Fuel cells and batteries

Fuel cells and batteries convert chemical energy to electrical energy. These are the devices which possess greater efficiency comparing with other energy converters. The importance of devices like these is of prime when we discuss coupling of energy conversion devices such as wind mills and solar cells. Fuel cells employ hydrogen fuel and oxygen oxidant. These two gases are pumped into a cell which contains cathode and an anode with an electrolyte. An external electrical load will draw electric current. Here electric current is due to the electrons which are separated from the hydrogen nucleus at the anode flow. These electrons get absorbed at the cathode by the hydrogen and oxygen ions forming H2O. The electrolyte is necessary which is responsible for the continuity of the circuit. At the initial stage fuel cells were used for manned space missions.