Coating method and coating equipment for energy storage electrode production

Abstract

The invention belongs to the technical field of electrode production, and particularly discloses a coating method and coating equipment for energy storage electrode production, which comprises the following steps: setting tension control parameters of a conductive base material, conveying the conductive base material, conveying functional slurry to a slit type coating device, conveying the conductive base material on which the wet coating is formed to a sectional drying system for drying treatment, and detecting the thickness and uniformity of the dried coating by using an online monitoring device; the coating equipment comprises a frame, a coating assembly is assembled on the frame, a material winding roller is arranged at the opposite position of the front end of the coating assembly, a carrier roller is arranged at the front end of the material winding roller, a leveling roller is arranged between the material winding roller and the coating assembly, a coating roller is arranged at the rear end of the coating assembly, and a winding roller is arranged at the rear end of the frame. According to the precise coating method for energy storage electrode production, the problem that in the traditional coating technology, the coating uniformity is poor is solved, and the distance between the coating die head and the coating roller can be precisely controlled through the matched design of the adjusting frame and the third air cylinder.

Description

Technical Field

[0001] This invention belongs to the field of electrode production technology, specifically a coating method and coating equipment for energy storage electrode production. Background Technology

[0002] As a core component of modern energy conversion and storage systems, the performance of energy storage devices largely depends on the manufacturing quality of their electrodes. A key process step in electrode manufacturing is the uniform coating of functional slurry onto a conductive substrate to form a functional coating. Traditional coating methods mainly include blade coating and slot die coating, but these techniques generally suffer from poor coating uniformity, significant edge effects, and unstable drying quality in industrial production, directly impacting cell capacity distribution and finished product consistency.

[0003] To improve coating quality, various improvement schemes have been proposed in existing technologies. For example, Chinese patent CN110252593A discloses a coating machine and its coating method, which controls the slit gap through an adjustment mechanism and uses a drying system to process the wet coating. However, this scheme lacks a slurry homogenization mechanism and vibration-assisted means, resulting in coating thickness fluctuations and uneven distribution. Furthermore, its drying system operates in a single temperature zone, which can easily lead to internal stress concentration due to rapid surface crusting, causing coating cracking and peeling. Chinese patent CN108816645B discloses a power lithium battery baseband extrusion coating system, which adjusts the substrate tension through a tension controller, but it does not form a closed-loop linkage with the coating parameters and is not suitable for high-speed coating scenarios. Existing technologies have failed to solve key problems such as coating cracking and insufficient thickness accuracy control under high-speed coating conditions.

[0004] Therefore, there is a need for a coating method and equipment that integrates ultrasonic vibration, segmented gradient drying, and real-time closed-loop feedback. Summary of the Invention

[0005] To address the above technical problems, this invention provides a coating method and equipment that integrates ultrasonic vibration, segmented gradient drying, and real-time closed-loop feedback, thereby solving problems such as poor coating uniformity, easy cracking during the drying process, and insufficient thickness control accuracy under high-speed coating in the prior art.

[0006] To solve the above technical problems, the technical solution of the present invention is: a coating method for producing energy storage electrodes, comprising the following steps:

[0007] (1) Set the tension control parameters of the conductive substrate and transport the conductive substrate. The tension control parameters include the linear tension value and the tension change rate of the substrate. The linear tension value is 20-25N and the tension change rate is no more than ±3%. The tension is adjusted in real time by PID control algorithm to ensure that the lateral deviation of the substrate is controlled within ±0.1mm at a running speed of not less than 80m / min.

[0008] (2) A functional slurry is fed into a slit coating device and uniformly coated onto the surface of the conductive substrate through a coating die to form a wet coating. The coating die has an internal flow channel and an adjustable discharge gap. The coating die is also equipped with an ultrasonic vibrator. During the coating process, ultrasonic vibration is applied to the functional slurry. The frequency of the ultrasonic vibration is 28-32kHz and the amplitude is 15-25μm. Before entering the coating die, the functional slurry is first buffered by the injection chamber inside the coating die, and then overflows upward through the connecting hole at its bottom into an overflow groove for homogenization. Finally, it is extruded through the slit between the overflow groove and the discharge nozzle.

[0009] (3) The conductive substrate with the wet coating is transported to a segmented drying system for drying. The drying system includes at least three independently temperature-controlled drying zones, wherein the first temperature zone is 65-75℃, the second temperature zone is 90-100℃, and the third temperature zone is 125-135℃. The first temperature zone adopts far-infrared radiation heating, and the second and third temperature zones adopt hot air circulation heating. The temperature fluctuation of each zone does not exceed ±1℃, forming a gradient drying to reduce the internal stress of the coating.

