Method of restoring performance of a fuel cell by providing reverse current pulses and corresponding fuel cell system

A system for operating a fuel cell comprises a fuel cell having an anode, an electrolyte and a cathode. An external power supply circuit connects the anode and cathode. There are a fi rst supplier for supplying a fuel to the anode, a second supplier for supplying oxidizer to the cathode, and a controller for intermittently providing reverse current charging to the fuel cell via the external power supply circuit.