What Is a Fuel Cell?
A fuel cell is essentially a battery that does not need recharging. As long as hydrogen and oxygen fuel are supplied, it can continue to supply heat and an electrical current indefinitely. A fuel cell consists of an electrolyte (a conductor of charged particles) between an anode (negatively charged electrode) and a cathode (a positively charged electrode). Once activated by a catalyst, the hydrogen gas separates into protons and electrons, and the electrons are conducted through a wire, forming an electrical current. The protons move through the electrolyte, where they combine with oxygen and other electrons to produce heat and a water byproduct.
A Schematic Fuel Cell
Picture Courtesy of the University of Illinois.