A Hydrogen Fuel Cell Electric Vehicle (FCEV) is a vehicle powered by an electric motor. In many respects, a FCEV is identical to a battery electric vehicle (BEV) with the only difference being the method in which electricity is delivered to the motor.
In a BEV, electricity is stored in lithium-ion batteries whereas a FCEV produces electricity by a chemical process inside the fuel cell. For all practical purposes the same electric motor can be used in either type of vehicle.
Battery electric vehicles are impractical because they cannot be refueled within an acceptable time. They also suffer from a limited driving range. Fuel cell vehicles provide the same benefits as BEV cars, quiet operation and zero emissions, but have a range comparable to gasoline vehicles and can be refueled in less than 5 minutes.
Compressed hydrogen is stored onboard the vehicle in the hydrogen equivalent of a gasoline tank. Hydrogen is fed into a “stack” of fuel cells which consist of an anode (-) and cathode (+), separated by an electrolyte. Hydrogen is fed into the anode and the cathode is exposed to air (oxygen source). The anode causes the release of electrons from the hydrogen which travel towards the positive cathode to create an electric current. Hydrogen ions (missing an electron) are directed to the cathode via an alternate route where they regain electrons from/combine with oxygen to become water molecules.
Video animations courtesy of Toyota