A double-sided surface coating and rolling all-in-one machine for solid-state battery electrode sheets
The integrated design of the double-sided surface coating roller press solves the problems of insufficient coating precision and high energy consumption of solid-state battery electrode sheets, and realizes efficient and low-energy ultra-thin coating, improving coating quality and yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HEYUAN LICHUANG (HUAIAN) NEW ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-07-14
- Publication Date
- 2026-06-23
AI Technical Summary
Existing technologies for the secondary coating process of solid-state battery electrodes suffer from problems such as insufficient coating precision, high energy consumption, solvent penetration leading to poor surface quality, and damage to active materials from repeated rolling.
The double-sided surface coating and roller pressing machine integrates the primary and secondary surface coating mechanisms with the roller pressing mechanism. It utilizes infrared heating drying and roller pressing integrated processes to achieve ultra-thin coatings while reducing energy consumption and improving coating quality.
It improves coating accuracy and efficiency, reduces energy consumption, reduces the number of equipment, avoids surface defects caused by solvent penetration, reduces particle size damage of active materials, and improves yield and thickness uniformity.
Smart Images
Figure CN224389185U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of battery electrode production technology, and in particular to a double-sided surface coating roll forming machine for solid-state battery electrodes. Background Technology
[0002] In novel solid-state batteries, an ultra-thin solid electrolyte layer is often coated a second time on the electrode surface, potentially eliminating the need for a separator in the cell. The secondary coating process on the electrode surface requires extremely high electrolyte layer thickness, typically 2-10 micrometers, and the surface flatness of the substrate (positive and negative electrodes) is far lower than that of metal foils. Therefore, the coating precision requirements for the equipment are very high. Conventional transfer coating and extrusion coating methods struggle to achieve the 2-10 micrometer precision, while microgravure coating is perfectly suited for ultra-thin coating.
[0003] The mainstream secondary coating method uses a separate gravure coating machine or integrates the gravure coating machine into the coating machine, employing a conventional gravure coating + single-roll cold pressing process. However, actual production has revealed the following problems:
[0004] 1. Secondary drying can easily cause electrode powder to fall off, surface bubbles in the secondary coating, and low efficiency of micro-coating.
[0005] 2. It is necessary to use an oven to dry the coated electrode sheets, which uses electrically heated air, and is equipped with a circulating fan and a dehumidifying fan. The equipment is numerous and energy-intensive.
[0006] 3. Since the coating substrate is a positive and negative electrode, and the electrode is a porous structure at the microscopic level, when the coating liquid is transferred to the electrode surface, the solvent will quickly penetrate into the electrode under the action of capillary force. Using traditional hot air heating and drying is slow, and after the solvent has completely penetrated into the electrode, the gas generated during the drying process can easily form microscopic defects such as pits and craters on the electrode surface during the exhaust process.
[0007] 4. The electrode sheet needs to go through "coating → rolling → surface coating → secondary rolling". Multiple rolling processes will damage the particle size of the active material. Utility Model Content
[0008] Purpose of this utility model: The technical problem to be solved by this utility model is to provide a double-sided surface coating and roller pressing integrated machine for solid-state battery electrode sheets, which addresses the deficiencies of the existing technology. This machine realizes the double-sided surface coating and roller pressing process, improving coating quality and efficiency while reducing energy consumption and simplifying equipment.
[0009] Technical Solution: To achieve the above objectives, this utility model provides a double-sided surface coating and rolling integrated machine for solid-state battery electrodes, including an unwinding mechanism, a surface coating mechanism, and a rolling mechanism connected in series with several rollers. The surface coating mechanism includes a primary surface coating mechanism and a secondary surface coating mechanism. Both the primary and secondary surface coating mechanisms have several infrared heating elements on one side of the surface coating to dry and heat the coated side. The surface coating surfaces of the primary and secondary surface coating mechanisms are respectively on the upper and lower surfaces of the electrode.
[0010] Furthermore, the primary surface coating mechanism includes a primary anilox roller, a primary auxiliary roller disposed opposite to the primary anilox roller, and a primary material box, which partially surrounds the primary anilox roller. The electrode sheet can pass through the gap between the primary anilox roller and the primary auxiliary roller, and the coating liquid in the primary anilox roller material box is carried up and evenly coated on the surface of the electrode sheet.
