Research Projects

Membrane electrolytes in fuel cell electrolytes (PEFC) are crucial for overall performance, and Nafion is the only stable electrolyte used for PEFC due to its high proton conductivity and superior mechanical and physio-chemical properties. However, Nafion has drawbacks at higher temperatures and fuel cross-over due to larger ionic cluster domains and radical attack during long-term operation. Researchers are working to develop more cost-competitive membrane electrolytes for its replacement. Membrane modification strategies include ionic cross-linking, covalent crosslinking, and preparing composite membranes. One new approach is using mechanically reinforced composite membranes with polytetrafluoroethylene (PTFE) backbones to improve high temperature performance. This porous PTFE film is chemically, mechanically, and dimensionally stable, potentially increasing long-term durability in demanding cell operation. Nafion has the best possible ionic conductivity values in the 100-200 mS cm-1 range and mechanical stability for PEFC during 10,000-hour durability. However, additives like silica, zirconia, zeolites, and carbon nanostructures can induce rigidity, reducing membrane stability. To improve Nafion membrane characteristics, researchers need to derive a stable substrate for re-inforcement of PFSA ionomers, such as PTFE support. This proposal proposes systematic reinforcement of short-chain ionomers and sulfophenylated polyphenylenes with expanded polymer substrate and incorporates radical scavengers to prevent radical attack on membranes in PEFC, even at low relative humidity.