System for multi-layer battery electrode fabrication

Abstract

A system for multi-layer battery electrode fabrication is provided. The system includes a first spreader coating system including a chamber for dispensing first powder particles onto a substrate, a first spreading coating assembly to create a first uniform coating of the first powder particles, and a first calendering assembly to create a first compressed powder coating on the substrate. The system includes a second spreader coating system including a chamber for dispensing second powder particles onto the first compressed powder coating, a second spreading coating assembly to create a second uniform coating of the second powder particles, and a second calendering assembly to create a second compressed powder coating on the first compressed powder coating. The first and second compressed powder coatings define a multi-layer coating on the electrode.

Description

SYSTEM FOR MULTI-LAYER BATTERY ELECTRODE FABRICATIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of a co-pending, commonly assigned U.S. Provisional Patent Application No. 63 / 617,849, which was filed on January 5, 2024. The entire content of the foregoing provisional application is incorporated herein by reference.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. One conventional manufacturing process is referred to as “spreader roller coating”, which is diagrammatically represented in FIG. 1.

[0003] The conventional spreader roller coating system 10 generally includes a chamber 12 that receives and dispenses powder particles 14 onto a moving substrate 16. Rollers 18, 20 on opposite ends of the system 10 maintain movement of the substrate 16 along a direction 22. The substrate 16 is passed through a pair of spreading rollers 24, 26 to spread the powder particles 14 uniformly on the surface of the substrate 16, with the powder particles 14 spread on the substrate 16 at a first thickness 28. The substrate 16 is subsequently passed through a pair of calender rollers 30, 32 which compress the powder particles 14 to a second thickness 34. The calender rollers 30, 32 densify and compress the powder particles onto the substrate surface, with such compression and densification causing the powder particles to adhere to each other and the substrate 16. 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.

[0004] Another 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 coatedmaterial on the metal foil therefore involves an additional step that also increases the overall cost of the manufacturing process.SUMMARY

[0005] In accordance with embodiments of the present disclosure, an exemplary system for multi-layer battery electrode fabrication is provided. In particular, multi-layer electrodes for batteries, such as Li-ion batteries, have attracted particular interest in the industry due to special properties offered by such multi-layer powder coating. For example, one special property offered by the multi-layer powder coating is that the resulting electrode has different porosity layers to allow for improved power behaviors. The multi-layer powder coating produces gradient electrode structures with tunable powder and energy performance. These performance properties replace the need to couple power and energy cells at the module level, thereby simplifying system level design and electronic requirements to manage two cell design configurations. The electrode performance tenability can be achieved by dry coating two chemistries, e.g., a layer of lithium iron phosphate for power performance with lithium nickel cobalt manganese oxide for energy performance, by controlling a low density layer for power and a high density layer for energy using the same chemistry, or the like. Ultimately, the multi-layer dry coating electrode reduces cost and extends the life of the battery.

[0006] Creation of the multi-layer powder coating with slurry-based electrode coating is difficult. The system provides a spreader roller coating assembly for creating multiple layers of the powder particle coating on the substrate. The system can create each powder particle coating layer with or without heat, can customize the thickness of each coating layer, and can use the same or different powder particles for each layer. The system provides an efficient and cost effective process to manufacture multi-layer electrodes with various thicknesses. Although two stations for coating are discussed herein, it should be understood that the system can include any number of stations to create two or more powder particle coating layers, depending on the specifications of the end user.

[0007] In accordance with embodiments of the present disclosure, an exemplary system for multi-layer battery electrode fabrication is provided. The system includes a first spreader coating system including a first powder particle chamber, a first spreading coating assembly, and a first calendering assembly. The first power particle chamber is configured to receive and dispense first powder particles onto a substrate to define a first coatingthickness of the first powder particles on the substrate. The first spreading coating assembly is configured to receive the substrate in-between to spread the first powder particles along the substrate into a first uniform coating having a first intermediate coating thickness. The first intermediate coating thickness is dimensioned smaller than the first coating thickness. The first calendering assembly is configured to receive the substrate inbetween to compress the first uniform coating into a first compressed powder coating (e.g., a first compressed powder coating layer) having a second coating thickness. The second coating thickness is dimensioned smaller than the first intermediate coating thickness.

