Ball mill assisted synthesis of Ni-YSZ cermet anode by electroless technique and their characterization

Ni-YSZ composite cermet used as the anode material for solid oxide fuel cell is prepared by electroless technique involving an important sensitization process of YSZ. In the present investigation, the sensitization process of YSZ is carried out through cost-effective controlled ball milling. The effect of milling speed on electrical, thermal and microstructural properties of such anodes is investigated and optimized at 45 rpm. Microstructural analysis of the synthesized Ni-YSZ cermets prepared under the optimized milling conditions showed a core-shell microstructure with YSZ as core and fine metallic Ni particulates as the shell. The interconnected metallic Ni creates a conductive pathway at room temperature. Such type of unique core-shell anode cermet, results in higher electrical conductivity (σ_800°C ∼ 500 S/cm) at much lower Ni content (∼33 vol%) compared to conventional anode cermet with thermal expansion coefficient (∼11.48 × 10^-6 K^-1) compatible to other cell components.