A fuel cell operates much like a battery but it can't be re-charged.
It uses the hydrogen stored in his tank. When the hydrogen finishes the tank should be re-filled (just as we do with the tank of our cars)
It consists of two electrodes a negative one and a positive one. The two electrodes are separated by an electrolyte. Ηydrogen atoms enter a fuel cell at the anode (positive electrode) and oxygen to the cathode (negative electrode). With the help of a catalyst hydrogen is split into protons and electrons. These charged particles follow different paths to the cathode. Electrons move through the external circuit producing electrical energy while the protons move through the electrolyte to the cathode, where they are connected with oxygen producing water and heat.