Composite anodes for improved performance of a direct carbon fuel cell

Direct carbon fuel cell (DCFC) technology has the potential to double the electric efficiency and halve the CO2 emissions compared with conventional coal fired power plants. The anode performance, long term stability and cell scalability, in addition to fuel feed mechanism, are the major issues for the development of this technology. In this study, lanthanum strontium cobalt ferrite (LSCF) - silver composite anode was evaluated in a scalable version of the DCFC tubular cell in a bed of carbon powder. Ag was added to increase lateral conductivity of the anode and reduce ohmic losses. The cell was operated for 100 h during which it was twice thermally cycled. The performance degradation was studied by employing electrochemical and structural characterisation techniques. The composite anode, in comparison to LSCF anode, produced a 60% improvement in the power density. The sources of performance degradation of the cell were found to be the partial decomposition of the perovskite phase and anode microstructure changes as revealed by XRD and SEM analysis in addition to the loss of carbon contact to the anode resulting from the continuous carbon consumption in the cell. (C) 2015 Elsevier B.V. All rights reserved.