Gravure roller for patterned coating of battery diaphragm as well as manufacturing method and coating method of gravure roller

Abstract

The invention provides a gravure roller for patterned coating of a battery diaphragm as well as a manufacturing method and a coating method of the gravure roller, and belongs to the technical field of battery diaphragm processing. High-quality processing of patterned coating of the battery diaphragm is realized through two optimization schemes: in the first scheme, glue solution residues are reduced through the design of the ceramic bottom layer, and the accuracy of a glue coating pattern is ensured through structural matching of micro ink cells, convex areas and concave areas, and meanwhile, the original air permeability of the diaphragm is reserved; in the second scheme, the electrowetting stack is combined with the partition pulse power supply assembly, intelligent control over carrying and releasing of the glue solution is achieved, the glue solution transferring efficiency is improved, and the gluing precision is further optimized. The manufacturing method of the two schemes is clear in process and high in operability, the corresponding coating method is efficient and stable, the requirement for large-scale production of the battery diaphragm can be met, and important industrial application value is achieved.

Description

Technical Field

[0001] This invention relates to the field of battery separator processing technology, and in particular to a gravure roller for patterned coating of battery separators, and its manufacturing and coating methods. Background Technology

[0002] In the production of battery separators, it is often necessary to apply a patterned adhesive (such as ceramic slurry, PVDF, etc.) to the separator surface to balance the separator's adhesion, air permeability, and electrolyte wettability. As a core component in the adhesive coating process, the groove structure on the surface of the gravure roller directly determines the shape, size, and distribution of the adhesive dots, thus affecting the coating quality of the separator.

[0003] Currently, the industry generally uses traditional gravure rollers for this process. Traditional gravure rollers are standard cylinders of equal diameter, and their surfaces are engraved with evenly distributed micro-cells (such as squares, rhombuses, etc.) to quantitatively carry and transfer the adhesive. The working process is as follows: the entire roller surface is dipped in adhesive, which is then scraped off by a doctor blade. The entire roller surface covered with cells then comes into contact with the diaphragm, thereby transferring the adhesive onto the diaphragm.

[0004] However, in actual coating processes, traditional gravure rollers often suffer from problems such as blank area contamination, adhesive tailing, and adhesion leading to uneven coating dot distribution and large fluctuations in adhesive amount. This not only causes a decline in key indicators such as the mechanical and electrical properties of the separator, but also may result in adhesive waste and increased production costs. In addition, the low efficiency of adhesive carrying and transfer makes it difficult to accurately control the precision of the coating pattern, and problems such as adhesive dripping and incomplete transfer are prone to occur during the coating process, which restricts the production quality and efficiency of battery separators.

[0005] Therefore, there is an urgent need to design a new type of gravure roller to solve the above-mentioned technical problems. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a gravure roller for patterned coating of battery separators, and its manufacturing and coating methods, to solve the problems of blank area contamination, adhesive residue contamination, and low transfer efficiency of gravure rollers in the prior art.

[0007] To achieve the above and other related objectives, the present invention provides the following technical solutions: In a first aspect, the present invention provides a gravure roller for patterned coating of battery separators, the gravure roller including a plurality of raised regions and recessed regions surrounding the raised regions, the top surface of the raised regions being a working plane, and the top surface of the raised regions being provided with micro-cells for carrying adhesive liquid.

[0008] Furthermore, the height difference (H) between the top surface of the raised region and the bottom surface of the recessed region is 0.1cm to 5.0cm. This height difference between the raised and recessed regions creates a gap between the recessed region and the diaphragm surface, preventing contact between them during the coating process.

[0009] Furthermore, the micro-pores are formed by laser engraving.

[0010] Furthermore, the distribution, shape, and area of ​​the raised regions on the roller surface correspond to the adhesive pattern to be formed on the diaphragm. The macroscopic shape of the raised regions includes, but is not limited to, circles, ellipses, polygons, stripes, rings, or combinations thereof. Their distribution array includes dot matrix, stripes, crosses, or custom irregular arrangements.

