Preparation and evaluation of new composites as anodes for intermediate-temperature solid oxide fuel cells

Composites, which consist of Sr-doped LaCrO3, CeO2, and NiO, were prepared according to a general formula (La0.7Sr0.3)1−xCexCr1−xNixO3−δ (x = 0-0.6) and were assessed as anodes for intermediate-temperature solid oxide fuel cells (ITSOFCs) in terms of phase structure, electrical conductivity, thermal expansion coefficient, and fuel cell performance. Results showed, for x > 0.2, CeO2 and NiO precipitated after being calcined at 800-1450 °C and dispersed on a doped LaCrO3 support. At 800 °C, the electrical conductivities of the composites (for x = 0.2, 0.4 and 0.6) in a humidified 3% H2O hydrogen atmosphere were 0.72, 1.22 and 4.89 Scm− 1, respectively. The average values of the thermal expansion coefficients of the composites (in a temperature range of 30-800 °C) were 11 × 10− 6 (x = 0.2) and 11.5 × 10− 6 K− 1 (x = 0.6). SOFCs with different anodes were characterized by current-voltage measurements and electrochemical impedance spectroscopy. The peak power density of a single cell with different composite anodes increased with increasing x. At 800 °C, the maximum power density was 81.5 mW cm− 2, and the area specific resistances of the single cells under open circuit condition were 3.1 (x = 0.2) and 1.6 Ω cm− 2 (x = 0.6) using humidified (3% H2O) hydrogen as fuel and ambient air as oxidant.