[0008] The system includes a second spreader coating system including a second powder particle chamber, a second spreading assembly, and a second calendering assembly. The second power particle chamber is configured to receive and dispense second powder particles onto the first compressed powder coating to define a third coating thickness of the second powder particles on the first compressed powder coating. The second spreading assembly is configured to receive the substrate in-between to spread the second powder particles along the first compressed powder coating into a second uniform coating having a second intermediate coating thickness. The second intermediate coating thickness is dimensioned smaller than the third coating thickness. The second calendering assembly is configured to receive the substrate in-between to compress the second uniform coating into a second compressed powder coating (e.g., a second compressed powder coating layer) having a fourth coating thickness. The fourth coating thickness is dimensioned smaller than the second intermediate coating thickness. The first compressed powder coating and the second compressed powder coating define a multi-layer coating on the substrate.

[0009] In some embodiments, the first spreading coating assembly and the second spreading coating assembly each include at least a pair spreading rollers. In some embodiments, the first calendering assembly and the second calendering assembly each include at least a pair calendering rollers. In some embodiments, multiple pairs of spreading and / or calendering rollers can be used. The first spreader coating system is disposed proximally along the substrate relative to the second spreader coating system.

[0010] The first powder particle chamber is disposed proximally along the substrate relative to the first spreading coating assembly, and the first spreading coating assembly is disposed proximally along the substrate relative to the first calendering assembly. The second powder particle chamber is disposed proximally along the substrate relative to thesecond spreading coating assembly, and the second spreading coating assembly is disposed proximally along the substrate relative to the second calendering assembly.

[0011] In some embodiments, the first powder particles and the second powder particles include at least one of cathode materials or anode materials. In some embodiments, formulations of the first powder particles and the second powder particles are the same. In some embodiments, formulations of the first powder particles and the second powder particles are different. In some embodiments, a thickness of the first compressed powder coating and a thickness of the second compressed powder coating is equal. In some embodiments, a thickness of the first compressed powder coating and a thickness of the second compressed powder coating is different. In some embodiments, the density of the coating layer (including the unit or powder loading parameter (mg / cm2) and / or thickness) can be the same or different for the first and second compressed powder coating layers.

[0012] The substrate can define a length extending between a proximal end and a distal end, and can define a width transverse to the length. The first uniform coating and the second uniform coating define uniformity in the respective first and second intermediate coating thicknesses along the width and the length of the substrate. During passage of the substrate through the first and second calendering assemblies, pressure is applied to the respective first and second uniform coating to create the respective first and second compressed powder coatings.

[0013] The first powder particles on the substrate in the first compressed powder coating are bonded together to form the first compressed powder coating and the first compressed powder coating is adhered to the substrate. The second powder particles on the first compressed powder coating are bonded together to form the second compressed powder coating and the second compressed powder coating is adhered to the first compressed powder coating.

[0014] In some embodiments, the system can include a powder removal assembly disposed between the first calendering assembly and the second spreading coating assembly. The powder removal assembly can be configured to remove uncompressed powder particles in the first compressed powder coating. In some embodiments, the system can include a powder removal assembly disposed distally from the second calendering assembly. The powder removal assembly can be configured to remove uncompressedpowder particles in the second compressed powder coating. The first and second compressed powder coatings can define densified areas of the respective first and second powder particles.

[0015] In accordance with embodiments of the present disclosure, an exemplary method of multi-layer battery electrode fabrication is provided. The method includes dispensing first powder particles onto a substrate with a first powder particle chamber of a first spreader coating system to define a first coating thickness of the first powder particles on the substrate. The method includes passing the substrate through a first spreading coating assembly of the first spreader coating system to spread the first powder particles along the substrate into a first uniform coating having a first intermediate coating thickness. The first intermediate coating thickness is dimensioned smaller than the first coating thickness. The method includes passing the substrate through a first calendering assembly of the first spreader coating system to compress the first uniform coating into a first compressed powder coating having a second coating thickness. The second coating thickness is dimensioned smaller than the first intermediate coating thickness.

