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Fuel cells generate electrical power quietly and efficiently, without pollution. A fuel cell is an electrochemical energy conversion device. It produces electricity from various external quantities of fuel (on the anode side) and an oxidant (on the cathode side) in the presence of an electrolyte.  Fuel cell use combustion redox reactions to produce electricity, the reactans undergo separated half-reaction and the electrons transferred through an external circuit. 
The invention of fuel cells
Sir William Grove invented the first fuel cell in 1839. Grove knew that water could be split into hydrogen and oxygen by sending an electric current through it (a process called electrolysis). He hypothesized that by reversing the procedure you could produce electricity and water. He created a primitive fuel cell and called it a gas voltaic battery. After experimenting with his new invention, Grove proved his hypothesis. Fifty years later, scientists Ludwig Mond and Charles Langer coined the term fuel cell while attempting to build a practical model to produce electricity.
Advantage of Fuel cells
1. clean and portable sources electricity.
2. fuel cells very efficient, converting about 75% of bond energy in fuel into electricity. In contrast, electric poer plant converst about 40% of the bond energy of coal into electricity.
3. Silberberg, CHEMISTRY The Molecular Nature and Change, Second Edition, McGraw-Hill Higher Education, 2000