Materials and nano-structural processes for use in solid oxide fuel cells: a review

Abstract

Solid oxide fuel cells (SOFCs) are considered to be the focus of investigation for energy systems owing to their efficiency in converting chemical energy into electrical energy, low carbon footprint, and fuel flexibility. Despite their high performance and durability, SOFCs suffer from critical problems such as carbon coking, agglomeration, and poor redox stability. This review presents research on the development of nanostructures for use in commercial SOFC systems and highlights various aspects of research and applications across the globe. The materials utilized for anodes, electrolytes, and cathodes are discussed and compared, detailing how their respective properties can attain high catalytic activity, conductivity, and stability at low temperatures with the aim of direct application using diverse fuels such as hydrogen, hydrocarbons, and carbon fuels. This review also discusses and compares the various processes used for the synthesis of the electrodes and electrolytes used in SOFCs, such as physical vapor deposition (PVD), chemical vapor deposition (CVD), infiltration, and in situ exsolution, that have gained much attention with a view to increase the active areas, decrease the Ohmic resistance, and reduce the manufacturing price.