Fuel Cells

19 Pages 4739 Words

and solid oxide) except for molten carbonate. The molten carbonate cell transfers the carbonate ions formed by the reaction of oxygen and carbon monoxide in the presence of electrons from the cathode side to the anode side to react with hydrogen and form water and two electrons for current. Thus the net flow of ions in the electrolyte is opposite of that in all other fuel cells, but since the current flows in the same direction as the other fuel cell types, the anode and cathode keep their polarity.
The fuel cell was first invented in 1839 by Sir William Grove, a professor of experimental philosophy at the Royal Institution in London. He tested what turned out to be the precursor to the phosphoric acid fuel cell by enclosing platinum in tubes of hydrogen and oxygen gas while submerging the tubes in sulfuric acid. (Fig. 3) Unfortunately, he was hampered by the inconsistency of cell performance (a common feature of cells today), but realized the importance of the three phase contact (gas, electrolyte and platinum) to energy generation. He spent most of his time searching for an electrolyte that would produce a more constant current. He found several electrolytes which produced current, but still struggled with consistent results. He also noted the potential of the energy production method commercially if hydrogen could replace coal and wood as energy sources (1).
Since that time, researchers world wide have attempted to increase cell performance electrically, chemically as well as physically. Their experiments ranged from an improved three phase contact to smart materials and the adoption of off gases from other power sources. After over 150 years of research, fuel cells can be divided into five major categories named after the electrolyte used in each; alkaline, solid polymer, phosphoric acid, molten carbonate and solid oxide. The five types resulted from the knowledge that heat accelerates chemical reaction rates and thus the electric...