[0016] The method includes dispensing second powder particles onto the first compressed powder coating with a second powder particle chamber of a second spreader coating system to define a third coating thickness of the second powder particles on the first compressed powder coating. The method includes passing the substrate through a second spreading assembly of the second spreader coating system to spread the second powder particles along the first compressed powder coating into a second uniform coating having a second intermediate coating thickness. The second intermediate coating thickness is dimensioned smaller than the third coating thickness. The method includes passing the substrate through a second spreading coating assembly of the second spreader coating system to compress the second uniform coating into a second compressed powder coating having a fourth coating thickness. The fourth coating thickness is dimensioned smaller than the second intermediate coating thickness. The first compressed powder coating and the second compressed powder coating define a multi-layer coating on the substrate.

[0017] In some embodiments, formulations of the first powder particles and the second powder particles can be different. The first powder particles on the substrate in the first compressed powder coating can be bonded together to form the first compressed powder coating and the first compressed powder coating can be adhered to the substrate. The second powder particles on the first compressed powder coating can be bonded together toform the second compressed powder coating and the second compressed powder coating can be adhered to the first compressed powder coating. The method can include passing the substrate through or under a powder removal assembly to remove uncompressed first or second powder particles in the respective first or second compressed powder coatings.

[0018] Any combination and / or permutation of embodiments is envisioned. Other objects and features will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the present disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To assist those of skill in the art in making and using the system for multi-layer battery electrode fabrication, reference is made to the accompanying figures, wherein:

[0020] FIG. l is a diagrammatic view of a conventional spreader roller coating system.

[0021] FIG. 2 is a diagrammatic view of an exemplary system for multi-layer battery electrode fabrication in accordance with embodiments of the present disclosure.DETAILED DESCRIPTION

[0022] FIG. 2 is a diagrammatic view of an exemplary system 100 for multi-layer battery electrode fabrication (hereinafter “system 100”). The system 100 can be used to manufacture a multi-layer coated substrate usable in, e.g., Li-ion batteries, solid state batteries, or the like. The system 100 uses spreader roller coating electrode manufacturing technology in two or more stations to duplicate a powder particle coating after the previous coating has been densified / compressed. The system 100 can be incorporated into a containment enclosure (e.g., a containment chamber) for deposition of the powder coating onto a substrate or web 102, e.g., a continuously moving substrate or web 102. In some embodiments, the web 102 can be a metal foil.

[0023] The web 102 includes a top surface 104 on which the powder coating is applied. The powder coating includes at least a cathode material or an anode material, e.g., for rechargeable lithium batteries, or the like. A binder material can be with the powder particles 1 18 as part of the dry powder coating applied to the web 102. In some embodiments, the bottom surface of the web 102 can also receive the powder coating either concurrently with the top surface or subsequent to the top surface being coated. Rollers106, 108 can be positioned on opposite proximal and distal ends 110, 112 of the web 102 and suspend the web 102 as it passes through the containment enclosure. The rollers 106, 108 can rotate in a combined manner to maintain the continuous movement of the web 102 through the containment enclosure in a web direction 114.

[0024] The system 100 includes a first chamber 116 configured to receive and dispense the powder particles 118 onto the top surface 104 of the web 102 (e.g., an assembly of a powder storage chamber and a dispensing / dispersing mechanism, or the like). The chamber 116 can be used to dispense the powder particles 118 onto the web 102 in, e.g., a centrally positioned mound form, or the like, for subsequent spreading by a first pair of spreading rollers 120, 122. In particular, the system 100 includes a first pair of spreading rollers 120, 122 positioned downstream or distally from the chamber 116. One spreading roller 120 is positioned adjacent to the top surface 104 of the web 102, and the other spreading roller 122 is positioned adjacent to the opposing bottom surface of the web 102, thereby sandwiching the web 102 between the rollers 120, 122. In some embodiments, rather than a single pair of spreading rollers 120, 122, the system 100 can include two or more pairs of spreading rollers arranged in series for improved powder particle 118 spreading. For example, each set of spreading rollers can incrementally spread the powder particles 118 on the web 102 to ensure gradual and even distribution of the powder particles 118. Such assembly of spreading rollers can be referred to as a spreading coating assembly.

