Fabrication and electrochemical performance of nickel- and gadolinium-doped ceria-infiltrated La0·2Sr0·8TiO3 anodes for solid oxide fuel cells

Abstract In this work, nickel and gadolinium-doped ceria (GDC)-infiltrated lanthanum strontium titanate (LST) anodes are fabricated, and their electrode performances under a hydrogen atmosphere is investigated in terms of the Ni:GDC ratios and cell operating temperature. The Ni/GDC-infiltrated LST anode exhibits excellent electrode performance in comparison with the Ni- or GDC-infiltrated anodes, which is attributed to the synergistic effect of an extended triple-phase boundary length by GDC and good catalytic activity for hydrogen oxidation because of the Ni particles. The polarization resistances (R p ) of Ni/GDC-infiltrated LST are 0.07, 0.08, and 0.12 Ω cm 2 at 800, 750, and 700 °C, respectively, which are approximately three orders of magnitude lower than that of the LST anode (68.5 Ω cm 2 at 700 °C). The effect of Ni and GDC on the electrochemical performance of LST was also investigated by using electrochemical impedance spectroscopy (EIS). The anode polarization resistance (R p ) is confirmed to be dependent on the content and dispersion state (microstructure) of the Ni and GDC nanoparticles.