[0010] (4) The thickness and uniformity of the dried coating are detected by an online monitoring device, and the detection data is fed back to the control system at a cycle of no more than 500 milliseconds. The control system adjusts the slurry delivery flow rate, substrate running speed or coating die gap parameter in real time through a closed-loop feedback algorithm according to the deviation between the detection data and the preset target value. The coating parameters are automatically adjusted through the closed-loop feedback system according to the detection results. The ultrasonic vibration, tension control parameters and segmented drying system work together to control the coating thickness deviation within ±1.5μm and avoid coating cracking and peeling.

[0011] Furthermore, in step (4), the online monitoring device uses an X-ray thickness gauge with a measurement accuracy of ±0.5μm and a scanning frequency of 2 times per second; the closed-loop feedback algorithm is a PID control algorithm.

[0012] To complement the above coating method, this application also provides a coating device for producing energy storage electrodes, including a frame, a coating assembly mounted on the frame, a material roll roller opposite to the front end of the coating assembly, a support roller at the front end of the material roll roller, a leveling roller between the material roll roller and the coating assembly, a coating roller at the rear end of the coating assembly, a take-up roller at the rear end of the frame, the coating roller being close to the output end of the coating assembly, and a conductive substrate wound on the material roll roller being conveyed forward through the space between the coating assembly and the coating roller; the coating assembly includes symmetrically arranged adjusting frames, a short shaft on the outer side of the adjusting frames, the adjusting frames being rotatably connected to the frame via the short shaft, a third cylinder being hinged to the lower end of the adjusting frames, and the tail of the third cylinder being hinged to the frame, a coating die head being mounted between the adjusting frames, the adjusting frames rotating on the frame via the third cylinder, thereby controlling the distance between the output end of the coating die head and the coating roller, and thus achieving the coating thickness.

[0013] Furthermore, the coating die head includes a lower die and an upper die. The upper die is fixed to the lower die by screws. One end of both the lower die and the upper die is provided with a discharge nozzle, which is opposite to the coating roller. The front surface of the lower die is connected to a material conveying hose. The functional slurry enters the coating die head through the material conveying hose and flows out from the discharge nozzle through the slit between the lower die and the upper die, adhering to the conductive substrate on the coating roller to complete the coating.

[0014] Furthermore, an injection cavity is provided inside the lower mold, and a material conveying hose is connected to the injection cavity. One end of the injection cavity passes through the side of the lower mold, and a sealing plate is provided at the through point for sealing. An overflow groove is provided on the upper surface of the lower mold, and a connecting hole is provided at the bottom of the overflow groove to connect with the injection cavity. A slit is provided on the upper surface of the lower mold between the overflow groove and the discharge nozzle.

[0015] Furthermore, the rear end of the frame is symmetrically pinned with a cantilever frame, which is close to the take-up roller. The lower end of the cantilever frame is rotatably connected to the take-up roller, and the upper end of the cantilever frame extends with a short rod, on which a second cylinder is hinged. The second cylinder is mounted on the frame.

[0016] Furthermore, a flattening driven roller is provided inside the frame and near the coating roller. A flattening drive roller is provided on one side of the flattening driven roller. Bearing seats are sleeved at both ends of the flattening drive roller, and a first cylinder is mounted on the bearing seats. The first cylinder is fixed inside the frame.

[0017] Furthermore, a first auxiliary roller unit is provided within the frame near the coating die head, and the first auxiliary roller unit consists of multiple rotating rollers.

[0018] Furthermore, a second auxiliary roller unit is provided within the frame near the cantilever, and the second auxiliary roller unit is also composed of multiple rotating rollers, with a steering roller provided between the first auxiliary roller unit and the second auxiliary roller unit.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] (1) The precision coating method for energy storage electrode production provided in this invention solves the key problems of poor coating uniformity, obvious edge effect, unstable drying quality and low production efficiency in traditional coating technology, and significantly improves the production quality and efficiency of energy storage electrodes. By setting up a combination of ultrasonic vibration and slurry homogenization path, the coating uniformity is significantly improved. The core innovations such as ultrasonic vibration-assisted coating technology and segmented gradient drying strategy provide reliable technical support for the large-scale industrial production of high-quality energy storage electrodes. By setting up tension control and closed-loop feedback synergy, the thickness is accurately controlled under high-speed coating, and the segmented gradient drying avoids internal stress concentration and reduces the risk of cracking. According to the actual production needs and the type of energy storage equipment, the process parameters can be flexibly adjusted to adapt to products with different specifications and performance requirements.