[0025] As illustrated in FIG. 2, the initial coating of the powder particles 118 creates an uncompressed coating layer 124 of a first thickness as measured from the top surface 104 of the web 102 to the top of the coating layer 124. In some embodiments, the initial coating layer 124 can be centrally positioned under the chamber 116 without covering the entire surface 104 of the web 102, e.g., a mound of powder, or the like. The web 102 moves continuously towards and between the spreading rollers 120, 122. As the web 102 passes between the spreading rollers 120, 122, the powder coating layer 124 is distributed along the top surface 104 of the web 102 to generate a uniform or substantially uniform coating layer 126. This uniform coating layer 126 defines a second thickness which is dimensioned smaller than the first thickness of the coating layer 124. The spreading rollers 120, 122 ensure that the powder coating is redistributed or spread over the web 102 to achieve the uniform coating along the entire top surface 104 of the web 102.

[0026] Thus, after passage of the web 102 through the spreading rollers 120, 122, the thickness of the powder coating layer 126 is uniform when viewed transversely across theweb 102 (e.g., uniform along both the width and length of the web 102). At this stage of the process, the powder coating can cover the entire top surface 104 of the web 102 with no uncoated areas formed. The powder coating also defines a substantially uniform thickness with a minimum thickness variation along the width and length of the web 102.

[0027] The web 102 is continuously moved to pass between a first pair of calender rollers 128, 130 disposed downstream or distally from the spreading rollers 120, 122. One calender roller 128 is positioned adjacent to the top surface 104 of the web 102, and the other calender roller 130 is positioned adjacent to the opposing bottom surface of the web 102, thereby sandwiching the web 102 between the rollers 128, 130. The calender rollers 128, 130 are configured to compress and densify the powder coating layer 126 to achieve a compressed powder coating layer 132 having a predetermined third thickness. The thickness of the compressed powder coating layer 132 is dimensioned smaller than the thickness of the powder coating layer 126. The densification step of the calender rollers 128, 130 can be performed with or without heat. In some embodiments, rather than a single pair of calender rollers 128, 130, the system 100 can include two or more pairs of calender rollers arranged in series for improved compression and densification of the powder coating layer 126. For example, each set of calender rollers can incrementally compress and densify the powder particles 118 to ensure gradual and even compression / densification of the powder coating layer 126. Such assembly of calender rollers can be referred to as a calendering assembly.

[0028] Prior to densification, the powder coating layer 126 sits on the web 102 without adhering to the web 102. After densification with the calender rollers 128, 130, the dry powder coating is adhered to the web 102 and powder particles 118 in the coating layer 132 are bonded together via a binder material in the coating layer 132 and / or mechanical force between the coating layer 132 and the web 102 due to the compressive forces applied to the powder coating. The combination of the chamber 116, the spreading rollers 120, 122, and the calender rollers 128, 130 can define a first spreading system or section of the system 100, and are used to form the first layer (i.e., the powder coating layer 132) of the multilayer electrode.

[0029] Downstream or distally from the calender rollers 128, 130, the system 100 includes a second spreading system or section having a second chamber 134, a second pair of spreading rollers 136, 138, and a second pair of calender rollers 140, 142. Although each of the spreading assemblies is illustrated as including single pairs of spreading andcalender rollers, in some embodiments, (as noted above) multiple pairs of spreading and / or calender rollers can be used. The second spreading system functions substantially similarly to the first spreading system. The second chamber 134 dispenses an initial coating layer 144 of powder particles 146. However, rather than dispensing the powder particles 146 on the top surface 104 of the web 102, the powder particles 146 are dispensed on the top surface of the coating layer 132. The powder particles 146 can be the same or different from the powder particles 118. In some embodiments, a different formulation or percentage of powder particles 1 18, 146 can be used for each layer. The thickness of the initial coating layer 144 can be the same or equal to the thickness of the coating layer 124. In some embodiments, the powder particles 146 can be centrally positioned under the chamber 134 without covering the entire surface of the coating layer 132, e.g., a mound of powder, or the like.

