BaCe_(0.8)Y_(0.2)O_(3-α)的溶胶-凝胶法合成及其电性能

Synthesis and Electrical Properties ofBaCe_(0.8)Y_(0.2)O_(3-α)

用溶胶 -凝胶法合成了BaCe0 8Y0 2 O3 -α固体电解质前驱体 ,并以低于通常固相反应 15 0～ 2 5 0℃的温度 (即14 0 0～ 15 0 0℃ )进行了烧结 .以烧结体样品为固体电解质、多孔性铂为电极 ,组成氢及氧浓差电池、氢 -空气燃料电池 ,测定了BaCe0 8Y0 2 O3 -α烧结体的质子和氧离子迁移数以及燃料电池的性能 ,并与高温固相反应法合成的样品进行了比较 .结果表明 ,烧结温度能显著影响溶胶 -凝胶法合成样品的质子迁移数及燃料电池性能 .烧结温度≥ 14 5 0℃时 ,质子迁移数近似为 1,燃料电池性能亦较高 ,烧结温度 <14 5 0℃时 ,质子迁移数 <1,燃料电池性能亦较低 .在14 0 0～ 15 0 0℃烧结的样品中 ,14 5 0℃下烧结的样品具有最高的电池性能 。

A precursor of BaCe0.8Y0.2O 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 temper ature solid state reaction. Using the sintered samples as solid electrolyte and porous platinum as electrodes, hydrogen and oxygen concentration cells as well a s hydrogen-air fuel cells were constructed. Proton and oxide-ion transport num bers as well as fuel cell peformance of the BaCe0.8Y0.2O3-α sinter were compared with the corresponding values of the BaCe0.8Y0 .2O3-α prepared by high temperature solid state reaction. The results indicated that the proton transport number and fuel cell performance of BaCe 0.8Y0.2O3-α synthesized by sol-gel method could be obviously a ffected by sintering temperature. When the sintering temperature was≥1450 ℃, t he proton transport number was approximately 1 and the fuel cell performance was good. However, when the sintering temperature was <1450 ℃, the proton transpo rt number was smaller than 1 and the fuel cell performance was poor. Among the s amples sintered at 1400～1500 ℃, the sample sintered at 1450 ℃ exhibited the o ptimal fuel cell performance, which was close to that of the sample prepared by high temperature solid state reaction.