Solid State Ionics, Vol.288, 32-35, 2016
SrCo1-xMoxO3 (-) (delta) perovskites as cathode materials for LaGaO3-based intermediate-temperature solid oxide fuel cells
SrCoO3 - delta is an important parent compound of functional materials. The structural instability limited its applications as intermediate-temperature solid oxide fuel cell (IT-SOFC) cathode materials. Here we reported the performances of SrCo1 - xMoxO3 (- delta) (SCM, x = 0.05-0.2) oxides with a tetragonal structure as potential cathode materials for IT-SOFCs based on La0.9Sr0.1Ga0.8Mg0.2O3 - delta (LSGM) electrolyte. The x = 0.05 sample was well crystallized in a single-phase tetragonal structure at room temperature, while impurity phase was observed in the x >= 0.1 samples. The SCM exhibited a good chemical compatibility with the LSGM electrolyte at 950 degrees C for 10 h. The Mo doping for Co significantly improved the structural stability and electrical conductivity of the SCM materials. The area specific resistances of the x = 0.05 and 0.1 cathodes on the LSGM electrolyte were 0.069 and 0.079 Omega cm(2) at 700 degrees C, respectively. The maximum power densities of the single-cells on a 300 mu m-thick LSGM electrolyte reached 795 and 687 mW cm(-2) at 800 degrees C for the x = 0.05 and 0.1 cathodes, respectively. The x = 0.05 composition is a promising candidate cathode for IT-SOFC application due to its good chemical compatibility, high conductivity and electrochemical performance. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Solid oxide fuel cell;Perovskite cathode;Doped strontium cobaltite;Phase stability;Thermal expansion;Electrochemical performance