钙掺杂的氧化铈用于中温SOFCs阳极材料研究

作为一种混合的离子-电子导体材料,掺杂的氧化铈已逐渐被用来作为SOFCs阳极材料或其组成部分之一加以研究,但主要以稀土掺杂剂为主,为了进一步降低采用阳极支撑构型的SOFCs的成本,研究了钙掺杂的氧化铈(CCO)。结果表明,掺杂20%钙的材料(20CCO)的电导率最高,850℃时在氢气气氛下的电导率可以达到0.209S·cm-1,远大于在空气气氛中的电导率。800℃时在空气中的电导率为0.041S·cm-1,比同样温度下阳极中经常采用的钐掺杂的氧化铈(SDC)的电导率低了约0.04S·cm-1。但这并不影响单电池的输出性能,分别以Ni-20CCO作为阳极,Sm0.5Sr0.5Co-SDC作为阴极,SDC作为电解质(厚约35μm)的单电池在650℃,氢气气氛下的最大输出功率可以达到623mW·cm-2。     

生物质气为燃料的燃料电池理论电动势计算

The electromotive force (e.m.f.) of solid oxide fuel cells using biomass produced gas (BPG) as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2, CO, CO2 and CH4. Compared with using hydrogen as a fuel, the e.m.f.for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition, the optimum amount of H2O to add is determined at various operating temperatures.Further the e.m.f, for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared.The study reveals that when using BPG as fuel, the depression of e.m.f, for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.     

Pd-Y合金膜的MOCVD研制

采用金属有机化合物的化学气相淀积法,以β-二酮螯合物为源物质,在多孔Al₂O₃衬底上成功制备了超薄钯钇合金膜.用Pd(AcAc)₂+Y(AcAc)₃混合源制备的钯钇合金膜的晶粒尺寸(21nm×10nm)比单独用Pd(AcAc)₂制备的钯膜的尺寸(30nm×10nm)小.XPS研究发现,制备的Pd-Y合金膜中Y/Pd比小于源物质的.氢的透气性实验表明,合金膜的氢渗透率高于Pd膜,且在200～350℃范围内渗透率稳定.     

生物质气为燃料的燃料电池理论电动势计算

在以生物质气体为燃料的固体氧化物燃料电池体系中,通过热力学平衡分析编程计算出700-1200 K时气体中各物种例如H2、CO、CO2和CH4的平衡组成,从而得到以氧化钇稳定氧化锆(YSZ)为电解质的电池理论电动势．碳沉积对电动势有显著影响．通过计算可以推测比较适宜的操作温度和增湿条件．还计算了以掺杂氧化铈为电解质的电池电动势,相比氢气为燃料时,使用生物质气体导致的电动势的下降比使用YSZ为电解质的电池要小的多．