Ba_(0.95)Ce_(0.9)Y_(0.1)O_(3-α)固体氧化物的离子导电性及其燃料电池性能

Ionic Conduction in Ba_(0.95)Ce_(0.9)Y_(0.1)O_(3-α)Solid Oxide and its Performance in Fuel Cell

以Ba0 .95Ce0 .9Y0 .1O3-α氧化物陶瓷为固体电解质 ,以多孔性Pt为电极材料 ,分别组成氢、氧浓差电池和氢_空气燃料电池 ,测定了 6 0 0～ 10 0 0℃范围内的浓差电池电动势 ,燃料电池的放电性能和电极极化性能 .结果表明 ,Ba0 .95Ce0 .9Y0 .1O3-α在氢气氛中几乎是一个纯质子导体 ,在氧气氛中是氧离子与电子空穴的混合导体 ,氧离子迁移数在 0 .3～ 0 .5之间 ,在氢_空气燃料电池条件下显示出混合离子 (质子 +氧离子 )导电性 ,总离子迁移数大于 0 .9.该燃料电池性能良好 ,Pt电极极化性能很小 ,最大输出电流密度为 6 80mA·cm- 2 (10 0 0℃ ) ,最大输出功率密度为 16 0mW·cm- 2 (10 0 0℃ ) .

Using Ba 0.95 Ce 0.9 Y 0.1 O 3-α as a solid electrolyte and porous platinum as electrodes,hydrogen and oxygen concentration cells and hydrogen_air fuel cell were constructed,respectively.Electromotive forces(MEFs)of the gas concentration cells and I_V characteristics of the fuel cell were detdrmined in the temperature range of 600～1 000 ℃.The Ba 0.95 Ce 0.9 Y 0.1 O 3-α exhibited almost the pure protonic conduction under hydrogen gas,and a mixed conduction of oxide_ion and electron hole with oxide_ion transport number of 0.3～0.5 under oxygen gas.It exhibited a mixed conduction of proton and oxide_ion with the total ion transport number above 0.9 under the fuel cell condition.The fuel cell showed satisfactory performances.The polarizations at both electrodes were very small.The maximum of short_circuit current density and power_output density drawn from the cell were about 680 mA·cm -2 and 160 mW·cm -2 at 1000 ℃,respectively.