Powder system and method for maintaining powder layer uniformity

Abstract

An example powder system is provided. The powder system includes a powder delivery system configured to delivery powder to a substrate, and a powder conditioning system configured to condition the powder on the substrate. The powder system includes at least one sensor configured to detect at least one characteristic associated with a mount of the powder collected upstream of the powder conditioning system. The powder system includes a processor configured to receive a signal from the at least one sensor representative of the detected at least one characteristic associated with the mound of the powder, and configured to adjust at least one operational parameter of the powder system based on the detected at least one characteristic.

Description

Attorney Docket No. 137174.00104POWDER SYSTEM AND METHOD FOR MAINTAINING POWDER LAYER UNIFORMITYCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 700,922, filed on September 30, 2024. The entire content of the foregoing provisional application is incorporated herein by reference in its entirety.BACKGROUND

[0002] A variety of batteries are available in the industry for different uses. Lithium- ion (Li-ion) batteries have generally become the predominant type of battery used in portable consumer electronics and electric vehicles. Fabrication of Li-ion batteries involves numerous steps, each of which can affect the quality of the battery itself, as well as the cost involved in manufacturing the battery. A conventional manufacturing process generally includes formation of an electrode slurry having an active material, a conductive additive, and a binder, mixed in an organic solvent, and the electrode slurry is applied to a metal foil material. Once applied to the foil material, the solvent is dried out or evaporated while the active electrode mixture remains attached to the metal foil material surface. In some instances, the solvent may be toxic and can necessitate additional steps for handling / discarding that increase the overall cost of the manufacturing process. The cost of removing the solvent from the coated material on the metal foil therefore involves an additional step that also increases the overall cost of the manufacturing process.

[0003] An alternative manufacturing technique used in the industry is electrostatic deposition (ESD), which is a solvent-free manufacturing process for electrode coating for Li-ion batteries. (See, e.g., B. Ludwig et al., Solvent-Free Manufacturing of Electrodes for Lithium-ion Batteries, Sci. Rep. 6, Article No. 23150, doi: 10.1038 / srep23150 (2016); M. Wang et al., The Influence of Polyvinylidene Fluoride (PVDF) Binder Properties on LiNio.33Coo.33Mno.33O2 (NMC) Electrodes Made by a Dry-Powder-Coating Process, J. Electrochem. Soc., Vol. 166, No. 10, A2151 (2019); H. Abe et al., Electrostatic Spray Deposition for Fabrication of Li-ion Batteries, Transactions of JWRI, Vol. 44, No. 2 (2015); and U.S. Patent No. 10,547,044). Rather than relying on a solvent mixture, the ESD process uses a dry powder of the active electrode mixture which is applied to the metal foil material. By removing the solvent from the mixture and the drying step from the manufacturing process, the overall process is simplified and becomes more economical,1MEl\58071277.vlAttorney Docket No. 137174.00104 resulting in a viable alternative for large-scale manufacturing. In particular, the solvent- free electrode coating technology is an attractive alternative to traditional manufacturing since it can significantly reduce energy consumption in the manufacturing process and thus significantly reduces the manufacturing cost of batteries.

[0004] In a conventional continuous dry powder ESD coating system, a web (e.g., a grounded electrically conductive substrate) passes continuously through a coating chamber while the dry powder mixture is fluidized and pneumatically conveyed from a hopper to an electrostatic spray gun. The electrostatic spray gun electrostatically charges the powders using tribo-charging or corona charging, and sprays the charged powders onto the web where they are deposited.

[0005] Another conventional manufacturing process for coating of a web is referred to as “spreader roller coating”. A spreader roller coating system generally includes a reservoir that receives and dispenses powder particles onto a moving web. The web is passed through a pair of spreading rollers to spread and distribute the powder particles uniformly on the surface of the web to achieve a uniform coating on the web. The web is subsequently passed through a pair of calender rollers which compress and densify the powder particles. Such compression and densification causing the powder particles to adhere to each other and the web. Compression and densification performed by the calender rollers with or without heating promotes cohesion and adhesion of the powder particles to the web, and after such process, a dry electrode is produced. Such spreader roller coating technology is described in, e.g., International Patent Application No. PCT / US23 / 69175, which is incorporated herein by reference in its entirety.

[0006] In some instances, the ESD coating method and the spreading roller coating method can be used in conjunction where first an ESD coated layer is produced on the web and then is subsequently refined by a spreading roller (or vice versa), as is described in International Patent Application No. PCT / US24 / 48849, filed on September 27, 2024, which is incorporated herein by reference in its entirety.

[0007] For both ESD coating and the spreading roller coating methods, rollers can be used for conditioning the powder applied to the web. Uniform distribution of the powder on the web surface is essential prior to passage through the roller(s) in order to achieve a uniform powder coating on the web without (or with minimal) structural deficiencies, e.g., low packing density, inadequate compaction, or the like. However, as powder is applied to the web surface, uneven areas of the powder can occur near the roller(s) over time, resulting in deficiencies in the output electrode.2MEl\58071277.vlAttorney Docket No. 137174.00104SUMMARY

[0008] In accordance with embodiments of the present disclosure, an exemplary powder system is provided. The powder system includes a powder delivery system configured to deliver powder to a substrate. The system includes a powder conditioning system configured to condition the powder on the substrate. The system also includes at least one sensor configured to detect at least one characteristic associated with a mound of powder collected upstream of the powder conditioning system and a processor configured to receive a signal from the at least one sensor representative of the detected at least one characteristic associated with the mound of the powder and configured to adjust at least one operational parameter of the powder system based on the detected at least one characteristic.

[0009] In some embodiments, the powder conditioning system can be a roller system including a first roller positioned over and extending across a width of the substrate in a direction perpendicular to a substrate moving direction. In some embodiments, a second roller can be disposed in series with the first roller over the substrate. The second roller can be located downstream of the first roller along the substrate moving direction. The powder conditioning system can be configured to condition the powder on the substrate by at least one of spreading, smoothening, and / or compaction. The first roller has a speed, a direction of rotation, an angle with respect to the substrate moving direction of the substrate, and a gap between a roller surface and the substrate. In some embodiments, the at least one sensor can include at least one of a vision system sensor, a laser displacement sensor, an eddy current sensor, a sonar sensor, capacitance sensor, magnetic sensor, or a radar sensor. The at least one characteristic associated with the mound of the powder can be a mound height, a mound width, mound density, mound physical profile, and / or a mound length.

[0010] In some embodiments the substrate moves from an upstream direction to a downstream direction relative to the powder delivery system. In such embodiments, adjusting the at least one operational parameter can include increasing or decreasing an amount of the powder delivered by the powder delivery system onto the substrate. In some embodiments, the powder delivery system can include a structure including a series of openings formed therein and extending along a width of the substrate. Each opening can be controlled separately / independently to selectively add or stop adding the powder to areas3MEl\58071277.vlAttorney Docket No. 137174.00104 of the substrate. In some embodiments, the powder removal system can include a structure with a series of openings formed therein and extending along a width of the substrate. In such embodiments, adjusting the at least one operational parameter can include selectively actuating the powder removal system to remove an amount of powder through one or more of the openings. In some embodiments, adjusting the at least one operational parameter can include changing a yaw angle of the second roller relative to the substrate moving direction to selectively remove an amount of the powder from the substrate. In some embodiments, adjusting the at least one operational parameter can include moving the first roller up or down relative to the substrate to selectively increase or decrease the gap between the roller surface and the substrate.

[0011] In some embodiments, the powder conditioning system can include a second roller disposed downstream of the first roller, and adjusting the at least one operational parameter includes adjusting a position of the second roller relative to the substrate due to increasing or decreasing the gap between the roller surface of the first roller and the substrate.

[0012] In accordance with embodiments of the present disclosure, an exemplary method of powder coating is provided. The method includes delivering a powder with a powder delivery system to a substrate, conditioning the powder on the substrate with a powder conditioning system, and detecting with at least one sensor at least one characteristic associated with a mound of the powder collected upstream of the powder conditioning system. The method includes receiving a signal from the at least one sensor at a processor, the signal representative of the at least one characteristic associated with the mound of the powder, and adjusting at least one operational parameter of the powder system with the processor based on the detected at least one characteristic.

[0013] In some embodiments, the powder conditioning system can be a roller system including a first roller positioned over and extending across a width of the substrate in a direction perpendicular to a substrate moving direction. The first roller has a speed, a direction of rotation, an angle with respect to the substrate moving direction of the substrate, and a gap between a roller surface and the substrate. The conditioning of the powder can include at least one of spreading, smoothening, and / or compaction.

[0014] In some embodiments, adjusting the at least one operational parameter can include increasing or decreasing an amount of the powder delivered by the powder delivery4MEl\58071277.vlAttorney Docket No. 137174.00104 system onto the substrate. In some embodiments, adjusting the at least one operational parameter can include selectively adding or stopping addition of the powder to areas of the substrate with the powder delivery system. In some embodiments, the powder delivery system can include a structure with a series of openings formed therein and extending along a width of the substrate, each opening controlled separately to selectively add or stop adding the powder to the areas of the substrate. In some embodiments, adjusting the at least one operational parameter can include selectively actuating a powder removal system including a structure with a series of openings formed therein and extending along a width of the substrate to remove an amount of powder through one or more of the openings. In some embodiments, adjusting the at least one operational parameter can include moving the first roller up or down relative to the substrate to selectively increase or decrease the gap between the roller surface and the substrate.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To assist those of skill in the art in making and using the powder system, reference is made to the accompanying figures, wherein:

[0016] FIG. 1 is a diagrammatic view of an exemplary powder system according to embodiments of the present disclosure.

[0017] FIG. 2 is a diagrammatic view of an exemplary powder system according to embodiments of the present disclosure, including a powder deposition system.

[0018] FIG. 3 is a diagrammatic view of an exemplary powder system according to embodiments of the present disclosure, including a mound and a sensor for detecting characteristics of a mound.

[0019] FIG. 4 is a diagrammatic view of an exemplary powder system in accordance with embodiments of the present disclosure, including a powder deposition system, a heater, and a mound feedback control system.

[0020] FIG. 5 is a diagrammatic view of an exemplary powder system according to embodiments of the present disclosure, including a powder delivery and / or removal system (e.g., a powder adjustment system).

[0021] FIG. 6 is a diagrammatic view of an exemplary powder system according to embodiments of the present disclosure, including a series of rollers configured to modify a camber relative to a substrate moving direction (e.g., a powder adjustment system).5MEl\58071277.vlAttorney Docket No. 137174.00104

[0022] FIGS. 7A-7C are front views of rollers usable with an exemplary powder system in accordance with embodiments of the present disclosure, including a flat roller (FIG. 7A), a camber roller (FIG. 7B), and a reverse camber roller (FIG. 7C) (e.g., a powder adjustment system).

[0023] FIGS. 8A-8C are diagrammatic views of pairs of rollers for an exemplary powder system in accordance with embodiments of the present disclosure, including (i) a large radius roller disposed below the web and a small radius roller disposed above the web (FIG. 8A), (ii) a small radius roller disposed below the web and a large radius roller disposed above the web (FIG. 8B), and (iii) equal radii rollers disposed below and above the web (FIG. 8C).

[0024] FIGS. 9A-9C are diagrammatic views of roller assemblies for an exemplary powder system in accordance with embodiments of the present disclosure, including (i) a roller with a planar support disposed below the web having a centerline offset to the right relative to a central axis of the roller (FIG. 9A), (ii) a roller with a planar support disposed below the web having a centerline offset to the left relative to a central axis of the roller (FIG. 9B), and (iii) a roller with a planar support disposed below the web having a centerline aligned with a central axis of the roller.

[0025] FIGS. 10A-10B are diagrammatic views of a roller assembly for an exemplary powder system in accordance with embodiments of the present disclosure relative to a mound of powder, including (i) a side view of a roller pair (FIG. 10A), and (ii) a top view of a roller and mound (FIG. 10B).

[0026] FIGS. 11A-11B are diagrammatic side views of a roller assembly for an exemplary powder system in accordance with embodiments of the present disclosure, including (i) an acceptable height and characteristics for a powder mound (FIG. 11 A), and (ii) an unacceptable height and characteristics for a powder mound (FIG. 1 IB).

[0027] FIGS. 12A-12C are diagrammatic views of a powder adjustment system for an exemplary powder system in accordance with embodiments of the present disclosure, including a top view (FIG. 12A), a side view (FIG. 12B), and a detailed view (FIG. 12C).

[0028] FIG. 13 is a diagrammatic side view of an exemplary powder system according to embodiments of the present disclosure, including a mound and a sensor for detecting characteristics of a mound.

[0029] FIG. 14 is a diagrammatic top view of an exemplary powder system according6MEl\58071277.vlAttorney Docket No. 137174.00104 to embodiments of the present disclosure, including a static sensor assembly for detecting mound characteristics.

[0030] FIG. 15 is a diagrammatic top view of an exemplary powder system according to embodiments of the present disclosure, including a dynamic sensor assembly for detecting mound characteristics.

