Hardware and manufacturing method for coating electrode material onto a substrate in a secondary ion battery manufacturing process.

Abstract

A reverse-rotating roller system for coating electrode material includes a roll-to-roll device including a feed roller that selectively feeds a conductive substrate from a substrate roll toward a receiving roller along a first direction. The reverse-rotating roller module, including the reverse-rotating roller, is stationary above the conductive substrate at a predetermined height. The direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate. The system further includes a continuous powder coating module located on the feed side of the reverse-rotating roller to continuously deposit a certain amount of dry powder mixture onto the conductive substrate before contact with the reverse-rotating roller. A contact roller scraper that contacts the reverse-rotating roller removes powder particles from the outer surface of the reverse-rotating roller.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 456,465, filed on April 1, 2023, entitled "HARDWARE AND MANUFACTURING METHODS TO COAT ELECTRODE MATERIALS TO SUBSTRATES IN SECONDARY IONIC BATTERY MANUFACTURING PROCESS", the entire disclosure of which is incorporated herein by reference.

Background Art

[0002] The innovation of portable electronic devices has attracted attention to efficient energy storage because, while the sizes of portable systems and devices such as smartphones, laptops, and smart health devices are shrinking, their energy needs are increasing. Electrochemical storage and conversion devices are expanding the capabilities of these systems in various fields, including portable electronic devices, aviation and aerospace technology, passenger and freight vehicles, and biomedical measurement devices. Electrochemical storage and conversion devices have specially processed design and performance attributes to provide compatibility with various application requirements and operating environments.

Summary of the Invention

[0003] This disclosure can be better understood by reference to the accompanying drawings, and many of its features and advantages will become apparent to those skilled in the art. The use of the same reference numerals in different drawings indicates similar or identical items.

Brief Description of the Drawings

[0004] [Figure 1] A perspective view of a reverse - rotation roller system according to some embodiments. [Figure 2] A top view of a reverse - rotation roller system according to some embodiments. [Figure 3] This is a side view of a reverse-rotating roller system according to several embodiments. [Figure 4] This is a side cross-sectional view of a reverse-rotating roller module according to several embodiments. [Figure 5] This is an exploded perspective view of a continuous powder coating module according to several embodiments. [Figure 6] This is a block diagram of a method for coating an electrode material onto a conductive substrate according to several embodiments. [Modes for carrying out the invention]

[0005] There is significant pressure to expand the capabilities of energy storage and conversion devices such as batteries, fuel cells, and electrochemical capacitors in an increasingly wide range of applications. Continuous development necessitates mechanically robust, reliable, and high-energy-density electrochemical storage and conversion devices that can achieve good performance in a useful range of operating environments. Many recent advances in electrochemical storage technology are due to the fabrication and integration of new materials for device components. For example, battery technology continues to advance rapidly, at least in part, through the development of electrode and electrolyte materials for these systems.

[0006] A secondary ion battery has multiple components, collectively called electrodes, with the cathode and anode being the most important and expensive parts of the battery being manufactured. Traditionally, many lithium-ion battery electrodes have been manufactured using a slurry coating process. In the slurry coating process, electrode precursor materials are dispersed in a solvent to create an electrode slurry. The main component of the solid mixture in the electrode slurry is the electrode active material in powder form. The mixture may also contain smaller amounts of conductive additives and polymer binders, both in powder form, with the electrode active material making up the majority of the solid mixture.

[0007] The electrode slurry is coated onto a metal current collector to remove the solvent and create a film on the metal current collector before undergoing a long, low-speed, energy-intensive drying process. The solvent removal / drying process is crucial because coating or drying-related defects at the anode or cathode are known to occur at this stage. This powder-slurry-film manufacturing method results in a dry electrode film adhered to or bonded to the metal current collector. The final state of the electrode is a dry film or layer of electrode material on the metal current collector. The solvent in the powder-slurry-film manufacturing method serves as a working medium for (i) proper mixing, homogeneous distribution, and easy spreading of the powder components in slurry form, and (ii) bonding of the solid mixture components to the electrode current collector substrate. The solvent must be completely removed before the electrode can be used.

[0008] From an environmental perspective, slurry processes are harmful because they often involve hazardous solvents such as N-methylpyrrolidone (NMP). Processes containing NMP require additional solvent recycling equipment in addition to drying equipment to prevent NMP from being released into the environment. This requirement to recover the solvent and prevent its release results in additional capital and operating costs when using slurry electrode manufacturing processes that contain NMP or other similar solvents. Therefore, there is a need for electrode manufacturing processes that avoid slurries and do not contain solvents. Solvent-free current collector coating processes are more energy and cost-effective by eliminating the energy-intensive drying step required to completely remove all mediator solvent species.

[0009] Solvent-free electrode coating manufacturing processes can facilitate an environmentally friendly supply chain for energy storage devices such as lithium-ion batteries. Drying equipment occupies a large footprint; however, drying equipment is not required in solvent-free electrode manufacturing processes. As a result, solvent-free processes require a much smaller industrial footprint. This means that solvent-free processes are not only more efficient from an operating cost standpoint, but are also easier to deploy on an industrial scale for new battery manufacturers or existing manufacturers looking to increase production.

[0010] To address these issues and improve electrode manufacturing, Figures 1-6 describe hardware and methods for coating an electrode material onto a substrate in a solvent-free manner by separating the electrode material mixing process from the bonding process that combines solid mixture components with the electrode current collector substrate. In some embodiments, a reverse-rotating roller system for coating the electrode material includes a roll-to-roll device including a feed roller that selectively feeds a conductive substrate from a substrate roll. The conductive substrate is oriented towards a receiving roller along a first direction. Furthermore, a reverse-rotating roller module, including the reverse-rotating roller, is stationary above the conductive substrate at a predetermined height. The direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate. The reverse-rotating roller system further includes a continuous powder coating module located on the feed side of the reverse-rotating roller module to continuously deposit a certain amount of dry powder mixture onto the conductive substrate before contact with the reverse-rotating roller. A contact roller scraper that contacts the reverse-rotating roller is configured to remove residual powder particles from the outer surface of the reverse-rotating roller.

