Fabrication and performance of solid oxide fuel cell anodes from core–shell structured Ni/yttria-stabilized zirconia (YSZ) powders

Abstract

A core–shell structured nickel/yttria-stabilized zirconia (Ni/YSZ) powder was synthesized by the hydrazine method from an aqueous nickel chloride solution (NiCl2·6H2O) with YSZ particles, which were prepared by a hydrothermal technique. The cationic surfactant cetyltrimethyl ammonium bromide (CTAB) was added to form the core–shell structure. Nano-sized YSZ shell particles were homogeneously coated onto the surface of the spherical Ni core particles. It was found that the addition of CTAB was crucial for the formation of the core–shell structured Ni/YSZ powder. The size of the YSZ shell particles affected the morphology of the Ni/YSZ core–shell powder. Finer YSZ shell particles led to a denser coverage of the Ni core particle. During the heat treatment of the Ni/YSZ core–shell powder in air, the Ni was partly oxidized to NiO, and a three-dimensional network structure of NiO and YSZ was obtained. The enhanced electrical conductivity in the Ni/YSZ anode because of the core–shell structured powder was considered to be due to the improved connectivity between the Ni and YSZ particles. The maximum power densities and the polarization resistances of the Ni/YSZ anode from the core–shell structured powder were 0.38, 0.57, and 0.84W/cm2 and 1.01, 0.52, and 0.25Ωcm2 at 700, 750, and 800°C, respectively.