A direct carbon fuel cell (DCFC) is a variation of the molten carbonate fuel cell (MCFC) which converts the chemical energy of carbon directly into electrical energy. Thus, the energy conversion efficiency is very high and correspondingly CO(2) emission is very low for given power output. DCFC as a high temperature fuel cell performs better at elevated temperatures (>800 degrees C) but because of the corrosive nature of the molten carbonates at elevated temperatures the degradation of cell components becomes an issue when DCFC is operated for an extended period of time. We explored the DCFC performance at lower temperatures (at 700 degrees C and less) using different sources of carbon, different compositions of electrolytes and some additives on the cathode surface to increase catalytic activity. Experiments showed that with petroleum coke as a fuel at low temperatures the ternary eutectic (43.4 mol % Li(2)CO(3) - 31.2 mol% Na(2)CO(3) - 25.4 mol % K(2)CO(3)) spiked by 20 wt % Cs(2)CO(3) performed better than any binary or ternary eutectics described in the published work by other researchers. Maximum power output achieved at 700 degrees C was 49 mW/cm(2) at a current density of 78 mA/cm(2) when modified cathode was fed with O(2)/CO(2) gases. Crown Copyright (C) 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.