A stable and easily sintering BaCe_(0.7)Sn_(0.1)Gd_(0.2)O_(3-δ) electrolyte for solid oxide fuel cells

摘要

BaCe_(0.7)Sn_(0.1)Gd_(0.2)O_(3-σ) (BCSG) and BaCe_(0.8) Gd_(0.2)O__(3-σ) (BCG) powders were prepared by solid-state reaction method. After exposure in 5% CO2+5% H2O+ 90% N2 at 500 °C for 5 h, the BCSG powders were hardly affected while the BCG powders decomposed into CeIO2 and BaCO3 phases. Moreover, the relative density of BCSG reaches 97%, while the BCG just displays 91% after sintering at 1,400 °C. The BCSG displays a conductivity of 0.01 S/cm at 700 °C in humid hydrogen, which is quite close to 0.012 S/cm for BCG. A fuel cell with BCSG exhibits 1.02 V for open circuit voltage, 420 mW/cm2 for peak performance and 0.23 Ω cm~2 for interfacial resistance at 700 °C, respectively.