ABSTRACT
At present, the entire world is experiencing serious issues concerning the shortage of fuel. The present energy sources are becoming rapidly exhausted and it will soon be a major problem to acquire power from conventional sources. Consequently, finding alternative sources of energy has become a priority. A fuel cell is one such alternative for the world in this regard. Solid oxide fuel cells (SOFCs) offer a clean, pollution-free technology to electro-chemically generate electricity at high efficiencies. A fuel cell’s efficiency crucially depends on the cathode performance. A potential cathode material must exhibit high electronic as well as oxygen-ion conductivity to increase the oxygen reduction reaction zone for enhancing the efficiency of SOFCs. In addition, the material should exhibit good catalytic activity and compatible mechanical properties. Consequently, mixed ionic and electronic conductors (MIECs) have attracted a great deal of attention. Many mixed oxides of the form A2BO4 (A = rare earth, alkaline earth; B = transition metal) that crystallize with the tetragonal K2NiF4-type structure (space group I4/mmm) have received renewed interest due to adequate oxygen conduction, strong required electro-catalytic activity, and thermal expansion coefficient (TEC) comparable with those of existing solid electrolytes.
