Cerium oxide-based electrolytes for low- and intermediate-temperature solid oxide fuel cells: state of the art, challenges and future prospects

Abstract

Solid oxide fuel cells (SOFCs) are important, efficient, and environmentally friendly energy conversion devices that also serve as solid oxide electrolysers, producing hydrogen and oxygen by reversing chemical reactions. Research and development of electrode and electrolyte materials is still very much needed for their efficient working in low (≤650 °C) and intermediate (650–850 °C) temperature regimes. The present article reviews undoped and doped ceria-based electrolytes in light of processing parameters such as synthesis methods, sintering time, temperature and different doping strategies. The article focuses primarily on the various factors that affect the conductivity of ceria-based electrolytes. Different approaches to enhance the conductivity and improve the cell parameters have also been discussed. Conclusion, challenges and direction for further research are also provided at the end of this article.