[0011] Referring to Figures 1 to 5, a reverse-rotating roller system according to a first embodiment is shown therein, indicated by reference numeral 100. The reverse-rotating roller system 100 includes a roll-to-roll device 102 which includes a dispensing roller 104 that selectively dispenses a conductive substrate 106 from a substrate roll 108. The conductive substrate 106 is oriented along a first direction of movement toward a receiving roller (not shown) (as indicated by the left-to-right arrows in Figures 1 to 4). In various embodiments, the reverse-rotating roller module 110 includes a reverse-rotating roller 112 stationarily positioned above the conductive substrate 106 at a predetermined height 114. The conductive substrate 106 is a conductive electrode substrate, which in various embodiments includes graphene-coated substrates, graphite-coated substrates, carbon-coated substrates, metal foils (including copper and aluminum), conductive polymers, conductive polymer-coated metal foils, carbon fiber mats, nickel foams, polyethylene terephthalate (PET) coated with a conductive layer, stainless steel mesh, titanium foil, and the like. The reverse-rotating roller 112 does not directly contact the conductive substrate 106. According to some embodiments, the height 114 between the conductive substrate 106 and the reverse-rotating roller 112 is set to a fixed height in the range of about 10 microns to 2 millimeters.

[0012] The continuous powder coating module 116 is located on the supply side 118 of the reverse-rotating roller module 110 and continuously deposits a fixed amount 122 (e.g., a pile or input amount of powder) of dry powder mixture 124 onto the conductive substrate 106 before contact with the reverse-rotating roller 112. In various embodiments, the pile or input amount of dry powder mixture 124 is deposited by the continuous powder coating module 116 in front of the reverse-rotating roller 112 (e.g., on the supply side 118 before the particles of dry powder mixture 124 come into contact with the reverse-rotating roller 112 due to the conductive substrate 106 moving along a first direction).

[0013] The dry powder mixture 124 comprises a mixture of intermediate-dried particles, each of which is a composite particle having a processed structure containing all the components necessary to produce an electrode. A fully functional battery electrode is produced by depositing these dry particles onto a current collector (e.g., a conductive substrate 106) and applying a combination of heat and / or pressure to bond the intermediate-dried particles to the current collector. For the purposes of this disclosure, intermediate-dried particles refer to particles having all the necessary components in the correct proportions, as in the case of an equivalent slurry without a solvent. Specifically, when the electrode is a cathode, the intermediate-dried particles have a binder and a conductive additive coated and mixed with the electrode active material. In some embodiments, the intermediate-dried particles are composite powders. In other embodiments, the intermediate-dried particles do not have to be composite powders.

[0014] In some embodiments, the dry powder mixture 124 includes a fluidizer mixed with intermediate-dried particles to alter the interparticle interactions that affect the spreading on the conductive substrate 106. The particle size distribution of the intermediate-dried particles in the dry powder mixture 124 is controlled to control the deposition and spreading on the conductive substrate 106. In various embodiments, the conductive substrate 106 is a metal foil that has been primed or pre-coated with carbon or other agents to improve electrode bonding or performance. For example, in one embodiment, the conductive substrate 106 is a corona-treated foil to improve adhesion to the dry powder mixture 124. In another embodiment, the conductive substrate 106 is a plasma-treated foil to improve adhesion to the dry powder mixture 124.

[0015] In various embodiments, the reverse-rotating roller 112 rotates in the opposite direction to the direction of movement of the conductive substrate 106. For example, referring to Figure 4, the tangential velocity direction 132 of the reverse-rotating roller 112 at the interface between the reverse-rotating roller 112 and the conductive substrate 106 (e.g., the point of minimum distance) is 180 degrees opposite to the first direction of movement of the conductive substrate 106. This interface between the roller and the substrate is sometimes called a nip where there is direct contact between the roller and the substrate, but is called an interface to clarify that there is a gap (e.g., of height 114) through which the dry powder mixture 124 passes. In this way, the reverse-rotating roller 112 positioned at a fixed height 114 on the conductive substrate 106 spreads the pile or amount of dry powder mixture 124, forming a thin film layer of dry powder mixture 124 on the conductive substrate 106. The reverse rotation motion of the reverse-rotating roller 112 helps to evenly distribute the compressive force, preventing skew or uneven compression and thus avoiding the formation of depressions or bumps in the material being compressed (e.g., the dry powder mixture 124).

[0016] In some embodiments, the reverse-rotating roller module 110 includes a flexible wiper or scraper to prevent the dry powder mixture 124 from moving to the opposite side. For example, as shown in Figure 4, the reverse-rotating roller module 110 includes a contact roller scraper 126 that contacts the reverse-rotating roller 112 and is configured to remove residual powder particles from the outer surface 128 of the reverse-rotating roller 112. In various embodiments, the contact roller scraper 126 is a flexible member (e.g., made of rubber) that extends substantially along the entire longitudinal length of the reverse-rotating roller 112 and is in direct contact with the outer surface of the reverse-rotating roller 112, thereby scraping off any residual powder particles from the outer surface 128 and returning them to the supply side 118 of the reverse-rotating roller module 110. In other words, the contact roller scraper prevents the powder particles of the dry powder mixture 124 from being carried by rotational motion to the top of the counter-rotating roller and falling onto the post-roller side 120 of the counter-rotating roller module 110 as uneven, loose powder (as opposed to passing properly under the counter-rotating roller 112 and appearing as a uniform film layer on the post-roller side 120).

[0017] The reverse-rotating roller system 100 also includes an orientation maintenance module 130 designed to maintain the conductive substrate 106 in a flat orientation under the reverse-rotating roller module 110. In some embodiments, the orientation maintenance module 130 is a high-precision support plate or vacuum table system that keeps the conductive substrate 106 uniformly flat and prevents trajectory displacement during the powder deposition and compression process, thereby achieving consistent layer thickness and adhesion across the substrate surface. In other embodiments, the orientation maintenance module 130 is a free-rotating roller or other mechanism that can maintain a flat and perpendicularly aligned orientation of the conductive substrate 106 with respect to the reverse-rotating roller module 110 and the reverse-rotating rollers 112.

[0018] It should be noted that the systems and methods for coating an electrode material onto a substrate using the reverse-rotating roller system 100 can be performed with or without the application of heat. For example, in some embodiments, the reverse-rotating roller system 100 includes a powder heating module (not shown) configured to heat a pile of dry powder mixture 124 and / or the conductive substrate 106 before contact with the reverse-rotating roller 112 in order to improve spreading characteristics. In some embodiments, prior to engagement with the reverse-rotating roller module 110, or a first section of the reverse-rotating roller module 110, the dry powder mixture 124 is preheated using a dedicated heating unit employing established powder heating techniques to bring the powder to an optimal temperature, thereby improving the powder's readiness for compression and adhesion to the electrode conductive substrate 106 upon contact with the reverse-rotating roller 112. For example, in some embodiments, the powder heating module includes, but is not limited to, a quartz lamp, an infrared heater, a laser (e.g., a CO2 laser, a diode laser, an ND-Yag laser), a heated gaseous fluid, a microwave radiation heater, and the like. In various embodiments, the dry powder mixture 124 is heated to a temperature in the range of 20°C to 200°C before contact with the reverse-rotating roller 112.

