Investigation of Nd2Ni0.9M0.1O4+δ (M = Ni, Co, Cu, Fe, and Mn) cathodes for intermediate-temperature solid oxide fuel cell

In order to improve the performance of intermediate temperature solid oxide fuel cells (IT-SOFCs), the effect of partial substitution of the transition metal M = Co, Cu, Fe and Mn for Ni in Nd2NiO4+δ on the crystal chemistry, electrical conductivity, thermal stability, chemical reactivity with YSZ electrolyte and electrochemical performance has been systematically investigated. The electrochemical performances of the cathode materials are tested on planar NiO-YSZ anode-supported cells fabricated with YSZ as electrolyte in size of 50 mm × 50 mm. Compared to Nd2NiO4+δ, each Nd2Ni0.9M0.1O4+δ material shows a decrease in electrical conductivity and an increase in lattice volume, oxygen vacancy concentration and chemical reactivity with YSZ electrolyte. The cell with Nd2Ni0.9Co0.1O4+δ cathode achieves the maximum power density of 530 mW cm−2 at 0.7 V at 800 °C. The cell with Nd2Ni0.9Cu0.1O4+δ cathode is the most stable in short-term test. A small amount of B-site doping in Nd2NiO4+δ does not cause any change in the cathode microstructure. The study demonstrates that a tradeoff between oxygen transport properties and electrical conductivity can be accomplished by appropriate selection of transition metal and level of cation B-site doping in Nd2NiO4+δ. Nd2Ni0.9M0.1O4+δ (M = Co, Cu) can be considered to be potential cathode materials in IT-SOFCs.