[0011] Furthermore, the shape, depth, and opening ratio of the micro-cells are designed according to the required amount of adhesive applied, and the shape of the micro-cells can be conical, grid-shaped, or oblique.

[0012] Furthermore, the micro-holes have an opening ratio of 20-60%, a depth of 10-50 μm, and an opening diameter of 20-80 μm.

[0013] As a preferred embodiment, the surface of the gravure roller is provided with a ceramic underlayer covering the raised and recessed areas. The thickness of the ceramic underlayer is less than the depth of the micro-cells, allowing the micro-cells to penetrate the ceramic underlayer after laser engraving. This invention, by providing a ceramic underlayer on the surface of the gravure roller, results in a smaller contact angle on the ceramic surface, making it less likely for adhesive residue to remain. Meanwhile, the micro-cells where adhesive retention is required have a larger contact angle due to the laser engraving exposing the underlayer, allowing for better adhesive retention and preventing contamination of the non-adhesive-coated blank areas of the diaphragm, thus preserving as much of its original breathability as possible.

[0014] Furthermore, the ceramic substrate is made of Al2O3 or Al2O3-TiO2 material, and Ra≤0.2μm.

[0015] Furthermore, the thickness of the ceramic substrate is 10~30μm.

[0016] Secondly, the present invention provides a method for manufacturing a gravure roller according to the first aspect, comprising the following steps: S1. Design the raised area according to the required adhesive pattern of the diaphragm, and then process the recessed and raised areas on the roller surface by CNC milling; S2. Spray a ceramic undercoat onto the entire roller surface and polish it to Ra≤0.2 μm; S3. Next, carve micro-cavities on the working surface of the raised area. The depth of the micro-cavities is greater than the thickness of the ceramic base layer.

[0017] Thirdly, the present invention provides a method for diaphragm coating using the gravure roller of the first aspect, comprising the following steps: (1) Rotate the above gravure roller in the glue tank so that the raised area is coated with glue; (2) Use a scraper to scrape off the adhesive from the sides of the raised area, leaving only the adhesive in the micro-crystals; (3) The gravure roller and the back roller are pressed together to press the diaphragm. At this time, only the working plane of the raised area is in contact with the diaphragm, and the adhesive in the micro-cells is accurately transferred to the diaphragm to form the preset adhesive pattern.

[0018] Fourthly, the present invention provides a gravure roller for patterned coating of battery separators. The gravure roller includes multiple raised areas and recessed areas surrounding the raised areas. The top surface of each raised area is a working plane, and the top surface of each raised area is provided with microscopic cavities for carrying adhesive. The difference lies in that the surface of each raised area is further provided with an electrowetting stack, which, from the inside out, includes a microelectrode layer, a dielectric layer, and a hydrophobic layer, such that the static contact angle θ0 of the top surface of the raised area is ≥110° when no power is applied, and the contact angle is reduced to θ0 when power is applied. EWOD ≤70°.

[0019] Furthermore, it also includes a partitioned pulse power supply component electrically connected to the microelectrode layer, the partitioned pulse power supply component being used to apply pulse voltage to the corresponding partitioned protrusion region when the protrusion region passes through the pressing position.

[0020] Furthermore, the partitioned pulse power supply assembly includes a multi-slip ring or a rotary transformer, and the microelectrode layer is divided into 4 to 32 partitions connected in parallel in the circumferential and / or axial directions.

[0021] Furthermore, the amplitude of the pulse voltage is 30~120 V, the frequency is 100 Hz~5 kHz, and the duty cycle is 5~40%. This invention involves stacking electrowetting layers on the top surface of the raised region (the surface of the micro-crystals). When no power is applied, the contact angle θ0 of the hydrophobic layer is ≥110°, allowing for better adhesion of adhesive and reducing dripping. However, when the microelectrode layer is energized, the contact angle of the raised region surface instantly drops to θ0. EWOD At ≤70°, it can quickly release the adhesive and complete the transfer of the adhesive to the battery separator.