[0019] Similarly, in various embodiments, the surface temperature of the reverse-rotating roller 112 is controlled. The reverse-rotating roller 112 is heated directly or indirectly to control the fluidity of the dry powder mixture 124 during spreading and coating. For example, in some embodiments, the reverse-rotating roller module 110 includes an integrated heating system configured to control the temperature of the outer surface 128 of the reverse-rotating roller 112. The integrated heating system is designed to allow precise temperature control across the roller surface to control the thermal conditions of the powder mixture deposited on the conductive electrode substrate and to apply a specific range of pressure to the powder-coated substrate, helping to achieve a uniformly compressed layer. Heat is applied to the reverse-rotating roller system 100 using a heated reverse-rotating roller or other heated roller to assist in conveying and / or tamping the dry powder mixture 124 on the conductive substrate 106. In various embodiments, the rollers are heated with any combination of circulating oil, gas or other fluids, infrared heating, resistance heating, etc. In some embodiments, heat is applied to the respective regions using varying magnetic or electric field heating. In addition, in some embodiments, a combination of two or more heat sources is applied to the rollers. In other embodiments, the reverse-rotating roller 112 is cooled to control the flowability of the dry powder mixture 124 during spreading and coating. In some embodiments, the diameter of the reverse-rotating roller 112 is modified to control the flowability of the dry powder mixture 124 during spreading and coating. For example, in various embodiments, the reverse-rotating roller 112 is heated to a temperature in the range of 20°C to 200°C.

[0020] In other embodiments, heat is applied to the conductive substrate 106 before coating with the dry powder mixture 124. In other embodiments, heat is applied to the conductive substrate 106 after it has been coated with the dry powder mixture 124. In other embodiments, the dry powder mixture 124 is heated before being applied to the conductive substrate. In other embodiments, the dry powder mixture 124 is heated after being applied to the conductive substrate. In some other embodiments, the dry powder mixture 124 is heated and then applied to the conductive substrate 106, which is also heated.

[0021] In some embodiments, the surface finish of the outer surface 128 of the reverse-rotating roller 112 is selected to adjust the coefficient of friction between the dry powder mixture 124 and the reverse-rotating roller 112. The material composition and surface roughness 128 of the reverse-rotating roller 112 are selected to adjust the frictional interaction between the dry powder mixture 124, the conductive substrate 106, and the reverse-rotating roller 112, ensuring optimal compression and layer consistency to achieve desired electrode layer characteristics. The surface finish of the outer surface 128 of the reverse-rotating roller 112 is also selected to adjust the coefficient of friction between the conductive substrate 106 and the reverse-rotating roller 112. For example, in some embodiments, the surface finish of the reverse-rotating roller is in the range of having an average surface roughness (Ra) value between 0.1 micron Ra (smooth) and 50 micron Ra, measured according to the ISO 21920 standard. The material selection of the reverse-rotating roller 112 is modified to control the flowability of the dry powder mixture 124 during spreading and coating. In addition, in some embodiments, the reverse-rotating roller 112 is electrically grounded to prevent electrostatic charge formation.

[0022] In some embodiments, the reverse rotation roller system 100 further includes a doctor blade (not shown) that aids in spreading the dry powder mixture 124. The dry powder mixture 124 is mound-shaped or spread on the uncoated side of the foil, and then the height of the doctor blade is adjusted to a height sufficient to apply a uniform coat of dry powder mixture 124 particles on the conductive substrate 106. In some embodiments, the fixed surface of the doctor blade rests on the conductive substrate 106. In other embodiments, the fixed surface of the doctor blade is above the conductive substrate 106 and never contacts the conductive substrate 106. In some embodiments, the doctor blade is stationary. In other embodiments, the doctor blade moves. In some embodiments, the leading and trailing profiles of the doctor blade are modified to be able to control the spread and coating of the dry powder mixture 124. In some embodiments, the surface roughness of the leading and trailing profiles of the doctor blade is modified to be able to control the spread and coating of the dry powder mixture 124. In some embodiments, the material selection of the doctor blade is modified to be able to control the spread and coating of the dry powder mixture 124.

[0023] In one embodiment, after the application and spreading of the dry powder mixture 124, heating and pressing of the dry powder mixture 124 on the conductive substrate 106 is performed (referred to as a roll-to-roll manufacturing process). In one embodiment, the dry powder mixture 124 containing intermediate dry particles is uniformly spread on the conductive substrate 106 and then heated and pressed after passing under the reverse rotation roller 112 to obtain a fully functional dry battery electrode. For example, in various embodiments, the reverse rotation roller system 100 includes a post-treatment compression module (not shown) disposed downstream of the reverse rotation roller module 110, and the post-treatment compression module includes one or more heating rollers configured to apply additional compressive force to the conductive substrate 106.

[0024] It should be appreciated that FIGS. 1-5 are described primarily in the context of providing the conductive substrate 106 to the counter-rotating roller 112 using a roll-to-roll mechanism. However, one of ordinary skill in the art will recognize that the counter-rotating roller system 100 may provide the conductive substrate 106 using a variety of other mechanisms without departing from the scope of the present disclosure. For example, in some embodiments, the conductive substrate 106 is provided to the counter-rotating roller 112 by sheet feeding, manual placement, or an automated conveyor system, enabling the processing of substrates of various forms and sizes. In some embodiments, the conductive substrate may remain stationary while the counter-rotating roller moves relative to the conductive substrate. In some embodiments, the application, heating, and pressing of the dry powder mixture 124 are performed on individual metal foil pieces. In some embodiments, regardless of whether it is a roll-to-roll process or a discrete process, the dry powder mixture 124 is applied and spread, and then fixed or pressed without applying heat with only pressure. In other embodiments, the conductive substrate 106 is fixed, and instead, the spreading mechanism (e.g., the counter-rotating roller 112) moves relative to the conductive substrate 106.

[0025] Referring to Figure 5, an exploded perspective view of a continuous powder coating module 116 according to one embodiment is shown therein. The continuous powder coating module 116 is configured to precisely control the volume and rate of the dry powder mixture 124 being fed onto the conductive substrate 106 by utilizing a real-time feedback mechanism for uniform deposition and optimal powder utilization. As shown, the powder coating module 116 includes a powder hopper 502 for holding the dry powder mixture 124. The powder hopper 502 includes a bottom plate 504 that fixes a sieve screen 506 (e.g., mesh) to the powder hopper 502. The powder hopper 502 is vibrated by an oscillator 508, thereby dispersing the particles of the dry powder mixture 124 from the bottom onto the conductive substrate 106 through the sieve screen 506 due to the mechanical vibration. In some embodiments, a vibrating powder hopper 502 with a control mesh opening is used to supply material to a reverse-rotating roller 112. According to various embodiments, the sieve screen 506 has a mesh or screen opening size in the range of US mesh size 10 (2000 micron opening) to US mesh size 1250 (10 micron opening). In some embodiments, the sieve screen 506 has a mesh or screen opening size in the range of US mesh size 50 (297 micron opening) to US mesh size 400 (37 micron opening).