[0021] (2) The coating device in this invention can precisely control the distance between the coating die head and the coating roller through the coordinated design of the adjustment frame and the third cylinder, thereby achieving precise adjustment of the coating thickness and improving the coating accuracy. The design of the cantilever frame and the second cylinder at the rear end of the frame optimizes the tension control during the winding process and reduces the deformation of the material during the winding process.

[0022] (3) The coating device of the present invention adopts a combination structure of upper mold and lower mold. Through the special design of injection cavity, overflow groove and slit, the uniform distribution of functional slurry in the coating process is ensured, and the coating quality is improved. The combined application of flattening driven roller and flattening driving roller, combined with the pressure control of the first cylinder, further improves the flatness of the substrate surface after coating. The overall structure is reasonably designed and the components work together to improve the automation level, production efficiency and product quality stability of the energy storage electrode production process. Attached Figure Description

[0023] Figure 1 This is the three-dimensional structure of the coating device in the present invention. Figure 1 .

[0024] Figure 2 This is the three-dimensional structure of the coating device in the present invention. Figure 2 .

[0025] Figure 3 This is an assembly diagram of the coating component and the leveling component in this invention.

[0026] Figure 4 This is the three-dimensional structure of the coating component in the present invention. Figure 1 .

[0027] Figure 5 This is the three-dimensional structure of the coating component in the present invention. Figure 2 .

[0028] Figure 6This is a cross-sectional view of the coating die head in this invention.

[0029] Figure 7 For the present invention Figure 6 Enlarged view of a portion of point A in the middle.

[0030] Figure 8 This is a schematic diagram of the coating device in operation according to the present invention.

[0031] The correspondence between the labels and component names in the attached figures is as follows:

[0032] 100. Frame; 101. Material roll roller; 1011. Support roller; 1012. Leveling roller; 102. Coating roller; 103. Flattening driven roller; 104. First cylinder; 1041. Flattening drive roller; 105. Second cylinder; 1051. Cantilever frame; 106. Take-up roller; 107. First auxiliary roller unit; 108. Directional roller; 109. Second auxiliary roller unit;

[0033] 200. Coating assembly; 201. Adjustment frame; 2011. Short shaft; 2012. Third cylinder; 202. Coating die head; 202a. Lower die; 202a1. Injection cavity; 202a2. Overflow groove; 202a3. Connecting hole; 202b. Upper die; 202c. Discharge nozzle. Detailed Implementation

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0036] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments. The present invention provides the following embodiments.

[0037] Example 1: A coating method for producing an energy storage electrode, comprising the following steps:

[0038] (1) Set the tension control parameters of the conductive substrate and transport the conductive substrate. The tension control parameters include the linear tension value and the tension change rate of the substrate. The linear tension value is 20-25N and the tension change rate does not exceed ±3%.

[0039] In this specific application, the conductive substrate is first mounted onto the unwinding device, with a linear tension value set to 20N and a tension variation rate not exceeding ±1%. A tension-sensing roller is used to monitor the tension of the conductive substrate in real time. A PID control algorithm drives a magnetic powder brake to precisely adjust the tension, ensuring the tension stability of the substrate at high speeds (80 meters / minute). Simultaneously, a CCD edge detection sensor monitors the lateral position of the substrate, and a servo motor adjusts the angle of the guide rollers to control the lateral deviation of the substrate within ±0.1mm.

[0040] (2) A functional slurry is fed into a slot coating device and uniformly coated onto the surface of the conductive substrate through a coating die to form a wet coating; the coating die has an internal flow channel and an adjustable discharge gap, and the coating die is integrated with an ultrasonic vibrator to apply ultrasonic vibration to the functional slurry during the coating process. The frequency of the ultrasonic vibration is 28-32kHz and the amplitude is 15-25μm.

[0041] In this embodiment, a piezoelectric ceramic ultrasonic vibrator is integrated into the lip of the coating die, with its operating frequency set at 28 kHz and amplitude at 15 μm. When the slurry flows through the die lip and is subjected to ultrasonic vibration, its apparent viscosity decreases instantaneously (shear thinning effect), which helps to form a more uniform flow field and a smoother coating surface. In addition, ultrasonic vibration can effectively suppress the accumulation and drying of slurry on the die lip, avoiding the clogging problems commonly found in traditional coating processes.

[0042] (3) The conductive substrate with the wet coating is transported to a segmented drying system for drying. The drying system includes at least three independently temperature-controlled drying zones, with the temperature increasing sequentially from low to high to achieve gradient drying. In step (3), the temperatures of the three zones of the drying system are: the first zone 65-75℃, the second zone 90-100℃, and the third zone 125-135℃. The first zone uses far-infrared radiation heating, while the second and third zones use hot air circulation heating.

