Composite diaphragm
By setting a color-developing adhesive layer at the tail of the diaphragm, the problem of inaccurate identification of the remaining amount of the diaphragm is solved, and efficient automated control of cell production is achieved, reducing cell production costs and failure risks.
Patent Information
- Application Number
- CN202422013549.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2034-08-19
AI Technical Summary
In the existing technology, inaccurate identification of the remaining amount of the separator leads to unqualified or wasted battery cells, and the existing color development process increases production costs and safety risks.
A composite diaphragm is designed with a color-developing adhesive layer at the tail end, which is used by the equipment to identify the remaining amount of diaphragm, automatically control the roll changing, and reduce diaphragm waste and production costs.
Improve cell assembly efficiency, reduce separator waste, lower production costs, reduce cell failure risk, and simplify equipment identification process.
Smart Images
Figure CN223828654U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of secondary battery technology, and specifically relates to a composite separator. Background Technology
[0002] In the manufacturing process of secondary batteries, winding is a common cell preparation process. During this process, identifying the remaining amount of separator and changing the separator roll are time-consuming and wasteful steps. Currently, the industry typically uses distance identification devices or operator experience to determine the remaining amount of separator. Due to differences in the separator's support roll and winding tension, the remaining amount is difficult to accurately identify. This often results in insufficient separator material during cell use, leading to defective and scrapped cells. Alternatively, to reduce cell scrap, the separator is changed when there is still a significant amount remaining, thus increasing production costs.
[0003] Previously, colored PET tape was typically used as an identification marker. The colored PET tape was affixed to the end of the separator. However, this method could cause the PET tape to get caught in the battery cell, leading to cell failure.
[0004] To address the above issues, existing solutions primarily focus on improving the color development process to reduce separator wear and tear. For example, some solutions propose using special materials instead of PET to manufacture the adhesive tape, minimizing its impact on the separator and battery cells. Other solutions suggest on-the-spot color development, such as spraying, to form a color coating near the separator's tail end, avoiding the use of PET and reducing separator wear. While these technologies reduce separator wear to some extent, several problems and drawbacks remain. First, the adhesive tape used to replace PET still has a chance of getting entangled in the battery cells, potentially causing cell failure or even safety risks. Second, on-the-spot color development places relatively high demands on manufacturers and raw material storage; the stability of the coating slurry and its transportation require significant resources. Finally, these technologies often require high equipment investment and maintenance costs, increasing production costs for companies.
[0005] Therefore, placing an identifiable marker near the end of the separator that has minimal impact on battery performance for warning of remaining separator quantity and roll replacement is of positive significance for the rapid and low-cost manufacturing of battery cells. Utility Model Content
[0006] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a composite diaphragm.
[0007] An embodiment of the present utility model also provides a composite diaphragm. The composite diaphragm includes a diaphragm and a color-developing adhesive layer provided on at least one side of the diaphragm. The thickness of the color-developing adhesive layer is 1-10 µm. The number of the color-developing adhesive layers provided on one side of the diaphragm is at least one. The distance between the color-developing adhesive layer and the tail of the diaphragm is L1, and the length of the diaphragm on one side of the battery cell is L2, where 0 < L1 ≤ 0.5L2.
[0008] The advantages and technical effects brought by the composite diaphragm of the present utility model are as follows:
[0009] (1) The composite diaphragm of the embodiment of the present utility model has a color-developing adhesive layer near the tail of the diaphragm. The color-developing adhesive layer can be used as a positioning mark for positioning the remaining amount of the diaphragm during the winding of the battery cell, improving the excellent rate of the secondary battery assembly process, reducing the waste of the diaphragm during roll change, and playing a role in cost reduction and efficiency improvement.
[0010] (2) In the composite diaphragm of the embodiment of the present utility model, the distance between the color-developing adhesive layer and the tail of the diaphragm is L1, and the length of the diaphragm on one side of the battery cell is L2, where 0 < L1 ≤ 0.5L2. In this case, when the device recognizes the color-developing adhesive layer near the tail of the diaphragm, the remaining amount of the diaphragm is not enough to meet the usage amount of the diaphragm on one side of a battery cell. At this time, the preparation of this battery cell will be automatically stopped and the roll change operation will be performed. This can perform the roll change when there is still less remaining diaphragm, reducing the usage loss of the diaphragm, and thus reducing the production cost of the battery cell.
