a positive electrode, a separator, and a negative electrode. The positive electrode, the separator, and the negative electrode are stacked and wound together to form a columnar structure. The positive electrode and / or the negative electrode are electrode structures as described above, and the external portion of the positive electrode and the external portion of the negative electrode are located at the end face of the columnar structure.
[0018] In another aspect, a battery is also provided, characterized in that it includes the above-mentioned wound cell, the wound cell further includes a first end face, the tab body is disposed on the side of the wound cell where the first end face is disposed, and the connecting portion is attached to the first end face.
[0019] In one embodiment, the diaphragm has an isolation portion extending out of the first end face, the isolation portion being attached to the first end face, and the connecting portion being attached to the side of the isolation portion opposite to the first end face.
[0020] The beneficial effects of this utility model are:
[0021] The present invention discloses an electrode structure in which a first empty foil portion is formed by extending the foil layer along a first direction to the outside of the active material layer for fixed connection with the electrode body. This eliminates the need for laser equipment to remove the active material layer, reducing process complexity and equipment investment. It also avoids the loss of electrode capacity caused by removing the active material layer and avoids the risk of introducing dust during the removal process, thereby improving the quality and safety performance of the battery.
[0022] Furthermore, the width of the first empty foil portion along the second direction is greater than the width of the outer portion along the second direction, so as to provide sufficient width to connect with the connecting portion, thereby increasing the contact length between the connecting portion and the first empty foil portion in the second direction, thereby increasing the overall contact area between the connecting portion and the first empty foil portion, improving the connection strength between the connecting portion and the first empty foil portion, that is, ensuring the connection strength between the tab body and the first empty foil portion. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the electrode structure in one embodiment;
[0024] Figure 2 This is a schematic diagram of the structure of the electrode body in one embodiment;
[0025] Figure 3 This is a schematic diagram of the electrode structure (folded state) in one embodiment;
[0026] Figure 4 This is a schematic diagram of the structure of a wound battery cell in one embodiment;
[0027] Figure 5 This is a front view of the battery in one embodiment;
[0028] Figure 6 This is a schematic diagram of the battery structure in one embodiment.
[0029] In the picture:
[0030] 1. Winded battery cell; 11. Positive electrode plate; 12. Negative electrode plate; 13. Separator; 1301. Isolation section; 14. First end face;
[0031] 100, Electrode body; 110, Foil layer; 111, First empty foil section; 112, Second empty foil section; 120, Active material layer; 200, Tab body; 210, Connecting part; 220, External part; 230, Tab adhesive; 300, Welding point. Detailed Implementation
[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.
[0033] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0035] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.
[0036] like Figures 1 to 3As shown, an electrode structure in this embodiment includes an electrode body 100 and an electrode tab body 200. The electrode body 100 includes a foil layer 110 and an active material layer 120 disposed on at least one side of the foil layer 110 in the thickness direction. One end of the foil layer 110 along a first direction is flush with the active material layer 120, and the other end of the foil layer 110 along the first direction extends beyond the active material layer 120 to form a first empty foil portion 111. The width of the first empty foil portion 111 along a second direction is L1. The first direction is the direction of the central axis of the wound cell 1 formed after the electrode structure is wound, and the second direction is perpendicular to the first direction. The electrode tab body 200 includes a connecting portion 210 and an external portion 220. The connecting portion 210 is connected to the first empty foil portion 111, and the external portion 220 is located on the side of the connecting portion 210 away from the first empty foil portion 111. The width of the external portion 220 along the second direction is L2, where L1 > L2.
[0037] In this embodiment, by forming a first empty foil portion 111 by extending the foil layer 110 along the first direction to the outside of the active material layer 120 for fixed connection with the tab body 200, it is not necessary to use laser equipment to remove the active material layer 120, thereby reducing process complexity and equipment investment. At the same time, it avoids the loss of electrode capacity caused by removing the active material layer 120, and also avoids the risk of introducing dust during the removal of the active material layer 120, thereby improving the quality and safety performance of the battery.
[0038] Furthermore, the width of the first empty foil portion 111 along the second direction is greater than the width of the outer portion 220 along the second direction, so as to provide sufficient width for connection with the connecting portion 210. This helps to increase the contact length between the connecting portion 210 and the first empty foil portion 111 in the second direction, thereby increasing the overall contact area between the connecting portion 210 and the first empty foil portion 111 and improving the connection strength between the connecting portion 210 and the first empty foil portion 111, that is, ensuring the connection strength between the tab body 200 and the first empty foil portion 111.
