Composite Oxygen Electrode Based on LSCM for Steam Electrolysis in a Proton Conducting Solid Oxide Electrolyzer

Abstract

This paper presents a ceramic composite oxygen electrode (La0.75Sr0.25)0.95Mn0.5Cr0.5O3-δ (LSCM) – BaCe0.5Zr0.3Y0.16Zn0.04O3-δ (BCZYZ) for steam electrolysis in a proton-conducting Solid Oxide Electrolyzer (SOE) with proton conducting electrolyte BCZYZ and fuel electrode BCZYZ/Ni at 700°C. AC impedance spectroscopy and I-V tests demonstrate two main processes from 0 to 2 V with 3%H2O/N2 vs 5% H2/Ar: reoxidation of the LSCM electrode below 1.2 V and oxidation of H2O above 1.2 V. The current density reaches 2 Acm−2 at 2 V with electrode polarization of 0.1 Ωcm2 and steam electrolysis shows short term stability with current efficiency of 22%.