[0011] For the composite diaphragm according to the embodiment of the present utility model, 0 < L1 ≤ 0.3L2.
[0012] For the composite diaphragm according to the embodiment of the present utility model, the color-developing adhesive layer is provided at the middle position in the width direction of the diaphragm, or the color-developing adhesive layer is provided at a position near the edge in the width direction of the diaphragm.
[0013] For the composite diaphragm according to the embodiment of the present utility model, the width of the color-developing adhesive layer extending in the width direction of the diaphragm is less than or equal to the width of the diaphragm.
[0014] For the label for diaphragm tail positioning according to the embodiment of the present utility model, the area of the color-developing adhesive layer is 0.5-5000 square millimeters.
[0015] For the label for diaphragm tail positioning according to the embodiment of the present utility model, the shape of the color-developing adhesive layer is strip-shaped, rectangular, square, triangular or circular. Description of the Drawings
[0016] Figure 1 It is a schematic cross-sectional structure diagram of a composite diaphragm of an embodiment of the present utility model.
[0017] Figure 2 It is a top - view structural schematic diagram of a composite diaphragm according to an embodiment of the present utility model.
[0018] Figure 3 It is a top - view structural schematic diagram of another composite diaphragm according to an embodiment of the present utility model.
[0019] Explanation of reference numerals: 2, color - showing adhesive layer; 3, diaphragm. Specific embodiments
[0020] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present utility model, rather than to be construed as a limitation to the present utility model.
[0021] The embodiments of the present utility model provide a composite diaphragm, as shown in Figure 1 , 2 , 3. It includes a diaphragm 3 and a color - showing adhesive layer 2 provided on at least one side of the diaphragm 3. The number of color - showing adhesive layers 2 provided on one side of the diaphragm 3 is at least one. The distance between the color - showing adhesive layer 2 and the tail of the diaphragm 1 is L1, and the length of the single - side diaphragm of the battery cell is L2, where 0 < L1 ≤ 0.5L2.
[0022] The composite diaphragm of the embodiments of the present utility model has a color - showing adhesive layer near the tail of the diaphragm. The color - showing adhesive layer can be used as a positioning mark for positioning the remaining amount of the diaphragm during the winding of the battery cell, improving the excellent rate of the secondary - battery assembly process, reducing the waste of the diaphragm during roll - changing, and playing a role in cost reduction and efficiency improvement.
[0023] In the composite diaphragm of the embodiments of the present utility model, the distance between the color - showing adhesive layer and the tail of the diaphragm is L1, and the length of the single - side diaphragm of the battery cell is L2, where 0 < L1 ≤ 0.5L2. For example, L1 is equal to 0.01L2, 0.05L2, 0.1L2, 0.2L2, 0.3L2, 0.4L2, 0.5L2, etc. In this case, when the device recognizes the color - showing adhesive layer near the tail of the diaphragm, the remaining amount of the diaphragm is not enough to meet the usage amount of the single - side diaphragm of one battery cell. At this time, the preparation of this battery cell will be automatically stopped and the roll - changing operation will be carried out. This can perform roll - changing when there is still less remaining diaphragm, reducing the usage loss of the diaphragm, and thus reducing the production cost of the battery cell. Preferably, 0 < L1 ≤ 0.3L2.
[0024] In the composite diaphragm of the embodiments of the present utility model, the number of color - showing adhesive layers provided on one side of the diaphragm is at least one. For example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. It can be understood that on the basis that the color - showing adhesive layer can be recognized by the device, the fewer the number of color - showing adhesive layers, the better.
[0025] The composite diaphragm according to embodiments of this utility model does not have any particular limitations on the position of the color-developing adhesive layer on the diaphragm, as long as it can be easily recognized by the equipment. For example, the color-developing adhesive layer can cover the entire width of the diaphragm, can be located in the middle of the width of the diaphragm, or can be located near the edge of the width of the diaphragm.
[0026] According to the composite separator of this utility model embodiment, the width of the color-developing adhesive layer extending in the width direction of the separator is less than or equal to the width of the separator. If the color-developing adhesive layer is unavoidably wound into the battery cell, the above-structured color-developing adhesive layer helps to reduce adverse effects on the battery cell performance.