[0043] In this specific application, after coating, the conductive substrate with the wet coating enters a segmented gradient drying system containing three independently temperature-controlled drying zones. The first zone is set at 65°C, using far-infrared radiation heating to provide gentle and uniform heat, allowing the solvent in the slurry to slowly evaporate from the inside out, forming a stable network structure. The second zone is set at 90°C, using hot air circulation heating. The third zone is set at 125°C, also using hot air circulation heating, but with a higher air velocity. The temperature of each zone is precisely regulated by a PID controller, with temperature fluctuations not exceeding ±1°C. This "slow first, fast later" gradient drying strategy effectively avoids the internal stress concentration caused by excessively rapid surface skinning in traditional drying processes, minimizing the risk of coating cracking and peeling.

[0044] (4) Use an online monitoring device to detect the thickness and uniformity of the coating after drying, and automatically adjust the coating parameters through a closed-loop feedback system based on the detection results. In step (4), the online monitoring device uses non-contact X-ray or laser thickness measurement technology, and the measured coating thickness data is transmitted to the control system at a cycle of no more than 500 milliseconds.

[0045] In this specific application, the dried coating is inspected by an online monitoring system. This system uses an X-ray thickness gauge to scan back and forth along the width of the substrate, measuring the thickness distribution of the entire coating with an accuracy of ±0.5μm. The data collected by the thickness gauge is transmitted to the central computing unit via a high-speed data bus at a frequency of twice per second. After processing by a dedicated algorithm, coating areal density and thickness uniformity indicators are generated. The target coating thickness is set at 50μm, with an allowable deviation range of ±1.5μm. When a thickness deviation exceeds the set range, the closed-loop feedback system automatically adjusts within 100 milliseconds: if the overall coating is too thick, the slurry supply flow rate is reduced or the substrate running speed is increased; if the overall coating is too thin, the slurry supply flow rate is increased or the substrate running speed is reduced; if the coating thickness distribution is uneven, the horizontal angle of the coating die and the uniformity of the discharge gap are adjusted.

[0046] Example 2: A coating method for producing an energy storage electrode, comprising the following steps:

[0047] (1) Set the tension control parameters of the conductive substrate and transport the conductive substrate. The tension control parameters include the linear tension value and the tension change rate of the substrate. The linear tension value is 20-25N and the tension change rate does not exceed ±3%.

[0048] In this specific application, the conductive substrate is first mounted onto the unwinding device, with a linear tension value set to 22.5 N and a tension variation rate not exceeding ±2%. A tension-sensing roller is used to monitor the tension of the conductive substrate in real time. A PID control algorithm drives a magnetic powder brake to precisely adjust the tension, ensuring the tension stability of the substrate at high speeds (80 m / min). Simultaneously, a CCD edge detection sensor monitors the lateral position of the substrate, and a servo motor adjusts the angle of the guide rollers to control the lateral deviation of the substrate within ±0.1 mm.

[0049] (2) A functional slurry is fed into a slot coating device and uniformly coated onto the surface of the conductive substrate through a coating die to form a wet coating; the coating die has an internal flow channel and an adjustable discharge gap, and the coating die is integrated with an ultrasonic vibrator to apply ultrasonic vibration to the functional slurry during the coating process. The frequency of the ultrasonic vibration is 28-32kHz and the amplitude is 15-25μm.

[0050] In this embodiment, a piezoelectric ceramic ultrasonic vibrator is integrated into the lip of the coating die, with its operating frequency set to 30kHz and amplitude to 20μm. When the slurry flows through the die lip and is subjected to ultrasonic vibration, its apparent viscosity decreases instantaneously (shear thinning effect), which helps to form a more uniform flow field and a smoother coating surface. In addition, ultrasonic vibration can effectively suppress the accumulation and drying of slurry on the die lip, avoiding the clogging problems commonly found in traditional coating processes.

[0051] (3) The conductive substrate with the wet coating is transported to a segmented drying system for drying. The drying system includes at least three independently temperature-controlled drying zones, with the temperature increasing sequentially from low to high to achieve gradient drying. In step (3), the temperatures of the three zones of the drying system are: the first zone 65-75℃, the second zone 90-100℃, and the third zone 125-135℃. The first zone uses far-infrared radiation heating, while the second and third zones use hot air circulation heating.

[0052] In this specific application, after coating, the conductive substrate with the wet coating enters a segmented gradient drying system, which contains three independently temperature-controlled drying zones. The first zone is set at 70°C, using far-infrared radiation heating to provide gentle and uniform heat, allowing the solvent in the slurry to slowly evaporate from the inside out, forming a stable network structure. The second zone is set at 95°C, using hot air circulation heating. The third zone is set at 130°C, also using hot air circulation heating, but with a higher air velocity. The temperature of each zone is precisely regulated by a PID controller, with temperature fluctuations not exceeding ±1°C. This "slow first, fast later" gradient drying strategy effectively avoids the internal stress concentration caused by excessively rapid surface skinning in traditional drying processes, minimizing the risk of coating cracking and peeling.

