A-site deficient (La0.6Sr0.4)(1-x)Co0.2Fe0.6Nb0.2O3-delta (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 La0.6Sr0.4Co0.2Fe0.8O3-delta (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 x 10(-6) K-1 at 30-900 degrees 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 oxygenevacancy 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 CH4, and shows favorable electrochemical stability running on CH4 fuel. (c) 2018 Elsevier Ltd. All rights reserved.