Nano-structured 7YSZ electrolyte layer for solid oxide fuel cell prepared by plasma spray-physical vapor deposition

Abstract:

Due to high thermal stability and purely oxide ionic conductivity, yttria-stabilized zirconia (YSZ) is the most commonly used electrolyte material for solid oxide fuel cell (SOFC). Standard electrolyte preparation techniques for planar SOFC comprise wet ceramic techniques like tape-casting or screen printing, requiring sintering steps at temperatures above 1300 ℃. Plasma spray-physical vapor deposition (PS-PVD) as a novel technique can provide a more rapid and cost efficient method to produce nano-structured electrolyte layer without sintering. High-temperature sintering requires long processing time and can lead to oxidation of metal alloys used as mechanical supports, or to detrimental inter-reactions between the electrolyte and adjacent electrode layers. Besides, the PS-PVD is different from traditional technique atmospheric plasma spray (APS) for various deposition mechanisms. Through this novel method, dense thin 7YSZ electrolyte layers with nano-structure are fabricated based on vapor deposition in PS-PVD processing. The 7YSZ electrolyte layer with a thickness of 8.7～12.3 μm was prepared, and its gas permeability can achieve 2.24～2.29 10-8 cm4gf-1s-1.