A vanadium-doped La0.5Sr0.5FeO3-δ perovskite as a promising anode of direct carbon solid oxide fuel cells for brown coal utilization

Direct carbon solid oxide fuel cell (DC-SOFC) is a potential and prospective technology to convert chemical energy from real-world coal fuels into electricity with environment friendliness and high efficiency. However, the limited three-phase reaction boundaries and the challenge of sluggish carbon oxidation activity have always hindered the development and application of DC-SOFCs. On this account, here vanadium-doped B-site-deficient La _0.5Sr _0.5FeO _3-δ (LSFV _x , x = 0, 0.05, 0.10, 0.15) perovskite materials are synthesized and developed as the anode of DC-SOFCs for brown coal utilization. The best electrochemical performance at 850 ℃ belongs to the LSFV _0.1 cell, delivering a maximum power density of 249 mW cm ⁻², and the lowest polarization resistance of 0.37 Ω cm ² ,along with the longest discharging time up to 8.65 h. Compared with the pure LSF, the electrochemical performances of all perovskites doped with vanadium have been greatly promoted, demonstrating that the doping of vanadium can effectively expand the three-phase reaction boundaries of the cell, thus enhance the catalytic activity due to the promotion of oxygen deficiencies and tailing of electronic structures.