Peneliti Kepala : Prof. Ir. Syoni Soepriyanto, M.Sc., Ph.D.
Anggota : Dr. Bonita Dilasari, ST., MT. ; Wahyudin Prawira Minwal, ST., MT. ; Yesi Aristanti, ST., MT.

SOFC tech has a great potential to be the cleanest, most efficient, and flexible technology for the conversion of chemical to electrical energy. The high operating temperature of SOFC (1000 °C) is a shortcoming that inhibits the commercialization of SOFC. Ceria is a promising solid electrolyte material for Intermediate Temperature (400-700 °C) Solid Oxide Fuel Cell (IT-SOFC).

In this study, LGDC and YGDC are made with dopant variation of 0, 10, 15, 20 mol % Gd2O3 while NGDC is made by dopant variation of 0, 10, 15, and 20 mol % Nd. Dry mixing was used as the method for powder preparation, and then the powder was compacted with pressure of 40 kN producing pellet-shaped samples with a diameter of 0,8 cm. The samples were sintered at 1200 °C, 1300 °C, and 1400 °C for 3, 4, and 5 hours. Sintered samples then examined by using X-ray-diffraction, SEM, and measured ionic-conductivity respectively.

The results showed that increased sintering temperature, sintering time, and value of mol % Gd2O3 can increase the value of ionic conductivity. The highest ionic conductivity values found in the samples with the composition of 20% mol Gd2O3 are equals to 0,0634 S/cm (LGDC), 0,0775 S/cm (YGDC), and 0,0861 S/cm (NGDC) at 600°C. Relationship between ionic conductivity and temperature can be expressed by the value of activation energy. Sample with the highest ionic conductivity has activation energy values of 0,54 eV (LGDC), 1,379 eV (YGDC), and 1,61 eV (NGDC).

Ionic conductivity optimum obtained respectively are 0,0634 S/cm, 0,0775 S/cm, dan 0,0861 S/cm at 600 °Cwhich are higher than minimum required for IT-SOFC. The activation energy calculated are 54,1×10-2 eV, 134×10-2 eV, and 161×10-2 eV. SEM result shows that less pores for YGDC compared to LGDC, which provides higher ionic conductivity result.