An innovative fabrication of Li-ion battery cathodes using suspension plasma spray

The research aimed to fabricate LiNi 0.33 Co 0.33 Mn 0.33 O 2 (NMC111) cathode layers for Li-ion batteries and highlight the potential of the Suspension Plasma Spray (SPS) process to fabricate battery cathodes. To create a stable feedstock, the NMC111 powder was reduced to sub-micron size using ball milling and formulated into suspensions with 1 wt% concentrations of sodium hexametaphosphate (SHMP) as a stabilizing agent and water as a solvent. SPS was performed on aluminium substrates at varying stand-off distances (SoDs) and gas flow parameters for uniformity in microstructure, controlling the thickness, and achieving diverse porosity in the coating layers. Analysis of the coatings via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) revealed the effect of SoD on coating thickness, surface roughness, and crystallinity. Further, inductively coupled plasma optical emission spectroscopy (ICP-OES) showed higher lithium retention at greater SoDs, indicating SPS's potential to enhance lithium content in NMC111 coatings with parameter finetuning. Additionally, the half-coin cell configuration tests were performed and minimal decay in capacity was measured for 10 cycles of charging-discharging for coatings deposited at 130 mm SoD, highlighting potential of SPS process to manufacture battery cathodes. • Stable NMC111 suspension achieved via finetuning of dispersant/solvent composition. • Tailored microstructure with well-formed primary and secondary NMC particles • SPS parameter tuning improved lithium retention in NMC111-based coatings. • SPS-coated coin cells exhibited minimal capacity loss over 10 charge-discharge cycles.