Atmospheric plasma spraying (APS) was applied to deposit Gd_0.2Ce_0.8O_1.9 (20GDC) coatings by using different H₂ flow rates (3-12 l/min), which aimed to explore the effect of H₂ flow rates on the powder melting and coating characteristics. The results showed that with increasing H₂ flow rates, the deposition state of 20GDC powder was changed from solid-liquid co-deposition to liquid deposition. Using a 6 l/min H₂ flow rate could obtain the best coating with a moderate melting degree, proper impact velocity, and cooling speed. Therefore, the as-sprayed coating possessed the lowest porosity of 7.1%, the highest electrical conductivity (29.3 mS/cm at 750℃), and the best output performance of NiO+GDC/GDC/Silver cell (196 mW/cm² at 700℃).
 

gadolinia-doped ceria coating; atmospheric plasma spray; microstructure; electrical property