[0026] In other embodiments, the vibrating powder hopper 502 provides feed material to the doctor blade. In some embodiments, the vibrating powder hopper 502 with a mesh bottom is stationary. In other embodiments, the vibrating powder hopper 502 moves along one axis when the conductive substrate 106 is being coated. In yet another embodiment, the powder hopper 502 moves back and forth across the width of the conductive substrate 106. In some embodiments, the mesh or opening size of the vibrating powder hopper 502 is modified to better control the spreading and coating of the dry powder mixture 124. In some embodiments, the hole size at the bottom of the vibrating hopper is not uniform. In some embodiments, the amplitude and frequency of the mechanical vibration are modified to control the spreading and coating of the dry powder mixture 124. In some embodiments, the width of the tank in the direction of movement relative to the conductive substrate 106 is modified to control the spreading and coating of the dry powder mixture 124. In other embodiments, the pile or input amount of the dry powder mixture 124 is deposited or supplied in front of the reverse-rotating roller 112 using other equipment. For example, in various embodiments, the continuous powder coating module 116 includes, but is not limited to, a star feeder, a screw feeder, and the like.

[0027] In addition, other apparatus for continuously coating the conductive substrate 106 includes an inclined vibrating table. The surface roughness of the base of the vibrating table, the amplitude and frequency of vibration, the height above the conductive substrate 106, the temperature of the vibrating table, and the addition of a gate toward the feeding edge of the table are parameters controlled to obtain good spreading and coating on the foil. Similarly, in other embodiments, the continuous powder coating module 116 includes a dry powder spraying system, such as a high-volume low-pressure (HVLP) spraying system or a low-volume low-pressure (LVLP) system, in which pressurized air or any other gaseous fluid aerosolizes the particles of the dry powder mixture 124 and transfers the particles to the conductive substrate 106. In various embodiments, the diameter and shape of the nozzle, the volume and pressure of the gaseous fluid, the temperature of the gaseous fluid, and the distance between the nozzle and the substrate are parameters modified to achieve better spreading and coating on the conductive substrate 106. In various embodiments, different combinations of feeding and leveling methods may be used, including, but are not limited to, multiple feeding methods and multiple leveling methods in series.

[0028] It should be noted that Figures 1 to 4 are described above primarily in the context of a single reverse-rotating roller 112 for the sake of illustration and explanation. However, those skilled in the art will recognize that the reverse-rotating roller system 100 may include any number of rollers without departing from the scope of the present disclosure. For example, in some embodiments, the reverse-rotating roller module 110 includes two or more reverse-rotating rollers arranged in series at different heights above a conductive substrate 106 to gradually increase the density of the electrode substrate (e.g., by reducing the thickness of the film layer) by sequentially applying compressive force, thereby optimizing the density and uniformity of the powder layer. In addition, those skilled in the art will recognize that two or more reverse-rotating rollers may be arranged at different heights, rotate at different speeds, have different surface finishes / textures, and / or be heated to different temperatures relative to each other.

[0029] Referring here to Figure 6, a block diagram of Method 600 for coating an electrode material onto a conductive substrate according to several embodiments is shown. For ease of illustration and explanation, Method 600 is described below in an illustrative context with reference to the reverse-rotating roller system of Figures 1 to 5. However, Method 600 is not limited to these illustrative situations and can instead be employed in any of the various possible configurations using the guidelines provided herein.

[0030] Method 600 begins in block 602 with depositing a fixed amount of dry powder mixture onto the surface of a conductive substrate upstream of the reverse-rotating roller. In various embodiments, the operation of block 602 includes continuously depositing a fixed amount of dry powder mixture as the conductive substrate moves along a first direction toward the reverse-rotating roller. For example, in the context of Figures 1 to 5, the continuous powder coating module 116 is located on the supply side 118 of the reverse-rotating roller module 110 and continuously deposits a fixed amount 122 of dry powder mixture 124 onto the conductive substrate 106 before contact with the reverse-rotating roller 112. The continuous deposit of a fixed amount of dry powder mixture onto the substrate is performed before engagement with the reverse-rotating roller, and the fixed amount is deposited to achieve a predetermined thickness of powder on the conductive substrate.

[0031] In various embodiments, the operation of block 602 also includes precisely controlling the volume and rate of the dry powder mixture being dispensed onto the substrate using a real-time feedback mechanism. For example, in some embodiments, the rate of powder deposition from the continuous powder coating module 116 closely matches the volume of the powder mixture being spread by the reverse-rotating roller 112 and passing underneath it, in order to prevent the dry powder mixture 124 from gradually accumulating on the supply side 118 of the reverse-rotating roller module 110, which eventually covers the contact roller scraper 126 and / or flows out from the conductive substrate 106 and the orientation maintenance module 130.

[0032] In various embodiments, the conductive substrate is primed or pre-coated with carbon or any other agent to improve electrode bonding or performance. In one embodiment, the foil can be corona-treated to improve adhesion to the dry powder mixture 124. In another embodiment, the foil can be plasma-treated to improve adhesion to the dry powder mixture 124. In various embodiments, a pile or input of the dry powder mixture 124 is deposited by a continuous powder coating module 116 in front of the reverse-rotating roller 112 (for example, on the supply side 118 before the particles of the dry powder mixture 124 come into contact with the reverse-rotating roller 112 as a result of the conductive substrate 106 moving along a first direction).

[0033] As shown in Figure 5, the powder coating module 116 includes a powder hopper 502 for holding a dry powder mixture 124 and is configured to precisely control the volume and rate of the dry powder mixture 124 being fed onto the conductive substrate 106 using a real-time feedback mechanism for uniform deposition and optimal powder utilization. The powder hopper 502 includes a bottom plate 504 that secures a sieve screen 506 (e.g., mesh) to the powder hopper 502. The powder hopper 502 is vibrated by an oscillator 508, thereby dispersing the particles of the dry powder mixture 124 from the bottom onto the conductive substrate 106 through the sieve screen 506 due to the mechanical vibration. In some embodiments, a vibrating powder hopper 502 with a control mesh opening is used to supply material to a reverse-rotating roller 112.

