Polybenzimidazole Fuel Cell Technology

Glossary Polybenzimidazoles (PBIs) A class of polymers recognized for their excellent thermal and chemical stability, PBIs have historically been spun into fibers and woven into thermal protective clothing. In the past decade, PBIs have been cast into membranes and incorporated into fuel cells. - Polymer electrolyte membrane (PEM) Also referred to as Proton Exchange Membranes, PEMs are semipermeable membranes that conduct and transport protons while preventing the transmission of gases and electrons. - Membrane electrode assembly (MEA) A device that is comprised of a PEM that is sandwiched between two electrodes. - Conventional imbibing The original process of impregnating polymer membranes with dopants. The precast, fully dense membranes are placed in baths of dopants and allowed to absorb the dopant which assists in proton conductivity. - PPA process A recently developed imbibing process, PBIs are polymerized and cast in a polyphosphoric