Change of Physical Properties of Ni/YSZ Cermets by the Continuous Reduction

Abstract

Ni/YSZ cermets made from commercial YSZ and pre-calcined YSZ powder were exposed to the reducing atmosphere of 1000°C continuously, in order to clarify the change of physical properties and internal microstructure. Ni particles were sintered between YSZ particles and porosity was changed and conductivity was decreased, regardless the pre-calcination of the YSZ. In the cermets made from pre-calcined YSZ, porosity and pore diameter were increased and higher conductivity was obtained even after the 300hrs reduction. This is thought to be derived from the change of the structure in the cermets. Furthermore, the use of pre-calcined YSZ was revealed to be usefull to maintain the initial generation performance of the cell.