[0022] Furthermore, the microelectrode layer is formed by sputtering or depositing a conductive metal material, with a total thickness of 50-300 nm. The conductive metal material is selected from at least one of Ti, Cr, Cu, Al, ITO, and Ti-Ni alloys.

[0023] Furthermore, the dielectric layer comprises Al2O3 deposited by ALD or Al2O3 with Parylene. The C stack has a total thickness of 0.30~1.50μm and a breakdown field strength ≥20 V / μm.

[0024] Furthermore, the hydrophobic layer is Teflon. AF or fluoroalkylsilane self-assembled films with a total thickness of 30~120nm.

[0025] Furthermore, the gravure roller body is made of an insulating material, or has an insulating coating on its surface. Specifically, the insulating coating is selected from polyimide (PI) coating or ceramic coating.

[0026] Furthermore, the thickness of the insulating coating is greater than the depth of the micro-cells, and the thickness of the insulating coating is 50~200μm.

[0027] Fifthly, the present invention provides a method for manufacturing a gravure roller according to the fourth aspect, comprising the following steps: S1. Design the raised area according to the required adhesive pattern of the diaphragm, and then process the recessed and raised areas on the roller surface by CNC milling; S2. Spray an insulating coating onto the entire roller surface to cover the entire roller surface; S3. Then, laser engrave micro-holes on the top surface of the raised area. The depth of the micro-holes is less than the thickness of the insulating coating. And shallow grooves for wiring are engraved on the sidewall of the raised area toward the bottom surface of the recessed area. S4. Sputtering or depositing conductive metal material on the surface of the micro-holes and in the shallow grooves of the wiring to form an electrically connected microelectrode layer and wire layer. S5. Then, a dielectric layer and a hydrophobic layer are deposited sequentially on the microelectrode layer and the wire layer. S6. Connect the microelectrode layer of the corresponding partition to the partition pulse power supply component through the wire layer and wire.

[0028] In a sixth aspect, the present invention provides a method for diaphragm coating using a gravure roller of the fourth aspect, comprising the following steps: (1) Rotate the above gravure roller in the glue tank so that the raised area is coated with glue; (2) Use a scraper to scrape off the adhesive from the sides of the raised area, leaving only the adhesive in the micro-crystals; (3) The gravure roller and the back roller are used to press the diaphragm together. When the target zone passes through the pressing zone, a pulse voltage is applied to the corresponding zone to reduce the contact angle of the top surface of the raised area from θ0≥110° to θ EWOD At an angle of ≤70°, the adhesive solution within the micro-cells is precisely transferred onto the diaphragm to form a pre-defined adhesive pattern.

[0029] Furthermore, sensors are installed in the pressing area to control the partition pulse power supply components.

[0030] As described above, the gravure roller for patterned coating of battery separators and its manufacturing and coating methods of the present invention have the following beneficial effects: The present invention achieves high-quality processing of patterned coating of battery separators through two optimized schemes. In Scheme 1, the design of the ceramic substrate reduces adhesive residue, and the structure of the micro-cells and raised / recessed areas ensures the accuracy of the coating pattern while preserving the original air permeability of the separator. In Scheme 2, the combination of the electrowetting layer stack and the partitioned pulse power supply component realizes intelligent control of adhesive carrying and release, improves adhesive transfer efficiency, and further optimizes coating accuracy. The manufacturing processes of both schemes are clear and highly operable, and the corresponding coating methods are efficient and stable, which can meet the needs of large-scale production of battery separators and have significant industrial application value. Attached Figure Description

[0031] Figure 1 The diagram shown is a structural schematic of the gravure roller disclosed in Embodiment 1 of the present invention.

