Electrochemical and mechanical properties of solid oxide fuel cell Ni/YSZ anode fabricated from NiO/YSZ composite powder

Abstract

The electrochemical and mechanical properties were investigated on Ni/Yttria-stabilized zirconia (YSZ) solid oxide fuel cells (SOFCs) anode fabricated from a NiO/YSZ composite powder. The composite powder was fabricated by dry milling of NiO and YSZ nanoparticles using attrition type apparatus without media balls for 30 min. The composite powder suppresses the microscopic as well as macroscopic segregation of the component during tape casting and subsequent sintering, resulting fine as well as the highly uniform anode microstructure. The anode supported SOFC made from the composite powder showed the maximum power density of 0.25 and 0.75 W.cm-2 at 700 and 800° C, respectively, which is significantly higher than that fabricated from the conventional powder mixture. Better performance can be attributed to the lower interfacial resistance due to the formation of huge amount of triple phase boundary consisting of Ni, YSZ and pore phases. The higher electrical conductivity would also contributed to the high performance. The equibiaxial flexural strength of NiO/YSZ fabricated from the composite powder was higher than that from the powder mixture. © 2011 The Ceramic Society of Japan.