Molten carbonate fuel cell with separate CO2 gas supply

A molten carbonate fuel cell (MCFC) unit cell design (i-MCFC) is introduced . In the i-MCFC, the CO2 gas necessary for the cathode operation is supplie d separately from the cathode gas by means of an additional gas channel thr ough the electrolyte tile (matrix). Therefore the i-MCFC cathode can be ope rated on air or 100% O-2. With the i-MCFC an MCFC with extended potential f or integration in other systems, trigeneration, is obtained. Furthermore wh en adding a small appropriate partial CO2 pressure (10(-3) bar) to the cath ode gas, the NiO dissolution which is a main problem limiting the MCFC life time, is solved even when the cell is operated at elevated pressures. Labor atory scale cells (3 cm(2)) built according to the i-MCFC design, operated at 100% O-2 cathode gas, performed better than the same cells driven under standard MCFC conditions. When using air as cathode gas the performance is comparable. Our cells suffered from a large ohmic resistance, but the expec ted large diffusion loss due to O2- and/ or CO2 diffusion was not observed. (C) 1999 The Electrochemical Society. S1099-0062(98)06-094-5. All rights r eserved.