A precursor of BaCe_(0.8)Y_(0.2)O_(3-α) electrolyte was synthesized by the sol-gel method and sintered at 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. Proton and oxide-ion transport numbers as well as fuel cell peformance of the BaCe_(0.8)Y_(0.2)O_(3-α) sinter were compared with the corresponding values of the BaCe_(0.8)Y_(0.2)O_(3-α) prepared by high temperature solid state reaction. The results indicated that the proton transport number and fuel cell performance of BaCe_(0.8)Y_(0.2)O_(3-α) synthesized by sol-gel method could be obviously affected by sintering temperature. When the sintering temperature was ≥ 1450 ℃, the proton transport number was approximately 1 and the fuel cell performance was good. However, when the sintering temperature was < 1450 ℃, the proton transport number was smaller than 1 and the fuel cell performance was poor. Among the samples sintered at 1400～1500 ℃, the sample sintered at 1450 ℃ exhibited the optimal fuel cell performance, which was close to that of the sample prepared by high temperature solid state reaction.

Key words: BARIUM OXIDE, CERIUM OXIDE, YTTRIUM OXIDE, SOLID ELECTROLYTE, PEROVSKITE TYPE STRUCTURE, FUEL CELLS, SOL-GEL PROCESS