A single step solution combustion approach for preparing gadolinia doped ceria solid oxide fuel cell electrolyte material suitable for wet powder and plasma spraying processes

摘要

The present study explores the versatility of solution combustion method for preparing powders of varying characteristics suitable for intermediate temperature solid oxide fuel cell (IT-SOFC) fabrication. The promising electrolyte material for IT-SOFC, Gd_(0.2)Ce_(0.8)O_(2-δ) (GDC), is considered for the present investigation. GDC powders consisting of sub-micron sized particles (<250 nm) and micron sized (>20 μm) particles are produced by varying the fuel used in the combustion reaction. Highly sinteractive nano-GDC powders prepared using oxalyl dihydrazide as a fuel results in dense pellets with high conductivity (3 × 10~(-4) Scm~(-1) at 400 ℃). This powder also results in a stable suspension suitable for wet powder spraying and electrophoretic deposition. Powders with larger particle size (>20 μm) prepared by solution combustion method using mixture of fuels, exhibits necessary flowability for atmospheric plasma spraying (APS). GDC coatings fabricated by APS using flowable powders are dense with superior adhesion between the splats. Good adhesion between the splats in the APS coatings is attributed to the higher level of melting of the combustion synthesized particles in the plasma flame owing to their low specific mass.