Proton conducting intermediate-temperature solid oxide fuel cells using new perovskite type cathodes

摘要

Sr_2Fe_(1.5)Mo_(0.5)O_(6-δ) (SFM) is proposed as the electrodes for symmetric solid oxide fuel cells (SOFCs) based on oxygen-ion conducting electrolytes. In this work SFM is investigated as the cathodes for SOFCs with proton conducting BaZr_(0.1)Ce_(0.7)Y_(0.2)O_(3-δ) (BZCY) electrolyte. SFM is synthesized with a combined glycine and citric acid method and shows very good chemical compatibility with BZCY under 1100 ℃. Anode-supported single cell (Ni-BZCY anode, BZCY electrolyte, and SFM-BZCY cathode) and symmetrical fuel cell (SFM-BZCY electrodes and BZCY electrolyte) are fabricated and their performances are measured. Impedance spectroscopy on symmetrical cell consisting of BZCY electrolyte and SFM-BZCY electrodes demonstrates low area-specific interfacial polarization resistance R_p, and the lowest R_p, 0.088 Ω cm~2 is achieved at 800 ℃ when cathode is sintered at 900 ℃ for 2 h. The single fuel cell achieves 396 mW cm~(-2) at 800 ℃ in wet H_2 (3 vol% H_2O) at a co-sintering temperature of 1000 ℃. This study demonstrates the potential of SFM-BZCY as a cathode material in proton-conducting intermediate-temperature solid oxide fuel cells.