Development of Tubular Solid Oxide Electrolysis Cells for Hydrogen Production

Tubular SOECs with operating temperature reduced to 700~800oC are developed. To improve cell performance at low temperatures, Sc2O3 stabilized ZrO2 is chosen as the electrolyte material and thickness of the electrolyte layer is tried to be controlled to about 10 μm. Test electrolysis cells are fabricated by using slurry coating method. Dependence of cell performance on operating conditions is measured. Further, AC impedance method is applied to the cells to estimate interfacial overvoltage. From the experiment, it is clarified that the hydrogen production rate at 750oC goes up to 3.6 sccm/cm2 at the thermoneutral voltage. This value is more than 2 times of that of the commercial alkaline electrolysers.