10 - Plasma-sprayed ceramic coatings for solid oxide fuel cells

Abstract

Solid oxide fuel cell (SOFC) is emerging as a promising key technology for future clean energy systems because of its higher efficiency, all-ceramics components, cogeneration, and so forth. Among the different types of SOFCs, the planar, tubular, and metal-supported SOFCs are propitious designs. Tape-casting, screen-printing, and plasma spraying are the important techniques employed for the fabrication of SOFCs. The plasma spraying technique has been widely employed to develop dense electrolyte, porous anode and cathode, and protective coatings for the metal end plates and interconnectors/bipolar plates of SOFCs. It is a very versatile technique and is widely employed for the fabrication of metal-supported SOFCs. It is a fast and economical process and enables direct deposition of the coatings with tailored porosities and without any post-sintering steps and thus avoids many problems caused due to high-temperature sintering. Plasma spraying has been widely used for the deposition of coatings such as MnCo2O4, MnCo1.8Fe0.2O4, Mn2CuO4, (La0.8Sr0.2)0.98MnO3, (Ca,Co)-doped LaCrO3, (La0.8Sr0.2)0.98MnO3, Mn2CuO4, La0.6Sr0.4Co0.2Fe0.8O3−δ, NiO-YSZ, and so forth. This chapter introduces SOFCs, the plasma spray technique, and various plasma-sprayed ceramic coatings for SOFCs. The main emphasis of this chapter is on the recent trends in the use of different variants of plasma spray techniques like air, vacuum, suspension, solution precursor, and low-pressure plasma spray for the deposition of ceramic coatings for SOFCs.