[0031] FIG. 16 is a flow chart of an exemplary process of mound characteristic measurement by powder systems of the present disclosure.DETAILED DESCRIPTION

[0032] The present invention relates to methods of battery electrode manufacturing where the active powdered material is applied to the current collector without the use of a solvent. Such dry techniques have inherent advantages over slurry coating, notably, the absence of a drying step and hazardous solvents. Moreover, there are additional advantages in the recycling and re-use of material which is deposited but not utilized in a coated metal foil. More specifically, powdered material may be removed in dry manufacturing techniques to shape sections of the electrode and reused, whereas in solvent-based approaches, material which is removed cannot be immediately re-used and must undergo some type of recycling procedure.

[0033] Dry battery electrode manufacturing relies upon a different set of processes for the various unit operations that are used to achieve design requirements imposed by battery electrode consumers. According to certain embodiments, the basic unit operations may include (1) deposition (or delivery) of powdered electrode materials to a metal foil controlling the amount of deposition and distribution across the width of the foil substrate, (2) leveling, planarizing, or otherwise smoothing the free surface of the deposited powder (e.g., conditioning) while monitoring key conditions of the powder and controlling key parameters of the system for optimal powder deposition and distribution, (3) precompressing the battery electrode material on the surface of the current collector and removing any excess powder as required to achieve a uniform distribution of powder, and (4) final compression of the battery electrode material on the current collector, followed further by post-processing operations (such as winding, slitting, wrapping, packaging, and the like). It should be understood that one or more steps can be duplicated depending on the needs of the system / user.7MEl\58071277.vlAttorney Docket No. 137174.00104

[0034] Dry battery materials may also be different in composition and structure than analogous slurry-based battery materials. Materials comprising a dry battery feedstock may include the following non-limiting examples: (1) an active material (such as NCM 622, NCM 811, LFP, graphite, and the like), (2) a polymeric binder such as PVDF (poly (vinylidene fluoride)), poly (ethylene oxide) and the like (as one skilled in the art will appreciate, such polymeric binders are selected in part based upon their stability during cycling of the battery for the active material which they may bind), and (3) a conductive additive such as graphite or carbon black. Further additives may also be included. In general, it is desirable to maximize, or at least promote to the extent possible, the mass fraction of active material present as a portion of the sum of all dry battery powder feedstock components (for example, exceeding 95% to 97%, 96 to 98%, or 98% to 99.5% according to the desired battery chemistry). The remaining balance of the mass in the dry battery feedstock would then include at least the polymeric binder and the conductive additive, the proportion of each chosen in response to desired performance characteristics for the battery electrode.

[0035] Owing to the large variation possible in dry battery powder feedstocks, the characteristics of the dry battery powder feedstocks may vary according to the type, physical characteristics, and proportion of materials within the dry battery powder feedstock mix. In particular, these and other characteristics of a dry battery powder feedstock may affect the interaction between a dry battery powder feedstock and the basic unit operations. It is thus desirable to design the unit operations to exhibit a minimal sensitivity to the characteristics of the dry battery powder feedstock. One way to improve the overall uniformity and characteristics of the resulting electrode is provided by the exemplary powder system discussed herein which includes various features to smooth, shape, spread, compact, and otherwise interact with a dry battery powder feedstock deposited on a moving web, including use of a feedback control system to monitor the powder characteristic and control key system parameters.

[0036] The system discussed herein, according to some embodiments, includes a pair of rollers disposed on opposing sides of a moving web to create a thin gap, or nip, at points of closest approach between the outer diameters of the rollers. In some embodiments, the rollers can be constrained such that the axes of the rollers are aligned parallel to each other and substantially perpendicular to the web moving direction. However, as discussed herein, in some embodiments, the rollers can be movable or pivotable such that the axes of the8MEl\58071277.vlAttorney Docket No. 137174.00104 rollers can be adjusted to different angles relative to the web moving direction to assist with movement / distribution and otherwise conditioning of the powder on the web. The rollers are generally characterized by a length (or face), a diameter, a state (such as a roughness, texture, or the like) of the roller surface, a direction of rotation, an angular speed of rotation, a pressure directed to the nip, among other characteristics.

[0037] As powder is deposited on the web and conditioned by the rollers, a mound or build-up of powder can occur immediately upstream of the roller. In particular, the term “upstream” refers to an area of the web which has not passed through / between the rollers, and the term “downstream” refers to an area of the web which has passed through / between the rollers and moves away from the rollers in a web moving direction. The term “mound” as used herein refers to any amount of powder greater in height over a threshold / baseline thickness of powder. For example, the system is intended to apply a predetermined thickness of powder onto the web and the conditioning system is designed to spread the powder to a desired, substantially uniform thickness prior to compression. The predetermined thickness of powder defines the threshold / baseline thickness of powder. Any amount of powder with a height above this predetermined thickness can be considered a “mound”, which can include a height (as measured from the web surface or the predetermined powder thickness surface), a width (as measured along the width of the web perpendicular to the web moving direction), and a depth (as measured along the web moving direction).

[0038] In some embodiments, any amount of powder build-up above the predetermined thickness can define an unacceptable mound detectable by the system. In some embodiments, any amount of powder below the predetermined / baseline thickness can necessitate adjustment of the system to reach the predetermined thickness at the roller (e.g., by depositing more powder onto the web to reach the desired predetermined thickness of powder). In some embodiments, the system can operate with an acceptable or desired mound, i.e., a mound having acceptable / desired height (a height above the threshold / baseline thickness of powder), width and / or depth characteristics that do not necessitate adjustment by the system (see, e.g., FIGS. 11A-11B). In such embodiments, the acceptable mound characteristics can be used as the threshold / baseline for determination of whether adjustment in operation by the system is needed. For example, if the detected mound is above the acceptable / desired mound characteristics, the system can operate to reduce the detected mound accordingly. Similarly, if the detected mound is9MEl\58071277.vlAttorney Docket No. 137174.00104 below the acceptable / desired mound characteristics, the system can operate to increase the detected mound accordingly.

[0039] In some embodiments, the acceptable height threshold for the powder mound can be based on the engagement of the powder mound with the roller surface and the measured angle at the roller (e.g., wetted angle 333 of FIGS. 11A and 11B). In some embodiments, the acceptable depth of the powder mound (as measured from the roller surface) can be between about, e.g., 0.5 mm-50 mm inclusive, 0.5 mm-40 mm inclusive, 0.5 mm-30 mm inclusive, 0.5 mm- 20 mm inclusive, 0.5 mm- 10 mm inclusive, 10-50 mm inclusive, 20-50 mm inclusive, 30-50 mm inclusive, 40-50 mm inclusive, 10-40 mm inclusive, 20-30 mm inclusive, 0.5 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, or the like. In some embodiments, the acceptable width of the powder mound can be dependent on the width of the substrate / web and the coated area of the web. For example, the mound width can be at least as wide as the coating width and should not be more than about 25 mm wider than the coating area. As an example, the substrate can be about 280 mm side with a coating width of about 250 mm. In such example, the mound width can be at least 250 mm wide, but should not exceed 275 mm, thereby maintaining a gap with the side edge of the substrate.

[0040] In some embodiments, detectable characteristics of the mound may include dynamic characteristics of the mound. Dynamic characteristics of the mound may include the rate of change of heights, widths, combinations thereof, or the like. Dynamic characteristics may include, e.g., wave-like motions of the mound, tumbling motions, oscillations in the mound (such as periodic or nearly periodic changes in a geometric dimension of the mound), or the like. Dynamic characteristics may include, e.g., a speed of the powder within the mound as compared to a speed of the powder on the web, the speed of the web, combinations thereof, or the like.

[0041] The exemplary powder system includes a monitoring / feedback loop that allows for detecting characteristics of the mound, and automatically adjusts operation of one or more components of the powder system to adjust the mound for optimized conditioning and compression. When the mound is too high, too low, or absent altogether, the monitoring / feedback loop can transmit signals to a controller for adequately regulating operation of the one or more components of the powder system in order to adjust the mound. The system includes monitoring of powder as it enters the powder conditioning system, sensing one or more of the characteristics of powder mounding, and using the10MEl\58071277.vlAttorney Docket No. 137174.00104 powder mound characteristics to control overall system performance. Some key system parameters include, but are not limited, to parameters such as, e.g., components of the powder delivery system, the web speed, components of the powder conditioning system that may be adjusted to deliver more powder in some cases or less powder in other cases, combinations thereof, or the like. Significantly improved uniformity and packing density in the powder layer can therefore be achieved, resulting in a higher quality electrode.

[0042] In some embodiments, a parameter or function of a conditioning roller in contact with the mound may be modified to control at least a characteristic of the mound. For example, in some embodiments, a rotational speed of the conditioning roller may be used to grow or shrink a geometric extent of the mound (such as a height of the mound or distance of the mound as measured from a face of the conditioning roll in an upstream direction). By way of non-limiting example, and for the case where the surface of the roller at smallest separation from the web moves in the direction of the web motion, decreasing the rate of rotation of the conditioning roller generally results in an increase of the geometric extents of the mound, whereas increasing the rate of rotation of the conditioning roller generally decreases the geometric extents of the mound. Further, the direction of rotation of the conditioning roller may be varied in response to detected mound characteristics. The direction of rotation may be varied, such that a point of closest approach on the roller relative to the web may exhibit a velocity in the direction of the web motion, or in the direction opposite the web motion. In such embodiments, rotating the roller in a direction of the web motion would generally reduce the geometric extents of the mound, and rotating the roller in a direction opposite the web motion would generally increase the geometric extents of the mound. In such embodiments, the speed of the roller in each direction can be used to adjust the desired effect on the geometric extent of the mound.

[0043] In some embodiments, a width of the mound may be controlled at least in part by a width of the coating which is presented to the mound and the conditioning roller. For example, a full web coating (e.g., a powder particle coating across the full width of the web upstream of the conditioning roller and the mound) may produce a mound of full width (relative to the web), whereas a coating presented to the pile of width which is less than the full width of the web may produce a mound exhibiting a width which is less than the full web width. In some embodiments, lane formation methods (such as masking, wiping, scraping, vacuuming, combinations thereof, or the like) can be used to control the extent to11MEl\58071277.vlAttorney Docket No. 137174.00104 which the width of the web is coated upstream of the mound and the conditioning roller.

[0044] The predetermined thickness target for the conditioned powder particle coating layer on the web can be monitored by a thickness sensor or a series of thickness sensors (e.g., spot-type or profile-type sensors, or the like). These sensors can be disposed downstream of one or all of the conditioning units to measure the thickness of the coating layer on the web after conditioning. Thickness feedback from the sensor or sensors can be used to change the conditioning process and / or incoming material deposition (in real-time or substantially real-time) based on the process flow diagram to increase or decrease the size of the characteristic mound to maintain a target, predetermined thickness downstream of the conditioning assembly. In some embodiments, multiple sensors can be used across the width of the web to give more granular thickness measurements. The sensor measurements can be used in a feedback loop to a controller, for example, to locally add or remove powder from the substrate in target locations based on detected thickness.

[0045] Similar to the above discussion of mound characteristic measurement and / or downstream coating layer thickness measurement, in some embodiments, direct mass loading measurement can be used alone or in combination with other measurements to control the mound characteristics to achieve target electrode properties (e.g., thickness, mass loading, or the like). In some embodiments, non-contact measurement methods for in-line mass loading measurements can be used, such as x-ray, beta gauge, ultrasonic, terahertz measurement systems, or the like. Such non-contact measurement methods allow for obtaining the mass loading measurements without direct contact with the powder coating, preventing undesired disturbances of the uniformity of the powder coating on the web.

[0046] According to some embodiments, characteristics of a coated layer (or amount of area coated on the moving web) may be assessed after interaction of a powder layer with the conditioning roller upstream of which is the formed mound, with these assessments being used to inform the system (e.g., a controller of the system) at least one control characteristic of the powder mound. In particular, the system can include one or more sensors configured to detect characteristics of the powder coating layer downstream of the conditioning assembly at which the mound is formed, and the detected characteristics are usable by a controller to adjust, e.g., operation of the conditioning assembly, deposition / removal of powder particles upstream of the conditioning assembly, or the like, to adjust the mound characteristics. These detected characteristics may be referred to as12MEl\58071277.vlAttorney Docket No. 137174.00104 post- mound coating characteristics. For example, a sensor may be incorporated directly downstream of the conditioning roller (such that no operation moving, modifying, rearranging, or otherwise intentionally affecting the powder layer intervenes between the conditioning roller and the sensor) to assess the quality, structure, orientation, state of continuity, of a property of the powder (such as a height, appearance, roughness, mass loading, density, volume fraction), or the like.

