Fabrication and performance of a proton-conducting solid oxide fuel cell based on a thin BaZr_(0.8)Y_(0.2)O_(3-δ) electrolyte membrane

摘要

A dense BaZr_(0.8)Y_(0.2)O_(3-δ) (BZY) proton-conducting electrolyte membrane is successfully fabricated on a NiO-BaZr_(0.1)Ce_(0.7)Y_(0.2)O_(3-δ) (NiO-BZCY) anode substrate by a co-pressing process after co-firing at 1400℃. BZY powders are synthesized via a citric acid-nitrate gel combustion process after calcination at 1100℃ The SEM results reveal that the BZY membrane is crack-free, very dense, and 20 μm thick. A single cell with Sm_(0.5)Sr_(0.5)CoO_(3-δ)-Ce_(0.8)Sm_(0.2)O_(2-δ) (SSC-SDC) as the cathode is assembled and tested with wet hydrogen (2% H_2O) 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 ℃, respectively. A maximum power density of 170 mW cm~(-2) is obtained at 700 ℃. Resistances of the testing cell are investigated under open circuit conditions at different operating temperatures by impedance spectroscopy.