Novel Nanocomposite Polymer Electrolyte Membranes for Fuel Cells

The state-of-the-art polymer electrolyte membrane (PEM) for fuel cells is based on perfluorosulfonic acid (PFSA) ionomers. Besides the high cost, PFSA materials face challenges such as decreased proton conductivity at high operating temperatures, water management issues and CO poisoning. Lower cost non-PFSA membranes with satisfactory performance have not been developed to date. The present proposal addresses this market need. The proposed Phase I program aims to develop a novel non-PFSA polymer electrolyte membrane, utilizing highly proton conducting heteropolyacids (HPAs) in an organic matrix in a way that has not been explored before. The novel HPA/polymer membrane has a unique structure that ensures that the active proton conducting species (HPA) are contained in a continuous interconnected channel. The overall objective of the Phase I program is to demonstrate the feasibility of a robust PEM that has high proton conductivity, low H2 and O2 cross-over and is highly durable for extended use in a fuel cell. NEI has partnered with a well- established fuel cell company to test membrane properties in a fuel cell assembly. The combined effort will advance the state-of-the-art of PEM for fuel cells. The Phase I program entails fabricating a set of PEM samples following the steps laid out in the proposal, characterizing the membrane structure, and evaluating its performance in a fuel cell environment. Membrane fabrication and structural characterization will be done at NEI, while membrane properties related to fuel cell performance will be carried out by our collaborator. Improving membrane performance while lowering cost will help overcome technical and economic obstacles in the commercialization of fuel cells. When the project is carried over into Phase III and beyond, fuel cells with improved proton exchange membranes will find more applications in the transportation, stationary, and portable sectors. The proposed polymer electrolyte membrane aims to expedite the implementation of PEM fuel cells in the transportation and stationary power sectors. Additionally, it will eliminate greenhouse gas emission. Commercial Applications and Other Benefits: The proposed novel PEM for fuel cells will have significantly improved proton conductivity and increased efficiency compared to state-of-the-art PEM based on PFSA ionomers. The membrane will be made of conventional materials that are not PFSA based, which means reduced material cost compared to PFSA ionomers. In addition, the developed membrane will have better high temperature (~120°C) performance than state-of-the-art PFSA membranes. Improving membrane performance while lowering the cost will expedite the implementation of PEM fuel cells, especially in the transportation sector. The proposed project will also support development of fuel cells for stationary power and auxiliary power applications.