[0047] In some embodiments, a sensor may be in the form of an optical inspection system, such as a computer vision system, or the like, to assess the surface appearance of a layer of power after interaction with a mound and conditioning roller (or multiple conditioning rollers). Optical imaging systems may include, e.g., lighting schemes (such as a type, intensity, wavelength, and / or orientation of light), to accentuate and / or suppress various features of an illuminated coating after interaction with the mound and conditioning roller. In some embodiments, lighting schemes may include brightfield illumination, where a light source is provided at an angle substantially parallel to the surface normal of a web upon which the powder coating is deposited, and in-line with an imaging sensor. In some embodiments, exemplary lighting sources may include darkfield illumination, where a light source is provided at an angle at or nearly perpendicular to the surface normal of a web upon which the powder coating is deposited. In some embodiments, exemplary lighting sources may include lighting at any angle at or between the range of angles defined by vectors which are perpendicular or parallel to the surface normal of a web upon which the powder is coated during imaging.

[0048] For embodiments where the appearance is assessed and used as an input to a feedback system, attributes of the appearance sensed may include at least one of, e.g., a state of continuity and uniformity of the coated material (including a degree to which the powder layer is contiguous, or otherwise interrupted by uncoated regions within coated regions), a roughness or surface texture of the coated material, a waviness of the coated material, the presence of regions which appear depleted or enriched with powder (including regions which appear depressed or prominent relative to adjacent regions in the powder coating), the appearance of defects or otherwise irregularities in the coating (including depleted or enriched regions, scar-like structures, groove-like structures, wood grain-like textures, or any other regular or irregular pattern), or any other visible surface property.

[0049] According to some embodiments, a thickness measurement of the coating may be assessed after interaction with the powder mound and conditioning roller (or rollers).13MEl\58071277.vlAttorney Docket No. 137174.00104Thickness measurements can include, e.g., an average thickness, a variation in the thickness (such as a standard deviation, kurtosis, skew, total variation, range, or the like) and may include variations of the thickness as compared to an average thickness or other reference values defined during operation of the thickness measurement, or any other metric assessed during measurement of the thickness (such as a comparison to a high thickness limit or low thickness limit, for example).

[0050] According to some embodiments, thickness measurements of the coating layer after interaction with the powder pound and conditioning roller(s) (or at any point of the fabrication process discussed herein) may be determined using a thickness gauge. In some embodiments, a thickness gauge may include a non-contact sensor including sensors which utilize, e.g., light reflectance, light interferometry, ultrasound, capacitance, inductance, or any other measurement principle. In some embodiments, a thickness gauge may be multiplexed to measure simultaneously from a first direction onto a first surface of a web where a coating is present (such that the thickness gauge probes the surface of the coating) and from a second direction onto a second surface of the web opposite the first surface. In such embodiments, the scheme of thickness measurement may be utilized to remove, adjust for, reduce, or otherwise eliminate variations in a determined thickness of the coating by variation or flutter in the position of the coating and web. In some embodiments in which light is utilized to determine a thickness of the coating, a point laser, sheet laser, or laser of another shape may be utilized to interact with the coating and reflect to a sensor for thickness determination.

[0051] According to some embodiments, a loading measurement of the coating may be assessed after interaction with the powder mound and conditioning roller(s). Loading measurements may include, e.g., an average loading, a variation in the loading (such as a standard deviation, kurtosis, skew, total variation, range, and the like) and may include variations of the loading as compared to an average loading or other reference value defined during operation of the loading measurement, or any other metric assessed during measurement of the loading (such as a comparison to a high loading limit or low loading limit, for example).

[0052] According to some embodiments, a loading measurement may be determined using a loading gauge. In some embodiments, a loading gauge may include, e.g., an x-ray source and detector, a beta ray source and detector, a terahertz source and detector, an ultrasonic source and detector, a measurement of mass over a specified area, combinations14MEl\58071277.vlAttorney Docket No. 137174.00104 thereof, or the like.

[0053] According to some embodiments, a post-mound coating characteristic (as detected or measured by the exemplary system) may include, e.g., an amount, degree, width, or otherwise extent of spreading of the powder material across the width of the web (such that the width of the web is the geometric extent of the web transverse to the direction of web motion). Such characteristic(s) may be assessed using a loading measurement, thickness measurement, or optical measurement (either individually or in combination).

[0054] FIG. 1 is a diagrammatic view of an exemplary powder system 100. FIG. 1 shows some key components of the system 100, but is a simplified for clarity and therefore does not show all of the components that would normally be included in the system 100, such as additional rollers or supports disposed below the web 140 in combination with rollers 108, 110, 112. Powder 101 is deposited on a web 140 or substrate with an initial thickness of 116 (Ptl). This initial thickness 116 can define the predetermined threshold / baseline thickness from which the mound is measured, e.g., any amount of powder above the thickness 116 immediately upstream of the roller 104 is considered a mound for purposes of this disclosure. As noted herein, in some instances, a baseline or threshold mound may be desired immediately upstream and in contact with the roller 104, and the system 100 can be operated to maintain the desired threshold mound. In some instances, no mound may be desired and the system 100 can operate to maintain the threshold / baseline thickness of the powder 101 without a mound. The web 140 is moved with a velocity in a web moving direction 134, e.g., from an upstream position to a downstream position. The powder 101 is conditioned by one or more rollers 102, 104 and 106. Although three rollers 102, 104, 106 are shown, it should be understood that the conditioning can be performed with a single roller, or with multiple rollers disposed in series. The bottom of the web 140 can be supported by rollers or other support structures (see, e.g., FIGS. 8A-8C and FIGS. 9A-9C). For example, the web 140 below each roller 102, 104, 106 can be supported by a roller or other support structure disposed underneath the web 140 and each respective roller 102, 104, 106.

[0055] Roller 102 is actuated to roll with a linear rotation speed of 108 (vti) and has a gap 118 between the bottom of the roller 102 and the web 140 surface (Ghi). The roller 102 conditions the powder 101 down to a thickness 120 (Pt2) by smoothening and / or spreading the powder 101 on the web 140 surface. Roller 104 continues the conditioning process and rotates at a linear rotational speed 110 (vt2). Roller 104 has a gap 124 between the bottom15MEl\58071277.vlAttorney Docket No. 137174.00104 or roller 104 and the web 140 (GI12). The gap 124 is dimensioned smaller than the gap 118 to further condition the powder 101 and output a smaller thickness downstream of the roller 104. In particular, the roller 104 conditions the powder 101 to a thickness 126 (Pts) dimensioned smaller than thickness 120. Roller 106 further conditions the powder 101 with a linear rotational speed of 112 (An). Roller 106 has a gap 130 between the bottom of roller 106 and the web 140 (Gha). The gap 130 is dimensioned smaller than the gap 124 to further condition the powder 101 and output a smaller thickness downstream of roller 106. The roller 106 conditions the powder to a thickness 132 (Pt4) dimensioned smaller than thickness 126. Therefore, roller 102 conditions the height of the powder 101 by changing the height by a thickness 114, roller 104 conditions the height of the powder 101 by changing the height by a thickness 122, and roller 106 conditions the powder 101 by changing the height by a thickness 128. The result is a smaller thickness of powder 101 on the web 140, with the powder layer having uniformity and increased packing density (e.g., robust densification).

[0056] Each of the conditioning rollers 102, 104 and 106 may perform one or more functions, which include spreading, surface smoothening, and / or compaction. The powder system 100 achieves all of these functions in a continuous processing system. The following are some characteristics / parameters of the system 100 shown in FIG. 1 which may be adjusted and / or monitored to ensure optimized conditioning can be performed:Pf = Powder Layer Thickness 116 After Deposition vf1= Linear Rotational Speed 108 of Conditioning Roller 102G / ix= Gap 118 Height Between Roller 102 and the Web 140Pt2= Powder Layer Thickness 120 After Conditioning Roller 102 vr2=Linear Rotational Speed 110 of Conditioning Roller 104Gh2= Gap Height 124 Between Roller 104 and the Web 140Pt3= Powder Layer Thickness 126 After Conditioning Roller 104 vr3= Linear Rotational Speed 112 of Conditioning Roller 106Gh3= Gap Height 130 Between Roller 106 and the Web 14016MEl\58071277.vlAttorney Docket No. 137174.00104Pt4= Powder Layer Thickness 132 After Conditioning Roller 106 vw = Linear Velocity of Web 140 Along Web Direction 134

[0057] The spreading function achieved by one or more rollers 102, 104, 106 achieves powder 101 mobility on the order of centimeters. This function corrects mass loading nonuniformities from the initial deposited powder 101 layer. This can be the first step in conditioning a powder 101 and the powder 101 at this stage tends to be the least compacted and can flow the most easily (e.g., powder 101 upstream of the rollers 102, 104, 106). To achieve optimal spreading, the linear rotational speed 108 and roller gap 118 height setting can be controlled as a function of the web 140 speed. The incoming powder layer thickness 116 after deposition, and the ability of the powder 101 to flow and be shaped (i.e., flowability) are critical and can be adjusted / varied by the system 100 to achieve the desired function without defects. In particular, the powder 101 has the ability to be brought to a state of flow. As used herein, the term “flowability” refers to the behavior of the powder in response to the force acting on the incoming powder layer. More flowable materials are typically free-flowing and are not highly cohesive (meaning the particles do not clump or agglomerate together, or they require minimal force to break apart clumps and agglomerations). The forces involved in conditioning should be high enough to break apart such powder clumps as the material passes through the process. Less flowable materials are more cohesive and cannot be spread / conditioned as easily. Such materials tend to form clumps and agglomerates that retain their shape / structure even after going through the conditioning process. These agglomerated materials can also lead to post-conditioning defects that are detrimental to the electrode performance. Less flowable powders are more cohesive and cannot be spread / conditioned easily. Such materials are difficult to process into a uniform coating layer on the substrate. In the exemplary conditioning system, the powder should exhibit former characteristics (i.e., more flowable) to create a substantially uniform coating layer free of large aggregates or defects as a result of the agglomerates or other material defects relating to poor flowability.

[0058] The tuning may be also dictated by the powder 101 being supplied. Although the settings can be optimized for spreading, in the process of spreading, there will likely be some degree of compaction and surface smoothening as well. During this function, since powder 101 is highly mobile, a powder 101 layer may build up upstream of the conditioning roller 102 (and / or rollers 104, 106), creating a mound of powder. Such mound can result in17MEl\58071277.vlAttorney Docket No. 137174.00104 disruptions in uniformity or compaction of the powder 101 downstream of the rollers. Therefore, it is preferable to adjust operation of the system 100 to address the mound build up, either by creating a uniformity in the mound or removing / minimizing the mound. As discussed herein, the system 100 includes powder adjustment system device which can be implemented to either selectively remove or add powder to the web to adjust the characteristics of the mound. In some embodiments, removal of the powder can be performed using, e.g., vacuum, wiping, guiding, combinations thereof, or the like as to minimize uncontrolled powder buildup, which can ultimately lead to potential defects and issues with the resulting electrode. In some embodiments, an amount of powder may be depleted or enriched at positions across the moving web. Such depletion and enrichment of the powder on the web may be performed in concert with removal of the powder. For example, if excess powder is detected in one area of the web, rather than removing the entire amount of excess powder, at least some of the excess powder may be moved along the surface of the web and repositioned or redistributed to assist in filling in areas necessitating more powder, or to level the powder thickness or distribution in general.

[0059] In some embodiments, the system 100 can rely on one or more sensors upstream of the mound to detect characteristics associated with the mound and / or the powder coating layer, with the detected characteristics usable to adjust operation of the system 100. In some embodiments, the system 100 can include one or more sensors downstream of the mound and the associated conditioning roller to detect characteristics associated with the downstream coating layer to adjust operation of the system 100. In some embodiments, the system 100 can incorporate characteristic detection from both upstream and downstream sensors relative to the conditioning roller(s) and mound to adjust operation of the system 100.

[0060] In some embodiments, simultaneous measurements of mound (e.g., pile) characteristics and characteristics of the powder layer after interaction with the mound and conditioning roller(s) may provide a useful and actionable connection between the properties of the powder mound and the coating produced after interaction with the powder mound and conditioning roller(s). In some embodiments, relationships established between the sensed properties of the mound and the coating may be utilized to inform control of the powder mound (e.g., via a controller and adjustment of operation of the system) to produce desirable characteristics and / or properties of the coating.

[0061] According to some embodiments, a computer-based scheme may be18MEl\58071277.vlAttorney Docket No. 137174.00104 implemented to learn and develop relationships between sensed mound characteristics and characteristics of the coating after interaction with the mound and conditioning roller(s). For example, in some embodiments, a collection of sensed mound characteristics may be collected over time. Simultaneously, sensed post-mound coating characteristics may be collected and correlated spatially to the sensed characteristics of the mound - such that characteristics of the mound are then connected with post-mound coating characteristics. Once connections are made between the mound and post-mound coating characteristics, desirable mound characteristics may be identified.

