Polymer electrolyte fuel cells (PEFCs) or proton exchange m- brane fuel cells (PEMFCs) have been suggested as alternatives to replace many existing energy conversion technologies, incl- inginternalcombustionenginesandbatteries.Themostsigni?cant advances in PEFC technology achieved in the last decade have occurredinareasrelatedtoautomotiveapplications, namelyco- start capabilities, enhanced durability and better understanding of watermanagementandmasstransportlosses. This volume of Modern Aspects of Electrochemistry is intendedtoprovideanoverviewofadvancementsinexperimental...