Coating diaphragm
By coating a heat-resistant ceramic layer on the base membrane and setting multiple adhesive layers, the problem of the single adhesive layer of the existing diaphragm is solved, realizing the diverse bonding of the diaphragm and the electrode sheet and increasing the electrolyte storage space, thus meeting the diversified production needs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2026-03-03
AI Technical Summary
Existing diaphragms typically only have one type of adhesive layer, which cannot meet diverse production needs, especially in terms of adhesion and electrolyte storage space.
A heat-resistant ceramic layer is coated on the base film, and an inorganic heat-resistant layer and two adhesive layers of different thicknesses are provided on one side of it, including a heat-resistant coating and first and second adhesives. The different thicknesses and distribution patterns meet the diverse bonding requirements between the diaphragm and the electrode sheet, and provide more storage space for the electrolyte.
It achieves adaptability of diaphragm and electrode sheet under different bonding requirements, improves bonding performance and electrolyte storage capacity, and meets diverse production needs.
Smart Images
Figure CN223967331U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery separator technology, and specifically to a coated separator. Background Technology
[0002] As is well known, there are two types of separators used in batteries: bare base membranes and coated separators. Bare base membranes are used relatively less in batteries due to their poor heat resistance. Coated separators are more commonly used in batteries. A coated separator refers to coating a functional layer onto the surface of the bare base membrane. For example, coating a heat-resistant ceramic layer to improve the overall heat resistance of the base membrane and enhance the safety performance of the battery; or coating an organic adhesive layer on the bare base membrane to improve the adhesion between the separator and the electrode sheets, thereby increasing the rigidity of the cell; or coating a heat-resistant ceramic layer and an organic adhesive layer on the bare base membrane to improve the heat resistance and adhesion of the separator, thereby improving the overall performance of the cell.
[0003] Existing diaphragms typically only have one type of adhesive layer, providing only one bonding site for the electrode sheets, which cannot meet diverse production needs. Utility Model Content
[0004] This invention addresses the shortcomings of existing technologies by providing a coated diaphragm that offers two different bonding heights to meet varying bonding requirements between the diaphragm and the electrode sheet.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A coated diaphragm includes a base film, one side of which is coated with a heat-resistant ceramic layer, and the other side of which is coated with a functional coating. The functional coating includes an inorganic heat-resistant layer, a first adhesive layer, and a second adhesive layer. The inorganic heat-resistant layer includes a plurality of heat-resistant coatings spaced apart on the surface of the base film. The first adhesive layer includes first adhesives distributed between adjacent heat-resistant coatings. The second adhesive layer includes second adhesives coated on the upper surface of the heat-resistant coatings.
[0007] Preferably, the heat-resistant coating has a rectangular cross-section, and the heat-resistant coatings are arranged at equal intervals along the MD and TD directions of the base film, with the long side of the heat-resistant coating parallel to the MD direction of the base film.
[0008] Preferably, the length of the long side of the heat-resistant coating body is 800 μm - 1200 μm, the length of the short side of the heat-resistant coating body is 300 μm - 500 μm, the spacing of the heat-resistant coating body in the MD direction of the base film is 500 μm - 800 μm, the spacing of the heat-resistant coating body in the TD direction of the base film is 300 μm - 500 μm, the coverage rate of the inorganic heat-resistant layer on the base film is 18% - 44%, and the thickness H1 of the heat-resistant coating body is 1 μm - 3 μm.
[0009] Preferably, the cross-section of the first adhesive body is circular, the coverage rate of the first adhesive layer on the base film is 2% - 10%, the particle size of the first adhesive body is 220 μm - 280 μm, and the thickness H2 of the first adhesive body is 3 μm - 7 μm.
[0010] Preferably, the cross-section of the second adhesive body is square, the coverage rate of the second adhesive layer on the top surface of the heat-resistant coating body is 30% - 100%, and the thickness H3 of the second adhesive body is 0.5 μm - 2 μm.
[0011] Preferably, H1, H2, and H3 satisfy the following conditional formula: 1.5 μm < H2 - (H1 + H3) < 5.5 μm.
[0012] Preferably, the thickness of the heat-resistant ceramic layer is 1 μm - 4 μm.