[0030] The web 102 moves continuously towards and between the spreading rollers 136, 138. As the web 102 passes between the spreading rollers 136, 138, the powder coating layer 144 is distributed along the top surface of the coating layer 132 to generate a uniform or substantially uniform coating layer 148. This uniform coating layer 148 defines a thickness which is dimensioned smaller than the thickness of the coating layer 144. The spreading rollers 136, 138 ensure that the powder coating is redistributed or spread over the coating layer 132 to achieve the uniform coating along the entire top surface of the coating layer 132.

[0031] Thus, after passage of the web 102 through the spreading rollers 136, 138, the thickness of the powder coating layer 148 is uniform when viewed transversely across the web 102 (e.g., uniform along both the width and length of the web 102 and the coating layer 132). At this stage of the process, the powder coating can cover the entire top surface 104 of the coating layer 132 with no uncoated areas formed. The powder coating also defines a substantially uniform thickness with a minimum thickness variation along the width and length of the web 102 and the coating layer 132.

[0032] The web 102 is continuously moved to pass between the second pair of calender rollers 140, 142 disposed downstream or distally from the spreading rollers 136, 138. One calender roller 140 is positioned adjacent to the top surface 104 of the coating surface 132, and the other calender roller 142 is positioned adjacent to the opposing bottom surface of the web 102, thereby sandwiching the web 102 between the rollers 140, 142. The calender rollers 140, 142 are configured to compress and densify the powder coatinglayer 148 to achieve a compressed powder coating layer 150 having a predetermined compressed thickness. The thickness of the compressed powder coating layer 150 is dimensioned smaller than the thickness of the powder coating layer 148. The densification step of the calender rollers 140, 142 can be performed with or without heat.

[0033] Prior to densification, the powder coating layer 148 sits on the coating layer 132 without adhering to the coating layer 132. After densification with the calender rollers 140, 142, the dry powder coating is adhered to the coating layer 132 (and indirectly to the web 102) and powder particles 148 in the coating layer 132 are bonded together via a binder material in the coating layer 150 and / or mechanical force between the coating layer 150 and the coating layer 132 due to the compressive forces applied to the powder coating.

[0034] The second spreading assembly thereby forms a second layer (i.e., the powder coating layer 150) on the first layer (i.e., the powder coating layer 132) of the multi-layer electrode. It should be understood that the type of powder particles used for the different layers, as well as the compressed thickness of the different layers, can be varied depending on the specifications of the end user. Additional spreading assemblies with a powder particle chamber, spreading rollers, and calender rollers can be incorporated into the system 100 downstream of the second spreading assembly to progressively add more powder coating layers to the electrode, if more than two layers are desired. A multi-layer electrode can thereby be fabricated through an efficient and cost effective process.

[0035] In some embodiments, a powder removal assembly 152, e.g., a vacuum, or the like, can be positioned at the distal end 112 of the system 100 to remove any uncompressed power particles. In some embodiments, a powder removal assembly 152 can be positioned after each set of calender rollers (e.g., after the calender rollers 128, 130, and after the calender rollers 140, 142) to remove any uncompressed powder particles before the subsequent layer of powder particles is deposited onto the previous coating layer.

