Name: Yasutaka Ohmine

gApplication of the wet-blasting treatment for a solid electrolyte disk to an enhancement of the fuel cell performanceh

Supervisor: Kazunori Sato


An wet-blasting treatment was performed for an yttria-stabilized zirconia (YSZ) disk in order to reduce the electrical resistance of the electrolyte without losing its mechanical strength and to increase the activity of the electrode reactions for solid oxide fuel cells. Optimum conditions of the wet-blasting treatment were experimentally determined for the selection of the grain size of alumina powders and the blasting pressure applied to the YSZ disk. The treated disk has a shape of the uniformly reduced thickness for the oxide-ion conducting part with a thick peripheral rim to support the disk against the external force.

A test cell was prepared using the Ni-YSZ cermet as the anode, (La,Sr)MnO3 as the cathode, and the treated YSZ disk. Measurements of the anodic and cathodic overpotentials by the current interruption method for the test cell using hydrogen as the fuel showed an appreciable decrease in the anodic overpotential at 600-850 degrees Celsius, compared with the reference cell using the untreated YSZ disk. Microstructural observations for the interfaces between the anode/cathode and the electrolyte by scanning electron microscopy indicate that the bonding structure at the interface affects the anodic overpotential. These results show that the wet-blasting treatment for YSZ electrolytes provides not only a sufficient deformation resistance against an external force but also a decrease of the interfacial resistance between the anode and electrolyte.