[0034] In other embodiments, the vibrating powder hopper 502 provides feed material to the doctor blade. In some embodiments, the vibrating powder hopper 502 with a mesh bottom is stationary. In other embodiments, the vibrating powder hopper 502 moves along one axis when the conductive substrate 106 is being coated. In yet another embodiment, the powder hopper 502 moves back and forth across the width of the conductive substrate 106. In some embodiments, the mesh or opening size of the vibrating powder hopper 502 is modified to better control the spreading and coating of the dry powder mixture 124. In some embodiments, the hole size at the bottom of the vibrating hopper is not uniform. In some embodiments, the amplitude and frequency of the mechanical vibration are modified to control the spreading and coating of the dry powder mixture 124. In some embodiments, the width of the tank in the direction of movement relative to the conductive substrate 106 is modified to control the spreading and coating of the dry powder mixture 124. In other embodiments, the pile or input amount of the dry powder mixture 124 is deposited or supplied in front of the reverse-rotating roller 112 using other equipment. For example, in various embodiments, the continuous powder coating module 116 includes, but is not limited to, a star feeder, a screw feeder, and the like.

[0035] In addition, in other embodiments, an inclined vibrating table continuously applies powder to the conductive substrate 106. The surface roughness of the base of the vibrating table, the amplitude and frequency of vibration, the height above the conductive substrate 106, the temperature of the vibrating table, and the addition of a gate toward the feeding edge of the table are parameters controlled to obtain good spread and coating on the foil. Similarly, in other embodiments, the continuous powder coating module 116 includes a dry powder spraying system, such as a high-volume low-pressure (HVLP) spraying system or a low-volume low-pressure (LVLP) system, in which pressurized air or any other gaseous fluid aerosolizes the particles of the dry powder mixture 124 and transfers the particles to the conductive substrate 106. In various embodiments, the diameter and shape of the nozzle, the volume and pressure of the gaseous fluid, the temperature of the gaseous fluid, and the distance between the nozzle and the substrate are parameters modified to achieve better spread and coating on the conductive substrate 106. In various embodiments, different combinations of feeding and leveling methods may be used, including, but are not limited to, multiple feeding methods and multiple leveling methods in series.

[0036] In other embodiments, heat is applied to the conductive substrate 106 before coating with the dry powder mixture 124. In other embodiments, heat is applied to the conductive substrate 106 after it has been coated with the dry powder mixture 124. In other embodiments, the dry powder mixture 124 is heated before being applied to the conductive substrate. In other embodiments, the dry powder mixture 124 is heated after being applied to the conductive substrate. In some other embodiments, the dry powder mixture 124 is heated and then applied to the conductive substrate 106, which is also heated. For example, in some embodiments, the reverse-rotating roller system 100 includes a powder heating module (not shown) configured to heat a pile of the dry powder mixture 124 before contact with the reverse-rotating roller 112 and / or heat the conductive substrate 106 in order to improve spreading characteristics. In some embodiments, prior to engagement with the reverse-rotating roller module 110, or the first section of the reverse-rotating roller module 110, the dry powder mixture 124 is preheated using a dedicated heating unit employing established powder heating technology to bring the powder to an optimal temperature, thereby improving the powder's readiness for compression and adhesion to the electrode conductive substrate 106 upon contact with the reverse-rotating roller 112. For example, in some embodiments, the powder heating module includes, but is not limited to, a quartz lamp, an infrared heater, a laser (e.g., a CO2 laser, a diode laser, an ND-Yag laser), a heated gaseous fluid, a microwave radiation heater, and the like. In various embodiments, the dry powder mixture 124 is heated to a temperature in the range of 20°C to 200°C before contact with the reverse-rotating roller 112.

[0037] Method 600 continues to feed the conductive substrate in block 604 along a first direction toward the reverse-rotating roller. With reference to Figures 1 to 4, in various embodiments, the reverse-rotating roller system 100 includes a roll-to-roll device 102 which includes a dispensing roller 104 that selectively dispenses the conductive substrate 106 from the substrate roll 108. The conductive substrate 106 is oriented along a first direction of movement toward a receiving roller (not shown) (as indicated by the left-to-right arrows in Figures 1 to 4). In some embodiments, the operation of block 604 further includes coordinating the unwinding operation of the conductive substrate from the substrate roll 108 in both continuous and intermittent dispensing at a variable speed.

[0038] In various embodiments, the operation of block 604 also includes maintaining the conductive substrate in a flat orientation under the reverse-rotating rollers. Referring, for example, to Figure 4, in various embodiments, the reverse-rotating roller system 100 also includes an orientation maintenance module 130 designed to maintain the conductive substrate 106 in a flat orientation under the reverse-rotating roller module 110. In some embodiments, the orientation maintenance module 130 is a high-precision support plate or vacuum table system that ensures the conductive substrate 106 remains uniformly flat and does not shift its trajectory during the powder deposition and compression process, thereby achieving consistent layer thickness and adhesion across the substrate surface. In other embodiments, the orientation maintenance module 130 is a free-rotating roller or other mechanism that can maintain a flat and perpendicularly aligned orientation of the conductive substrate 106 with respect to the reverse-rotating roller module 110 and the reverse-rotating rollers 112.

[0039] In other embodiments, supplying the conductive substrate to a reverse-rotating roller, rather than utilizing a roll-to-roll mechanism, includes sheet feeding, manual placement, or an automated conveyor system, enabling the processing of substrates of various shapes and sizes. In some embodiments, the conductive substrate may remain stationary while the reverse-rotating roller moves relative to the conductive substrate. In some embodiments, the application, heating, and pressurization of the dry powder mixture 124 are performed on a separate piece of metal foil.

[0040] Method 600 continues in block 606 by spreading a certain amount of dry powder mixture on the surface of the conductive substrate, at least in part, based on the reverse rotational motion of the reverse-rotating roller, such that the direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate. With respect to Figure 4, in various embodiments, the reverse-rotating roller module 110 includes a reverse-rotating roller 112 stationarily positioned above the conductive substrate 106 at a predetermined height 114.

[0041] The reverse-rotating roller 112 rotates in the opposite direction to the direction of movement of the conductive substrate 106, forming a constant layer thickness and powder density across the conductive substrate. For example, referring to Figure 4, the tangential velocity direction 132 of the reverse-rotating roller 112 at the interface between the reverse-rotating roller 112 and the conductive substrate 106 (e.g., the point of minimum distance) is 180 degrees opposite to the first direction of movement of the conductive substrate 106. This interface between the roller and the substrate is sometimes called a nip where there is direct contact between the roller and the substrate, but is called an interface to clarify that there is a gap (e.g., of height 114) through which the dry powder mixture 124 passes. In this way, the reverse-rotating roller 112 positioned at a fixed height 114 on the conductive substrate 106 spreads the pile or input amount of the dry powder mixture 124, forming a thin film layer of the dry powder mixture 124 on the conductive substrate 106. The reverse rotational motion of the reverse-rotating roller 112 helps to evenly distribute the compressive force, preventing skew or uneven compression and thus avoiding the formation of depressions or bumps in the material being compressed (e.g., the dry powder mixture 124). Furthermore, the reverse rotational speed of the reverse-rotating roller 112 is adjustable to control the spreading and coating of the dry powder mixture 124.

