Development of a Press-Type Direct Carbon Fuel Cell for Higher and More Stable Power Output

Abstract

© 2018 The Electrochemical Society. A triple phase boundary reaction site was formed in a direct carbon fuel cell (DCFC) when the char wetted by molten carbonate was in contact with the anode. It has been reported that gases such as CO2 covered the anode during discharge, leading to high anode overpotential. In this study, a press-type DCFC was developed to overcome this issue. By pressing the perforated anode on the carbon/carbonate-packed bed, it was expected that the carbon particles would remain in contact with the anode, while the gas products would be released through the perforation due to their buoyancy. As a result, the power output achieved with the press-type DCFC was higher and more stable as compared with the conventional DCFC. The anodic impedance spectra showed that the arc size of the press-type DCFC was much smaller than that of the conventional DCFC. This was particularly noticeable at the low frequencies, indicating the anode resistance caused by the mass transfer processes including the gas products and the contact between the anode and carbon particles to be significantly less in the press-type DCFC.