REVERSIBLE SHUNTS FOR OVERCHARGE PROTECTION IN POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

Described herein is a polymer-electrolyte-membrane fuel cell (PEMFC) that incorporates a shunt into the membrane separator that becomes electronically conductive around a well-defined anodic onset potential, thereby preventing excessive anodic potentials at the positive electrode that would otherwise drive deleterious parasitic reactions such as catalyst dissolution or catalyst and carbon oxidation.