[0032] Component designation explanation 1. Roller body; 2. Raised area; 21. Microscopic cavities; 3. Depressed area. Detailed Implementation

[0033] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. It should be noted that, unless otherwise specified, the following embodiments and features described herein can be combined with each other.

[0034] Example 1 Please see Figure 1 This embodiment provides a gravure roller for patterned coating of battery separators. The roller body 1 is made of steel, with a total length of 150cm and a standard diameter of 40cm. Multiple raised areas 2 and recessed areas 3 surrounding the raised areas are provided on the roller surface. The raised areas 2 are hexagonal, arranged in an "island" pattern, with a side length of 5mm. The hexagonal raised areas 2 are evenly distributed in an array with a spacing of 5mm in both the axial and circumferential directions on the roller surface. The top surface of the raised areas 2 is 1cm higher than the bottom surface of the recessed areas 3. The top surface of the raised areas is a working plane, and the top surface of the raised areas 2 has micro-cells 21 for carrying the adhesive. The depth of the micro-cells 21 is 40μm, and the opening ratio is 35%, used to control the amount of adhesive applied to each raised area.

[0035] The method for diaphragm coating using the above-mentioned gravure roller includes the following steps: (1) Install the above gravure roller on the coating machine and make the gravure roller rotate at a uniform speed to dip into the PVDF adhesive; (2) Adjust the angle and pressure of the scraper to ensure that it can completely scrape the adhesive off the sides of the recessed and raised areas, leaving only the adhesive in the mesh cavity on the top of the raised area. (3) Guide the diaphragm substrate through the pressing area between the gravure roller and the back roller, adjust the pressure to make the raised area of ​​the gravure roller fully contact the diaphragm for coating.

[0036] Ultimately, a hexagonal array of adhesive dots with clear boundaries, no crosstalk, and a side length of approximately 5 mm was obtained on the diaphragm, and the non-adhesive-coated areas were completely free of contamination.

[0037] Example 2 This embodiment provides a gravure roller for patterned coating of battery separators. The roller body is made of steel, with a total length of 150cm and a standard diameter of 40cm. The roller surface has multiple raised areas and recessed areas surrounding the raised areas. The raised areas are circular, arranged in an "island" pattern, with a diameter of 5mm. The circular raised areas are evenly distributed in an array with a spacing of 5mm in both the axial and circumferential directions on the roller surface. The top surface of the raised areas is 1cm higher than the bottom surface of the recessed areas. A ceramic substrate covering the raised and recessed areas is provided on the roller surface, with a thickness of 20μm. The top surface of the raised areas is a working plane, and micro-cells for carrying adhesive are formed on the top surface of the raised areas by laser engraving. The depth of the micro-cells is 40μm, and the opening ratio is 35%, used to control the amount of adhesive applied to each individual dot.

[0038] The manufacturing method of the gravure roller includes the following steps: S1. Design the raised area according to the required adhesive pattern of the diaphragm, and then process the recessed area on the roller surface by CNC milling, and the remaining area forms the raised area; S2. Spray a ceramic base layer onto the entire roller surface to cover all raised and recessed areas. The thickness of the ceramic base layer is 20μm. Then polish the surface of the ceramic base layer to Ra≤0.2μm. S3. Next, carve micro-cavities on the top surface of the raised area. The depth of the micro-cavities is 40μm.

[0039] The method for diaphragm coating using the above-mentioned gravure roller includes the following steps: (1) Install the above gravure roller on the coating machine and make the gravure roller rotate at a uniform speed to dip into the PVDF adhesive; (2) Adjust the angle and pressure of the scraper to ensure that it can completely scrape the adhesive off the sides of the recessed and raised areas, leaving only the adhesive in the mesh cavity on the top of the raised area. (3) Guide the diaphragm substrate through the pressing area between the gravure roller and the back roller, adjust the pressure to make the raised area of ​​the gravure roller fully contact the diaphragm for coating.

[0040] Ultimately, a circular array of adhesive dots with clear boundaries, no crosstalk, and a diameter of approximately 5 mm was obtained on the diaphragm, and the non-adhesive-coated areas were completely free of contamination.

