Molten Carbonate Fuel Cells

Abstract

Article Outline Glossary Definition of the Subject Introduction Components of MCFC Performance Analysis Future Directions Bibliography Glossary Activation overpotential Voltage loss due to slow chargetransfer rate on the electrode surface Anode A porous electrode where hydrogen is oxidized with carbonate ions CO 2À 3 À Á to steam and carbon dioxide Basicity Log(K d) of molten carbonates where K d is the equilibrium constant of the reaction CO 2À 3 Â Ð k d O 2À þ CO 2 similarly to the pH of aqueous solutions Cathode A porous electrode where oxygen is reduced with carbon dioxide to carbonate ions CO 2À 3 À Á Effectiveness factor (e) A ratio of overpotential without pore diffusion resistance to that with pore diffusion resistance Electrolyte Molten carbonates providing ionic paths for the electrode reactions with combinations of Li 2 CO 3 , Na 2 CO 3 , and K 2 CO 3 Exchange current density (i o) An actual current density of an electrode at net zero current indicating catalytic activity of the electrode Fuel cell A system of continuous electrochemical energy conversion from chemical energy to electricity mostly by oxidation of hydrogen and reduction of oxygen Internal resistance Electrical resistance of cell components Mass transfer Transport of reactants and products to/from the electrode surface Matrix Ceramic porous material holding molten carbonates by capillary forces Ohmic loss (IR) Voltage loss due to electrical resistance of cell components