[0042] It should be noted that the operation of block 606 for coating electrode material onto a substrate using reverse rotational motion can be performed with or without the application of heat. For example, in some embodiments, the surface temperature of the reverse-rotating roller 112 is controlled. The reverse-rotating roller 112 is heated directly or indirectly to control the fluidity of the dry powder mixture 124 during spreading and coating. For example, in some embodiments, the reverse-rotating roller module 110 includes an integrated heating system configured to control the temperature of the outer surface 128 of the reverse-rotating roller 112. The integrated heating system is designed to allow precise temperature control across the roller surface to control the thermal conditions of the powder mixture deposited on the conductive electrode substrate and to apply a specific range of pressure to the powder-coated substrate, helping to achieve a uniformly compressed layer. Heat is applied to the reverse-rotating roller system 100 using a heated reverse-rotating roller or other heated roller to assist in conveying and / or tamping the dry powder mixture 124 on the conductive substrate 106. In various embodiments, the rollers are heated with any combination of circulating oil, gas or other fluids, infrared heating, resistance heating, etc. In some embodiments, heat is applied to each region using a changing magnetic field or electric field heating. In addition, in some embodiments, a combination of two or more heat sources is applied to the roller. In other embodiments, the reverse-rotating roller 112 is cooled to control the flowability of the dry powder mixture 124 during spreading and coating. In some embodiments, the diameter of the reverse-rotating roller 112 is changed to control the flowability of the dry powder mixture 124 during spreading and coating. For example, in various embodiments, the reverse-rotating roller 112 is heated to a temperature in the range of 20°C to 200°C.

[0043] In other embodiments, the reverse-rotating roller system 100 further includes a doctor blade (not shown) to assist in spreading the dry powder mixture 124. The dry powder mixture 124 is piled up or spread on the uncoated side of the foil, and the height of the doctor blade is then adjusted to a height sufficient to apply a uniform coat of dry powder mixture 124 particles onto the conductive substrate 106. In some embodiments, the fixed surface of the doctor blade rests on the conductive substrate 106. In other embodiments, the fixed surface of the doctor blade is above the conductive substrate 106 and never in contact with the conductive substrate 106. In some embodiments, the doctor blade is stationary. In other embodiments, the doctor blade moves. In some embodiments, the leading and trailing profiles of the doctor blade are modified to control the spreading and coating of the dry powder mixture 124. In some embodiments, the surface roughness of the leading and trailing profiles of the doctor blade is modified to control the spreading and coating of the dry powder mixture 124. In some embodiments, the material selection of the doctor blade is modified to control the spreading and coating of the dry powder mixture 124.

[0044] Method 600 continues to scrape residual powder particles from the outer surface of the reverse-rotating roller based on a contact roller scraper in contact with the reverse-rotating roller in block 608. With respect to Figure 4, in various embodiments, the reverse-rotating roller module 110 includes a flexible wiper or scraper to prevent the dry powder mixture 124 from moving to the opposite side. For example, as shown in Figure 4, the reverse-rotating roller module 110 includes a contact roller scraper 126 in contact with the reverse-rotating roller 112, configured to remove residual powder particles from the outer surface 128 of the reverse-rotating roller 112. In various embodiments, the contact roller scraper 126 is a flexible member (e.g., made of rubber) that extends along substantially the entire longitudinal length of the reverse-rotating roller 112 and is in direct contact with the outer surface of the reverse-rotating roller 112, thereby scraping any residual powder particles from the outer surface 128 and returning them to the supply side 118 of the reverse-rotating roller module 110. In other words, the contact roller scraper prevents the powder particles of the dry powder mixture 124 from being carried by rotational motion to the top of the counter-rotating roller and falling onto the post-roller side 120 of the counter-rotating roller module 110 as uneven, loose powder (as opposed to passing properly under the counter-rotating roller 112 and appearing as a uniform film layer on the post-roller side 120).

[0045] In some embodiments, the operation of block 608 is followed by heating and / or pressurizing (referred to as a roll-to-roll manufacturing process) of the dry powder mixture 124 on the conductive substrate 106, thereby compressing the powder-coated substrate to form an electrode layer. In one embodiment, the dry powder mixture 124, containing intermediate-dried particles, is spread uniformly on the conductive substrate 106, then heated and pressurized after passing under a reverse-rotating roller 112 to obtain fully functional dry cell electrodes. For example, in various embodiments, the reverse-rotating roller system 100 includes a post-processing compression module (not shown) located downstream of the reverse-rotating roller module 110, the post-processing compression module including one or more heating rollers configured to apply additional compressive force to the conductive substrate 106. In some embodiments, whether it is a roll-to-roll process or a discrete process, the dry powder mixture 124 is coated and spread, and then fixed or pressurized by pressure only without heat.

[0046] It should be noted that Figures 1 to 6 are described above primarily in the context of a single reverse-rotating roller 112 for the sake of illustration and explanation. However, those skilled in the art will recognize that the reverse-rotating roller system 100 may include any number of rollers without departing from the scope of this disclosure. In some embodiments, after a conductive substrate is coated with a dry powder mixture 124, post-processing compression pressure is applied using two rollers similar to those in a conventional rolling mill. The roller diameter, roller surface finish and roughness, roller material selection, roller speed, any coatings on the rollers (nitriding, anti-slip, non-stick, corrosion protection), roller temperature, and the gap between the rollers are important for control to obtain the appropriate final electrode thickness.

[0047] For example, in some embodiments, the reverse-rotating roller module 110 includes two or more reverse-rotating rollers arranged in series at different heights above the conductive substrate 106 to optimize the density and uniformity of the powder layer, which is sometimes called lamination, by sequentially applying compressive force to gradually increase the density of the electrode substrate (e.g., by reducing the thickness of the film layer). In addition, those skilled in the art will recognize that the two or more reverse-rotating rollers may be arranged at different heights, rotate at different speeds, have different surface finishes / textures, and / or be heated to different temperatures relative to each other.

[0048] In some embodiments, there are consecutive pairs of rollers that continuously compress the foil with the coated dry powder mixture 124. This is achieved by reducing the distance between the two rollers in each consecutive pair of rollers. In some embodiments, there is only one roller, and instead of the other rollers, there may be a fixed object / plate / table / curved surface on which the foil slides. In some embodiments, the angle of the wrap is changed between the foil and the roller to improve the bonding of the dry powder mixture 124 to the conductive substrate 106. In some embodiments, the rollers are completely replaced by an inclined upper belt and a flat lower belt, the gap of which decreases continuously along the length of the belt. The belt can be made of various materials, and the foil coated with the dry powder mixture 124 moves along the belt. In another embodiment, both the upper and lower belts are inclined. These belts may or may not be heated.

