(Invited) Advanced Electrode and Electrolyte Materials for Proton Conducting Solid Oxide Electrolysis Cells

Abstract

Hydrogen production by using proton-conducting solid oxide electrolysis cells (SOECs) has been acknowledged as a promising approach to effectively utilize the clean renewable energies and nuclear heat and to decarbonize. To deliver fast and durable hydrogen production during intermediate-to-low temperature (400~600○C) operation, some critical components such as oxygen electrode and electrolyte are important for achieving high electrolysis performance under realistic conditions, particularly in high steam pressure. In this presentation, the recent developments on praseodymium cobaltite-based PrNixCo1-xO3-δ electrode and Sc-doped BaZrO3-based electrolyte are respectively introduced. The triple conductive electrode demonstrates high activity and stability towards water splitting reaction, and to down-select the optimal composition, a series of optimization study have been carried out to understand structure-property relationship, chemical/performance stability in high steam condition, and interfacial stability. For electrolyte, the hydration behavior, proton conductivity, transference number, and chemical stability are studied to disclose the effect of dopant on increasing effective proton concentration, and the underlying mechanism is also investigated by experimental characterizations.