High-Performance Protonic Ceramic Electrochemical Cells for Hydrogen Production and Electricity Generation at Intermediate Temperatures

Abstract

Achieving energy conversion between electricity power and hydrogen in protonic ceramic electrochemical cells (PCECs) is an emerging and attractive approach to store intermittent renewable energies which can be converted back to electricity in reversible operation. Economically competitive PCEC systems have distinct advantages over conventional oxygen-ion conducting counterpart (O-SOC), but further materials innovation is still needed to improve cell performance at reduced operating temperature (400~600○C), enhance system lifetime and reduce cost. To achieve efficient electrochemical hydrogen and power production with stable operation, highly robust and durable oxygen electrode is urgently desired to facilitate water oxidation and oxygen reduction reactions, which are the critical technical barriers for both electrolysis and fuel cell operation at reduced temperatures. The recent efforts in this study have been focused on developing new triple conducting electrode with perovskite or layered perovskite structure for high-performance and stable PCECs. The systematic material characterizations are carried out to evaluate the feasibility of activity, stability and interface compatibility, such as Fourier-transform infrared spectroscopy, high-temperature X-ray diffraction, hydrogen permeation and first-principal computation. The catalytic activity towards water splitting reaction is demonstrated in various electrochemical performance evaluation at 400~600○C. The long-term durability of the PCEC is examined to show the high resistance against transient current density change in reversible operation and high steam concentration.