Improvement of plasma-sprayed YSZ electrolytes for solid oxide fuel cells by alumina addition

Abstract

Atmospheric plasma spray is a fast and economical process for deposition of yttria-stabilized zirconia (YSZ) electrolyte for solid oxide fuel cells. YSZ powders have been used to prepare plasma-sprayed thin ceramic films on the metallic substrate employing plasma spray technology at atmospheric pressure. Alumina doping was employed to improve the structural characteristics and electrical properties of YSZ. The effect of alumina addition from 1 to 5 wt.% on the properties of plasma-sprayed YSZ films was investigated. It was found that the gas permeability of the Al-doped YSZ electrolyte layer reached a level of 8.6×10 −7 cm 4 gf −1 s −1 , which is a necessary value for the practical operation of solid oxide fuel cells. Alumina doping considerably increased the ionic conductivity of plasma-sprayed YSZ. The open circuit voltage of the alumina-doped YSZ coating was approximately equal to the theoretical value for dense YSZ material.

Normal spectral emittance of Inconel 718 aeronautical alloy coated with yttria stabilized zirconia films

“…The atmospheric plasma spraying process for thermal barrier coating preparation is very well described in the literature [2,14]. The chemical composition of Inconel 718 (substrate), in weight percentage, is shown in Table 1.…”

Colloidal Shaping of 8 mol% Yttria‐Stabilized Zirconia Electrolyte Honeycomb Structures by Microwave‐Assisted Thermal Gelation of Methyl Cellulose

“…The conductivity at 800, 700, and 650°C is estimated as 0.071, 0.036, and 0.022 S/cm, respectively, and conductivity at intermediate temperature ranging (650-800°C) is found to be relatively higher than that of the reported value for planar 8YSZ electrolyte. [26][27][28] Honeycomb structures owing to its unique monolithic structures, maximum heat capacity per unit weight by the virtue of its low relative densities and high surface to volume ratio in comparison with the solid counter parts permits rapid heat transfer leading to quick start-up times and reduced thermal gradients contributing toward the better efficiencies. Further, the channelized flow of hot gases also enhances the heat transfer resulting in better homogeneity.…”