[0053] (4) Use an online monitoring device to detect the thickness and uniformity of the coating after drying, and automatically adjust the coating parameters through a closed-loop feedback system based on the detection results. In step (4), the online monitoring device uses non-contact X-ray or laser thickness measurement technology, and the measured coating thickness data is transmitted to the control system at a cycle of no more than 500 milliseconds.

[0054] In this specific application, the dried coating is inspected by an online monitoring system. This system uses an X-ray thickness gauge to scan back and forth along the width of the substrate, measuring the thickness distribution of the entire coating with an accuracy of ±0.5μm. The data collected by the thickness gauge is transmitted to the central computing unit via a high-speed data bus at a frequency of twice per second. After processing by a dedicated algorithm, coating areal density and thickness uniformity indicators are generated. The target coating thickness is set at 50μm, with an allowable deviation range of ±1.5μm. When a thickness deviation exceeds the set range, the closed-loop feedback system automatically adjusts within 300 milliseconds: if the overall coating is too thick, the slurry supply flow rate is reduced or the substrate running speed is increased; if the overall coating is too thin, the slurry supply flow rate is increased or the substrate running speed is reduced; if the coating thickness distribution is uneven, the horizontal angle of the coating die and the uniformity of the discharge gap are adjusted.

[0055] Example 3: A coating method for producing an energy storage electrode, comprising the following steps:

[0056] (1) Set the tension control parameters of the conductive substrate and transport the conductive substrate. The tension control parameters include the linear tension value and the tension change rate of the substrate. The linear tension value is 20-25N and the tension change rate does not exceed ±3%.

[0057] In this specific application, the conductive substrate is first mounted onto the unwinding device, with a linear tension value set to 25N and a tension variation rate not exceeding ±3%. A tension-sensing roller is used to monitor the tension of the conductive substrate in real time. A PID control algorithm drives a magnetic powder brake to precisely adjust the tension, ensuring the tension stability of the substrate at high speeds (80 meters / minute). Simultaneously, a CCD edge detection sensor monitors the lateral position of the substrate, and a servo motor adjusts the angle of the guide rollers to control the lateral deviation of the substrate within ±0.1mm.

[0058] (2) A functional slurry is fed into a slot coating device and uniformly coated onto the surface of the conductive substrate through a coating die to form a wet coating; the coating die has an internal flow channel and an adjustable discharge gap, and the coating die is integrated with an ultrasonic vibrator to apply ultrasonic vibration to the functional slurry during the coating process. The frequency of the ultrasonic vibration is 28-32kHz and the amplitude is 15-25μm.

[0059] In this embodiment, a piezoelectric ceramic ultrasonic vibrator is integrated into the lip of the coating die, with its operating frequency set at 32kHz and amplitude at 25μm. When the slurry flows through the die lip and is subjected to ultrasonic vibration, its apparent viscosity decreases instantaneously (shear thinning effect), which helps to form a more uniform flow field and a smoother coating surface. In addition, ultrasonic vibration can effectively suppress the accumulation and drying of slurry on the die lip, avoiding the clogging problems commonly found in traditional coating processes.

[0060] (3) The conductive substrate with the wet coating is transported to a segmented drying system for drying. The drying system includes at least three independently temperature-controlled drying zones, with the temperature increasing sequentially from low to high to achieve gradient drying. In step (3), the temperatures of the three zones of the drying system are: the first zone 65-75℃, the second zone 90-100℃, and the third zone 125-135℃. The first zone uses far-infrared radiation heating, while the second and third zones use hot air circulation heating.

[0061] In this specific application, after coating, the conductive substrate with the wet coating enters a segmented gradient drying system containing three independently temperature-controlled drying zones. The first zone is set at 75°C, using far-infrared radiation heating to provide gentle and uniform heat, allowing the solvent in the slurry to slowly evaporate from the inside out, forming a stable network structure. The second zone is set at 100°C, using hot air circulation heating. The third zone is set at 135°C, also using hot air circulation heating, but with a higher air velocity. The temperature of each zone is precisely regulated by a PID controller, with temperature fluctuations not exceeding ±1°C. This "slow first, fast later" gradient drying strategy effectively avoids the internal stress concentration caused by excessively rapid surface skinning in traditional drying processes, minimizing the risk of coating cracking and peeling.

