Solid Oxide Fuel Cells

Solid Oxide Fuel Cells (SOFCs) are nowadays one of the most promising devices for stationary clean energy production, due to their minimal Green House Gas (GHG) emissions, fuel flexibility (from hydrogen to hydrocarbons and biogas), high efficiency, and power density. They are essentially multilayer structures were a solid dense electrolyte is sandwiched between two porous electrodes. The mechanical resistance of the cell is given by the supporting element, most commonly the thick anode and the electrolyte is an yttria doped zirconia ionic conductor. The single cells are then connected through metallic plates that act as current collectors. Even if this technology is in the verge of commercialization, more work is needed to improve the lifespan and reliability of the single device. In this respect a major role is played by materials. Most of the work is at the moment devoted to reducing the temperature of operation (most commonly 800°C) using most performant materials (such as protonic conductors, ceria-based anionic conductors, etc.), reduce the amount of critical elements and improve the resistance of interconnectors and sealant. The article thoroughly revised the materials considered for the development of the single cell (electrolyte, cathode, and anode) and the cells stack (interconnector, sealant) in light of the more promising actual studied.