Assessment of LnBaCo1.6Ni0.4O5+δ (Ln = Pr, Nd, and Sm) double-perovskites as cathodes for intermediate-temperature solid-oxide fuel cells

► Investigation on structure and properties of double-proveskites LnBaCo1.6Ni0.4O5+δ as IT-SOFC cathodes. ► Thermal expansion coefficients of LnBaCo1.6Ni0.4O5+δ are lowered while retaining desirable electrochemical performance. ► LnBaCo1.6Ni0.4O5+δ exhibits good chemical compatibility with SDC electrolyte at temperatures below 950  °C.