Synthesis and electrochemical properties of (Pr–Nd) 1− ySr yMnO 3− δ and (Pr 1− xNd x) 0.7Sr 0.3MnO 3− δ as cathode materials for IT-SOFC

Abstract

(Pr–Nd) 1− y Sr y MnO 3− δ (P-NSM, y = 0.2, 0.25, 0.3, 0.35) powders made from commercial Pr–Nd mixed oxide, as well as (Pr 1− x Nd x ) 0.7Sr 0.3MnO 3− δ (PN3SM, x = 0, 0.5, 0.7, 1) were synthesized by a glycine-nitrate process and characterized as cathode materials for intermediate temperature solid oxide fuel cell (IT-SOFC). XRD patterns showed the powders had formed pure perovskite phase after being calcined at 800 °C for 2 h. (Pr–Nd) 0.7Sr 0.3MnO 3− δ (P-N3SM) achieved a high conductivity of 194 S cm −1 at 500 °C and showed a good chemical stability against YSZ at 1150 °C. And the thermal expansion coefficient of P-N3SM/YSZ cathode was 11.1 × 10 −6 K −1, which well matched YSZ electrolyte film. The tubular SOFC with P-N3SM/YSZ cathode exhibited the maximum power densities of 415, 367, 327 and 282 mW cm −2 at 850, 800, 750 and 700 °C, respectively, which indicated P-N3SM was potentially applied in SOFC for low cost.