[0036] In some embodiments, the compressive force range provided by the calender rollers of the system 100 can be about, e.g., 10-2000 N / mm or higher, inclusive, 10-1900 N / mm inclusive, 10-1800 N / mm inclusive, 10-1700 N / mm inclusive, 10-1600 N / mm inclusive, 10-1500 N / mm inclusive, 10-1400 N / mm inclusive, 10-1300 N / mm inclusive, 10-1200 N / mm inclusive, 10-1100 N / mm inclusive, 10-1000 N / mm inclusive, 10-900 N / mm inclusive, 10-800 N / mm inclusive, 10-700 N / mm inclusive, 10-600 N / mm inclusive, 10-500 N / mm inclusive, 10-400 N / mm inclusive, 10-300 N / mm inclusive, 10-200 N / mminclusive, 10-100 N / mm inclusive, 10-50 N / mm inclusive, 10-20 N / mm inclusive, 20-2000N / mm inclusive, 30-2000 N / mm inclusive, 40-2000 N / mm inclusive, 50-2000 N / mm inclusive, 100-2000 N / mm inclusive, 200-2000 N / mm inclusive, 300-2000 N / mm inclusive, 400-2000 N / mm inclusive, 500-2000 N / mm inclusive, 600-2000 N / mm inclusive, 700-2000 N / mm inclusive, 800-2000 N / mm inclusive, 900-2000 N / mm inclusive, 1000-2000 N / mm inclusive, 1100-2000 N / mm inclusive, 1200-2000 N / mm inclusive, 1300-2000 N / mm inclusive, 1400-2000 N / mm inclusive, 1500-2000 N / mm inclusive, 1600-2000 N / mm inclusive, 1700-2000 N / mm inclusive, 1800-2000 N / mm inclusive, 1900-2000 N / mm inclusive, 20-1500 N / mm inclusive, 20-1000 N / mm inclusive, 20-500 N / mm inclusive, 20-300 N / mm inclusive, 10 N / mm, 20 N / mm, 30 N / mm, 40 N / mm, 50 N / mm, 60 N / mm, 70 N / mm, 80 N / mm, 90 N / mm, 100 N / mm, 200 N / mm, 300 N / mm, 400 N / mm, 500 N / mm, 600 N / mm, 700 N / mm, 800 N / mm, 900 N / mm, 1000 N / mm, 1100 N / mm, 1200 N / mm, 1300 N / mm, 1400 N / mm, 1500 N / mm, 1600 N / mm, 1700 N / mm, 1800 N / mm, 1900 N / mm, 2000 N / mm or above, or the like. In some embodiments, the compressive force of each pair of calender rollers can be the same. In some embodiments, the compressive force of each pair of calender rollers can be different (e.g., depending on the desired thickness, the type of powder particles used, to accommodate for the previous coating layers, or the like).

[0037] 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.

Claims

CLAIMS:

1. A system for multi-layer battery electrode fabrication, the system comprising: a first spreader coating system including:(i) a first power particle chamber configured to receive and dispense first powder particles onto a substrate to define a first coating thickness of the first powder particles on the substrate;(ii) a first spreading coating assembly configured to receive the substrate in-between to spread the first powder particles along the substrate into a first uniform coating having a first intermediate coating thickness, wherein the first intermediate coating thickness is dimensioned smaller than the first coating thickness; and(iii) a first calendering assembly configured to receive the substrate inbetween to compress the first uniform coating into a first compressed powder coating having a second coating thickness, wherein the second coating thickness is dimensioned smaller than the first intermediate coating thickness; and a second spreader coating system including:(i) a second power particle chamber configured to receive and dispense second powder particles onto the first compressed powder coating to define a third coating thickness of the second powder particles on the first compressed powder coating;(ii) a second spreading assembly configured to receive the substrate inbetween to spread the second powder particles along the first compressed powder coating into a second uniform coating having a second intermediate coating thickness, wherein the second intermediate coating thickness is dimensioned smaller than the third coating thickness; and(iii) a second calendering assembly configured to receive the substrate inbetween to compress the second uniform coating into a second compressed powder coating having a fourth coating thickness, wherein the fourth coating thickness is dimensioned smaller than the second intermediate coating thickness; wherein the first compressed powder coating and the second compressed powder coating define a multi-layer coating on the substrate.

2. The system of claim 1, wherein the first spreading coating assembly and the second spreading coating assembly each include at least a pair spreading rollers.

3. The system of claim 1, wherein the first calendering assembly and the second calendering assembly each include at least a pair calendering rollers.

4. The system of claim 1, wherein the first spreader coating system is disposed proximally along the substrate relative to the second spreader coating system.