[0062] Desirable mound characteristics may be identified through several means. In some embodiments, desirable mound characteristics may be identified by a multiparameter regression. In some embodiments, desirable mound characteristics may be identified using a convoluted neural network. In some embodiments, desirable mound characteristics may be identified using a principal component analysis, or other similar dimensionality reduction technique. In some embodiments, a combination of two or more detection means discussed herein can be used for identification of desirable mound characteristics. Once desirable mound characteristics have been identified by the system, a controller associated with mound attributes may be commanded to control the mound and achieve the desired mound characteristics by adjusting one or more operational elements of the system. In this way, the output of the coating and the desired or threshold post-mound coating characteristic may be achieved.

[0063] In the next stage, roller 104 can smoothen, flatten, or otherwise planarize the powder 101. The smoothening process achieves a powder mobility that is much less than the spreading function. Typically, the smoothing function can achieve a powder mobility on the order of millimeters to micrometers. The smoothening process can reduce defects, such as surface roughness, voids, pits, or other non-uniformities, which are on the order of millimeters to micrometers. These defects can be leveled, filled in, and smoothened out by the system 100. In some embodiments, the system 100 can include a similar powder adjustment system disposed upstream of the roller 104 to add and / or remove powder to adjust a mound build-up upstream of the roller 104, thereby avoiding potential defects in the powder layer during the smoothening process at the roller 104.

[0064] The third stage roller 106 can be used for compaction of the powder 101. Compaction achieves powder mobility on the order of micro-meters and is typically in the vertical direction where the powders mobilize towards the web 140. In this step, low forces19MEl\58071277.vlAttorney Docket No. 137174.00104(e.g., lower than calendering forces) can be applied with the roller 106 targeted to achieve an initial compaction before calendering. The amount of force applied by the roller 106 can be less than forces typically used during calendering or roll pressing of granular materials, such low forces (relative to calendering and roll pressing forces) enabling compaction without unnecessary deformation and damage to both the web and particles. In some embodiments, the forces applied during the conditioning process can be, e.g., less than about 10 N / mm, as compared to calendering operations which typically use forces greater than about 10 N / mm. This initial compaction step can require relative velocity differences between the web 140 and the roller 106 so that the layer does not delaminate to the roller 106. Typically, the compaction step with low force can achieve compactions to about, e.g., 45-55% void volume fractions. Essentially, the powder layer can be consolidated ahead of any compaction resistance, which occurs at lower void volume fractions. A high force calender is then required to achieve lower void volume fractions. In some embodiments, a powder adjustment system can be included in the system 100 upstream of the roller 106 to adjust any imperfections in the powder build-up immediately upstream of the roller 106.

[0065] FIG. 2 is a diagrammatic view of a powder system 200 with a powder deposition system 204. FIG. 2 shows a spool 202 that delivers web 224 moving downstream in the direction 226. The powder deposition system 204 is disposed at the upstream end of the system 200 and is configured to deposit powder onto the web 224 surface. Although a single powder deposition system 204 is illustrated, it should be understood that the system 200 can include multiple systems 204 to deposit powder between different subsequent stages of the powder coating process.

[0066] After powder has been deposited onto the web 224, the web 224 passes through a powder conditioning system 260 that achieves uniformity and high compaction density of the powder before calendering. In some embodiments, the system 260 can include one or more rollers, e.g., three double rollers: 206 and 212, 208 and 214, and 210 and 216, for performing the conditioning steps. In some embodiments, each of the roller pairs can perform one or more conditioning operations, such as spreading, smoothening, and / or compaction. In some embodiments, each of the roller pairs can be configured to perform only one (or primarily one) of the conditioning operations. After conditioning, the web 224 passes through one or more pairs of rollers used as calendering rollers 218 and 220, and is subsequently collected by a collection spool 222. the collection spool 222 can wind the coated web 226, which can be used to form an electrode.20MEl\58071277.vlAttorney Docket No. 137174.00104

[0067] Powder can be deposited onto the web by any deposition method known in the industry that includes the ability to uniformly load a mass of powder onto the web that allow for mass loading uniformity, a suitable surface finish and compaction. Some embodiments of deposition methods include, but are not limited to, e.g., electrostatic deposition, powder feeding rollers, nozzles, screw feeders, combinations thereof, or the like. Including the powder conditioning system 260 in the system 200 ensures that the layer of powder on the web downstream of the system 260 is uniform, highly compacted, and essentially free of imperfections, enabling the powder layer to calender at higher speeds relative to traditional systems (with no delamination or separation of the layer), thereby achieving a densified and uniform final coating. The powder deposition system 204 can deliver powder onto the web uniformly across the width of the web.

[0068] In some embodiments, in addition to depositing powder generally onto the web surface, the powder deposition system 202 can be used to selectively add powder to one or more portions of the web that are partial (e.g., not across the entire width of the web). For example, in some embodiments, the powder deposition system 202 can include a structure with a series of openings formed therein and extending along a width of the substrate. Each opening can be controlled separately to either add powder to the entire width of the web, or selectively add or stop adding the powder to areas of the substrate along its width. Such deposition system can be used to assist with reduction of a powder mound forming immediately upstream of one of the conditioning rollers.

[0069] The conditioning system 260 includes one or more pairs of rollers or rolls. Each pair of rolls can define a nip through which a powder coated web passes. A “nip”, as the term is used herein, refers to a thin gap at points of closest approach between the outer diameters of the rolls. The nip is configured to, at least for a portion of the web travel, interfere with the free surface of the powder. The interference of the roll with the free surface will have the action of, e.g., leveling, spreading, compacting, otherwise planarizing, or combinations thereof, at least a portion or section of the powder interacting with and traveling through the nip on the moving web.

[0070] In some embodiments, one roll may have a different radius from another roll. In some embodiments, a pair of rolls may have different radii. For example, a pair of rolls may have a first roll and a second roll, where the first roll interacts directly and primarily with the free surface of the powder and the second roll interacts directly and primarily with the first roll. The radius of the first roll may be the same as the radius of the second roll.21MEl\58071277.vlAttorney Docket No. 137174.00104However, the first roll may have a radius that is larger than the second radius. The amount by which the radii may be different can be expressed by a ratio of radii, such as given by the first radius divided by the second radius. The ratio of radii may be in some embodiments between: (i) 0.05 and 0.2, inclusive, (ii) between 0.1 and 0.3, inclusive, (iii) between 0.25 and 0.5, inclusive, (iv) between 0.4 and 0.8, inclusive, (v) between 0.75 and 1, inclusive, (vi) between 0.9 and 1.1, inclusive, (vi) between 1 and 5, inclusive, (vii) between 4 and 10, inclusive, (viii) between 5 and 20, inclusive, (ix) between 10 and 50, inclusive, (x) between 25 and 100, or the like.

[0071] FIGS. 8A-8C are diagrammatic views of different configurations of roller assemblies which can be used in the exemplary system. In some embodiments, as shown in FIG. 8A, the assembly can include a roller 802 disposed above the web and having a radius 814 dimensioned smaller than a radius 816 of a roller 804 disposed below the web. In some embodiments, as shown in FIG. 8B, the assembly can include a roller 806 disposed above the web and having a radius 818 dimensioned greater than a radius 820 of a roller 808 disposed below the web. In some embodiments, as shown in FIG. 8C, the assembly can include rollers 810, 812 with radii 822, 824 dimensioned substantially equally. In each instance, the central longitudinal axes of the top and bottom rollers can be aligned, although it is envisioned that an offset of the axes may be used as well.

[0072] In some embodiments, the variable radii between top and bottom rollers in the conditioning system can be used to create different deflections of the web, as compared to rollers having equal radii. The different deflection of the web can impart a different strain and / or rate of strain on the powder, which can be advantageous for certain mismatched configurations depending upon properties of the powder and / or processing conditions (such as a speed of the web, web tension, powder layer height, combinations thereof, or the like). As an example, a roller with a larger radius disposed on the bottom of the web (as compared to a smaller radius roller on the top of the web, as shown in FIG. 8A) can result in longer durations of straining, as compared to the opposite configuration (as shown in FIG. 8B).

[0073] In some embodiments, a roll contacting a free surface of powder may be opposed by a lower surface which is not configured to rotate (e.g., a planar or flat supporting surface). The nip in such a case is then formed by the point (or points) of closest approach between the roll contacting the free surface and the stationary surface opposite the rotating roll. Some embodiments may include: (1) a planar surface opposing a powder contacting roller, (2) a curved surface opposing a powder contacting roller, (3) a surface22MEl\58071277.vlAttorney Docket No. 137174.00104 which is planar beneath the powder contacting roller, but also exhibiting curved surfaces at upstream and downstream locations on the lower surface, combinations thereof, or the like.

[0074] For example, FIGS. 9A-9C illustrate different configurations of a roller disposed above the web and non-roller support structures disposed below the web. In each instance, the rollers 902, 904, 906 are disposed above the web and are in direct contact with the powder deposited on the web. The support structure 924 disposed below the web in FIG. 9A includes a substantially flat, non-rolling or moving surface in contact with bottom of the web and intended to create a surface against which pressure is applied when the roller 902 contacts the powder. The support structure 924 includes opposing leading and trailing top edges with a curved edge defining a radius 908, 910, respectively. In some embodiments, the radii 908, 910 can be equal. In some embodiments, the radii 908, 910 can be different. In FIG. 9A, the centerline of the support structure 924 is offset from the central longitudinal axis of the roller 902 towards the trailing direction along the web moving direction, such that the front or leading edge of the support structure 924 is offset from the central axis of the roller 902 by only a distance 912 which is less than half of the structure 924 width.

[0075] In some embodiments, having different radii at the leading and trailing edges of the support structure can create a different deflection on the web, which imparts a different strain and / or rate of strain on the powder (similar to the discussion regarding FIGS. 8A- 8C). For example, a large radius at the leading edge can result in a smaller rate of strain as material approaches the nip. This can depend upon the web tension (e.g., larger tension can negate any effect of a large radius as the web is pulled taut), the layer of powder, the amount of compaction, the total expected strain of the layer of powder traversing the nip (e.g., the relative change in the powder layer dimension), combinations thereof, or the like. In some embodiments, the offset position of the support structure centerline relative to the roller central axis (as shown in FIGS. 9 A and 9B) can present the layer of powder with a flat (horizontal) surface beneath a compaction roller. Alternatively, the offset can tune the onset or offset of a change in the powder layer height as constrained by the horizontal surface.

[0076] The support structure 926 in FIG. 9B similarly includes a flat surface and leading / trailing top corners having a curved radius 914, 916, respectively. However, in the configuration of FIG. 9B, the centerline of the support structure 926 is offset towards the leading direction relative to a central longitudinal axis of the roller 904, such that the rear23MEl\58071277.vlAttorney Docket No. 137174.00104 or trailing edge of the support structure 926 is offset from the central axis of the roller 904 by only a distance 918 which is less than half of the structure 926 width.

[0077] The support structure 928 in FIG. 9C similarly includes a flat surface and leading / trailing top corners having a curved radius 920, 922. However, in the configuration of FIG. 9C, the centerline of the support structure 928 is centered and aligned with the central longitudinal axis of the roller 906 such that an equal distance 924, 926 of the support structure 928 extends on either side of the roller 906.

[0078] The rolls may be controlled to a specific gap at the nip. A gap between the nip is defined by the distance of closest approach between the faces of the opposing rollers. The gap is typically controlled or defined as a process variable. In particular, the system can be configured to selectively adjust the gap based on signals received from sensors regarding the conditioning process, e.g., a mound or dips formed directly upstream of a roller. According to some embodiments, a gap may be determined based upon the height and properties of a powder depositing on a moving web. Typically, larger gaps can be specified for larger amounts of incoming powder, and larger gaps may be specified for a dry battery electrode powder feedstock that exhibits greater resistance to shear deformation. According to some embodiments, a gap at the nip may be between: (i) 50 and 100 um, inclusive, (ii) 75 and 150 um, inclusive, (iii) 100 and 125 um, inclusive, or the like. The precision and accuracy with which the gap is set and maintained is also important, and variations of between (a) 50 and 25 um, inclusive, (b) 30 and 10 um, inclusive, (c) 15 and 8 um, inclusive, (d) 10 and 5 um, inclusive, (e) 6 to 1 um, inclusive, may be used.

[0079] The setting of the gap or the gap’ s setpoint can scale with the amount and history of the incoming powder. For example, and according to some embodiments, a just deposited amount of battery electrode powder feedstock with height H on a web of thickness W can be successfully processed by passing through a first pair of rolls with a first nip configured with height [Hl to_f+H_w] to produce a powder thickness [H2_i] (which may be different than the nip less the web thickness) where the ratio is rl=[Hl_i] / [Hl_f]. Then, the web can be configured to travel through, and be successfully processed by, a second pair of rolls with a second nip configured with height [H2_f+H_w] to produce a powder thickness |H3_i |, with the ratio r2 = [H2_i] / [H2_f] . The ratios rl and r2 may be different, and in some embodiments, rl>r2 for successful processing.