[0062] (4) Use an online monitoring device to detect the thickness and uniformity of the coating after drying, and automatically adjust the coating parameters through a closed-loop feedback system based on the detection results. In step (4), the online monitoring device uses non-contact X-ray or laser thickness measurement technology, and the measured coating thickness data is transmitted to the control system at a cycle of no more than 500 milliseconds.

[0063] In this specific application, the dried coating is inspected by an online monitoring system. This system uses an X-ray thickness gauge to scan back and forth along the width of the substrate, measuring the thickness distribution of the entire coating with an accuracy of ±0.5μm. The data collected by the thickness gauge is transmitted to the central computing unit via a high-speed data bus at a frequency of twice per second. After processing by a dedicated algorithm, coating areal density and thickness uniformity indicators are generated. The target coating thickness is set at 50μm, with an allowable deviation range of ±1.5μm. When a thickness deviation exceeds the set range, the closed-loop feedback system automatically adjusts within 500 milliseconds: if the overall coating is too thick, the slurry supply flow rate is reduced or the substrate running speed is increased; if the overall coating is too thin, the slurry supply flow rate is increased or the substrate running speed is reduced; if the coating thickness distribution is uneven, the horizontal angle of the coating die and the uniformity of the discharge gap are adjusted.

[0064] like Figure 1-2 as well as Figure 8As shown, to complement the above coating method, this application also provides a coating device for producing energy storage electrodes, including a frame 100, on which a coating assembly 200 is mounted. A material roll roller 101 is positioned opposite the front end of the coating assembly 200, around which an uncoated substrate is wound. The substrate is released by constant-speed rotation, facilitating coating by the coating assembly 200. A support roller 1011 is provided at the front end of the material roll roller 101 to support the released substrate and prevent it from bending downwards due to its own weight. A leveling roller 1012 is provided between the material roll roller 101 and the coating assembly 200. Typically, a pair of leveling rollers 1012 are provided. The released substrate passes under the leveling roller 1012, thereby compressing and stretching the substrate to achieve a stretching effect. A coating roller 102 is provided at the rear end of the coating assembly 200, on which the released substrate adheres, facilitating extrusion by the coating assembly 200. The slurry is applied to the substrate. A take-up roller 106 is provided at the rear end of the frame 100 to take up the substrate after the slurry is applied. The coating roller 102 is close to the output end of the coating assembly 200 to prevent dripping. The conductive substrate wound on the material roll roller 101 is conveyed forward through the coating assembly 200 and the coating roller 102. The coating assembly 200 includes symmetrically arranged adjustment frames 201. A short shaft 2011 is provided on the outer side of the adjustment frame 201. The adjustment frame 201 is rotatably connected to the frame 100 through the short shaft 2011. A third cylinder 2012 is hinged to the lower end of the adjustment frame 201, and the tail of the third cylinder 2012 is hinged to the frame 100. A coating die head 202 is assembled between the adjustment frames 201. The adjustment frame 201 rotates on the frame 100 through the third cylinder 2012, thereby controlling the distance between the output end of the coating die head 202 and the coating roller 102, thereby achieving the coating thickness.

[0065] exist Figure 4-6 In this embodiment, the coating die head 202 includes a lower die 202a and an upper die 202b. The upper die 202b is fixed to the lower die 202a by screws. Screw fixing allows for precise adjustment of the die gap, thereby controlling the coating thickness and uniformity, facilitating adaptation to different coating process requirements. Both the lower die 202a and the upper die 202b have a discharge nozzle 202c at one end. The discharge nozzle 202c serves a guiding function, preventing the slurry from dripping directly after extrusion and failing to coat the substrate effectively. The discharge nozzle 202c is positioned opposite the coating roller 102 to ensure accurate coating of the slurry onto the substrate. A feed hose 203 is connected to the front surface of the lower die 202a for material supply. The functional slurry enters the coating die head 202 through the feed hose 203 and flows out through the discharge nozzle 202c through the slit between the lower die 202a and the upper die 202b, adhering to the conductive substrate attached to the coating roller 102 to complete the coating process. Figure 7In the lower mold 202a, an injection cavity 202a1 is provided. The injection cavity 202a1 is the main receiving area for the slurry. The conveying hose 203 is connected to the injection cavity 202a1 to ensure a stable supply of slurry. One end of the injection cavity 202a1 penetrates the side of the lower mold 202a, and a sealing plate is provided at the penetration point to facilitate cleaning and maintenance and effectively prevent slurry leakage, ensuring the system's sealing performance. An overflow groove 202a2 is provided on the upper surface of the lower mold 202a, and a connecting hole 202a3 is provided at the bottom of the overflow groove 202a2 to communicate with the injection cavity 202a1. In this embodiment... The slurry is filled into the injection chamber 202a1 through the delivery hose 203. When the injection chamber 202a1 is full, it overflows upward into the overflow groove 202a2 through the connection hole 202a3. During the upward overflow process, the slurry will be more uniform due to its own weight. Therefore, when the slurry is discharged from the overflow groove 202a2 and applied to the substrate, it is more uniform and will not have the disadvantage of uneven application caused by different forces in traditional extrusion. Furthermore, a slit is provided on the upper surface of the lower mold 202a and between the overflow groove 202a2 and the discharge nozzle 202c to facilitate the flow of slurry.

