Deposition of a Thin-Film CGO Electrolyte for Solid Oxide Fuel Cells

Reducing the operating temperature of solid oxide fuel cells (SOFCs) from 800-1000°C is one of the main SOFC research goals. It can be achieved by lowering the thickness of an electrolyte (ZrO2:Y2O3 (YSZ) is widely used as electrolyte material). On the other hand the problem can be solved by using of another electrolyte material with high ionic conductivity at intermediate temperatures. Therefore the present study deals with magnetron sputtering of ceria gadolinium oxide (CGO), which has a higher conductivity compared to YSZ. The microstructure of CGO layers deposited on porous NiO/YSZ substrates by reactive magnetron sputtering of Ce:Gd cathode is investigated. Current voltage characteristics (CVC) of a fuel cell with NiO/YSZ anode, CGO electrolyte and LSCF/CGO cathode were obtained. It was shown that the power density of a fuel cell with CGO electrolyte weakly depends on the operating temperature in the range of 650-750°C in contradistinction to YSZ electrolyte, and is about 600-650 mW/cm2.