[0041] Example 3 This embodiment provides a gravure roller for patterned coating of battery separators. The roller body is made of steel, with a total length of 150cm and a standard diameter of 40cm. The roller surface has multiple raised areas and surrounding recessed areas. The raised areas are hexagonal, arranged in an "island" pattern, with a side length of 5mm. The hexagonal raised areas are evenly distributed in an array with a spacing of 5mm in both the axial and circumferential directions on the roller surface. The top surface of each raised area is 1cm higher than the bottom surface of the recessed areas. The top surface of each raised area is a working plane and has micro-cells for carrying the adhesive. The depth of these micro-cells is 40μm, and the opening ratio is 35%, used to control the amount of adhesive applied to each raised area. The surface of the raised area is also provided with an electrowetting layer stack, which includes a microelectrode layer, a dielectric layer and a hydrophobic layer from the inside out. The microelectrode layer is divided into 8 partitions along the circumference. The microelectrode layer of each partition is electrically connected to a pulse power supply component of one of the partitions, so that the static contact angle θ0 of the top surface of the raised area of ​​the partition is ≥110° when no power is applied, and the contact angle is reduced to θ when power is applied. EWOD ≤70°.

[0042] The manufacturing method of the gravure roller includes the following steps: S1. Design the raised area according to the required adhesive pattern of the diaphragm, and then process the recessed and raised areas on the roller surface using CNC. S2. Spray an Al2O3 ceramic coating onto the entire roller surface, so that the ceramic coating covers the entire roller surface, and the thickness of the ceramic coating is 120μm. S3. Laser engrave micro-holes on the top surface of the raised area. The depth of the micro-holes is 40μm. And engrave shallow grooves (20μm wide and 10μm deep) on the sidewall of the raised area toward the bottom surface of the recessed area. S4. Then, 10 nm Ti / Cr and 200 nm Al are sputtered sequentially on the surface of the raised area and in the shallow trench of the wiring to form a microelectrode layer and a wire layer. S5. Then, Al2O3 (0.5μm) is deposited sequentially on the microelectrode layer and the wire layer to form a dielectric layer, and then a Teflon-AF (100nm) hydrophobic layer is spin-coated. S6. Divide all microelectrode layers into 8 partitions along the circumference, and electrically connect the microelectrode layers of the corresponding partitions to the partition pulse power supply components through wire layers and wires.

[0043] The method for applying a diaphragm coating using the gravure roller includes the following steps: (1) Rotate the above gravure roller in the glue tank so that the raised area is coated with glue; (2) Use a scraper to scrape off the adhesive from the sides of the raised area, leaving only the adhesive in the micro-crystals; (3) The gravure roller and the back roller are used to press the diaphragm together. When the target zone passes through the pressing zone, a pulse voltage is applied to the corresponding zone. The pulse parameters are 80V, 2kHz, 20% duty cycle, and phase error ≤ ±2 ms. This causes the contact angle of the top surface of the raised area to decrease from θ0≥110° to θ EWOD At an angle of ≤70°, the adhesive solution within the micro-cells is precisely transferred onto the diaphragm to form a pre-defined adhesive pattern.

[0044] Example 4 This embodiment provides a gravure roller for patterned coating of battery separators. The roller body is made of steel, with a total length of 150cm and a standard diameter of 40cm. The roller surface has multiple raised areas and surrounding recessed areas. The raised areas are hexagonal, arranged in an "island" pattern, with a side length of 5mm. The hexagonal raised areas are evenly distributed in an array with a spacing of 5mm in both the axial and circumferential directions on the roller surface. The top surface of each raised area is 1cm higher than the bottom surface of the recessed areas. The top surface of each raised area is a working plane and has micro-cells for carrying the adhesive. The depth of these micro-cells is 40μm, and the opening ratio is 35%, used to control the amount of adhesive applied to each raised area. The surface of the raised area is also provided with an electrowetting layer stack, which includes a microelectrode layer, a dielectric layer and a hydrophobic layer from the inside out. The microelectrode layer is divided into 8 partitions along the circumference. The microelectrode layer of each partition is electrically connected to a pulse power supply component of one of the partitions, so that the static contact angle θ0 of the top surface of the raised area of ​​the partition is ≥110° when no power is applied, and the contact angle is reduced to θ when power is applied. EWOD ≤70°.