[0039] In one embodiment, the connecting portion 210 is welded to the first empty foil portion 111, and the connecting portion 210 and the first empty foil portion 111 are connected by a plurality of welding points 300, all of which are spaced apart along a second direction. The side surfaces of the connecting portion 210 and the first empty foil portion 111 that are connected to each other have the same area and overlap, ensuring that the connecting portion 210 is completely fitted to the first empty foil portion 111, reducing space occupation and material waste.
[0040] Furthermore, the first empty foil portion 111 has a dimension L3 along the first direction, which is 2.5-5mm, so as to provide enough welding positions for a row of welding points 300 in the first direction during welding operations, thereby reducing foil consumption while ensuring welding effect.
[0041] In one embodiment, L1 = nL2, where n is 2-3, to increase the welding length between the connecting part 210 and the first empty foil part 111 in the second direction, thereby increasing the overall welding area between the connecting part 210 and the first empty foil part 111 and improving the welding fixation strength between the connecting part 210 and the first empty foil part 111.
[0042] In one embodiment, the foil layer 110 further extends a second empty foil portion 112 along the first direction. The second empty foil portion 112 is disposed on at least one side of the first empty foil portion 111 along the second direction to achieve the function of protecting the active material layer 120. The first empty foil portion 111 has a dimension L3 along the first direction, and the second empty foil portion 112 has a dimension L4 along the first direction, where L3 > L4. Specifically, L4 is 0.5-2 mm, so as to minimize foil loss while ensuring the protection of the active material layer 120.
[0043] In one embodiment, the first empty foil portion 111 is located in the middle of the electrode body 100 along the second direction, so as to ensure that after the electrode body is wound to form the wound cell 1, the tab body 200 can be located in the middle of the wound cell 1, which facilitates the wiring and connection with external devices.
[0044] In one embodiment, the tab body 200 is further provided with tab adhesive 230, which is connected to the external part 220. The tab adhesive 230 fixes the tab body 200 to the outer casing of the battery (not shown in the figure) and serves as insulation and protection. The dimension of the tab adhesive 230 along the second direction is L5, where L5 > L2, so that the connecting part 210, the external part 220, and the tab adhesive 230 form an "earth" shaped structure, ensuring the stability of the overall structure of the tab body 200.
[0045] In one embodiment, the side of the connecting portion 210 along the thickness direction forms an angle with the side of the foil layer 110 along the thickness direction, and the side of the connecting portion 210 along the thickness direction forms an angle with the side of the external portion 220 along the thickness direction. Specifically, the side of the connecting portion 210 along the thickness direction forms a 90° angle with the side of the foil layer 110 along the thickness direction and / or the side of the connecting portion 210 along the thickness direction forms a 90° angle with the side of the external portion 220 along the thickness direction. In actual operation, by bending the connecting portion 210 at a 90° angle relative to the foil layer 110 and attaching the connecting portion 210 and the first empty foil portion 111 to one side of the battery, the space occupied by the tab body 200 in the first direction is reduced, which helps to avoid the overall battery volume being too large. The connecting portion 210 and the external portion 220 are also bent at a 90° angle, so that the length direction of the external portion 220 continues to extend along the first direction, avoiding interference with the connection between the battery and external devices.
[0046] On the other hand, such as Figure 4 As shown, this embodiment also provides a wound battery cell 1, including a positive electrode 11, a separator 13 and a negative electrode 12. The positive electrode 11, the separator 13 and the negative electrode 12 are stacked and wound together to form a columnar structure. The positive electrode 11 and / or the negative electrode 12 are the electrode structures described above. The external portion 220 of the positive electrode 11 and the external portion 220 of the negative electrode 12 are located on the end face of the columnar structure, which facilitates the wiring and connection with external devices.
[0047] On the other hand, such as Figure 5 and Figure 6 As shown, this embodiment also provides a battery, including the above-mentioned wound cell 1, wherein the wound cell 1 further includes a first end face 14, and a tab body 200 is disposed on the side of the wound cell 1 where the first end face 14 is disposed. The connecting part 210 is bent at 90° and attached to the first end face 14 to reduce the length of the tab body 200 along the first direction, thereby helping to avoid the tab body 200 being too long and affecting the overall volume of the battery, and reducing the space occupied by the battery.