5. The system of claim 1, wherein the first powder particle chamber is disposed proximally along the substrate relative to the first spreading coating assembly, and the first spreading coating assembly is disposed proximally along the substrate relative to the first calendering assembly.

6. The system of claim 1 , wherein the second powder particle chamber is disposed proximally along the substrate relative to the second spreading coating assembly, and the second spreading coating assembly is disposed proximally along the substrate relative to the second calendering assembly.

7. The system of claim 1, wherein a thickness and / or a density of the first compressed powder coating and a thickness and / or a density of the second compressed powder coating is equal.

8. The system of claim 1, wherein a thickness and / or a density of the first compressed powder coating and a thickness and / or a density of the second compressed powder coating is different.

9. The system of claim 1 , wherein the substrate defines a length extending between a proximal end and a distal end, and further defines a width transverse to the length, and wherein the first uniform coating and the second uniform coating define uniformity in the respective first and second intermediate coating thicknesses along the width and the length of the substrate.

10. The system of claim 1, wherein during passage of the substrate through the first and second calendering assemblies, pressure is applied to the respective first and second uniform coating to create the respective first and second compressed powder coatings.

11. The system of claim 1, wherein the first powder particles on the substrate in the first compressed powder coating are bonded together to form the first compressed powder coating and the first compressed powder coating is adhered to the substrate.

12. The system of claim 1, wherein the second powder particles on the first compressed powder coating are bonded together to form the second compressed powder coating and the second compressed powder coating is adhered to the first compressed powder coating.

13. The system of claim 1, comprising a powder removal assembly disposed between the first calendering assembly and the second spreading coating assembly, wherein the powder removal assembly is configured to remove uncompressed powder particles in the first compressed powder coating.

14. The system of claim 1, comprising a powder removal assembly disposed distally from the second calendering assembly, wherein the powder removal assembly is configured to remove uncompressed powder particles in the second compressed powder coating.

15. The system of claim 1, wherein the first and second compressed powder coatings define densified areas of the respective first and second powder particles.

16. A method of multi-layer battery electrode fabrication, the method comprising: dispensing first powder particles onto a substrate with a first powder particle chamber of a first spreader coating system to define a first coating thickness of the first powder particles on the substrate; passing the substrate through a first spreading coating assembly of the first spreader coating system to spread the first powder particles along the substrate into a first uniform coating having a first intermediate coating thickness, wherein the first intermediate coating thickness is dimensioned smaller than the first coating thickness; passing the substrate through a first calendering assembly of the first spreader coating system to compress the first uniform coating into a first compressed powder coating having a second coating thickness, wherein the second coating thickness is dimensioned smaller than the first intermediate coating thickness;dispensing second powder particles onto the first compressed powder coating with a second powder particle chamber of a second spreader coating system to define a third coating thickness of the second powder particles on the first compressed powder coating; passing the substrate through a second spreading assembly of the second spreader coating system to spread the second powder particles along the first compressed powder coating into a second uniform coating having a second intermediate coating thickness, wherein the second intermediate coating thickness is dimensioned smaller than the third coating thickness; and passing the substrate through a second spreading coating assembly of the second spreader coating system to compress the second uniform coating into a second compressed powder coating having a fourth coating thickness, wherein the fourth coating thickness is dimensioned smaller than the second intermediate coating thickness; wherein the first compressed powder coating and the second compressed powder coating define a multi-layer coating on the substrate.

17. The method of claim 16, wherein formulations of the first powder particles and the second powder particles are different.

18. The method of claim 16, wherein the first powder particles on the substrate in the first compressed powder coating are bonded together to form the first compressed powder coating and the first compressed powder coating is adhered to the substrate.

19. The method of claim 16, wherein the second powder particles on the first compressed powder coating are bonded together to form the second compressed powder coating and the second compressed powder coating is adhered to the first compressed powder coating.

20. The method of claim 16, comprising passing the substrate through or under a powder removal assembly to remove uncompressed first or second powder particles in the respective first or second compressed powder coatings.

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