[0045] The manufacturing method of the gravure roller includes the following steps: S1. Design the raised area according to the required adhesive pattern of the diaphragm, and then process the recessed and raised areas on the roller surface using CNC. S2. Spray an Al2O3-TiO2 (13 wt%) ceramic coating onto the entire roller surface, so that the ceramic coating covers the entire roller surface and the thickness of the ceramic coating is 120 μm. S3. Then, laser engrave micro-holes on the top surface of the raised area. The depth of the micro-holes is 40μm. Shallow grooves (20μm wide and 10μm deep) are engraved on the sidewall of the raised area toward the bottom surface of the recessed area. S4. Then, 10 nm Ti / Cr and 200 nm Cu are sputtered sequentially on the surface of the raised area and in the shallow groove of the wiring to form a microelectrode layer and a wire layer. S5. Then, Al2O3 (0.4μm) and Parylene-C (0.5μm) are deposited sequentially on the microelectrode layer and the wire layer to form a dielectric layer, and a fluoroalkylsilane self-assembled film (80nm) is spin-coated to form a hydrophobic layer. S6. Divide all microelectrode layers into 16 circumferential zones, and electrically connect the microelectrode layers of the corresponding zones to the zone pulse power supply components through wire layers and wires.

[0046] The method for applying a diaphragm coating using the gravure roller includes the following steps: (1) Rotate the above gravure roller in the glue tank so that the raised area is coated with glue; (2) Use a scraper to scrape off the adhesive from the sides of the raised area, leaving only the adhesive in the micro-crystals; (3) The gravure roller and the back roller are used to press the diaphragm together. When the target zone passes through the pressing zone, a pulse voltage is applied to the corresponding zone. The pulse parameters are 100V, 1kHz, 20% duty cycle, and phase error ≤ ±2 ms. This causes the contact angle of the top surface of the raised area to decrease from θ0≥110° to θ EWOD At an angle of ≤70°, the adhesive solution within the micro-cells is precisely transferred onto the diaphragm to form a pre-defined adhesive pattern.

[0047] In summary, this invention achieves high-quality processing of patterned coating for battery separators through two optimized schemes: In Scheme 1, the design of the ceramic substrate reduces adhesive residue, and the structural combination of micro-cells and raised / recessed areas ensures the accuracy of the coating pattern while preserving the original air permeability of the separator; In Scheme 2, the combination of electrowetting stack and partitioned pulse power supply component enables intelligent control of adhesive carrying and release, improving adhesive transfer efficiency and further optimizing coating precision. Both schemes have clear manufacturing processes, strong operability, and efficient and stable coating methods, meeting the needs of large-scale battery separator production and possessing significant industrial application value. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial utilization value.

[0048] The terms used in this specification, such as "upper," "lower," "left," "right," "front," "back," "middle," and "one," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of the invention.

[0049] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. All equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A gravure roll for patterned coating of battery separator, characterized by, The intaglio roller comprises a plurality of raised areas and recessed areas surrounding the raised areas, and the top surface of the raised areas is provided with micro-cells for carrying glue.

2. The gravure roll according to claim 1, characterized in that The height difference between the top surface of the raised areas and the bottom surface of the recessed areas is 0.1cm-5.0cm; the micro-cells are formed by laser engraving; the opening rate of the micro-cells is 20-60%, the depth is 10-50μm, and the aperture is 20-80μm.