[0080] The rolls may be controlled to a specific normal, or compressive, force across24MEl\58071277.vlAttorney Docket No. 137174.00104 the nip. In some embodiments, the force applied by the rolls can be adjustable by the system in response to user input and / or automatically based on sensor signals transmitted to a central controller to optimize the conditioning process. In such embodiments, the positive of each roll can be independently adjustable along a z-axis perpendicular to the surface of the web. According to certain embodiments, a pressure on the nips may be provided in a direction that would generally try and close the gap between the rollers. That is, the force applied would be compressive as viewed by a material transitioning the nip between the rolls, such that the force would tend, or attempt, to consolidate the powder. The force imposed upon the rolls is generally small as compared to calendering forces, but may be useful to bring the powdered battery electrode material to a state of stress where the powdered material may deform without flaws.

[0081] In some embodiments, the rollers 206, 208, 210, 212, 214 and 216 can rotate at different speeds and in different directions. In particular, the conditioning rollers need not rotate in the same direction or with the same speed, and such different direction and / or speed can be used to vary the type of conditioning being performed on the powder. In some embodiments, the speed and direction of the rollers can be the same.

[0082] In some embodiments, the rolls may exhibit a specific surface texture, pattern, and / or shape. For example, the rolls may exhibit a specific surface finish (such as a mirror finish), texture, pattern, or even shape. The specific surface texture, pattern, or shape may be different between any two pair of rolls defining a nip, or any two pair of rolls among all rolls in a series of nips. The rolls may also exhibit a specific material on the roll surface. Such differences can be used to change the conditioning effect on the powder passing through the respective rolls.

[0083] According to some embodiments, it may be desirable to clean, remove powder, re-condition, or otherwise interact with the rolls in a manner which changes the surface property of the rolls during their operation. For example, and according to some embodiments, it may be desirable to utilize a vacuum or other suction device to remove powder from a surface of a roll after a free surface of powder has interacted with a roll. Further procedures or actions may be performed solely or in concert, and in addition to, or in place of, the vacuum or other suction device, such as: (1) a heating step, (2) a cooling step, (3) a wet cleaning step (such as with an organic solvent), (4) a mechanical buffing or polishing step, (5) a scraping step, (6) a step involving gas impinging on the roll surface, other means to remove powder or powder remnants from the surface of the roll, or25MEl\58071277.vlAttorney Docket No. 137174.00104 combinations thereof.

[0084] Cleaning the rolls may occur in response to a sensor input indicating that a roll requires cleaning, and / or a programmed interaction based upon time or amount of material processed. A sensor input may include a vision-based sensor, a capacitive sensor, an inductive sensor, or any other sensor capable of measuring a property of the roll surface which varies with an amount of powder interacting with the roll surface.

[0085] As discussed herein, the conditioning system can include a pair of rolls / rolling elements through which the web passes. The pair of rolls can be aligned so there is uniform contact between the web and rolls along central the longitudinal axis (width) of the rolls. The pair of rolls accepts a powder coated web that contacts both rolls on opposing sides, and runs through the nip point to be conditioned. The pair of rolls may be configured in a variety of states with respect to the rotation rate of the rolls, the direction (and speed) of travel of the web. In some embodiments, the web speed can be between (i) 1 and 5 m / min, inclusive, (ii) 4 and 10 m / min, inclusive, (iii) 5 and 20 m / min, inclusive, (iv)10 and 50 m / min, inclusive, (v) 25 and 100 m / min, inclusive, (vi) 50 and 200 m / min, inclusive, or the like.

[0086] Co-rolling is defined as one roll of the pair of rolls rotating in the same direction as the web direction at a different tangential speed than the linear web speed. In some embodiments, the linearized roll speed (the linear speed of a point on the surface of the roll) can be slower than the web speed. However, in some cases, the roll speed may need to rotate faster than web speed for certain materials, is the controller of the system can be configured to receive signals regarding these conditions and can regulate these conditions without modification to the hardware such that the same rolls can be used. In some embodiments, roll speeds for co-rolling can range anywhere from 0-100 meters per minute, inclusive.

[0087] Anti-rolling is defined as one roll of the pair of rolls rotating in the opposite direction of the web direction. In some embodiments, the roll interacting directly with the free surface of the powder can be configured in the anti-rolling state. Roll speed in the antirolling direction can range from 0-100 meters per minute, inclusive, and can be dependent on powder material on the web and the web speed of the system.

[0088] In some cases, the two rolls in the system can rotate in opposite directions from each other. In some embodiments, this means the upper / top roll (the roll interacting with26MEl\58071277.vlAttorney Docket No. 137174.00104 the free surface of the deposited powder) rotates in the anti-rolling direction. The bottom roll (which is uncoated or has a compressed layer of less mobile battery material) rotates in the co-rolling direction. The web is not driven by the pair of rolls in the conditioning subsystem, but a nip point can be used to control web speed and web tension in the subsystem.

[0089] The conditioning subsystem uses lower forces than the calendering stage. In some embodiments, the conditioning stage rollers can use forces in a range from, e.g., about 0-10 N / mm, inclusive, and is applied across a roll with a length between 200 and 400 mm with a diameter between 70 and 400 mm. In some embodiments, the roll can have a length of up to about 3000 mm. As the roll length increases, the force across the roll increases linearly. Rolls with greater geometric extents (length, diameter) may have larger compressive forces, whereas rolls with lesser geometric extents (length, diameter) may have lower compressive forces. In some embodiments, a controller and sensors can be used to actively control the force applied during the calendering stage to achieve / maintain a target force on the coating layer coming into the conditioning subsystem and the calendering subsystem. In general, the magnitude of force applied across a roll will vary linearly with the length of a roll. This assumes that other geometric parameters of the system are held constant. The force scales with geometric similarity as the length of the roller is varied. In some embodiments, for rolls between 500 and 800 mm with a diameter between 140 and 800 mm, a force may be between 500 and 1000 pounds, inclusive. However, other roll sizes and forces are also envisioned.

[0090] In some embodiments, roll diameters for the conditioning subsystem can range from about 25-200 mm, inclusive. In some embodiments, roll diameter may be different for each top or bottom roll in the system. According to some embodiments, a roll may have a diameter of (a) 25 to 100 mm, inclusive, (b) 50 to 150 mm, inclusive, (c) 100 to 200 mm, inclusive, (d) 150 to 300 mm, inclusive, (e) 200 to 350 mm, or the like.

[0091] In some embodiments, roll length can be dependent on a width of the web and can range from about 300 to 3000 mm, inclusive. In some embodiments, it may be desirable to maintain the length of the roll at or greater than the width of the web carrying the dry battery electrode powder material.

[0092] In some embodiments, the roll material may be chosen for reliability and favorable interaction with the dry powder battery feedstock material. In some27MEl\58071277.vlAttorney Docket No. 137174.00104 embodiments, acceptable roll materials are generally ferrous but may include other materials. Materials can be selected which form inert and hard surface layers. In some embodiments, the roll material can include: (1) stainless steel, (2) tool steel, (3) carbon steel, (4) aluminum, (5) ceramic, (6) polymer, combinations thereof, or the like.

[0093] In some embodiments, it may be desirable that the roll material chosen exhibits some amount of compliance, such as an elastomeric material or other engineered surface designed to exhibit a stress and strain response similar to an elastomer. Such compliant materials may include rubbers, plastics, foams, polymers, and fluid-filled membranes such as liquid or gas filled bladders, annuli, and the like. In some embodiments, the compliance may result in deflections on the order of a particle size of the dry powder battery electrode material being processed. For example, in the case where the average particle size (such as the diameter on a volume basis) is between about 5 and 15 microns, a deflection may be between about 0 and 10 times the average particle size (so between about 0 and 150 microns, according to this non-limiting example).

[0094] Rolls including a roll material with some amount of compliance may be constructed in a variety of ways. In some embodiments, a roll can be made from a compliant material. In some embodiments, a roller can use a coating, layer, or otherwise section of pre-defined depth upon the surface of metallic, ceramic, hard polymer, or other relatively mechanically rigid (as compared to the compliant material) material. In some embodiments, a roll can utilize a compliant material with a thickness of between about 50 um and 1 mm, inclusive, 500 um and 5 mm, inclusive, 2 mm and 10 mm, inclusive, or thicker than 15 mm.

[0095] In some embodiments, the thickness of a layer may be chosen based upon the compliance of the compliant material - in particular to tune, select, or otherwise engineer a mechanical stiffness (such as a stiffness in compression) of the compliant material which interacts with the powder.

[0096] In some embodiments, surface coatings may be desirable to impart physical toughness and favorable interactions with the dry powder battery feedstock materials. In some embodiments, it may be desirable to select surface coatings which exhibit high hardness and reduce sticking of the dry powder battery feedstock materials to the rolls. In some embodiments, various surface coatings can be applied to the above materials including: (i) chrome plating, (ii) tungsten carbide, (iii) silicon carbide, (iv) ceramic coating, (v) polymer coating, combinations thereof, or the like.28MEl\58071277.vlAttorney Docket No. 137174.00104

[0097] In some embodiments, surface coatings for powder-contact components of the system (such as rollers) may include, e.g., diamond-like carbon, anodized aluminum, Teflon-impregnated anodized aluminum, hard chrome, cubic boron nitride, nitride materials (including silicon nitride, aluminum nitride, titanium nitride, chromium nitride, or the like), ceramics (including oxide ceramics and non-oxide ceramics, such as: aluminum oxide (alumina), magnesium oxide (magnesia), silicon oxide (silica), spinel, titanium carbide, titanium carbonitride, tungsten carbide, or the like), or any other material to provide a desirable characteristic for powder-roll interaction.

[0098] At least one surface in a pair of rolls interacts with the free surface of the powder and may affect the height and density of the powder layer. In some embodiments, it may be desirable to provide different textures on rolls which interact with the powder as compared to rolls which interact primarily (or only) with the moving web. For example, the roll interacting or in contact with the powder can have a texture or coating, while the roll in contact with the bottom (e.g., uncoated) surface of the web can be substantially planar and without a coating.

[0099] In some embodiments, surface roughness of the rolls may be quantified using a roughness average measurement (Ra), or other metric computed from a profile or area scan of a surface of the roll. In some embodiments, a Ra value for non-patterned rolls can be equal to or less than about 0.2 micrometers (pm), inclusive. According to some embodiments, a Ra value for non-patterned rolls can be between about, e.g., 0.2 micrometers and 2 micrometers (inclusive), 1.5 and 5 micrometers (inclusive), 2 and 10 micrometers (inclusive), 5 and 20 micrometers (inclusive), or the like.

[0100] In some embodiments, depending upon the degree of interaction required between a roller and powder on a moving web, a random pattern may be utilized. Such a pattern may exhibit a roughness well in excess of about 0.2 um, and, according to some embodiments, may be utilized where aggressive interaction is desired between the roll and the powder layer. Such aggressive interaction may be characterized by decreased density of the powder layer as compared to the input density, and net removal of powder (such that a loading of mass per area on the moving web) may be decreased after interacting with a random pattern.

[0101] In some embodiments, random patterns may be produced using a variety of methods, including abrasives. In some embodiments, sanding or the application of other29MEl\58071277.vlAttorney Docket No. 137174.00104 abrasives may be utilized to create a random pattern on the surface of a roll. Various sandpapers or similar abrasives are available in a variety of surface textures to impart rough (e.g., 120 grit) to smooth (e.g., 1200 grit). In some embodiments, surface textures can be present in an irregular, random pattern or configuration on the surface of the roll.

[0102] In some embodiments, media blasting may be utilized to create a random or irregular pattern. For example, by spraying abrasive material at high speed toward to the surface of the roll, the abrasives will locally remove and / or deform material from the surface of the roll to create a texture or pattern. Materials which may be used will dependent upon the material(s) from which the surface of the roll is formed, but various glasses, sands, abrasives (e.g., AI2O3, SiC, SiCh), plastics, walnut shells, and other materials may be used.

[0103] In some embodiments, a variety of patterns impressed onto the powder may be used. In some embodiments, patterns formed with a regular shape or configuration are utilized. Such patterns can be used in instances where the patterns are configured to accept and mobilize specific volumes of powdered materials that lie on the moving web. In some embodiments, it may be desirable to present the powder on the moving web with a surface feature which may capture and convey away from the web an amount of powder which is not desired to transit beyond the nip to the next stage or unit operation of the battery electrode manufacturing process. Such an outcome may be desired, for example, when a deposition approach is extremely crude and uncontrolled. Further applications of rollers with regular patterns may be useful in the comminution of a powder on a web where the powder contains agglomerated clumps of powdered battery feedstock materials. Many patterns are feasible for such embodiments, and include knurl patterns, machine patterns, or the like.

[0104] Knurl patterns are commonly observed as diamond or strip features patterns with length scales (feature-to-feature) of 1 to 3 mm, inclusive. The patterns may be aligned with any direction on the surface of the roll, including along the direction of the axis, along the circumference, or at any angles between those generating axial and circumferential patterns.

