The Electrochemical Principle of Fuel Cells

Fuel cells work with the movement of ions across their electrolyte when air and fuel are supplied to the cell. Using SOFC technology as an example, air is ionized at the cathode and sets up a flow of oxygen ions through the electrolyte.

When the ions reach the fuel at the anode they oxidize the hydrogen to H2O and the CO to CO2. In doing so they release electrons, and if the anode and cathode are connected to an external circuit, this flow of electrons becomes dc current. This process continues as long as fuel and air are supplied to the cell.

To supply the air and fuel an air blower and fuel compressor are usually needed. Other equipment, such as a heat exchanger, start-up and shutdown systems, instrumentation and controls, as well as safety equipment are also needed for a safe and reliable power system.