[0027] The composite diaphragm of this utility model does not have any particular limitation on the shape of the color-developing adhesive layer, and it can be any shape. For example, the shape of the color-developing adhesive layer can be strip, rectangle, square, triangle or circle, or other regular or irregular shapes.
[0028] In this embodiment of the composite separator, the thickness of the color-developing adhesive layer is 1~10µm. When the thickness of the color-developing adhesive layer is too small, it is difficult for the equipment to identify it. When the thickness of the color-developing adhesive layer is too large, if it is wound into the battery cell, it will negatively impact the battery cell's performance.
[0029] The composite diaphragm of this invention does not have a particular limitation on the size of the color-developing adhesive layer, as long as it can be detected by the equipment. For example, the area of the color-developing adhesive layer can be 0.5~5000 square millimeters, such as 0.5 square millimeters, 50 square millimeters, 500 square millimeters, 1000 square millimeters, 2000 square millimeters, 3000 square millimeters, 4000 square millimeters, 5000 square millimeters, etc. It can be understood that, provided the color-developing adhesive layer can be recognized by the equipment, the smaller the area of the color-developing adhesive layer, the better.
[0030] The present invention does not impose any particular restrictions on the structure of the diaphragm. For example, it may consist of only a diaphragm base membrane, or it may include a diaphragm base membrane and a diaphragm coating.
[0031] In some embodiments, the diaphragm may include a base membrane and optionally a functional coating. The base membrane may be at least one of a polyolefin membrane, an aramid membrane, a polyimide membrane, and a nonwoven membrane. The functional coating contains functional particles that may be at least one of an aqueous or oil-based polyvinylidene fluoride (PVDF) particle, an aqueous or oil-based polymethyl methacrylate (PMMA) particle, ceramic particles, boehmite, or functional coating particles used in the prior art for the surface of the base membrane.
[0032] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.
[0033] Example 1
[0034] (1) Design and manufacture a color transfer tape.
[0035] ① The substrate of this tape is polyester film (i.e. release film) with a thickness of 0.02mm.
[0036] ② Prepare a color-developing adhesive layer slurry, which consists of the following components: color developer, binder, thickener, wetting agent, dispersant, and solvent. The color developer is phthalocyanine blue, the binder is polyvinylidene fluoride, the thickener is polyvinyl alcohol, the wetting agent is polyether-modified siloxane, the dispersant is phosphate ester, and the solvent is water. The weight ratio of each component is color developer: binder: thickener: wetting agent: dispersant: solvent = 2:4:0.2:0.5:0.1:96.2.
[0037] ③ Use a coating machine to evenly coat the color-developing adhesive layer slurry onto the surface of the polyester film. The coating speed is 30±5m / min, the winding tension is 8±2kg, and the coating amount of the color developer is 0.5g / m².
[0038] ④ The coated polyester film is dried to obtain a color-developing transfer tape. The drying temperature is 80℃ and the drying time is 10 minutes. The thickness of the color-developing adhesive layer in this color-developing transfer tape is 2µm.
[0039] (2) Cut the color transfer tape into actual application widths of 10 mm and actual application lengths of 195 mm. The area of the cut color transfer tape is 1950 square millimeters.
[0040] (3) Select the required separator, which includes a base polyethylene film and ceramic coatings on both sides of the base film. The width of the separator is 195mm. The design length of the separator on one side of the cell is L2. The length direction of the color transfer tape obtained after cutting in step (2) is consistent with the width direction of the separator. The cut color transfer tape is applied to the separator at 5m (i.e., L1=0.3L2) after winding up, and the polyester film is peeled off, leaving the color adhesive layer, to obtain the following: Figures 1-2 The diaphragm shown has a color-developing adhesive layer.
[0041] (4) During the diaphragm winding process, the equipment identifies the color bonding layer, realizes automatic shutdown of the equipment, and then performs roll changing.
[0042] Example 2
[0043] The method in this embodiment is the same as that in Example 1, except that the color developer is reactive yellow, the binder is styrene-butadiene rubber, the thickener is sodium carboxymethyl cellulose, the wetting agent is polyether-modified polydimethylsiloxane, the dispersant is polyacrylate, and the solvent is dimethylformamide.
