Challenges and prospects of anodes for solid oxide fuel cells (SOFCs)

A solid oxide fuel cell (SOFC) is an energy conversion device, which directly converts chemical fuels (e.g., H-2, CO, and CxHy) into electricity and heat with high efficiency up to about 90 %. The main by-product CO2 when hydrocarbons used as fuels can be sequestrated or subsequently chemically transformed into chemical fuels (e.g., CO) by electrolysis using renewable energy sources, such as solar and wind. The state-of-the-art nickel and yttria-stabilized zirconia (YSZ) composite (Ni-YSZ) anode is deactivated in the presence of ppm level of H2S and forming coke in hydrocarbons at the operating temperature of SOFCs. Currently, mixed ion and electron conducting (MIEC) metal oxides are being considered as alternatives for Ni-YSZ anode in SOFCs. In this review, we report the recent development of MIEC metal oxides anodes for advanced SOFCs.