Desenvolvimento e testes de células a combustível suportadas pelo anodo com eletrólitos depositados por spin-coating

Abstract

The present study shows the development of anode-supported solid oxide fuel cells (SOFC) using conventional yttria stabilized zirconia (YSZ) materials and wet chemistry techniques for both the synthesis and deposition of components. Electrodes have been synthesized at IPEN by using wet chemistry techniques, which result in controlled phase composition and homogeneous particle size distribution. Ceramic suspensions of YSZ were developed for their deposition by spin coating to attain ~10 μm thick layers with a reduced number of coating steps. Half-cells (anode support/electrolyte) are co-sintered in the 1300 - 1500°C temperature range. Strontium-doped lanthanum manganite cathodes were deposited by wet powder spray of ethanol-based suspensions, followed by a heat treatment at 1200°C. The electrochemical properties of single SOFCs were measured in the 600-800°C temperature range, using humidified hydrogen (3 vol. % H2O) as fuel and air as the oxidant. The main results evidenced that electrolyte layers are dense and homogeneous, as inferred from scanning electron microscopy analysis. Single SOFCs showed open circuit voltage of ~1V and good performance at intermediate temperatures, further confirming the gas tightness and good quality of spin coated electrolyte layers.