多孔NiO/钇稳定氧化锆陶瓷的水系流延成型

AQUEOUS TAPE CASTING OF POROUS NiO/YTTRIA-STABILIZED ZIRCONIA CERAMICS

采用水系流延工艺制备了阳极支撑型固体氧化物燃料电池的阳极材料NiO/钇稳定氧化锆(yttria-stabilized zirconia,YSZ)陶瓷。研究了分散剂聚丙烯酸(polyacrylic acid,PAA)和pH值对YSZ和NiO颗粒的zeta电位以及65%(质量分数,下同)NiO/35%YSZ浆料黏度的影响。结果表明:在pH=9.6和加入分散剂时,NiO和YSZ颗粒的zeta电位绝对值达到最大值;当PAA的含量为NiO/YSZ粉料的0.8%时,NiO/YSZ浆料黏度最小。浆料中添加石墨粉作为造孔剂能提高阳极材料的孔隙率。石墨粉在聚乙烯吡咯烷酮的作用下均匀分布在阳极烧结体中。石墨粉的含量对阳极烧结体中的开口孔隙率有重要的影响,在石墨粉的含量为25%,阳极烧结体的孔隙中的开口孔隙率占全部孔隙率的98%。

Porous anode NiO/yttria-stabilized zirconia （YSZ） ceramics for anode-supported solid oxide fuel cells were fabricated via the aqueous tape casting process. The effect of polyacrylic acid （PAA） dispersant content and the pH value on the zeta potential of YSZ and NiO particles as well as the viscosity of the 65% （mass fraction, the same below） NIO/35% YSZ slurries was studied. The results show that the absolute zeta potential of YSZ and NiO particles reaches a maximum value at a pH value of -9.6. The viscosity of the NiO/YSZ slurry with 0.8% PAA is the lowest. The porosity of NiO/YSZ ceramics can be increased by adding graphite as pore-forming material in the NiO/YSZ slurries. Graphite particles coated with polyvinyl pyrrolidone can be dispersed uniformly in NiO/YSZ ceramics after sintering. The content of graphite has a significant influence on the porosity of NiO/YSZ ceramics. The ratio of open porosity to total porosity of the NiO/YSZ ceramics is 98% when the graphite content is 25%.