[0011] Furthermore, the primary anilox roller is positioned below the electrode plate, the primary material box contains coating liquid, and the primary material box is equipped with a primary doctor blade. The distance between the primary doctor blade and the primary anilox roller is adjustable. The primary doctor blade can adjust the thickness of the coating liquid applied to the primary anilox roller.
[0012] Furthermore, the secondary surface coating mechanism includes a secondary anilox roller, a transfer roller disposed opposite to and in contact with the secondary anilox roller, a secondary auxiliary roller disposed opposite to the other side of the transfer roller, and a secondary material box, which partially surrounds the secondary anilox roller. The transfer roller can effectively change the coating direction of the secondary coating mechanism, preventing coating liquid droplets from falling onto the electrode.
[0013] Furthermore, the secondary anilox roller and transfer roller are positioned above the electrode sheet, the secondary material box contains coating liquid, the secondary material box is equipped with a secondary scraper, and the distance between the secondary scraper and the secondary anilox roller is adjustable.
[0014] Furthermore, several infrared heating elements are provided on both sides of the electrode sheet between the secondary coating mechanism and the rolling mechanism.
[0015] Furthermore, the rolling mechanism includes a stretching mechanism and a set of single-roll cold-pressing rollers, and the front end of the stretching mechanism is also provided with a roller-type electromagnetic heating device.
[0016] Furthermore, the infrared heating element is an infrared heating lamp tube.
[0017] As can be seen from the above technical solution, compared with the prior art, this utility model has the following beneficial effects:
[0018] 1. Compared to sequential surface coating and rolling, this invention can simultaneously perform double-sided ultra-thin coating and rolling, saving time, improving efficiency, and reducing energy consumption. First, compared to a separate surface coating process, integrating rolling with surface coating reduces the need for an unwinding and rewinding system. Second, compared to coating ovens, which require electrically heated air and a circulating fan and dehumidifying fan, this design reduces the need for a circulating fan. Third, compared to hot air drying, infrared heating directly heats the slurry, resulting in less heat loss to the equipment casing, rollers, etc.
[0019] 2. When using infrared drying, the first step is to dry only the wet film on the surface of the electrode to ensure that it does not stick to the roller and that the solvent that has penetrated into the pores of the electrode is completely dried by infrared heating after the subsequent double-sided coating is completed. This ensures that no gas escapes too quickly during the drying process, which could lead to poor surface appearance.
[0020] 3. Since no coating oven is used, the electrode sheets can be directly observed with the blade. Surface coating abnormalities can be detected in time during rolling, and surface coating parameters can be adjusted immediately to avoid batch defects. The tightness of the rubber roller and the tightness of the doctor blade can be adjusted immediately to improve the situation. Abnormalities can be detected and adjusted immediately, better solving the hidden problem of poor surface coating appearance.
[0021] 4. This utility model completes the process in one rolling, which can reduce the proportion of active material particle size destruction. Attached Figure Description
[0022] Figure 1 This is a simplified structural diagram of a double-sided surface coating roll forming machine for solid-state battery electrodes according to the present invention.
[0023] Figure 2 This is a top view of a double-sided surface coating roller pressing machine for solid-state battery electrodes, as described in this utility model.
[0024] In the diagram: 1-unwinding mechanism, 2-rolling mechanism, 21-stretching mechanism, 22-single-roll cold press roller, 3-first-stage surface coating mechanism, 31-first-stage anilox roller, 32-first-stage auxiliary roller, 33-first-stage material box, 34-first-stage doctor blade, 4-second-stage surface coating mechanism, 41-second-stage anilox roller, 42-transfer roller, 43-second-stage auxiliary roller, 44-second-stage material box, 45-second-stage doctor blade, 5-infrared heating element, 6-electromagnetic heating device, 7-electromagnetic pole piece. Detailed Implementation
[0025] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.
[0026] like Figure 1-2As shown, a double-sided surface coating and rolling machine for solid-state battery electrodes includes an unwinding mechanism 1, a surface coating mechanism, and a rolling mechanism 2 connected in series by several rollers. The surface coating mechanism includes a primary surface coating mechanism 3 and a secondary surface coating mechanism 4. Both the primary surface coating mechanism 3 and the secondary surface coating mechanism 4 have several infrared heating elements 5 on one side of the surface coating to dry and heat the coated side. The surface coating surfaces of the primary surface coating mechanism 3 and the secondary surface coating mechanism 4 are respectively on the upper and lower surfaces of the electrode.