[0049] Accordingly, as described herein, Figures 1 to 6 illustrate techniques for improving electrode manufacturing for use in batteries, more specifically electrochemical energy storage devices such as lithium-ion batteries, by helping to reduce capital and operating costs, energy consumption, and eliminate or minimize the use of toxic and environmentally harmful materials. This disclosure can be applied to both anode electrode manufacturing and cathode electrode manufacturing of secondary ion batteries such as lithium-ion batteries and sodium-ion batteries.

[0050] Throughout this disclosure, numerical values ​​represent an approximate measure or limit of a range that includes slight deviations from a given value, embodiments having approximately the same value as the value mentioned, and embodiments having exactly the same value as the value mentioned. Except for the examples provided at the end of the detailed description, all numerical values ​​of parameters (e.g., quantities or conditions) in this specification, including the appended claims, should be understood to be modified in all cases by the term “about,” regardless of whether “about” actually appears before the numerical value. “About” indicates that the numerical value described allows for some degree of inaccuracy (using several approaches to the accuracy of the value, such as approximate or reasonably close to the value). Where the inaccuracy provided by “about” is not otherwise understood in the art in this ordinary sense, “about” as used herein indicates at least the variation that may arise from the ordinary methods of measuring and using such parameters. For example, “about” may include variation of 5% or less, optionally 4% or less, optionally 3% or less, optionally 2% or less, optionally 1% or less, optionally 0.5% or less, and in certain embodiments, optionally 0.1% or less. In addition, the disclosure of the range includes the disclosure of all values ​​within the entire range, as well as any further subdivided ranges, including the endpoint and subranges given to the range.

[0051] It should be noted that not all of the activities or elements described above are required in the general description, and that some of the activities or devices may not be required. Furthermore, one or more additional activities may be performed or elements may be included in addition to those described. Moreover, the order in which the activities are listed does not necessarily indicate the order in which they are performed. Also, concepts are described with reference to specific embodiments. However, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of this disclosure as set forth in the following claims. Therefore, this specification and the drawings should be considered illustrative rather than restrictive, and all such modifications are intended to be within the scope of this disclosure.

[0052] Merits, other advantages, and solutions to problems have been described above with respect to specific embodiments. However, merits, advantages, solutions to problems, and any features that may give rise to or make more prominent any merits, advantages, or solutions should not be construed as important, necessary, or essential features of any or all of the claims. Furthermore, the disclosed subject matter can be modified and implemented in different but equivalent ways that are obvious to those skilled in the art who have merit to the teachings of this specification, so the specific embodiments disclosed above are merely illustrative. It is not intended to limit the details of the structure or design shown herein to anything other than those set forth in the following claims. Accordingly, it is clear that the specific embodiments disclosed above may be changed or modified, and all such variations are considered to be within the scope of the disclosed subject matter. Accordingly, the protection sought herein is as set forth in the following claims.

[0053] In addition to the embodiments described herein, examples of certain combinations are within the scope of this disclosure, some of which are detailed below.

[0054] Example 1: A roll-to-roll device including a supply roller for selectively supplying a conductive substrate from a substrate roll, wherein the conductive substrate is oriented toward a receiving roller along a first direction; a reverse-rotating roller module including a reverse-rotating roller stationarily positioned above the conductive substrate at a predetermined height, wherein the direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate; a continuous powder coating module positioned on the supply side of the reverse-rotating roller module for continuously depositing a certain amount of dry powder mixture onto the conductive substrate before contacting the reverse-rotating roller; and a contact roller scraper configured to contact the reverse-rotating roller and remove residual powder particles from the outer surface of the reverse-rotating roller.

[0055] Example 2. The system of Example 1, wherein the continuous powder dispenser includes a vibrating hopper sieve.

[0056] Example 3. The system of Example 1, wherein the reverse-rotating roller module includes two or more reverse-rotating rollers arranged in series.

[0057] Example 4. The system of Example 1, further comprising a post-processing compression module located downstream of the reverse-rotating roller module, the post-processing compression module including one or more heated rollers configured to apply additional compressive force to a conductive substrate.

[0058] Example 5. The system of Example 1, wherein the conductive substrate is made of a material selected from the group consisting of graphene-coated substrates, graphite-coated substrates, carbon-coated substrates, copper foil, aluminum foil, metal foil, conductive polymer, conductive polymer-coated metal foil, carbon fiber mat, nickel foam, polyethylene terephthalate (PET) coated with a conductive layer, stainless steel mesh, and titanium foil.

[0059] Example 6. The system of Example 1, further comprising an orientation maintenance module configured to maintain a conductive substrate in a flat orientation below a reverse-rotating roller module.

[0060] Example 7. The system of Example 1, further comprising an integrated heating system in which a reverse-rotating roller module is configured to regulate the temperature of the entire outer surface of the reverse-rotating roller.

[0061] Example 8. A method comprising the steps of depositing a certain amount of dry powder mixture onto the surface of a conductive substrate at a position upstream of a reverse-rotating roller; supplying the conductive substrate toward the reverse-rotating roller along a first direction; spreading a certain amount of dry powder mixture onto the surface of the conductive substrate, at least partially based on the reverse rotational motion of the reverse-rotating roller, wherein the direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate; and scraping off residual powder particles from the outer surface of the reverse-rotating roller based on a contact roller scraper in contact with the reverse-rotating roller.

[0062] Example 9. The method of Example 8, further comprising the step of distributing a conductive substrate from a substrate roll of a roll-to-roll apparatus.

[0063] Example 10. The method of Example 8, wherein the step of depositing a certain amount of dry powder mixture further includes the step of continuously depositing a certain amount of dry powder mixture as the conductive substrate moves along a first direction toward a reverse-rotating roller.

[0064] Example 11. The method of Example 8, further comprising the step of preheating the dry powder mixture before engaging with the reverse-rotating roller.

[0065] Example 12. The method of Example 11, wherein the step of preheating the dry powder mixture includes a step of heating the dry powder mixture to a temperature in the range of 20°C to 200°C.

[0066] Example 13. The method of Example 8, further comprising the step of heating the outer surface of a reverse-rotating roller to a temperature in the range of 20°C to 200°C.

[0067] Example 14. The method of Example 8, further comprising the step of maintaining the conductive substrate in a flat orientation under a reverse-rotating roller.

[0068] Example 15. An apparatus comprising a reverse-rotating roller module including a reverse-rotating roller stationarily positioned at a predetermined height above a conductive substrate, wherein the direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate, a continuous powder coating module positioned on the supply side of the reverse-rotating roller module for continuously depositing a certain amount of dry powder mixture onto the conductive substrate before contact with the reverse-rotating roller, and a contact roller scraper configured to contact the reverse-rotating roller and remove residual powder particles from the outer surface of the reverse-rotating roller.

