采用一种钐掺杂的氧化铈(SDC)-碳酸盐复合物作为低温固体氧化物燃料电池(LTSOFC)的电解质. 利用交流阻抗测试400～700℃不同气氛下的导电性能: 电解质的电导率在大约500℃发生突变, 表明传导机理发生改变; 500℃以上电导率随碳酸盐组分增加而增大; 还原性气氛下的电导率高于氧化性气氛下的电导率. 以不同碳酸盐含量的电解质材料制备阳极支撑型单电池, 运行中发现, 在阴极和阳极侧均有水产生, 说明同时存在氧离子和质子传导. 电流-电压特性和功率特性显示, 所有复合物电解质均有优于纯SDC电解质的电池性能, 其中碳酸盐含量为20wt%时性能最好, 500℃开路电压为1.00V, 最大功率密度达415mW·cm^-2.

A novel composite material based on mixture of samarium-doped ceria (SDC)-carbonate was studied as electrolyte in low temperature solid oxide fuel cells. The phase and microstructures of composite electrolyte were examined by XRD and SEM. The electrical conductivity was investigated by AC impedance spectroscopy at 400--700℃ in different atmospheres. An abrupt change in the conductivity at about 500℃ indicates that different mechanisms affect transfer in different temperature ranges. The conductivity increases with the carbonate fraction above 500℃. The conductivity in reduce atmosphere is higher than that in oxide atmosphere. An anode-supported fuel cell using SDC-carbonate as electrolyte was fabricated and tested. The result shows that all the composite electrolytes exhibit better performance than pure SDC electrolyte. The electrolyte with 20wt% carbonate can achieve the highest power density of 415mW·cm^-2 and an open circuit voltage of 1.00V at 500℃.