[0027] The unwinding mechanism 1 releases the battery electrode 7 and passes it through the first-stage surface coating mechanism 3, the second-stage surface coating mechanism 4 and the rolling mechanism in sequence. The first-stage surface coating mechanism 3 and the second-stage surface coating mechanism 4 can uniformly coat the battery electrode 7 on the upper and lower sides respectively. After each single-sided coating, the battery electrode 7 is initially dried by the infrared heating element 5, and then rolled by the rolling mechanism 2.
[0028] Specifically, the primary surface coating mechanism 3 includes a primary anilox roller 31, a primary auxiliary roller 32 disposed opposite to the primary anilox roller 31, and a primary material box 33, which partially surrounds the primary anilox roller 31.
[0029] The first-stage anilox roller 31 is located below the electrode sheet, the first-stage material box 33 contains coating liquid, the first-stage material box 33 is equipped with a first-stage scraper 34, and the distance between the first-stage scraper 34 and the first-stage anilox roller 31 is adjustable.
[0030] Specifically, the secondary surface coating mechanism 4 includes a secondary anilox roller 41, a transfer roller 42 positioned opposite and in contact with the secondary anilox roller 41, a secondary auxiliary roller 43 positioned opposite the other side of the transfer roller 42, and a secondary material box 44, which partially surrounds the secondary anilox roller 41. Since the secondary surface coating mechanism 4 coats the battery electrode 7, and both the secondary material box 44 and the secondary anilox roller 41 are located above the battery electrode 7, if the secondary anilox roller 41 directly applies the coating liquid to the battery electrode 7 after dipping it in the coating liquid, the coating liquid could easily drip onto the battery electrode 7 due to the angle, resulting in uneven coating. Therefore, the transfer roller 42 is introduced here. The coating liquid dipped in the secondary anilox roller 41 is transferred to the transfer roller 42, and then applied to the battery electrode 7 via the transfer roller 42. This changes the coating angle and effectively avoids the aforementioned problem.
[0031] Specifically, the secondary anilox roller 41 and the transfer roller 42 are located above the electrode sheet, the secondary material box 44 contains coating liquid, the secondary material box 44 is provided with a secondary scraper 45, and the distance between the secondary scraper 45 and the secondary anilox roller 41 is adjustable.
[0032] Preferably, a plurality of infrared heating elements 5 are provided on both sides of the electrode sheet between the secondary coating mechanism 4 and the rolling mechanism 2.
[0033] Preferably, the rolling mechanism 2 includes a stretching mechanism 21 and a set of single-roll cold-pressing rollers 22, and the front end of the stretching mechanism 21 is also provided with a roller-type electromagnetic heating device 6.
[0034] Specifically, the infrared heating element 5 is an infrared heating lamp tube.
[0035] This utility model discloses a double-sided surface coating and rolling integrated machine for solid-state battery electrodes. During operation, the battery electrodes 7 are first threaded sequentially. Then, the infrared heating element 5 and electromagnetic heating device 6 are activated to bring the equipment temperature to the required level. Next, the primary scraper 34 and secondary scraper 45 are installed and adjusted, and the wet film coating and drying parameters are adjusted. After passing through the primary surface coating mechanism 3, an ultra-thin coating is formed on the battery electrodes 7. The infrared heating element 5 then performs preliminary drying. After passing through the secondary surface coating mechanism 4, an ultra-thin coating is formed on the underside of the battery electrodes 7. This coating is then further dried by the infrared heating element 7, and finally, after continuous heating by the electromagnetic heating device 6, it is stretched and rolled by the stretching mechanism 21 and single-roll cold-press roller 22, achieving a better compaction state for the electrodes.
[0036] Example 1:
[0037] The double-sided surface coating roller pressing machine provided by this utility model is used to produce 80µm electrode sheets; wherein the substrate (positive electrode roll) has a thickness of 220µm, based on 20% LATP-2% PVDF-NMP slurry with a viscosity of 260~300. mPs, belt speed 5m / min, infrared heating lamp drying, roller gap set at approximately 110um, pressure approximately 60T, no abnormalities such as roller sticking during belt feeding; after drying, the electrode thickness was measured at 16 positions with a fixed interval of 5cm on both sides, and the thicknesses were 162.5, 160.4, 160.6, 160.2, 159.8, 162.2, 161.0, 160.2, 160.2, 160.7, 161.9, 160.8, 163.1, 159.5, 161.5, and 160.6um respectively, with a thickness distribution between 159 and 163um; the surface appearance of the electrode after rolling was good, and the electrode toughness was good; the compaction density was approximately 3.4g / cm3, and the electrode broke once.
