Fabrication and performance of a proton-conducting solid oxide fuel cell based on a thin BaZr0.8Y0.2O3−δ electrolyte membrane

A dense BaZr0.8Y0.2O3−δ (BZY) proton-conducting electrolyte membrane is successfully fabricated on a NiO–BaZr0.1Ce0.7Y0.2O3−δ (NiO–BZCY) anode substrate by a co-pressing process after co-firing at 1400 °C. BZY powders are synthesized via a citric acid–nitrate gel combustion process after calcination at 1100 °C. The SEM results reveal that the BZY membrane is crack-free, very dense, and 20 μm thick. A single cell with Sm0.5Sr0.5CoO3−δ–Ce0.8Sm0.2O2−δ (SSC–SDC) as the cathode is assembled and tested with wet hydrogen (2% H2O) as the fuel and static air as the oxidant. The open circuit voltages (OCVs) are 0.953, 0.987, 1.014, and 1.039 V at 700, 650, 600, and 550 °C, respectively. A maximum power density of 170 mW cm−2 is obtained at 700 °C. Resistances of the testing cell are investigated under open circuit conditions at different operating temperatures by impedance spectroscopy.