Improving the chemical stability of BaCe0.8Sm0.2O3 − δ electrolyte by Cl doping for proton-conducting solid oxide fuel cell

BaCeO3 based ceramics have demonstrated high proton conductivity and have been extensively investigated as electrolytes for solid oxide fuel cells (SOFCs). However, these materials are not chemically stable and are prone to reaction with CO2 in air at the typical SOFC operating conditions. This work presents a novel strategy to improve the chemical stability of BaCeO3 based ceramics to CO2 in air while still maintaining high proton conductivity by introducing barium chloride precursor in the powder synthesis process. As an example, BaCe0.8Sm0.2O3 − δ with Cl doping has demonstrated significant enhancement in chemical stability in the presence of CO2 in air without compromising its high proton conductivity.

► Chemical stability of BCS against CO2 in air is enhanced by Cl doping.
► No significant effects on electrochemical performance are made by Cl addition.
► The doping of Cl can be easily achieved by using BaCl2 as the precursors.