LAUSR

Abstract A-site deficient (La 0.6 Sr 0.4 ) 1– x Co 0.2 Fe 0.6 Nb 0.2 O 3– δ ( x  = 0, 0.05 and 0.10) symmetrical electrodes (hereafter denoted as LSCFN, LSCFN5, and LSCFN10, respectively) are obtained by doping Nb at the B site of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3– δ (LSCF) cathode. All three electrodes display excellent structural stability both in cathode and anode conditions. The thermal expansion coefficients of the electrodes range within 13.4–14.3 × 10 −6  K −1  at 30–900 °C in air and 5% H 2 /Ar, and these values are close to those of common electrolytes. Furthermore, 20-h electrochemical impedance stability test results indicate that LSCFN10 as anode or cathode possesses excellent electrochemical stability. The introduction of A-site deficiency into LSCFN results in obviously increased oxygen–vacancy concentration and improved electrochemical performance. A single cell with LSCFN10 symmetrical electrode operates well in various fuels, such as H 2 , sulfur-containing syngas, ethanol, and CH 4 , and shows favorable electrochemical stability running on CH 4 fuel.