SOFC Stacks for Mobile Applications

Abstract

Solid Oxide Fuel Cells (SOFCs) are gaining more and more importance as auxiliary power units (APU), e.g. for passenger cars, trucks and airplanes. In this context, the main challenge is the development of SOFC stacks, which fulfill the strong requirements for mobile applications, e.g. low weight and volume, high power densities with reformate gases and low degradation rates under dynamic operating conditions. The paper presents results of investigations of SOFC short stacks and stacks for mobile applications, which were developed in an industrial consortium. The stack design is based on stamped metal sheet bipolar plates, into which anode supported cells are integrated. The stacks were electrochemically characterized mainly by long-term measurements, by current-voltage measurements and by impedance spectroscopy. The SOFC stacks were operated at different temperatures, varying fuel gas compositions and different fuel gas flow rates. The electrochemical performance, the uniformity, the voltage losses and the degradation mechanisms of the short stacks were analyzed.