Enhanced Performance of Ag-Doped Oxygen Electrode Based Solid Oxide Electrolyser Cell under High Temperature Electrolysis of Steam

Abstract

Solid oxide electrolyser (SOE) has been receiving increasing attention due to its potential applications in large-scale hydrogen production and carbon dioxide recycling for fuels. Improving the performance of SOE cell through oxygen electrode development has been of main interest because the major polarization loss of the SOE cell is at the oxygen electrode during high temperature electrolysis (HTE). In the present study, Ag was doped into (La0.75Sr0.25)0.95MnO3+δ(LSM) based oxygen electrode of Ni/YSZ cathode-supported SOE cell through a solid state method enhanced by ball milling. Short stacks were manufactured using doped and undoped cells and tested under HTE of steam at 800°C up to 150h for in situ comparative study of doping effect. The cells with doped oxygen electrodes showed less polarization loss, lower resistance and improved performance by comparison with the undoped cell. Post-mortem examination revealed Ag migrated from the current collecting layer to the electrolyte/anode interface, which may promote the cell performance.