[0044] Example 3
[0045] The method in this embodiment is the same as that in embodiment 1, except that the color transfer tape is cut into an actual application width of 10 mm and an actual application length of 156 mm. The area of the cut color transfer tape is 1560 square millimeters.
[0046] Example 4
[0047] The method in this embodiment is the same as that in embodiment 1, except that the color transfer tape is cut into an actual application width of 20mm and an actual application length of 195mm. The area of the cut color transfer tape is 3900 square millimeters.
[0048] Example 5
[0049] The method in this embodiment is the same as that in Embodiment 1, except that the thickness of the color-developing adhesive layer is 5µm.
[0050] Example 6
[0051] The method in this embodiment is the same as that in Embodiment 1, except that the thickness of the color-developing adhesive layer is 10µm.
[0052] Example 7
[0053] The method in this embodiment is the same as that in embodiment 1, except that L1 = 0.05L2.
[0054] Example 8
[0055] The method in this embodiment is the same as that in embodiment 1, except that L1 = 0.1L2.
[0056] Example 9
[0057] The method in this embodiment is the same as that in embodiment 1, except that L1 = 0.5L2.
[0058] Example 10
[0059] (1) Design and manufacture a color transfer sticker, which consists of a polyester film (i.e., release film) with a thickness of 0.02 mm and a color-developing adhesive layer disposed on the surface of the polyester film. The color transfer sticker is circular in shape and has a diameter of 40 mm.
[0060] (2) Select the required separator, which includes a base polyethylene film and ceramic coatings on both sides of the base film. The width of the separator is 195mm. The design length of the separator on one side of the cell is L2. Apply the color transfer stickers from steps (1) to the separator near the edges on both sides in the width direction and 5m away from the roll-up (i.e., L1=0.3L2). Remove the polyester film, leaving the color adhesive layer, to obtain the desired result. Figure 3 The diaphragm shown has a color-developing adhesive layer.
[0061] (3) During the diaphragm winding process, the equipment identifies the color bonding layer, realizes automatic shutdown of the equipment, and then performs roll changing.
[0062] Compared with related technologies, the beneficial effects of embodiments 1-10 of this utility model are as follows:
[0063] (1) Improved efficiency: The method of applying and peeling off polyester film tape used in this embodiment of the utility model is convenient to operate and can be used as needed, which is conducive to improving production efficiency; at the same time, the equipment recognizes color-coded labels to achieve automatic control, which improves the working efficiency of the equipment.
[0064] (2) Cost reduction: This utility model embodiment does not require on-site preparation of slurry for coating, which reduces the investment in consumables such as tooling and equipment, and eliminates the need to consider the long-term storage and transportation cycle of the slurry, thus greatly reducing the production cost of enterprises;
[0065] (3) Reduced failure risk: The color transfer scheme of this utility model fully considers the risk that there is a certain probability of the color bonding layer being wound into the cell. The material selection has been verified to have no substantial impact on the cell performance, which greatly reduces the risk of cell failure.
[0066] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0067] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A composite diaphragm, characterized in that, The battery cell includes a separator and a color-developing adhesive layer disposed on at least one side of the separator. The thickness of the color-developing adhesive layer is 1–10 μm. At least one color-developing adhesive layer is disposed on one side of the separator. The distance between the color-developing adhesive layer and the tail of the separator is L1. The length of the separator on one side of the battery cell is L2. <L1≤0.5L2。 2. The composite diaphragm according to claim 1, characterized in that, 0 <L1≤0.3L2。 3. The composite diaphragm according to claim 1, characterized in that, The color-developing adhesive layer is disposed in the middle position in the width direction of the diaphragm, or the color-developing adhesive layer is disposed near the edge in the width direction of the diaphragm.
4. The composite diaphragm according to claim 1, characterized in that, The width of the color-developing adhesive layer extending in the width direction of the diaphragm is less than or equal to the width of the diaphragm.
5. The composite diaphragm according to claim 1, characterized in that, The area of the color-developing adhesive layer is 0.5 to 5000 square millimeters.
6. The composite diaphragm according to claim 1, characterized in that, The color-developing adhesive layer can be rectangular, square, triangular, or circular.