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 Nd 2 NiO 4+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 Nd 2 NiO 4+δ , each Nd 2 Ni 0.9 M 0.1 O 4+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 Nd 2 Ni 0.9 Co 0.1 O 4+δ cathode achieves the maximum power density of 530 mW cm −2 at 0.7 V at 800 °C. The cell with Nd 2 Ni 0.9 Cu 0.1 O 4+δ cathode is the most stable in short-term test. A small amount of B-site doping in Nd 2 NiO 4+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.