Low temperature electrode materials synthesized by citrate precursor method for solid oxide fuel cells

Abstract

Homogeneous nanocrystalline NiO–Ce_0.9Ln_0.1O_2–δ (Ln = La, Sm, Gd, and Pr) composite anode and nanocrystalline Ce_0.9Gd_0.1O_2–δ electrolyte material have been successfully synthesized by citrate precursor method. LSCF has been synthesized by conventional solid state method and used as cathode material in our studies. The synthesized powders have been characterized by powder X-ray diffraction, microscopy, and surface area studies. The average crystallite size of the anode materials has been found to be in the range of 5–15 nm by HRTEM. Highly dense electrolyte and porous electrode materials have been observed by FESEM and confirmed by BET surface area studies. Three cells have been fabricated successfully. Based on the performance of the three cells containing three different anode materials we have achieved better electrochemical characteristics in Ni–GDC with maximum power density of 302 mW cm^–2 and open circuit voltage of 1.012 V at 500 °C. The difference in the performance of the cells containing Ni–GDC as compared to Ni–LDC and Ni–SDC anode is due to changes in the microstructure and crystallite size of anode which affects the electrochemical performance of the cells. The performances of all the cells containing nanocomposite powders are suitable anode materials for low temperature SOFCs.