[0066] It is worth noting that in the coating step, the pre-prepared functional slurry is added to the storage container and delivered to the coating die head 202 at a constant flow rate through the delivery hose 203 by a precision gear pump. Before delivery, the slurry is filtered through a stainless steel filter with a precision of 5μm to remove large particulate impurities that may clog the coating die head 202.

[0067] exist Figure 3 In the frame 100, a flattening driven roller 103 is provided near the coating roller 102. A flattening drive roller 1041 is provided on one side of the flattening driven roller 103. Bearing seats are sleeved at both ends of the flattening drive roller 1041, and a first cylinder 104 is mounted on the bearing seats. The first cylinder 104 is fixed inside the frame 100. In this embodiment, the substrate after the slurry is applied is squeezed by the flattening driven roller 103 and the flattening drive roller 1041 to a certain extent, so that the thickness of the slurry applied on the substrate is uniform.

[0068] exist Figure 8In the frame 100, a cantilever frame 1051 is symmetrically pinned to the rear end. The cantilever frame 1051 is close to the take-up roller 106, and the lower end of the cantilever frame 1051 is rotatably connected to the take-up roller. A short rod extends from the upper end of the cantilever frame 1051, and a second cylinder 105 is hinged to the short rod. The second cylinder 105 is mounted on the frame 100 and, in this embodiment, controls the rotation of the cantilever frame 1051 through the second cylinder 105, thereby adjusting the distance between the take-up roller at the bottom of the cantilever frame 1051 and the take-up roller 106, so that the winding tightness can be controlled when the substrate is wound. A first auxiliary roller unit 10 is provided inside the frame 100 near the coating die head 202. 7. The first auxiliary roller unit 107 is composed of multiple rotating rollers; a second auxiliary roller unit 109 is provided in the frame 100 near the cantilever 1051, and the second auxiliary roller unit 109 is also composed of multiple rotating rollers. A guide roller 108 is provided between the first auxiliary roller unit 107 and the second auxiliary roller unit 109. The first auxiliary roller unit 107 and the second auxiliary roller unit 109 in this embodiment are commonly used components of existing roller conveyors. They are mainly used to adjust the tension of the conveyed material and to turn and support the conveyed material. Therefore, they are not disclosed in detail in this embodiment, but can be based on existing technology.

[0069] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A coating method for producing an energy storage electrode, characterized in that, Includes the following steps: (1) Set the tension control parameters of the conductive substrate and transport the conductive substrate. The tension control parameters include the linear tension value and the tension change rate of the substrate. The linear tension value is 20-25N and the tension change rate is no more than ±3%. The tension is adjusted in real time by PID control algorithm to ensure that the lateral deviation of the substrate is controlled within ±0.1mm at a running speed of not less than 80m / min. (2) A functional slurry is fed into a slit coating device and uniformly coated onto the surface of the conductive substrate through a coating die to form a wet coating. The coating die has an internal flow channel and an adjustable discharge gap. The coating die is also equipped with an ultrasonic vibrator. During the coating process, ultrasonic vibration is applied to the functional slurry. The frequency of the ultrasonic vibration is 28-32kHz and the amplitude is 15-25μm. Before entering the coating die, the functional slurry is first buffered by the injection chamber inside the coating die, and then overflows upward through the connecting hole at its bottom into an overflow groove for homogenization. Finally, it is extruded through the slit between the overflow groove and the discharge nozzle. (3) The conductive substrate with the wet coating is transported to a segmented drying system for drying. The drying system includes at least three independently temperature-controlled drying zones, wherein the first temperature zone is 65-75℃, the second temperature zone is 90-100℃, and the third temperature zone is 125-135℃. The first temperature zone adopts far-infrared radiation heating, and the second and third temperature zones adopt hot air circulation heating. The temperature fluctuation of each zone does not exceed ±1℃, forming a gradient drying to reduce the internal stress of the coating. (4) The thickness and uniformity of the dried coating are detected by an online monitoring device, and the detection data is fed back to the control system at a cycle of no more than 500 milliseconds. The control system adjusts the slurry delivery flow rate, substrate running speed or coating die gap parameter in real time through a closed-loop feedback algorithm according to the deviation between the detection data and the preset target value. The coating parameters are automatically adjusted through the closed-loop feedback system according to the detection results. The ultrasonic vibration, tension control parameters and segmented drying system work together to control the coating thickness deviation within ±1.5μm and avoid coating cracking and peeling.