3. The gravure roll of claim 1 wherein, The roller surface of the intaglio roller is provided with a ceramic bottom layer covering the raised areas and the recessed areas, the thickness of the ceramic bottom layer is less than the depth of the micro-cells, so that the micro-cells penetrate the ceramic bottom layer after laser engraving.

4. The gravure roll according to claim 3, characterized in that The ceramic bottom layer is made of Al2O3 or Al2O3-TiO2 material, and the thickness of the ceramic bottom layer is 10-30μm.

5. An engraved roll for patterned coating of battery separator, characterized in that, The intaglio roller comprises a plurality of raised areas and recessed areas surrounding the raised areas, the top surface of the raised areas is provided with micro-cells for carrying gum solution; the surface of the raised areas is also provided with an electrowetting layer stack, the layer stack comprises a micro-electrode layer, a dielectric layer and a hydrophobic layer from inside to outside, so that the static contact angle θ0 of the top surface of the raised areas is ≥110° when not electrified, and the contact angle is reduced to θ EWOD ≤70° when electrified.

6. The gravure roll of claim 5 wherein, Further comprising a partitioned pulse power supply assembly electrically connected to the micro-electrode layer, the partitioned pulse power supply assembly is used to apply a pulse voltage to the corresponding raised area when the raised area passes through the pressing position; the amplitude of the pulse voltage is 30-120V, the frequency is 100Hz-5kHz, and the duty cycle is 5-40%.

7. The gravure roll of claim 5 wherein, The microelectrode layer is formed by sputtering or depositing a conductive metal material, with a total thickness of 50-300 nm, the conductive metal material being selected from at least one of Ti, Cr, Cu, Al, ITO, and Ti-Ni alloy; the dielectric layer comprises ALD-deposited Al2O3 or Al2O3 and Parylene C, with a total thickness of 0.30-1.50 μm and a breakdown field strength ≥ 20 V / μm; and the hydrophobic layer is Teflon AF or a fluoroalkylsilane self-assembled film, with a total thickness of 30-120 nm.

8. The gravure roll of claim 5 wherein, The roller body of the intaglio roller is made of insulating material, or is provided with an insulating coating; the thickness of the insulating coating is greater than the depth of the micro-cells, the thickness of the insulating coating is 50-200μm, and the insulating coating is selected from a polyimide coating or a ceramic coating.

9. A method of manufacturing a gravure roll as claimed in claims 5 to 8, characterized in that The method comprises the following steps: S1, design the raised areas according to the glue application pattern required by the diaphragm, and then mill the recessed areas and the raised areas on the roller surface by numerical control milling; S2, spray an insulating coating on the entire roller surface to cover the entire roller surface; S3, laser engrave micro-cells on the top surface of the raised areas, the depth of the micro-cells is less than the thickness of the insulating coating, and a trace shallow groove is engraved on the side wall of the raised area to the bottom surface of the recessed area; S4, sputter or deposit a conductive metal material on the surface of the micro-cells and the trace shallow groove to form an electrically connected micro-electrode layer and a conductor layer; S5, then deposit a dielectric layer and a hydrophobic layer on the micro-electrode layer and the conductor layer in sequence; S6, electrically connect the micro-electrode layer of the corresponding partition to the partitioned pulse power supply assembly through the conductor layer and the conductor.

10. A method of patterning coating of a battery separator, characterized by, The intaglio roller of any one of claims 5-8 comprises the following steps: (1) rotate the above intaglio roller in the glue tank to make the raised areas dip in the glue; (2) use a scraper to remove the glue on the side surface of the raised areas, leaving only the glue in the micro-cells; (3) The diaphragm is pressed by the gravure roller and the backing roller. When the target partition passes through the pressing area, the pulse voltage is applied to the corresponding partition, so that the contact angle of the top surface of the convex area is reduced from θ0≥110° to θ EWOD ≤70°, and the glue solution in the micro network hole is accurately transferred to the diaphragm to form a preset glue coating pattern.

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