Authors: S.J. Paddison, M. Eikerling, T.A. Zawodzinski_Jr. and L.R. Pratt
Affilation: Los Alamos National Laboratory, United States
Pages: 115 - 116
Keywords: molecular modeling, proton conduction, polymer electrolyte membranes, Nafion®
Molecular mechanisms of proton conduction in polymer electrolyte membranes are addressed by ab initio molecular dynamics calculations, utilizing the VASP program, on the model system trifluoromethane sulfonic acid monohydrate solid. After establishing that the experimental crystal is stably simulated, these computations are used to seek crystal defects that might contribute to proton conduction. The most favorable defect found involves formation of a Zundel ion, H5O2 +, and H-bonded, paired sulfonate groups. The energy of this defect is 0.3-0.4eV above the energy of the undefected solid, in suggestive agreement with the observed activation energy for proton transport in minimally hydrated Nafion®.