[0013] Preferably, the thickness H1 of the heat-resistant coating body is 1.5 μm - 2.5 μm.
[0014] Preferably, the thickness H3 of the second adhesive body is 1 μm - 1.5 μm.
[0015] Preferably, the particle size of the first adhesive body is 200 μm - 300 μm.
[0016] Compared with the prior art, the present utility model has obvious advantages and beneficial effects. Specifically, by providing the first adhesive layer and the second adhesive layer with different thicknesses on the base film, different bonding requirements between the separator and the electrode sheet can be satisfied; by providing heat-resistant coating bodies distributed at intervals, more storage space can be provided for the electrolyte.
[0017] To more clearly illustrate the structural features, technical means, and the specific purposes and functions achieved by the present utility model, the following further details the present utility model with reference to the attached drawings and specific embodiments: Description of the Drawings
[0018] Figure 1 It is a schematic cross-sectional view of the structure of Embodiment 1 of the present utility model;
[0019] Figure 2This is a top view of the functional layer structure of Embodiment 1 of this utility model;
[0020] Figure 3 This is a top view of the functional layer structure of Embodiment 2 of this utility model;
[0021] Figure 4 This is a top view of the functional layer structure of Embodiment 3 of this utility model.
[0022] Explanation of reference numerals in the attached diagram:
[0023] 10. Base film; 11. Heat-resistant ceramic layer; 12. Heat-resistant coating; 13. First adhesive; 14. Second adhesive. Detailed Implementation
[0024] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the position 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.
[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0026] Please refer to Figure 1-2 As shown, an embodiment 1 of this utility model discloses a coated diaphragm, comprising a base film 10. One side of the base film 10 is coated with a heat-resistant ceramic layer 11, and the other side is coated with a functional coating. The functional coating includes an inorganic heat-resistant layer, a first adhesive layer, and a second adhesive layer. The inorganic heat-resistant layer includes a plurality of heat-resistant coating bodies 12 spaced apart on the surface of the base film 10. The first adhesive layer includes first adhesive bodies 13 distributed between adjacent heat-resistant coating bodies 12. The second adhesive layer includes second adhesive bodies 14 coated on the upper surface of the heat-resistant coating bodies 12. This utility model, by providing first and second adhesive layers of different thicknesses on the base film 10, can meet different bonding requirements between the diaphragm and the electrode sheet; by providing spaced heat-resistant coating bodies 12, it can provide more storage space for the electrolyte.
[0027] Specifically, the thickness of the heat-resistant ceramic layer 11 is preferably 1 μm - 4 μm.
[0028] Specifically, the cross-section of the heat-resistant coating body 12 is rectangular, the heat-resistant coating bodies 12 are arranged at equal intervals along the MD and TD directions of the base film 10, and the long sides of the heat-resistant coating bodies 12 are parallel to the MD direction of the base film 10.
[0029] Specifically, the length of the long side of the heat-resistant coating body 12 is 800 μm - 1200 μm, the length of the short side of the heat-resistant coating body 12 is 300 μm - 500 μm, the spacing of the heat-resistant coating bodies 12 in the MD direction of the base film 10 is 500 μm - 800 μm, and the spacing of the heat-resistant coating bodies 12 in the TD direction of the base film 10 is 300 μm - 500 μm. During actual production, the space between adjacent heat-resistant coating bodies 12 can store electrolyte.
[0030] More specifically, the thickness H1 of the heat-resistant coating body 12 is 1 μm - 3 μm. Preferably, the thickness H1 of the heat-resistant coating body 12 is 1.5 μm - 2.5 μm. The coverage rate of the inorganic heat-resistant layer on the base film 10 is preferably 18% - 44%, more preferably 23% - 39%.
[0031] Specifically, the cross-section of the first adhesive body 13 is circular. The coverage rate of the first adhesive layer on the base film 10 is preferably 2% - 10%, more preferably 4% - 8%. The particle size of the first adhesive body 13 is preferably 200 μm - 300 μm, more preferably 220 μm - 280 μm. The thickness H2 of the first adhesive body 13 is 3 μm - 7 μm.
[0032] Specifically, the cross-section of the second adhesive body 14 is square. The coverage rate of the second adhesive layer on the top surface of the heat-resistant coating body 12 is preferably 30% - 100%, more preferably 40% - 90%, and even more preferably 50% - 80%. The thickness H3 of the second adhesive body 14 is preferably 0.5 μm - 2 μm, more preferably 1 μm - 1.5 μm.
