The hybrid direct carbon fuel cell (HDCFC), combining molten carbonate fuel cell and solid oxide fuel cell technology, is capable of converting solid carbon directly into electrical energy without intermediate reforming. Here, we report the investigation of the HDCFC with yttria stabilized zirconia (YSZ) electrolyte, NiO-YSZ anode and lanthanum strontium manganite (LSM) cathode using the eutectic mixture of 62 mol% Li(2)CO(3) and 38 mol% K(2)CO(3). An open circuit voltage (OCV) of 0.71 V at 800 degrees C is recorded without the carbonate which increases to 1.15-1.23V in the presence of the carbonate at the same temperature. In addition, the cell's OCV is enhanced not only by the thermal history but also by the carbonate, which is in excess of 1.57 V after the high temperature treatment. Electrochemical performance analysis indicates a suitable amount of the carbonate enhanced the carbon oxidation. With 1 mm robust thick electrolyte and commercial carbon, the cell (1.13 cm(2) active area) generates the peak density of 50 mW cm(-2) at 800 degrees C. There are significant losses from electrolyte resistance, which would be overcome by the application of a thinner electrolyte. (C) 2010 Elsevier B.V. All rights reserved.