Tuning High-Performance YSZ-Based Intermediate Temperature Solid Oxide Fuel Cells: Engineering SOFC Cathode Structures

Solid Oxide Fuel Cells (SOFCs) are solid-state electrochemical devices that operate at high temperature (above 700C) and are capable of efficiently converting the chemical energy stored in the bonds of fuel molecules (i.e., H₂, CO, hydrocarbons) to electrical energy. SOFCs are composed of a cathode compartment that reduces gas-phase O₂ to oxygen ions. The oxygen ions diffuse through a ceramic oxygen ion conducting electrolyte to the anode, where the fuel is oxidized. One of the limiting factors with SOFCs is the operation at very high temperatures (~800C) to achieve reasonable electrochemical rates. Many efforts have been reported in lowering the operating temperature of these systems. In this work, we demonstrate that significant performance improvements at intermediate temperatures can be achieved by improving the cathode-electrode kinetics. We show that incorporation of nanostructured layered mixed metal oxides in porous scaffolds of ion-conducting oxides (i.e. YSZ) at the cathode can lead to significant power density improvements at temperatures of 550-600C.