Effect of treatment temperature on microstructure and properties of nickel-zirconia anode materials for solid oxide fuel cells

In this work, the structural, mechanical and electrical properties of YSZ-NiO anode ceramics before and after reduction in pure H2 and Ar-5 vol.%H2 mixture were studied. The NiO to Ni phase transformations that occur in the anode under reducing and reduction-oxidation (redox) cycling conditions and the impact on anode microstructure, strength and electrical conductivity have been examined. The results show that the redox treatment of the YSZ−NiO ceramic specimens influences on their properties controversially. At the treatment temperature 600° a structure providing improved physical and mechanical properties of the material is formed. However, at the treatment temperature 800° an anode structure with an array of microcracks is formed that significantly reduces the strength and electrical conductivity of the material. The results of this investigation show that reduction condition of YSZ-NiO is a powerful tool for influence on properties of the anode substrate.