[0048] In one embodiment, the separator 13 has an isolation portion 1301 extending out of the first end face 14. The isolation portion 1301 is attached to the first end face 14. The connecting portion 210 is bent at 90° and attached to the end of the isolation portion 1301 away from the first end face 14. The isolation portion 1301 can prevent the connecting portion 210 welded to the first empty foil portion 111 from directly contacting the wound cell 1 and causing a short circuit, thereby improving the safety of the battery.
[0049] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. A pole piece structure, characterized by, include: An electrode body (100) includes a foil layer (110) and an active material layer (120) disposed on at least one side of the foil layer (110) in the thickness direction. One end of the foil layer (110) along a first direction is flush with the active material layer (120), and the other end of the foil layer (110) along the first direction extends outside the active material layer (120) to form a first empty foil portion (111). The width of the first empty foil portion (111) along a second direction is L1. The first direction is the direction of the central axis of the wound cell formed after the electrode structure is wound, and the second direction is perpendicular to the first direction. The electrode body (200) includes a connecting part (210) and an external part (220). The connecting part (210) is connected to the first empty foil part (111). The external part (220) is located on the side of the connecting part (210) away from the first empty foil part (111). The width of the external part (220) along the second direction is L2, where L1 > L2.
2. The pole piece structure of claim 1, wherein The connecting part (210) is welded to the first empty foil part (111), and the connecting part (210) and the first empty foil part (111) are connected by a plurality of welding points (300), and all the welding points (300) are spaced apart along the second direction.
3. The pole piece structure of claim 2, wherein, The connecting part (210) and the first empty foil part (111) have the same side area and overlap each other.
4. The pole piece structure according to any one of claims 1 to 3, characterized in that The first empty foil portion (111) has a dimension L3 along the first direction, and L3 is 2.5-5mm.
5. The pole piece structure according to any one of claims 1 to 3, characterized in that L1 = nL2, where n is 2-3.
6. The pole piece structure according to any one of claims 1 to 3, characterized in that The foil layer (110) further extends a second empty foil portion (112) along the first direction. The second empty foil portion (112) is disposed on at least one side of the first empty foil portion (111) along the second direction. The first empty foil portion (111) has a dimension of L3 along the first direction, and the second empty foil portion (112) has a dimension of L4 along the first direction, where L3 > L4.
7. The pole piece structure of claim 6, wherein, L4 is 0.5-2mm.
8. The pole piece structure according to any one of claims 1 to 3, characterized in that The first empty foil portion (111) is located in the middle of the electrode body (200) along the second direction.
9. The pole piece structure according to any one of claims 1 to 3, characterized in that The electrode body (200) is also provided with electrode adhesive (230), the electrode adhesive (230) is connected to the external part (220), and the dimension of the electrode adhesive (230) along the second direction is L5, where L5 > L2.
10. The pole piece structure according to any one of claims 1 to 3, characterized in that The side of the connecting part (210) along the thickness direction is set at an angle to the side of the foil layer (110) along the thickness direction, and the side of the connecting part (210) along the thickness direction is set at an angle to the side of the external part (220) along the thickness direction.
11. The pole piece structure of claim 10, wherein, The side of the connecting portion (210) along the thickness direction is arranged at a 90° angle to the side of the foil layer (110) along the thickness direction; and / or, The side of the connecting part (210) along the thickness direction is set at a 90° angle with the side of the external part (220) along the thickness direction.
12. A wound battery cell, comprising a positive electrode (11), a separator (13), and a negative electrode (12), wherein the positive electrode (11), the separator (13), and the negative electrode (12) are stacked and wound to form a columnar structure, characterized in that, The positive electrode (11) and / or the negative electrode (12) are electrode structures according to any one of claims 1 to 11, wherein the external portion (220) of the positive electrode (11) and the external portion (220) of the negative electrode (12) are located at the end face of the columnar structure.
13. A battery, characterized by The winding battery cell (1) as described in claim 12 further includes a first end face (14), the tab body (200) is disposed on the side of the winding battery cell (1) on which the first end face (14) is disposed, and the connecting part (210) is attached to the first end face (14).
14. The battery of claim 13, wherein, The diaphragm (13) has an isolation portion (1301) extending out of the first end face (14), the isolation portion (1301) being attached to the first end face (14), and the connecting portion (210) being attached to the side of the isolation portion (1301) opposite to the first end face (14).