Chapter 4 - Proton-conducting electrolyte materials

Abstract

Proton-conduction in some oxides is first discovered by Iwahara et al. in 1981, which opens a new chapter for the development of solid oxide fuel cells (SOFCs). Different from the working principle of traditional SOFCs using oxygen-ion conducting electrolytes in which oxygen ions migrate from the cathode side to the anode side, protons passed through the electrolyte membrane from the anode side to the cathode side in proton-conducting SOFCs. In this case, H2O is formed at the cathode side which avoids the fuel dilution that happens for oxygen-ion conducting SOFCs. Although the development history of proton-conducting SOFCs is much shorter than that for oxygen-ion conducting SOFCs, it has been flourishing in recent years as it fits the current trend of lowering the working temperatures for SOFCs. This chapter will introduce the development of proton-conducting electrolyte materials and their applications in SOFCs.