[0105] Various patterns may be created in the roll using machining operations. Machining operations may include bringing a stationary tool to a rotating surface of the roll (as on a conventional lathe), bringing a rotating tool into interference with a stationary or slowly-moving roll (as on a mill), or a combination of a rotating tool and a rotating roll (as30MEl\58071277.vlAttorney Docket No. 137174.00104 on a Swiss Lathe, or on a mill with a rotary table, for example). The patterns may serve a similar purpose as the knurl previously described, although greater control and profile specification are available with machined patterns.

[0106] Axial grooves may be applied along the axis of the roll with profiles that may be square, angled, circular, elliptical, or any other profile. Circumferential grooves may be applied along the circumference of the roll with profiles that may be square, angled, circular, elliptical, or any other profile. Wavy grooves (e.g., along circumference or axis direction) may be applied in a hybrid form neither purely axial nor circumferential with a wave-like pattern. The wavy grooves may be parameterized with a wavelength (circumferential distance required for the pattern or wave to repeat) and an amplitude (axial distance change in the wave). Waves may also be machined in a transverse direction, that is aligned and undulating about the axial direction.

[0107] FIG. 3 shows a detailed view of an exemplary powder system 300 configured to detect / identify formation of a mound 312 and regulate one or more portions of the system 300 to adjust the detected characteristics of the mound 312. In some embodiments, the system 300 can be configured to adjust operation to remove some of the powder 316 on the web 320 to reduce the mound 312 formation. In some embodiments, the system 300 can be configured to adjust operation to selectively add powder to portions of the web to create a uniform mound 312 across the entire width of the web. In some embodiments, the system 300 can be configured to adjust operations by angling the roller to move some powder from the surface of the web to reduce the mound 312. In embodiments with at least one angled roller, a surface opposing the at least one angled roller may be of a diameter larger or smaller than the angled roller, or may be a substantially planar surface, or any other surface suitable of forming a nip with the at least one angled roller.

[0108] In the system 300, a roller 310 is being fed a web 320 on which powder 316 has already been deposited. It should be understood that the roller 310 can be, e.g., roller 102, roller 104, roller 106, or one or more of the conditioning rollers of FIG. 1. The height or thickness of the powder 316 layer relative to the top surface of the web 320 represents the baseline or threshold thickness desired for initial deposition on the web 320. As is clearly illustrated in FIG. 3, the mound 312 defines a height above the threshold / baseline thickness of the powder coating. Although FIG. 3 illustrates the mound 312 as having a height above the powder 316, it should be understood that the mound 312 includes a width31MEl\58071277.vlAttorney Docket No. 137174.00104 extending along a direction parallel to the axis of the roller 310, and a depth measured as the distance along the web direction 322 (e.g., away from the roller 310). The roller 310 is configured to spread, smooth out and / or compress the powder 316, and reduces the height of the powder 316 to an output height or thickness 318. The roller 310 is rotating with a rotational velocity 324. The web 320 is moving along the direction 322 from an upstream position to a downstream position.

[0109] As powder 316 is spread, smoothed and / or compressed by the roller 310, the mound 312 of excess powder beings to form. The mound 312 forms immediately upstream and adjacent to the roller 310. Typically, the mound 312 is in direct contact with at least a portion of the roller 310 surface. The system 300 includes one or more sensors 314 configured to detect one or more characteristics of the mound 312, e.g., a mound height, width, depth, or the like. In particular, the sensors 314 are configured to identify when the mound 312 begins to form, and the dimensions / location of the mound 312.

[0110] The sensor 312 sends signals to a controller 326 of the system 300 to indicate that the mound 312 is forming. In some embodiments, the signals can be transmitted to the controller 326 to adjust operation to reduce any mound 312 formation above the baseline thickness of the powder 316. In some embodiments, the system 300 can operate with an acceptable mound 312 forming by the roller 310, with adjustment only needed if detection of there is deviation of the characteristics of the mound 312 relative to the baseline or acceptable threshold (e.g., the mound 312 growing above the baseline or acceptable thresholds, the mound 312 reducing below the desired baseline or acceptable thresholds, or the like) (see, e.g., FIGS. 11A-11B). In some embodiments, the signals can be transmitted to the controller 326 when after a predetermined threshold characteristic has been reached for the mound 312. For example, if the mound 312 height above the thickness of the powder 316 is above X amount, the width of the mound 312 is above Y amount, the depth of the mound 312 is above Z amount, combinations thereof, or the like. In some embodiments, the values for X, Y and Z can be dependent on material properties of the powder 316. The controller 326, in turn, regulates operation of one or more features / parameters of the system 300 to modify the mound 312. For example, if the mound is detected to be too big (height, width and / or depth), action can be taken by the system to reduce the amount of powder being deposited on the web and / or powder adjustment units of the system can be actuated to remove and / or redistribute some of the powder to reduce the mound size. As another example, if the mound is detected to be too small (height, width32MEl\58071277.vlAttorney Docket No. 137174.00104 and / or depth), the gap between the roller and the powder can be decreased, more powder can be deposited on the web, or the like, to increase the mound size.

[0111] For example, the controller 326 can initiate addition of powder selectively upstream of the roller 310 to fill in gaps around the mound 312, thereby creating a uniform mound 312 along the entire width of the roller 310. As another example, the controller 326 can initiate removal of powder selectively upstream of the roller to reduce / remove the mound 312. As another example, the controller 326 can selectively stop which areas of the web receive powder from the powder deposition system to avoid providing more powder to areas having the mound 312. As another example, the controller 326 can camber the roller 310 to guide and move powder off the web surface to reduce / remove the mound 312.

[0112] As noted, during passage of the web 320 under the roller 310, a powder mound 312 can form directly upstream of the roller 310. The size of the mound 312 can indicate the effectiveness and stability of the process, which can affect the uniformity of the coated layer output by the system 300. If the mound is “too small” then the system is not performing the required work to achieve the target coating improvements. If the mound is “too big” defects may be introduced into the coating. The stable operating range can be dependent on the characteristics of the powder. Some important characteristics that can affect the likelihood and frequency of mound 312 formation can include, e.g., powder flowability, particle size, bulk density, and theoretical density.

[0113] The sensor 314 for detection of the powder mound 312 characteristics can be, e.g., a combination of vision systems, laser displacement, eddy currents, sonar, radar, and / or other sensors which provide information related to physical volumetric, mass, or density of the powder mound 312. A control feedback loop within a master control system (e.g., with controller 326) is established for a given powder type which inputs the sensory feedback and outputs a set of instructions to the processing equipment to keep the powder mound within a specified operating window.

[0114] In some embodiments, the controller 326 can be programmed to take different actions based on the type of powder being applied due to the different characteristics associated with the powder. In some embodiments, the controller 326 can perform the same actions for any type of powder used. A variety of one or more process / parameter control adjustments can be made by the controller 326 made depending on the desired effect. Such adjustments can include, but are not limited to adjusting: (i) the mass flow rate33MEl\58071277.vlAttorney Docket No. 137174.00104 from the deposition system, (ii) the distribution of material being deposited across its width, (iii) changing the gap of the conditioning roller (such as the magnitude or creating a taper from side to side), (iv) the speed of the conditioning roller, (v) the yaw or tram (rotational position relative to the machine direction), (vi) calculated and selective addition of powder along specific sections of the web to fill in gaps between one or more mounds, (vii) calculated and selective removal of powder from specific sections of the coating upstream of the conditioning roller (e.g., using a powder removal system with controlled orifices along the web width), combinations thereof, or the like. The listed process adjustment can be used in any combination as directed by the master control algorithm within the master control system (e.g., controller 326).

[0115] The system can include additional sensors 314 disposed downstream of the roller 310 to verify the condition of the powder at various stages of the process. The sensors 314 can be read by the control systems (e.g., controller 326) and the process can be adjusted / regulated as needed to correct for unwanted variation in the powder coating. For example, the sensor 314 can be positioned upstream of each conditioning roller to determine if mound formation is occurring at each stage of conditioning. If mound formation is detected, the system 300 can include the powder adjustment systems inbetween the respective conditioning rollers to independently adjust one or more parameters of the system 300 to remove / reduce or create uniformity in the mound. Similarly, sensors 314 can be positioned downstream of each conditioning roller to detect uniformity and / or compaction issues in the coated web.

[0116] FIG. 13 is another diagrammatic side of an exemplary powder system 1100 including a sensor 1102 for detecting characteristics associated with a mound 1104 formed immediately upstream of a conditioning roller 1106. The system 1100 generally includes a powder deposition assembly 1108 configured to deposit powder particles 1110 onto a web 1112 moving in a web direction 1114. As the web 1112 is passed through a nip of a conditioning roller 1106, a mound 1104 can form on the surface of the web 1112, with the mound 1104 defining at least a height greater than a height of the powder particle 1110 coating upstream of the conditioning roller 1106. After conditioning, the web 1112 continues to travel downstream of the conditioning roller 1106 with a conditioned powder particle coating 1116, e.g., having a thickness dimensioned less than a thickness of the powder particles 1110 upstream of the conditioning roller 1106.

[0117] One or more sensors 1102 can be disposed adjacent to the mound 1104 and can34MEl\58071277.vlAttorney Docket No. 137174.00104 be used to detect one or more characteristics associated with the mound 1104. The characteristics associated with the mound 1104 can be any discussed herein. The sensor 1102 can include a field-of-view 1118 configured to encompass at least a portion of the mound 1104. In some embodiments, similar sensors 1102 can be used to detect characteristics associated with the powder particles 1110 upstream and / or downstream of the conditioning roller 1106. In some embodiments, the sensor 1102 can be communicatively connected to a controller 1120 and the controller 1120 can, in turn, be connected to the powder deposition assembly 1108 and / or the conditioning roller 1106.

[0118] Thus, based on signals received from the sensor 1102 regarding the characteristics of the mound 1104 (and / or characteristics of the powder particle coating layer), the controller can be used to adjust or adapt operation of, e.g., the powder deposition assembly 1108, the conditioning roller 1106, or combinations thereof, to maintain the mound 1104 at the desired level. Output signals of the measurements taken by the sensor 1102 can therefore be used as inputs into a control scheme to control the mound 1104 behavior.

[0119] The exemplary systems discussed herein can include a variety of sensors for detecting the mound characteristics. As a non-limiting example, in some embodiments, a powder system 1200 can include multiple static sensors 1202 mounted near or upstream a conditioning roller 1204 to detect the height, width and depth of a mound 1206 forming directly upstream of the conditioning roller 1204 (see, e.g., FIG. 14). In some embodiments, the static sensors 1202 can be disposed adjacent to each other or can be laterally spaced along a direction parallel to a central longitudinal axis of the conditioning roller 1204. Thus, as powder particles 1208 are dispensed onto a web 1210 moving along direction 1212 towards the conditioning roller 1204, the mound 1206 can form and the static sensors 1202 can be used to detect characteristics of the mound 1206 at fixed positions relative to the conditioning roller 1204.

[0120] As another non-limiting example, in some embodiments, a powder system 1250 can include a dynamic sensor 1252 capable of traversing laterally in either direction 1254, 1256 parallel to the central longitudinal axis of the conditioning roller 1204 (see, e.g., FIG. 15). In some embodiments, a single sensor 1252 can be used. In some embodiments, multiple dynamic sensors 1252 can be used. The sensor 1252 can travel laterally along a path or track such that the single sensor 1252 can detect characteristics of the mound 1202 along the entire width of the mound 1202, i.e., across the width of the web 1210. The35MEl\58071277.vlAttorney Docket No. 137174.00104 sensor 1252 can output data representative of a mound 1202 profile for analysis and use by a controller to regulate one or more components of the system 1250.

[0121] FIG. 16 shows a flow chart of an exemplary process of mound characteristic measurement, as performed by any of the systems discussed herein. At step 1300, measurement is taken of one or more characteristics of a mound of powder particles formed immediately upstream and adjacent to a conditioning roller. At step 1302, a determination is made whether the mound is in control (i.e., the mound is within the threshold or baseline permissible characteristics). If the mound is found to be within the permissible threshold or baseline characteristics, at step 1304, no changes are made to the incoming process of powder deposition and conditioning.

[0122] If the mound is found to be outside of the permissible threshold or baseline characteristics, at step 1306, a determination is made whether the mound characteristics are high or low. As used herein, “OOC” refers to out-of-control; specifically, the mound characteristics or shape may be detected as outside of the predetermined range, which would then trigger a response from the control system to correct this out-of-control state. If the mound characteristic is low, at step 1308, a determination is made whether the characteristic is low globally (along the entire mound) or locally (at one or more specific areas of the mound without continuity). If the low characteristic is local, at step 1310, a determination is made regarding the locations of the low characteristic. As used herein, “CD” refers to the absolute position in a cross -direction of the web (the direction perpendicular to the direction of travel of the substrate or the width of the coated layer); or more simply, the CD can be represented by the left and right sides of the web. Once the location is determined, at step 1312, a controller can be used to regulate local powder deposition upstream of the conditioning roller and mound to locally increase the powder deposition in the detected low points.

