New fabrication technique for a Ni–YSZ composite anode from a core–shell structured particle

In this study, we propose a new fabrication technique for a Ni–YSZ (yttria-stabilized zirconia) composite anode widely used in solid oxide fuel cells (SOFCs). A spherical core–shell structure consisting of a micron-sized Ni (core) and nano-sized YSZ (shell) was prepared by a high-speed mixing technique from metallic a Ni and YSZ powder mixture. The core–shell Ni–YSZ powder was then heat-treated at 1450 °C in an air atmosphere. During the early stage of the heat-treatment between 300 and 550 °C, it seemed that the surface of the Ni core was oxidized and the Ni particles were coated with a relatively dense NiO thin layer. As the heat-treatment temperature increased, the Ni core particles erupted, which led to uniformly distributed Ni particles in the YSZ framework. The resulting Ni–YSZ composite exhibited better electrical conductivity and ASR for anode polarization than a commercially available Ni–YSZ cermet anode. ► We synthesized a core-shell Ni–YSZ composite powder by a high speed mixing technique. ► A nano Ni–YSZ powder can be obtained by heat-treating the Ni–YSZ in air atmosphere. ► The obtained anode showed good electrical conductivity and polarization resistance.