Synthesis Of BaCe_1-xY_xO_3-α Solid Electrolyte And Its Fuel Cell Performance

In this study, the precursor of BaCe0.8Y0.2O3-a electrolyte was synthesized by sol-gel method and sintered at the temperature of 1400 -1500, which was 150- 250 lower than that used by traditional high temperature solid state reaction. Using the sintered samples as solid electrolyte and porous platinum as electrodes, hydrogen and oxygen concentration cells as well as hydrogen-air fuel cells were constructed. The proton and oxide-ion transport numbers and the fuel cell performances of BaCe0.8Y0.2O3-a sinter were determined and compared with those of the sample synthesized by high temperature solid-state reaction. The results indicated that the proton transport number and fuel cell performance of synthesized by sol-gel method could be obviously affected by the sintering temperature. When sintering temperature 1450, the proton transport number was approximately 1 and the fuel cell performance was good, but sintering temperature 1450, the proton transport number was 'smaller than 1 and the fuel cell performance was poor. The sample sintered at 1450 exhibited the best fuel cell performance, which wasclose to that of the sample prepared by high temperature solid state reaction, among the samples sintered at 1400-1500 .In this study, we also investigated the electrode polarization characteristics of the fuel cell based BaCe0.8Y0.2O3-a Using BaCe0.9Y0.1O3-a oxide ceramic as solid electrolyte and porous Pt as electrode material, hydrogen-air fuel cell was constructed. The ohmic voltage fall and polarization characteristics of the fuel cell on discharging were determined in the temperature range of 600-1000 by current interruption method. It is clear that the excellent performances of the fuel cell are closely related to the small polarization, the polarization of both the electrodes decreases with increasing temperature and the polarization of cathode is smaller than that of anode.