[0123] If the low characteristic is global, at step 1314, a determination is made whether to change the powder deposition or operation of the conditioning roller (CR). If the powder deposition is to be adjusted, at step 1316, the controller can increase the deposition amount upstream of the mound in a global manner. If the conditioning roller operation is to be adjusted, at step 1318, a determination is made whether to change the roll step or gap setting. At step 1320, a conditioning roller gap can be decreased. At step 1322, the top conditioning roller speed can be decreased. In some embodiments, the system can determine that adjustment of two or more of the powder deposition, gap, and roll speed36MEl\58071277.vlAttorney Docket No. 137174.00104 may be made in combination to achieve the desired mound characteristics.

[0124] If the mound characteristic is determined to be high, at step 1324, a determination is made whether the high characteristic is global or local. If local, at step 1326, a determination is made regarding the location of the high characteristics along the mound. At step 1328, a controller can be used to locally decrease the powder deposition corresponding with the high characteristics of the mound to reduce the mound characteristics.

[0125] If the high mound characteristic is global, at step 1330, a determination is made whether to change the deposition or the conditioning roller operation. At 1332, a controller can be used to decrease the amount of powder deposition upstream of the mound in a global manner, e.g., across the width of the web. At 1334, a determination can be made whether to change the roller speed or gap setting. At 1336, the gap under the conditioning roller can be increased to allow more powder through, thereby decreasing the mound characteristic. At 1338, the top roller speed can be increased to pass more powder through the nip. In some embodiments, the system can determine that adjustment of two or more of the powder deposition, gap, and roll speed may be made in combination to achieve the desired mound characteristics.

[0126] FIG. 10A is a diagrammatic side view that shows a roller 336, 338 pair and a mound 312 of powder 340 forming directly upstream and against the roller 336 as the web 320 moves along direction 322. In particular, FIG. 10A shows an upper roller 336 and a lower roller 338. The powder mound 312 has a height 334 and a width 350 (see FIGS. 10A and 10B), with the height 334 measured from the top of the powder 340 and the width measured from the frontmost or leading edge of the roller 336. A distance 330 (Wp) can define the leading or frontmost edge of the mound 312 relative to the central axis of the roller 336. In some embodiments, the distance 330 for an acceptable mound 312 (i.e., a mound that does not necessitate adjustment of operation by the system to reduce or increase the mound) can be about, e.g., 50 mm or less, inclusive (as measured from center of the conditioning roller 336). In some embodiments, the distance 330 should not be smaller than about 0.1 mm. In some embodiments, the distance 330 can be between about, e.g., 0.1-50 mm inclusive, 0.1-40 mm inclusive, 0.1-30 mm inclusive, 0.1-20 mm inclusive, 0.1-10 mm inclusive, 0.1-5 mm inclusive, 5-50 mm inclusive, 10-50 mm inclusive, 20-50 mm inclusive, 30-50 mm inclusive, 40-50 mm inclusive, 10-40 mm inclusive, 20-30 mm inclusive, 0.1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, or the like. As an37MEl\58071277.vlAttorney Docket No. 137174.00104 example, the distance 330 (Wp) in FIG. 11A diagrammatically illustrates an acceptable mound 312, while a distance 331 (Wp) in FIG. 1 IB illustrates an unacceptable mound 312.

[0127] The web 320 is moving in the direction 322 carrying upstream powder 340 to the roller 336 and downstream powder 342 away from the roller 336. FIG. 10B is a diagrammatic top view that shows a top roller 336 and the mound 312 of powder 340 from FIG. 10A. The mound 312 outline is shown with a width 350. The width of the mound 312 is generally controlled to be within about 5 mm or about 10 mm of either edge. In some embodiments, the width 350 cannot exceed the target electrode width by more than 20 mm (e.g., 10 mm per side). In some embodiments, the width 350 can be at the edge of the web 320. As an example, detection of the mound 312 beyond or below the 10 mm distance from the edge of the web 320 can initiate adjustment of operation to increase or decrease the width 350 of the mound 312. The roller 336 rotates in the direction 354 and the web 320 moves in the direction 322. In general, when the height 332 of the mound 312 becomes too high, e.g., beyond a predetermined threshold height 332, the width 350 of the mound 312 also tends to become too wide, e.g., beyond the 10 mm threshold. Thus, the mound 312 height 332 and width 350 can be correlated and monitored together for adjustment of the system operation.

[0128] FIG. 11A is a diagrammatic side view that shows a roller 336, 338 pair and a mound 312 of powder 340, where the mound 312 has characteristics (e.g., height, width, depth, or the like) that are acceptable. In particular, FIG. 11A shows a roller 336 and a mound 312 that is within acceptable limits / thresholds. The upper roller 336 is disposed above the lower roller 338 on opposing sides of the web 320. An upstream powder layer 340 is fed to the roller 336. The powder on the web 320 moves in the direction 322, i.e., from upstream to downstream.

[0129] The powder forms a mound 312 that engages the frontmost or upstream portion of the roller 336 over what is referred to herein as a wetted angle 333, i.e., a radial contact angle between the powder and the roller 336 face. In some embodiments, the wetted angle 333 for a mound 312 that is considered acceptable or within threshold limits can be between about, e.g., 2 and 20 degrees, inclusive. The wetted angle 333 can be measured from the bottom dead center of the roller 336. A wetted angle 333 smaller than 2 degrees or larger than 20 degrees can be considered unacceptable, and can trigger a parameter adjustment of the powder layer, roll gap setting, or any other operational parameters discussed herein. The height 334 of the mound can be an acceptable threshold height (FIG. 11 A), while a38MEl\58071277.vlAttorney Docket No. 137174.00104 height 332 can be a height considered unacceptable and requires modification of the system operation (FIG. 1 IB). In some embodiments, the distance 330 of the mound 312 can be less than about 50 mm and greater than about 0.1 mm. The powder is carried by the web 320 after the rollers 336 and 338 downstream and shown as the downstream powder layer 342. It should be understood that the acceptable height 334 of the mound 312 may be adjusted based on the radius of the roller 336 being used. For example, the acceptable mound height 334 can increase proportionally as the radius of the roller 336 increases, with the assumption that the acceptable angle 332 remains the same regardless of roller 336 radius. The acceptable distance 330 (e.g., depth) of the mound 312 should generally remain the same with changes in the roller 336 radius, although it is envisioned that the distance 330 can also be varied proportionally as the roller 336 radius changes.

[0130] FIG. 1 IB is a diagrammatic side view that shows the roller 336, 338 pair and a mound 312 of powder from FIG. 11 A, except the mound 312 has been decreased at least in height 332 and depth 331 to a level which is below the acceptable threshold mound height and width. Due to the reduced height and width, the wetted angle 333 is also smaller and is not considered acceptable. Detection of such reduction in mound 312 characteristics can trigger adjustment of operation of one or more parameters of the system to reach the desired mound 312 characteristics.

[0131] FIG. 4 is a diagrammatic view of a powder system 400 with a powder deposition system 202, an optional heater 424, and a powder adjustment system 430. System 400 can be substantially similar in structure and / or function to the powder system 200, with the addition of the powder adjustment system 430 and the heater 424. Although shown as being upstream of the roller 206, it should be understood that the powder adjustment system 430 can be positioned directly upstream of each conditioning roller 206, 208, and can include the sensor 314 of FIG. 3.

[0132] The powder adjustment system 430 allows material to be selectively added, removed and / or adjusted in response to the feedback control system monitoring a mound forming directly upstream of the first roller 206. In some embodiments, a heater 424 may be used at any point in the conditioning process. For example, placing a heater 424 in between the conditioning steps at rollers 208 and 210, as shown, can enable improved compaction. In some embodiments, it may be desirable to place a heater 424 to activate the binder in between the conditioning rollers for improved adherence to the web surface and compaction between powder particles. In some embodiments, binder activation may39MEl\58071277.vlAttorney Docket No. 137174.00104 include locally melting the binder components to adhere in a more significant way to either, or both of, the metal web, active material, and conductive additives. In some embodiments, the heater 424 can be placed at the end of any part of the process. In some embodiments, other steps that can be placed before, in-between, and afterwards can include, e.g., electromagnetic powder leveling, acoustic vibration, and / or additional powder deposition steps.

[0133] FIG. 5 is a diagrammatic view of a powder system 500 including a powder adjustment system 516. The powder adjustment system 516 can be placed upstream of any one of the conditioning rollers. Therefore, although FIG. 5 illustrates a single roller 510, it should be understood that each conditioning roller can include the adjustment system 516 discussed herein. In some embodiments, the powder adjustment system 516 can include a roller 510 with a pivot point or hinge capable of being actuated to change / adjust the camber of the roller 510 (e.g., changing yaw angle). In particular, the “normal” operation can include the roller 510 orientated such that the central longitudinal axis of the roller 510 is oriented substantially perpendicularly to the web movement direction 522. However, if a sensor 514 (e.g., sensor 314) detects formation of a mound 511 in an area 512 immediately upstream and adjacent to the roller 510, the orientation of the roller 510 can be varied to help guide the excess powder off the web 520. As shown in FIG. 5, the mound 511 can form along the entire width of the roller 510 or can form in independent areas of the area 512.

[0134] The sensor 514 monitors key physical characteristics of the mound 511 and communicates with the controller to adjust operation of one or more parameters of the system to remove, reduce or create uniformity with the mound 511. Although illustrated as positioned across the entire width of the web 520, in some embodiments, the sensor 514 can be a single sensor centrally mounted or multiple individual sensors in communication with the controller.

[0135] In some embodiments, a powder adjustment system 516 can include a structure (e.g., a cylindrical tube) with separate orifices 518 positioned over the entire width of the web 520. In some embodiments, the structure can be connected to a powder source such that, upon detection of the mound 511, the system 516 can selectively open the orifices 518 and deposit powder in certain areas of the web 520 to “fill the gaps” between the mounds 511, thereby creating a uniformity in the mound 511 along the entire width of the web 520. In some embodiments, the structure can be connected to a powder source such that, upon40MEl\58071277.vlAttorney Docket No. 137174.00104 detection of the mound 511, the system 516 can selectively close the orifices 518 aligned with the mound 511 and continue depositing powder through the remaining open orifices 518 to “fill the gaps” between the mounds 511. In such embodiments, the system 516 can operate as a powder deposition system in which all orifices 518 are typically open until the mound 511 is detected. In some embodiments, the structure can be connected to a suction source such that, upon detection of the mound 511, the system 516 can selectively open the orifices 518 aligned with the mound 511 to remove some powder from the web 520 surface, thereby reducing the amount of powder traveling to the mound 511, which results in reduction of the mound 511.

[0136] In some embodiments, the powder adjustment system 516 can be implemented to remove the powder using a vacuum. In some embodiments, the system 516 can include wiping, or guiding as to minimize uncontrolled powder buildup, leading to potential defects and issues. In some embodiments, the powder adjustment system 516 may redirect the flow of powder by changing the camber of the roller 510. For example, the roller 510 can be rotated (changing its yaw) in a clockwise (positive camber) or counterclockwise (negative camber) direction. The adjustment can be made by the feedback control system (e.g., a controller in communication with the sensor 514) based on the condition of the powder mound 512 and the mound characteristics detected by the sensor 514.

[0137] In some embodiments, the system 500 can include a sensor 524 downstream of the roller 510 to provide feedback to the controller regarding the powder layer characteristics / quality. In some embodiments, the powder adjustment system 516 can remove a layer of powder to a degree required by the control system depending on the position of the mound 511. It should be understood that the powder layer may not always be evenly distributed across the surface of the web. In fact, the powder layer may vary as a function of the width across the face of the web. The orifices 518 of the powder adjustment system 516 can be individually controlled to remove powder along the width of the web. For example, there may be an excess of powder in the center of the web in which case more powder can be removed at the center upstream of the mound 511, or there may be too much powder delivered on one edge in which case that edge can have more powder removed by the powder adjustment system 516. As a further example, and as compared to a desired amount of powder, there may be too much powder on both edges and not as much (or too little) in the center, in which case the edges can have more powder removed and / or the center can be provided with additional powder. The amount of powder that is removed can41MEl\58071277.vlAttorney Docket No. 137174.00104 be a function of how strong the vacuum is and where the powder is removed, which affects which of the separate orifices 518 are enabled for removal operation.

[0138] FIG. 6 shows a system 600 with a series of rollers 605, 606, 608 where the camber is changed relative to the web moving direction 602. For example, if a mound is detected upstream of a roller, the camber can be changed based on signals from the sensor. In a neutral or normal position, the roller 604 can be positioned in an orientation with its central longitudinal axis perpendicular to the direction 602. If redirection of powder is needed to adjust or remove the mound, the roller 604 (or downstream rollers 606, 608) can be pivoted to adjust their angle relative to the direction 602 in the manner shown in FIG. 6. By placing one or more of the rollers 604, 606, 608 at a relative angle to the web direction 602, powder can be directed in a strategic manner for removal or reduction of some initial contact forces due to potential non-uniformities in the incoming powder layer. In this case roller 606 has been oriented to be at an angle 610 that is greater than 90 degrees with respect to the direction 602. Roller 608 has been oriented to be at an angle 612 smaller than 90 degrees with respect to the direction 602. The pivoting of the roller can be performed for the roller having the detected mound directly upstream of it, while the other rollers can remain in their normal / neutral position. The rollers are therefore independently movable based on signals from the controller / sensor feedback loop.

