中文摘要：

研究了Bi2O3-BaO-SiO2-RxOy玻璃体系的结构及封接性能.应用密度泛函理论计算获得了Bi2O3在SiO2玻璃网络中的能量最优结构,从理论上确定了铋作为网络中间体最可能以[BiO3]形式存在,并讨论了Ba2＋、Al3＋等在玻璃中的作用及其存在的可能结构.结果表明,该玻璃的热膨胀系数在50～530℃温度为11×10-6 K-1,与氧化钇稳定氧化锆（热膨胀系数10.2×10-6 K-1）电解质和不锈钢SUS430（热膨胀系数11.3×10-6 K-1）合金连接体相匹配.对玻璃粉体进行物相分析表明,该硅酸盐玻璃为非晶体,与理论分析相一致.将氧化钇稳定氧化锆电解质和SUS430合金连接体用Bi-Ba-Si-O玻璃在高温下进行封接实验,结果说明三相界面结合紧密,气密性良好.实验选定的Bi-Ba-Si-O玻璃材料基本满足固体氧化物燃料电池对封接材料的要求.

英文摘要：

The sealing properties and structure of Bi2O3-BaO-SiO2-RxOy（Bi-Ba-Si-O） glass were studied for fabricating solid oxide fuel cells（SOFC）.The density functional theories（DFT） were employed for the structure optimization of Bi2O3 into SiO2 glass networks,and was theoretically determined to be the most possible structure of bismuth as interconnections in the Bi-Ba-Si-O glass.The functions and possible existence structures of Ba2＋ and Al3＋ were also discussed.According to experimental investigations,the coefficient of thermal expansion（CTE） of the Bi-Ba-Si-O glass is 11×10-6K-1（50 to 530℃） which can be matched with the YSZ electrolyte（CTE： 10.2×10-6K-1） and the SUS430 steel metallic interconnect（CTE： 11.3×10-6K-1）.Data form XRD analysis show that the Bi-Ba-Si-O glass is amorphous and consistent with the theoretical analysis.When the Bi-Ba-Si-O glass is used as sealing materials for SOFC,the glass,the SUS430 metallic interconnect and the YSZ electrolyte adhere well with good air-tightness.It is concluded that the Bi-Ba-Si-O glass can meet the requirements of SOFC sealing materials.