[0038] Example 2:
[0039] The double-sided surface coating roller pressing machine provided by this utility model is used to produce 300µm of electrode sheets; wherein the substrate (positive electrode roll) has a thickness of 220µm, based on 20% LATP-2% PVDF-NMP slurry with a viscosity of 260~300. mPs, belt speed 5m / min, infrared heating lamp drying, roller gap set at approximately 110um, pressure approximately 60T, no abnormalities such as roller sticking during belt feeding, good surface appearance of the electrode sheet after rolling, good electrode sheet toughness; final output of 240 meters of good electrode sheet, yield rate 80%; after drying, coating thickness was measured at 16 locations with a fixed interval of 2cm on both sides, the thicknesses were 161.4, 162.0, 160.0, 158.8, 159.7, 160.8, 159.9, 160.2, 160.6, 162.6, 159.9, 159.0, 161.1, 159.9, 159.6, 158.9um, with a thickness distribution between 159 and 163um; compaction density approximately 3.4g / cm3, 0 electrode sheet breakages.
[0040] Example 3
[0041] The double-sided surface coating roller pressing machine provided by this utility model is used to produce 300µm of electrode sheets; wherein the substrate (positive electrode roll) has a thickness of 210µm, based on 25% LATP-4% PVDF-NMP slurry with a viscosity of 260~300. mPs, belt speed 5m / min, infrared heating lamp drying, roller gap set at approximately 110um, pressure approximately 60T, no abnormalities such as roller sticking during belt feeding, good surface appearance of the electrode sheet after rolling, good electrode sheet toughness; final output of 255 meters of good electrode sheet, yield rate 85%; after drying, coating thickness was measured at 16 locations with a fixed interval of 2cm on both sides, the thicknesses were 152.5, 152.5, 154.3, 152.5, 154.2, 152.7, 154.0, 151.1, 152.9, 153.2, 152.3, 155.1, 151.3, 153.5, 151.7, 155.6um, with a thickness distribution between 151 and 156um; compaction density approximately 3.4g / cm3, electrode sheet belt breakage once.
[0042] Comparative Example 1
[0043] The process employs conventional gravure coating followed by single-roll cold pressing, sequentially applying single-layer coating, reverse double coating, and roll pressing to produce 80µm electrode sheets. The substrate (positive electrode roll) has a thickness of 220µm, based on a 20% LATP-2% PVDF-NMP slurry with a viscosity of 260~300. mPs, belt speed 5m / min, normal oven drying, no abnormalities such as sticking to rollers or scraping during belt feeding; the roller gap was set to about 110um, the pressure to about 60T, and after rolling, the coating thickness at 16 locations was measured at a fixed interval of 2cm on both sides. The thicknesses were 162.0, 161.0, 159.4, 162.2, 158.9, 160.3, 162.0, 160.3, 160.6, 158.5, 160.5, 162.2, 160.3, 160.9, 158.9, and 157.2um, with a thickness distribution between 156 and 163um; the compaction density was about 3.4g / cm3, and the electrode broke twice.
[0044] Comparative Example 2
[0045] The process employs conventional gravure coating followed by single-roll cold pressing, sequentially applying single-layer coating, reverse double coating, and roll pressing to produce 300µm electrode sheets. The substrate (positive electrode roll) has a thickness of 220µm, based on a 20% LATP-2% PVDF-NMP slurry with a viscosity of 260~300. mPs, belt speed 5m / min, normal oven drying, no abnormalities such as sticking to rollers or scraping during belt feeding; roller gap set at approximately 110um, pressure at approximately 60T, 219m of good products produced, yield rate 73%; after rolling, with a fixed 2cm interval on both sides, the coating thickness at 16 locations was measured, and the thicknesses were 161.1, 158.9, 161.5, 159.4, 157.1, 160.1, 160.9, 162.3, 159.7, 159.7, 159.8, 160.8, 161.9, 159.6, 160.0, 162.3um, with a thickness distribution between 156 and 163um; compaction density approximately 3.4g / cm3, electrode breakage occurred 3 times.
