Preparation of YSZ electrolyte coating on conducting porous Ni–YSZ cermet by DC and pulsed constant voltage electrophoretic deposition process for SOFCs applications

Abstract

In this article, electrolyte coating of solid oxide fuel cells (SOFCs) based on yttria stabilized zirconia (YSZ) on Ni-YSZ cermet fuel cells anode in ethanol was investigated using pulsed constant voltage and DC electrophoretic deposition (EPD). The NiO-YSZ substrate was prepared by hydraulic pressing of mixed YSZ, NiO and starch powders following pre-sintering at 1200 °C for 3 h. The NiO-YSZ composite was reduced in hydrogen atmosphere in order to produce Ni-YSZ cermet. The suspension properties and EPD process parameters were investigated. The YSZ electrolyte was sintered at 1350 °C for 4 h. The morphology of sintered YSZ electrolyte coating was investigated by scanning electron microscope (SEM) and optical microscopy (OM). Results showed that dense and uniform coatings were deposited in ethanol with solid concentration of 10 g/L of YSZ, 0.5 g/L of iodine at distance of anode to cathode being 5 mm. The thickness of YSZ electrolyte after 6 min of deposition with pulsed constant voltage and DC electrophoretic deposition were 20 and 88 ± 1 μm, respectively.