Proton exchange membrane nanocomposites

Organic-inorganic nanocomposite proton conducting membranes have been an important thrust in the search for novel materials that outperform the state-of-the-art all-polymer membranes in fuel cells. Nanocomposite proton exchange membranes may provide routes to increased conductivity at low relative humidity, decreased methanol permeability without a conductivity penalty, enhanced mechanical properties, and long-term durability. A variety of nanocomposite architectures have been explored for fuel cell membranes including polymers of varying chemical compositions including Nafion, inert polymer supports, inorganic additives that serve as desiccants, proton conducting inorganic additives, and additives that are primarily designed to impeded methanol transport. This review highlights recent advances in the understanding of the unique properties of nanocomposite proton exchange membranes and how the coupling between the organic and inorganic phases can enhance the properties a nanocomposite material for targeted application in fuel cells. Original data is also presented in terms of understanding how inorganic phases influence the binding of water within the polymer and thus the transport properties of the nanocomposite.