2. The coating method for producing energy storage electrodes according to claim 1, characterized in that: In step (2), the online monitoring device uses an X-ray thickness gauge with a measurement accuracy of ±0.5μm and a scanning frequency of 2 times per second; the closed-loop feedback algorithm is a PID control algorithm.

3. A coating apparatus for producing energy storage electrodes, used to implement step 2 of claim 1, characterized in that: The system includes a frame (100), on which a coating assembly (200) is mounted. A material roll roller (101) is provided at the front end of the coating assembly (200), and a support roller (1011) is provided at the front end of the material roll roller (101). A leveling roller (1012) is provided between the material roll roller (101) and the coating assembly (200). A coating roller (102) is provided at the rear end of the coating assembly (200), and a take-up roller (106) is provided at the rear end of the frame (100). The coating roller (102) is close to the output end of the coating assembly (200). The conductive substrate wound on the material roll roller (101) is conveyed forward through the space between the coating assembly (200) and the coating roller (102). The coating assembly (200) includes symmetrically arranged adjustment frames (201). A short shaft (2011) is provided on the outer side of the adjustment frame (201). The adjustment frame (201) is rotatably connected to the frame (100) through the short shaft (2011). A third cylinder (2012) is hinged to the lower end of the adjustment frame (201), and the tail of the third cylinder (2012) is hinged to the frame (100). A coating die (202) is assembled between the adjustment frames (201). The adjustment frame (201) rotates on the frame (100) through the third cylinder (2012), thereby controlling the distance between the output end of the coating die (202) and the coating roller (102), thereby achieving the coating thickness.

4. The coating equipment for producing energy storage electrodes according to claim 3, characterized in that: The coating die head (202) includes a lower die (202a) and an upper die (202b). The upper die (202b) is fixed to the lower die (202a) by screws. One end of the lower die (202a) and the upper die (202b) is provided with a discharge nozzle (202c). The discharge nozzle (202c) is opposite to the coating roller (102). The front surface of the lower die (202a) is connected to a material conveying hose (203). The functional slurry enters the coating die head (202) through the material conveying hose (203) and flows out from the discharge nozzle (202c) through the slit between the lower die (202a) and the upper die (202b), and coats the conductive substrate attached to the coating roller (102) to complete the coating.

5. The coating equipment for producing energy storage electrodes according to claim 4, characterized in that: The lower mold (202a) has an injection cavity (202a1) inside, and the material conveying hose (203) is connected to the injection cavity (202a1). One end of the injection cavity (202a1) passes through the side of the lower mold (202a), and a sealing plate is provided at the through point for sealing. The upper surface of the lower mold (202a) has an overflow groove (202a2), and the bottom of the overflow groove (202a2) is provided with a connecting hole (202a3) that is connected to the injection cavity (202a1). A slit is provided on the upper surface of the lower mold (202a) between the overflow groove (202a2) and the discharge nozzle (202c).

6. The coating equipment for producing energy storage electrodes according to claim 3, characterized in that: The rear end of the frame (100) is symmetrically pinned with a cantilever frame (1051). The cantilever frame (1051) is close to the take-up roller (106), and the lower end of the cantilever frame (1051) is rotatably connected to the take-up roller. The upper end of the cantilever frame (1051) extends with a short rod, and a second cylinder (105) is hinged on the short rod. The second cylinder (105) is mounted on the frame (100).

7. The coating equipment for producing energy storage electrodes according to claim 3, characterized in that: A flattening driven roller (103) is provided inside the frame (100) and near the coating roller (102). A flattening drive roller (1041) is provided on one side of the flattening driven roller (103). Bearing seats are sleeved at both ends of the flattening drive roller (1041), and a first cylinder (104) is mounted on the bearing seats. The first cylinder (104) is fixed inside the frame (100).

8. The coating equipment for producing energy storage electrodes according to claim 3, characterized in that: The frame (100) is provided with a first auxiliary roller unit (107) near the coating die head (202), and the first auxiliary roller unit (107) is composed of multiple rotating rollers.

9. The coating equipment for producing energy storage electrodes according to claim 8, characterized in that: The frame (100) is provided with a second auxiliary roller unit (109) near the cantilever (1051), and the second auxiliary roller unit (109) is also composed of multiple rotating rollers. A guide roller (108) is provided between the first auxiliary roller unit (107) and the second auxiliary roller unit (109).

Images