[0069] Example 16. Apparatus of Example 15, wherein the continuous powder dispenser includes a vibrating hopper sieve.

[0070] Example 17. The apparatus of Example 15, wherein the reverse-rotating roller module includes two or more reverse-rotating rollers arranged in series.

[0071] Example 18. The apparatus of Example 15, further comprising a post-processing compression module located downstream of the reverse-rotating roller module, the post-processing compression module including one or more heated rollers configured to apply additional compressive force to a conductive substrate.

[0072] Example 19. The apparatus of Example 15, wherein the conductive substrate is made of a material selected from the group consisting of graphene-coated substrates, graphite-coated substrates, carbon-coated substrates, copper foil, aluminum foil, metal foil, conductive polymer, conductive polymer-coated metal foil, carbon fiber mat, nickel foam, polyethylene terephthalate (PET) coated with a conductive layer, stainless steel mesh, and titanium foil.

[0073] Example 20. The apparatus of Example 15, further comprising an orientation maintenance module configured to maintain a conductive substrate in a flat orientation under a reverse-rotating roller module. [Explanation of Symbols]

[0074] 100 Reverse Rotation Roller System 102 Roll-to-roll device 104 Distribution Roller 106 Conductive substrate 108 PCB rolls 110 Reverse Rotation Roller Module 112 Reverse Rotating Roller 114 Prescribed height 116 Continuous powder coating module 118 Supply side 120 Post Roller Side 122 Fixed amount 124 Dry powder mixture 126 Contact Roller Scraper 128 External surface 130 Orientation Maintenance Module 132 Tangential velocity direction 502 Powder Hopper 504 Bottom plate 506 sieve screen 508 transducer

Claims

1. System (100), A roll-to-roll device including a feeding roller for selectively feeding a conductive substrate from a substrate roll, wherein the conductive substrate is oriented toward a receiving roller along a first direction, A reverse-rotating roller module including a reverse-rotating roller stationarily positioned at a predetermined height above the conductive substrate, wherein the direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate, A continuous powder coating module is provided on the supply side of the reverse-rotating roller module to continuously deposit a certain amount of dry powder mixture onto the conductive substrate before contact with the reverse-rotating roller, A contact roller scraper configured to contact the reverse-rotating roller and remove residual powder particles from the outer surface of the reverse-rotating roller, A system (100) comprising the above.

2. The system according to claim 1, wherein the continuous powder dispenser includes a vibrating hopper sieve.

3. The system according to claim 1, wherein the reverse-rotating roller module includes two or more reverse-rotating rollers arranged in series.

4. The system according to claim 1, further comprising a post-processing compression module located downstream of the reverse-rotating roller module, the post-processing compression module including one or more heated rollers configured to apply additional compressive force to the conductive substrate.

5. The system according to claim 1, wherein the conductive substrate comprises a material selected from the group consisting of a graphene-coated substrate, a graphite-coated substrate, a carbon-coated substrate, copper foil, aluminum foil, metal foil, a conductive polymer, a conductive polymer-coated metal foil, a carbon fiber mat, nickel foam, polyethylene terephthalate (PET) coated with a conductive layer, stainless steel mesh, and titanium foil.

6. The system according to claim 1, further comprising an orientation maintenance module configured to maintain the conductive substrate in a flat orientation below the reverse-rotating roller module.

7. The system according to claim 1, further comprising an integrated heating system configured to adjust the temperature of the entire outer surface of the reverse-rotating roller module.

8. Method (600), A step of depositing a certain amount of dry powder mixture onto the surface of a conductive substrate at a position upstream of the reverse-rotating roller, The steps include supplying the conductive substrate toward the reverse-rotating roller along a first direction, A step of spreading a certain amount of the dry powder mixture onto the surface of the conductive substrate, at least partially based on the reverse rotational motion of the reverse-rotating roller, wherein the direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate; The steps include scraping off residual powder particles from the outer surface of the reverse-rotating roller based on a contact roller scraper that contacts the reverse-rotating roller, and Method (600), including.

9. The method according to claim 8, further comprising the step of supplying the conductive substrate from a substrate roll of a roll-to-roll device.

10. The method according to claim 8, wherein the step of depositing a certain amount of the dry powder mixture further includes the step of continuously depositing the certain amount of the dry powder mixture as the conductive substrate moves toward the reverse-rotating roller along the first direction.

11. The method according to claim 8, further comprising the step of preheating the dry powder mixture before engaging with the reverse-rotating roller.

12. The method according to claim 11, wherein the step of preheating the dry powder mixture includes the step of heating the dry powder mixture to a temperature in the range of 20°C to 200°C.

13. The method according to claim 8, further comprising the step of heating the outer surface of the reverse-rotating roller to a temperature in the range of 20°C to 200°C.

14. The method according to claim 8, further comprising the step of maintaining the conductive substrate in a flat orientation under the reverse-rotating roller.

15. It is a device, A reverse-rotating roller module including a reverse-rotating roller stationarily positioned at a predetermined height above a conductive substrate, wherein the direction of the tangential velocity of the reverse-rotating roller at the interface between the reverse-rotating roller and the conductive substrate is 180 degrees opposite to the first direction of movement of the conductive substrate, A continuous powder coating module is provided on the supply side of the reverse-rotating roller module to continuously deposit a certain amount of dry powder mixture onto the conductive substrate before contact with the reverse-rotating roller, A contact roller scraper configured to contact the reverse-rotating roller and remove residual powder particles from the outer surface of the reverse-rotating roller, A device equipped with the following features.

16. The apparatus according to claim 15, wherein the continuous powder dispenser includes a vibrating hopper sieve.

17. The apparatus according to claim 15, wherein the reverse-rotating roller module includes two or more reverse-rotating rollers arranged in series.

18. The apparatus according to claim 15, further comprising a post-processing compression module located downstream of the reverse-rotating roller module, the post-processing compression module including one or more heated rollers configured to apply additional compressive force to the conductive substrate.

19. The apparatus according to claim 15, wherein the conductive substrate comprises a material selected from the group consisting of a graphene-coated substrate, a graphite-coated substrate, a carbon-coated substrate, copper foil, aluminum foil, metal foil, a conductive polymer, a conductive polymer-coated metal foil, a carbon fiber mat, nickel foam, polyethylene terephthalate (PET) coated with a conductive layer, stainless steel mesh, and titanium foil.

20. The apparatus according to claim 15, further comprising an orientation maintenance module configured to maintain the conductive substrate in a flat orientation below the reverse-rotating roller module.

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