Fuel cell

A fuel cell is the electrochemical device which converts the chemical energy of the fuel into electricity without involving a combustion cycle. The first fuel cell was developed in 1839 in England by Sir William Grove. However, the application of fuel cell was first demonstrated by Francis T. Bacon in 1959 when his model generated 5 kW at 24 V. Its practical application began during the 1960s when the US space programme chose fuel cells over nuclear power and solar energy. Fuel cells provided power to the Gemini, Apollo and Skylab spacecraft, and continue to be used to provide electricity and water to space shuttles.

Principle operation of the acid electromagnetic cell

It is known that electrolysis of water produces hydrogen and oxygen. In a fuel cell the process is reversed where these gases combine in an electrochemical cell to generate electricity and water.

Fuel cell electrodes are made porous in order to provide a large number of pockets where the gas, the electrolyte and the electrode are in contact for chemical reaction. A fuel cell like any other battery consists of two electrodes and an electrolyte. However, a fuel cell differs from a battery in the sense that both the reactants (i.e. hydrogen and oxygen) are not permanently contained in the electrochemical cell but are fed into it from an external supply, when electric power is required. In fuel cells, platinum coated special graphite plates are used as the electrodes, separated by an electrolyte. The fuel is hydrogen gas which is supplied at the anode side where the hydrogen molecules are effectively reduced to hydrogen ions which move on into the electrolyte.

Electrons so liberated at the anode build up a negative potential and travel towards the cathode through an externally connected circuit. Oxygen gas is supplied at the cathode where it is reduced by hydrogen ions to produce water. Electrochemical reactions coupled with movement of hydrogen ions through the electrolyte generate an electric potential, which causes electric current to flow through the load. This reaction is exothermic, which results in heating up the cell. A stream of air is circulated on the cathode side of the cell which absorbs enough heat to maintain outlet air and steam at 180°C which is optimum for best performance of the cell.

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