Enhancing stability of double perovskite electrode by vanadium doping for symmetrical solid oxide cell

Using solid oxide cells to produce and utilize hydrogen is an effective method for addressing energy demands. In this study, vanadium (V) was doped into the B site of the La 0.3 Sr 1.7 Fe 1.3 Ni 0.2 Mo 0.5 O 6-δ double perovskite, which served as the electrode material for symmetrical solid oxide cells. Doping with high-valence V 4+ /V 5+ reduced both the average Fe valence state and the concentration of oxygen vacancies, while simultaneously decreasing the reducing activity of the material and enhancing its stability. After operating at 750 °C and ± 400 mA cm −2 for 150 h, the degradation rates for Cell-LSFNM were 4.56 % and 8.32 %, respectively, while those for Cell-LSFVNM were only 0 % and 3.32 %, respectively. Although V doping slightly diminished the electrochemical performance of the single cell, it significantly improved long-term operational stability in solid oxide fuel/electrolysis cell (SOFC/SOEC) modes.