Fabrication and performance of solid-state Li-ion battery constituents fabricated by plasma spraying using different feedstock

Solid-state thin-film batteries (SSTBs) have the potential to revolutionize energy storage technology by offering significant improvements over traditional Li-ion batteries. Despite their promise, SSTBs face considerable processing challenges, and fabricating high-performance battery cells is still far from realization. In this context, thermal spraying presents a promising alternative to vacuum-based thin film coating processes for fabricating battery constituents. However, problems associated with exposure of Li-based feedstock to high plasma temperature leading to Li loss and formation of secondary phases are of prime concern. In this work, an attempt has been made to fabricate anode, cathode and solid electrolyte (SE) coatings on Al substrates by plasma spraying using different types of feedstocks, namely powders, suspensions and solution precursors. Additionally, efforts were also made to develop a half-cell (Al|anode|SE) and full-cell (Al|anode|SE|cathode) battery coating by stacking the anode, SE and cathode. The developed coatings were comprehensively characterized to analyze microstructure, phases, and elemental composition. The electrochemical performance of the coating was evaluated using a galvanostatic charge/discharge (GCD) test, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). This work offers insights into the microstructure, stoichiometry and electrochemical performance of battery coatings by plasma processing of different feedstock and lays the foundation for future development.