“WHAT TO KNOW ABOUT… Fuel cell stacks”
The fuel cell stack is the device which provides the electric engine of Fuel Cell Electric Vehicles (FCEVs) with electricity.
In the fuel cell gaseous hydrogen is oxidized and converted into electricity and heat. In order to avoid damaging the fuel cell, the produced heat has to be removed through an adapted cooling system.
The fuel cell can be seen as an electrochemical reactor composed of two electrodes, the anode and the cathode, which are separated by an electrolyte (an electricity conducting medium which allows the movement of matters in form of ions). PEMFC (proton exchange membrane fuel cell) use a proton exchange membrane as a solid electrolyte. The structure and conductivity of the membranes determine their operating conditions in terms of temperature and humidity. This type of fuel cells is the more adapted for automotive uses.
Following reactions occur in the fuel cell:
At the anode: gaseous hydrogen (H2) is oxidized and protons enter the electrolyte and are transported to the cathode.
At the cathode: the supplied oxygen reacts with the protons by producing water and electrons which flow in the external circuit to supply the engine with electricity.
The exhaust of fuel cells is only water vapour. Neither air pollutants nor CO2 are emitted, which makes FCEVs a solution for environment, heath and climate friendly transport.