Effect of dip coating parameters on microstructure and thickness of 8YSZ electrolyte coated on NiO-YSZ by sol-gel process for SOFCs applications

8 mol % Yttria stabilized zirconia (8YSZ) coatings are widely used as electrolytes in solid oxide fuel cells (SOFCs). In this study, sol-gel process was used in order to in-situ synthesis of 8YSZ electrolyte layer on NiO-8YSZ substrate applying dip coating method. Solid content, viscosity and withdrawal speed were investigated as effective parameters that affect quality and thickness of coatings. Fourier transform infrared radiation (FTIR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) analyses were used to evaluate the microstructure of 8YSZ film. A dense and uniform coating was obtained with increasing solid content. Reduced viscosity also yielded a better uniformity and formed crack free coatings. Thickness of coatings was controlled by withdrawal speed. Results reveal that a dense and uniform coating was obtained with molar ratio of 1 & xfffd; Propanol 10 using sol only 5min after preparation. Minimum thickness was measured 10 mu m at withdrawal speed of 1 cm/ min.

Automated summary

In this study, a sol-gel process was used to synthesize 8YSZ electrolyte layer on NiO-8YSZ substrate. The results showed that solid content and viscosity were important parameters affecting the quality and thickness of the coatings. Higher solid content and lower viscosity resulted in dense and uniform coatings, while the withdrawal speed controlled the thickness of the coatings.