[0046] Comparative Example 3
[0047] The process employs conventional gravure coating followed by single-roll cold pressing, sequentially applying single-layer coating, reverse double coating, and roll pressing to produce 300µm electrode sheets. The substrate (positive electrode roll) has a thickness of 210µm, based on a 25% LATP-4% PVDF-NMP slurry with a viscosity of 260~300. mPs, belt speed 5m / min, normal oven drying, no abnormalities such as sticking to rollers or scraping during belt feeding; roller gap set at approximately 110um, pressure at approximately 60T, 225m of good products produced, yield rate 75%; after rolling, with a fixed 2cm interval on both sides, the coating thickness at 16 locations was measured, and the thicknesses were 155.9, 150.7, 154.0, 153.7, 154.3, 151.6, 152.6, 152.2, 153.5, 152.4, 150.9, 155.3, 154.2, 152.3, 153.5, and 151.4um respectively, with a thickness distribution between 151 and 156um; compaction density approximately 3.4g / cm3, electrode strip breakage occurred 3 times.
[0048] Comparing the above embodiments and comparative examples, it can be seen that the electrode sheet produced by the double-sided surface coating roller pressing integrated machine provided by this utility model has improved thickness consistency, smaller standard deviation, more uniform thickness and better consistency, and fewer belt breakages and higher yield.
[0049] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present utility model, and these improvements should also be considered within the protection scope of the present utility model.
Claims
1. A double-sided surface coating and rolling press for solid-state battery electrodes, comprising an unwinding mechanism (1), a surface coating mechanism, and a rolling mechanism (2) connected in series by a plurality of rollers, characterized in that, The coating mechanism includes a primary coating mechanism (3) and a secondary coating mechanism (4). Both the primary coating mechanism (3) and the secondary coating mechanism (4) have several infrared heating elements (5) on one side of the coating to dry and heat the coated side. The coating surfaces of the primary coating mechanism (3) and the secondary coating mechanism (4) are on the upper and lower surfaces of the electrode, respectively.
2. The double-sided surface coating roll forming machine for solid-state battery electrodes according to claim 1, characterized in that, The primary surface coating mechanism (3) includes a primary anilox roller (31), a primary auxiliary roller (32) disposed opposite to the primary anilox roller (31), and a primary material box (33) which partially surrounds the primary anilox roller (31).
3. A double-sided surface coating roll forming machine for solid-state battery electrodes according to claim 2, characterized in that, The first-stage anilox roller (31) is located below the electrode sheet. The first-stage material box (33) contains coating liquid and a first-stage scraper (34) is provided inside the first-stage material box (33). The distance between the first-stage scraper (34) and the first-stage anilox roller (31) is adjustable.
4. A double-sided surface coating roll forming machine for solid-state battery electrodes according to claim 1, characterized in that, The secondary surface coating mechanism (4) includes a secondary anilox roller (41), a transfer roller (42) that is opposite to and in contact with the secondary anilox roller (41), a secondary auxiliary roller (43) that is opposite to the other side of the transfer roller (42), and a secondary material box (44) that is partially surrounded by the secondary anilox roller (41).
5. A double-sided surface coating roll forming machine for solid-state battery electrodes according to claim 4, characterized in that, The secondary anilox roller (41) and transfer roller (42) are located above the electrode sheet. The secondary material box (44) contains coating liquid and is equipped with a secondary scraper (45). The distance between the secondary scraper (45) and the secondary anilox roller (41) is adjustable.
6. A double-sided surface coating roll forming machine for solid-state battery electrodes according to claim 1, characterized in that, Several infrared heating elements (5) are also provided on both sides of the electrode between the secondary coating mechanism (4) and the rolling mechanism (2).
7. A double-sided surface coating roll forming machine for solid-state battery electrodes according to claim 1, characterized in that, The rolling mechanism (2) includes a stretching mechanism (21) and a set of single-roll cold-pressing rollers (22). The front end of the stretching mechanism (21) is also provided with a roller-type electromagnetic heating device (6).
8. A double-sided surface coating roll forming machine for solid-state battery electrodes according to claim 6, characterized in that, The infrared heating element (5) is an infrared heating lamp tube.