All-solid-state direct carbon fuel cells with thin yttrium-stabilized-zirconia electrolyte supported on nickel and iron bimetal-based anodes

Solid oxide fuel cells (SOFCs) with thin yttrium-stabilized-zirconia (YSZ) electrolyte supported on composite anode of nickel-iron bimetal and YSZ are prepared and operated directly on Fe-loaded activated carbon fuel, without any liquid medium or purging gas. The composition of the anode is represented as Ni1-xFexO delta (x = 0, 0.05, 0.1, 0.2, 0.3)-YSZ. Experiment result shows that such kind of all-solid-state direct carbon solid oxide fuel cells (DC-SOFCs) perform well at 800 degrees C, giving maximum output power densities in the range of 425-529 mW cm(-2). Similar to the case of a SOFC operated on hydrogen fuel, a small amount of Fe addition into the Ni-based anode can improve the performance of a DC-SOFC and the optimum composition is x = 0.1. A DC-SOFC with Ni0.9Fe0.1O delta-YSZ anode, loaded with 2.5 g Fe-loaded activated carbon fuel, is steadily operated at a constant current density of 0.1 A cm(-2) for 15 h at 800 degrees C. The anodes and the DC-SOPCs are characterized through XRD, AC impedance spectroscopy, and SEM measurements. The superior performance of the Fe-added anode is analyzed accordingly. (c) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.