Particle states in plasma and their effects on properties of Ni/YSZ spray coatings for SOFC anode applications.

摘要

A process of atmospheric plasma spray (APS) deposition has been developed for the deposition of high performance anode coatings, which are essential for achieving high power density in solid oxide fuel cells (SOFC). This research studies new feedstock materials, including nano-components of MO and YSZ (300 nm), obtained through a spray drying method. Nano-crystalline powder, YSZ_(40vol%)NiO_(30vol%)Graphite_(30vol%) has been synthesized by a spray drying method using a combination of polyvinyl alcohol and polyvinyl pyrrolidone. Morphological analysis of the coating at different hydrogen gas flow rates was done with a scanning electron microscope (SEM). The oxidation and decomposition behaviors of the coatings were studied by TG/DTA analysis. Thermo-gravimetric results giving the reduction of graphite during the spray process showed that the change in mass of the coating is less than that of the powder. The microhardness and electrical conductivity of the spray coatings were measured using the Vickers hardness and four-probe DC method. A maximum electrical conductivity of 651 S/cm at 800 °C was achieved, which is higher than the standard required value of 160 S/cm.