Induction Plasma Synthesis of Nano-Structured SOFCs Electrolyte Using Solution and Suspension Plasma Spraying: A Comparative Study

Abstract

In this paper, two plasma spraying technologies: solution plasma spraying (SolPS) and suspension plasma spraying (SPS) were used to produce nano-structured solid oxide fuel cells (SOFCs) electrolytes. Both plasma spraying processes were optimized in order to achieve the thin gas-tight electrolytes. The comparison of the two plasma spraying processes is based on electrolyte phase, microstructure, morphology, as well as on plasma deposition rate. The results show that nano-structured thin electrolytes (~5 μm thick) have been successfully SPS deposited on porous anodes with a high deposition rate. Compared to the electrolytes produced by SolPS, the SPS-deposited electrolyte layer is much denser. During the SPS process, fine droplets of 0.5-1 μm in diameter impact on the surface of the coating and penetrate into the pores of the anode. As the stresses are reduced on the resulting 0.5-2 μm splats, there is no apparent microcracks network on the splats, this resulting in highly gas-tight coatings. It is demonstrated that the SPS process is beneficial for the improvement of the performance of the films to be used as SOFC electrolytes.