[0033] Specifically, H1, H2, and H3 preferably satisfy the following conditional formula: 1.5 μm < H2 - (H1 + H3) < 5.5 μm. More preferably, 2 μm < H2 - (H1 + H3) < 5 μm. Even more preferably, 2.5 μm < H2 - (H1 + H3) < 4.5 μm. Particularly preferably, 3 μm < H2 - (H1 + H3) < 4 μm.
[0034] As Figure 3 shown, it is a schematic structural diagram of Embodiment 2 of the present utility model. During actual production, the cross-section of the second adhesive body 14 can also be square.
[0035] As Figure 4 The diagram shown is a structural schematic of Embodiment 3 of this utility model. In actual production, the cross-section of the second adhesive 14 can also be elliptical.
[0036] It should be noted that in actual production, when the bonding requirements between the separator and the electrode sheet are not high, a low-pressure process can be used when the separator and the electrode sheet are hot-pressed. In this case, only the first adhesive layer provides the bonding sites. When the bonding requirements between the separator and the electrode sheet are very high, a high-pressure process can be used when the separator and the electrode sheet are hot-pressed. In this case, both the first adhesive layer and the second adhesive layer provide the bonding sites.
[0037] In summary, this invention can meet the different bonding requirements between the diaphragm and the electrode sheet by setting a first adhesive layer and a second adhesive layer of different thicknesses on the base film; and by setting a heat-resistant coating with spaced distribution, it can provide more storage space for the electrolyte.
[0038] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Therefore, any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the actual technical aspects of the present utility model shall still fall within the scope of the technical solution of the present utility model.
Claims
1. A coated separator comprising a base film, characterized by, The base film is coated with a heat-resistant ceramic layer on one side and a functional coating layer on the other side, the functional coating layer comprises an inorganic heat-resistant layer, a first adhesive layer and a second adhesive layer, the inorganic heat-resistant layer comprises a plurality of heat-resistant coating bodies distributed on the surface of the base film, the first adhesive layer comprises first adhesive bodies distributed between adjacent heat-resistant coating bodies, and the second adhesive layer comprises second adhesive bodies coated on the top surface of the heat-resistant coating bodies.
2. The coated separator of claim 1, wherein, The cross section of the heat-resistant coating body is rectangular, the heat-resistant coating bodies are arranged at equal intervals along the MD and TD directions of the base film, and the long side of the heat-resistant coating body is parallel to the MD direction of the base film.
3. The coated separator of claim 2, wherein, The length of the long side of the heat-resistant coating body is 800-1200 μm, the length of the short side of the heat-resistant coating body is 300-500 μm, the interval of the heat-resistant coating body in the MD direction of the base film is 500-800 μm, the interval of the heat-resistant coating body in the TD direction of the base film is 300-500 μm, the coverage of the inorganic heat-resistant layer on the base film is 18-44%, and the thickness H1 of the heat-resistant coating body is 1-3 μm.
4. The coated separator of claim 3, wherein, The cross section of the first adhesive body is circular, the coverage of the first adhesive layer on the base film is 2-10%, the particle size of the first adhesive body is 220-280 μm, and the thickness H2 of the first adhesive body is 3-7 μm.
5. The coated separator of claim 4, characterized in that, The cross section of the second adhesive body is square, the coverage of the second adhesive layer on the top surface of the heat-resistant coating body is 30-100%, and the thickness H3 of the second adhesive body is 0.5-2 μm.
6. The coated separator of claim 5, wherein, The H1, H2 and H3 satisfy the following condition formula: 1.5 μm < H2-(H1+H3) < 5.5 μm.
7. The coated separator of any of claims 1-6, wherein, The thickness of the heat-resistant ceramic layer is 1-4 μm.
8. The coated separator of claim 6, wherein, The thickness H1 of the heat-resistant coating body is 1.5-2.5 μm.
9. The coated separator of claim 6, wherein, The thickness H3 of the second adhesive body is 1-1.5 μm.
10. The coated separator of claim 6, wherein, The particle size of the first adhesive body is 200-300 μm.