Preparation and electrochemical performance of Pr2Ni0.6Cu0.4O4 cathode materials for intermediate-temperature solid oxide fuel cells

Abstract

Cathode material Pr2Ni0.6Cu0.4O4 (PNCO) for intermediate-temperature solid oxide fuel cells (IT-SOFCs) is synthesized by a glycine–nitrate process using Pr6O11, NiO, and CuO powders as raw materials. X-ray diffraction analysis reveals that nanosized Pr2Ni0.6Cu0.4O4 powders with K2NiF4-type structure can be obtained from calcining the precursors at 1000°C for 3h. Scanning electron microscopy shows that the sintered PNCO samples have porous microstructure with a porosity of more than 30% and grain size smaller than 2μm. A maximum conductivity of 130Scm−1 is obtained from the PNCO samples sintered at 1050°C. A single fuel cell based on the PNCO cathode with 30μm Sm0.2Ce0.8O1.9 (SCO) electrolyte film and a 1mm NiO–SCO anode support is constructed. The ohmic resistance of the single Ni–SCO/SCO/PNCO cell is 0.08Ωcm2 and the area specific resistance (ASR) value is 0.19Ωcm2 at 800°C. Cell performance was also tested using humidified hydrogen (3% H2O) as fuel and air as oxidant. The single cell shows an open circuit voltage of 0.82V and 0.75V at 700°C and 800°C, respectively. Maximum power density is 238mWcm−2 and 308mWcm−2 at 700°C and 800°C, respectively. The preliminary tests have shown that Pr2Ni1−xCuxO4materials can be a good candidate for cathode materials of IT-SOFCs.