ABSTRACT
We have proposed an energy storage system using SOFC-SOE (Solid Oxide Fuel Cells and Solid Oxide Electrolysis Cells) reversible cells, where the cells work alternately as fuel cells and as steam electrolysis cells. This paper describes the basic test facility and its results. Test cells were 23 mm in diameter and 200μm in thickness. Solid oxide electrolyte, 8 mol% yttria stabilized zirconia (YSZ), was manufactured by a tape casting method. A Ni/YSZ-cermet electrode and a Sr-doped LaMnO3 (LSM) electrode were both screen printed and sintered at elevated temperatures. A single cell was put in an electric furnace and the temperature was maintained at 1000°C. Hydrogen gas and air were provided for fuel cell tests. Conversely, steam and air were provided for the electrolysis cell tests. For both conditions, polarization measurements were carried out using the current interruption method. Effects of electrode compositions on overpotentials and solid electrolyte degradation were also evaluated.
