NiO-YSZ-石墨水系浆料的研制及其在注浆成型制备固体氧化物燃料电池中的应用

Ni-YSZ(钇稳定氧化锆)金属陶瓷普遍被用作固体氧化物燃料电池(SOFC)的阳极材料，其氧化物浆料的性质对湿法制备的SOFC的性能具有重要影响. 通过zeta 电位分析，研究了NiO-YSZ双分散相水系浆料的稳定性. 对六种分散剂作用于NiO、YSZ 表面的zeta 电位进行研究，发现采用的阴离子分散剂和两性分散剂使NiO 和YSZ在水中带有相反电荷而引起迅速絮凝； 采用阳离子分散剂聚二烯二甲基氯化铵(PDAC)时，NiO 和YSZ因带有正电荷相互排斥而稳定分散于水中，在此基础上，加入作为SOFC阳极造孔剂的石墨，采用聚乙烯吡咯烷酮(PVP)作为石墨的分散剂，制备出了NiO-YSZ-石墨的稳定水系浆料. 采用此浆料通过注浆成型制得阳极支撑管，进而组装成SOFC单电池. 该单电池在800℃时最大功率密度达到509 mW·cm^-2； 扫描电镜(SEM)分析表明电极与电解质间接触良好，阳极孔洞分布均匀.

Preparation of NiO-YSZ-Graphite Aqueous Slurry and Its Application in Fabricating Solid Oxide Fuel Cells by Slip-Casting

Cermet of Ni-YSZ (yttrium-stabilized zirconia) is commonly used as the anode material of solid oxide fuel cells (SOFCs) and the properties of the NiO-YSZ slurry has a significant effect on the performance of SOFCs prepared by wet processes. The stability of the NiO-YSZ slurry was investigated through zeta potential analysis. The effects of six dispersants on the surface zeta potentials of NiO and YSZ were examined. It was found that the zeta potential of NiO was opposite to that of YSZ when the anionic or amphoteric dispersant existed. When the cationic dispersant poly(diallyldimethylammonium chloride) (PDAC) was used, the zeta potentials for both NiO and YSZ were positive and they could be simultaneously suspended in water. By adding graphite, which is used as the pore former when fabricating the SOFC anode, into the NiO-YSZ suspension and using polyvinylpyrrolidone (PVP) as the dispersant of graphite, a stable NiO-YSZgraphite aqueous slurry was successfully prepared. The slurry was used to fabricate anode supports for SOFCs with the slip-casting technique. A typical single anode-supported SOFC showed a maximum power density of 509 mW·cm^-2 at 800℃. The microstructure of the SOFC with the anode support was examined by scanning electron microscope (SEM) analysis and it was found that the electrolyte and anode bonded well and the pores were homogenously distributed in the anode.