Fuel cells

 The cells which convert chemical energy of a fuel directly into electrical energy  are called fuel cells. These are the voltaic cells are used to generate electrical energy without the use of thermal devices like boiler, turbines. The conventional method of conversion of chemical energy of a fuel into electrical energy involves combustion of a fuel to liberate heat. A fuel cell system has a matching pair of electrodes. These are the anode, which supplies electrons, and the cathode, which absorbs electrons. Both electrodes must be immersed in and separated by an electrolyte. Electrolytes may be a liquid or a solid. A fuel, such as hydrogen, is supplied to the anode, where it is oxidized, producing hydrogen ions and electrons. Fuel cells are designed in such a way that the materials to be oxidised and reduced at the electrodes are stored outside the cell and are constantly supplied to the electrodes. One of the most successful fuel cells uses the reaction of hydrogen and oxygen to form water and is known as H2O2 fuel cell. The H2-O2 fuel cell is also called Bacon cell after the name of its inventor and it is used to Apollo space Missions. The water vapours produced during the reaction were condensed and added to drinking water supply for the astronauts. Fuel cells are pollution free working. There is no harmful or objectionable product formed in fuel cells. The efficiency of fuel cells is approximately 70-75%, which is much higher than the conventional cells.


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