[0139] FIGS. 7A-7C show a flat roller 702, a camber roller 708, and a reverse camber roller 814 capable of being incorporated into the exemplary powder system in one or more combinations, or individually. FIG. 7A is a flat roller 702 configured to process and condition powder 704 evenly across its surface and on the surface of the web 706. FIG. 7B is a camber roller 708 configured to move powder 710 away from the center of the web 712. FIG. 7C is a reverse camber roller 714 configured to move powder 716 towards the center of the web 718. The different types of rollers can be used selectively as part of a powder adjustment system upstream of a conditioning roller detected to have a mound forming immediately upstream of the conditioning roller, thereby reducing the powder distribution to minimize or prevent the mound. Thus, the powder adjustment system can include several independently available features capable of adjusting powder distribution for address the detected characteristics of the mound.

[0140] FIGS. 12A-12C are diagrammatic views of a powder adjustment system 1000 which can be incorporated into the exemplary powder system discussed herein. In some embodiments, the system 1000 is configured to redirect or reposition the powder to allow42MEl\58071277.vlAttorney Docket No. 137174.00104 for an improved conditioning process and mound control. In some embodiments, the system 100 can be used to selectively remove or add powder along the web. For example, the substrate or web 1002 is initially coated with a powder layer 1004. This powder layer 1004 can initially pass through a portion of a conditioning assembly along direction 1006, or may be directly passed to a powder adjustment or manipulation mechanism 1008 before any conditioning occurs. The mechanism 1008 material can be chosen for reliability and / or favorable interaction with the incoming powder layer 1004, e.g., stainless steel, tool steel, carbon steel, aluminum, ceramic, polymer, or the like.

[0141] The mechanism 1008 includes a structure configured to be selectively positioned over the power layer 1004 (e.g., selectively lowered or raised, depending on use necessity). In some embodiments, the bottom surface of the mechanism 1008 can be positioned just above the moving web 1002. In some embodiments, the bottom surface of the mechanism 1008 can be positioned against the top surface of the web 1002 (or a previously conditioned / calendered coating on the web 1002). The bottom surface of the structure includes channels or openings 1010 formed therein and separated by solid sections 1012. The mechanism 1008 therefore includes multiple openings 1010 formed along the bottom edge or surface configured to guide the powder through the openings 1010, thereby forming lanes 1014 (e.g., strips) of powder on the web 1002 separated by lanes 1016 of modified or removed powder. In some embodiments, the solid sections 1012 can “plow” through the powder to direct the powder through the openings 1010. As noted above, in some embodiments, the system 1000 can be used to selectively remove or add powder. For example, the solid sections 1012 can include a vacuuming feature to remove powder, thereby leaving only the lanes 1014 of powder. In some embodiments, the vacuuming feature can be activated based on feedback from sensors detecting the mound formation. As a further example, the openings 1010 can include dispensers for selectively dispensing powder onto the web 1002. In some embodiments, the redirecting by the mechanism 1008 can be activated based on feedback from sensors detecting the mound formation.

[0142] In some embodiments, the mechanism 1008 can completely or essentially completely remove the powder from the lanes 1016 (e.g., by redirecting and / or vacuuming), such that the web 1002 is uncoated in the lanes 1016. In some embodiments, the mechanism 1008 can only partially move the powder from the web 1002 at the lanes 1016, such that some layer of powder remains at the lanes 1016. However, in all instances, the amount of powder in the lanes 1014 is greater in height relative to the web 1002 as43MEl\58071277.vlAttorney Docket No. 137174.00104 compared to the amount of powder in the lanes 1016. In some embodiments, the entire surface of the web 1002 can be coated with the layer 1004 (up to or near the opposing side edges), and the mechanism 1008 can be used to form lanes 1016 at the edges of the web 1002 and one or more lanes 1016 between the edges of the web 1002, as shown in FIG. 12A. In some embodiments, powder can be enriched or depleted to varying amounts. For example, powder can be partially or incompletely removed from some areas. Some amounts of incompletely or partially removed powder can be deposited to other regions of the web or removed to a separate apparatus for reuse.

[0143] In some embodiments, the mechanism 1008 may provide a means to locally enrich and / or deplete powder on the web 1002. Depletion and enrichment may produce regions of the powder with lower height and / or areal loading versus areas which have higher height and / or areal loading. Various mechanisms 1008 can be used to achieve the enrichment and / or depletion of the powder. As non-limiting examples, such mechanisms 1008 can include, e.g., obstructions placed in the moving powder which appear stationary relative to the moving powder (such as plows, rakes, grooved features in rollers and roller shaped objects, or the like). Control of such obstructions may be effectuated by placement of the obstructions relative to the web 1002 and powder. Placement attributes may include, e.g., a density of the obstruction features (such as a number of features per web 1002 width), the geometric extent of the obstruction features, the depth of engagement of the obstruction features into the powder layer, combinations thereof, or the like.

[0144] In some embodiments, the geometric extent of the obstruction features may be defined relative to a thickness (or height) of the powder presented to (or about to interact with) the obstruction features. In particular, the relevant geometric ratio can be the size of the obstruction feature relative to the thickness of the powder which interacts with the obstruction feature. In some embodiments, the obstruction features may be characterized by, e.g., a length to describe the extent of the obstruction feature in a direction of web 1002 motion, a width to describe the extent of the obstruction feature in a direction perpendicular to web 1002 motion, a height in a direction parallel to the surface normal of the web 1002, combinations thereof, or the like. In some embodiments, the width may be between about 1 and 5 units (inclusive) of the powder height, between about 2 and 10 units of the powder height (inclusive), between about 5 and 15 units of the powder height (inclusive), greater than about 10 units of the powder height, or the like. The length and height of the obstruction feature may be on the same order as the width, but can generally be substantially44MEl\58071277.vlAttorney Docket No. 137174.00104 greater than the width, as measured using the units relative to the powder height.

[0145] In some embodiments, the obstruction features may exhibit a profile selected based upon the interaction of the profile with the incoming powder. In some embodiments, desirable interactions may include, e.g., a plowing, tumbling, spreading, enrichment, depletion, or the like, interaction of the powder with the obstruction. Profiles of the obstructions may include shapes and structures resembling, e.g., plows, diamonds, spheres, circular section, cylinders, ellipses, triangles, tapered shapes, or the like.

[0146] In some embodiments, the spacing between the openings 1010 and the solid sections 1012 can be substantially equal to form equal widths of strips or lanes 1014, 1016. In some embodiments, the spacing can be different. FIG. 12C shows a detailed view of the lanes 1014, 1016 formed by the mechanism 1008. In some embodiments, the size of the openings 1010 can be selected based on the desired powder lane 1014 dimensions (e.g., height 1018 and / or width 1020). In some embodiments, the size of the openings 1010 can be selectively adjustable to narrow or expand depending on input dimensions for the height 1018 and / or width 1020 desired by the user. In some embodiments, the distance 1022 (e.g., void) between the openings 1010 can also be adjustable to allow for customization of the lane 1014 formation. In some embodiments, the number of openings 1010 can be adjustable to create a smaller or greater number of lanes 1014.

[0147] After the mechanism 1008 has adjusted or redistributed the powder into the lanes 1014, 1016, the web 1002 can be fed into one or more components of a conditioning assembly 1024, which condition the powder into a powder layer 1026. The layer 1026 fully covers the desired surface area of the web 1002 across the entire width of the web 1002 after conditioning. The mechanism 1008 can therefore be used to redirect or reposition powder initially distributed on the web 1002 before and / or after conditioning has occurred.

[0148] While exemplary embodiments have been described herein, it is expressly noted that these embodiments should not be construed as limiting, but rather that additions and modifications to what is expressly described herein also are included within the scope of the invention. Moreover, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations, even if such combinations or permutations are not made express herein, without departing from the spirit and scope of the invention.45MEl\58071277.vl

Claims

1. Attorney Docket No. 137174.00104CLAIMS:

1. A powder system, comprising: a powder delivery system configured to deliver powder to a substrate; a powder conditioning system configured to condition the powder on the substrate; at least one sensor configured to detect at least one characteristic associated with a mound of the powder collected upstream of the powder conditioning system; and a processor configured to receive a signal from the at least one sensor representative of the detected at least one characteristic associated with the mound of the powder, and configured to adjust at least one operational parameter of the powder system based on the detected at least one characteristic.

2. The powder system of claim 1, wherein the powder conditioning system is a roller system comprising a first roller positioned over and extending across a width of the substrate in a direction perpendicular to a substrate moving direction.

3. The powder system of claim 2, comprising a second roller disposed in series with the first roller over the substrate, wherein the second roller is located downstream of the first roller along the substrate moving direction.

4. The powder system of claim 1, wherein the powder conditioning system is configured to condition the powder on the substrate by at least one of spreading, smoothening, and / or compaction.

5. The powder system of claim 2, wherein the first roller has a speed, a direction of rotation, an angle with respect to the substrate moving direction of the substrate, and a gap between a roller surface and the substrate.

6. The powder system of claim 1, wherein the at least one sensor comprises at least one of a vision system sensor, a laser displacement sensor, an eddy current sensor, a sonar sensor, capacitance sensor, magnetic sensor, or a radar sensor.46MEl\58071277.vlAttorney Docket No. 137174.001047. The powder system of claim 1, wherein the at least one characteristic associated with the mound of the powder is a mound height, a mound width, mound density, mound physical profile, and / or a mound length.

8. The powder system of claim 1, wherein the substrate moves from an upstream direction to a downstream direction relative to the powder delivery system, and wherein adjusting the at least one operational parameter includes increasing or decreasing an amount of the powder delivered by the powder delivery system onto the substrate.

9. The powder system of claim 8, wherein the powder delivery system comprises a structure including a series of openings formed therein and extending along a width of the substrate, wherein each opening is controlled separately to selectively add or stop adding the powder to areas of the substrate.

10. The powder system of claim 1, comprising a powder removal system including a structure with a series of openings formed therein and extending along a width of the substrate, and wherein adjusting the at least one operational parameter includes selectively actuating the powder removal system to remove an amount of powder through one or more of the openings.

11. The powder system of claim 3, wherein adjusting the at least one operational parameter comprises changing a yaw angle of the second roller relative to the substrate moving direction to selectively remove an amount of the powder from the substrate.

12. The powder system of claim 5, wherein adjusting the at least one operational parameter comprises moving the first roller up or down relative to the substrate to selectively increase or decrease the gap between the roller surface and the substrate.

13. The powder system of claim 12, wherein the powder conditioning system comprises a second roller disposed downstream of the first roller, and adjusting the at least one operational parameter adjusting a position of the second roller relative to the substrate due to increasing or decreasing the gap between the roller surface of the first roller and the substrate.47MEl\58071277.vlAttorney Docket No. 137174.0010414. A method of powder coating, comprising: delivering a powder with a powder delivery system to a substrate; conditioning the powder on the substrate with a powder conditioning system; detecting with at least one sensor at least one characteristic associated with a mound of the powder collected upstream of the powder conditioning system; receiving a signal from the at least one sensor at a processor, the signal representative of the at least one characteristic associated with the mound of the powder; and adjusting at least one operational parameter of the powder system with the processor based on the detected at least one characteristic.

15. The method of claim 14, wherein powder conditioning system is a roller system comprising a first roller positioned over and extending across a width of the substrate in a direction perpendicular to a substrate moving direction, and wherein the first roller has a speed, a direction of rotation, an angle with respect to the substrate moving direction of the substrate, and a gap between a roller surface and the substrate.

16. The method of claim 14, wherein conditioning of the powder comprises at least one of spreading, smoothening, and / or compaction.

17. The method of claim 14, wherein adjusting the at least one operational parameter comprises increasing or decreasing an amount of the powder delivered by the powder delivery system onto the substrate.

18. The method of claim 14, wherein adjusting the at least one operational parameter comprises selectively adding or stopping addition of the powder to areas of the substrate with the powder delivery system, and wherein the powder delivery system including a structure with a series of openings formed therein and extending along a width of the substrate, each opening controlled separately to selectively add or stop adding the powder to the areas of the substrate.

19. The method of claim 14, wherein adjusting the at least one operational parameter comprises selectively actuating a powder removal system including a structure with a series of openings formed therein and extending along a width of the substrate to remove an amount of powder through one or more of the openings.48MEl\58071277.vlAttorney Docket No. 137174.0010420. The method of claim 15, wherein adjusting the at least one operational parameter comprises moving the first roller up or down relative to the substrate to selectively increase or decrease the gap between the roller surface and the substrate.49MEl\58071277.vl

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