Electrode coating is the process in battery manufacturing where the mixed slurry of active material, binder, solvent, and conductive additives is applied onto the thin current collector foil (typically copper for anodes, aluminum for cathodes). This is usually done using techniques like slot-die coating, doctor blade coating, or other roll-to-roll processes. The goal is to deposit a uniform layer of the slurry at a specific loading (mass per area) on the foil. As part of the coating process, the electrodes are dried to evaporate the solvent, leaving behind a solid layer of active material bonded to the foil. Uniformity in electrode coating is crucial; inconsistencies can lead to variations in cell performance or potential long-term cell safety concerns. Coating quality parameters include loading uniformity, absence of defects like pinholes, cracking or agglomerates, and adhesion to the foil.
NOVONIX has slot die coaters in its pilot production line. By experimenting with different coating parameters—such as solids content of the slurry, coating speed, die gap, or drying temperature—NOVONIX can optimize the quality of electrodes made from novel materials. NOVONIX employs quality checks weighing for loading, adhesion testing and visual inspection for defets. If a new material poses challenges (e.g., a slurry tends to settle or has poor viscosity), NOVONIX will adjust the mixing procedure or slurry formulation to improve coating. By perfecting electrode coating techniques, NOVONIX ensures that when a battery material moves from lab to fabrication, it can be processed effectively and result in high-performance electrodes.
