Abstract
The perfluorosulfonic acid(PFSA)membrane doped with two-dimensional conductive filler Ti3C2Tx is a fuel cell proton exchange mem-brane with high application potential.Experimental studies showed that the proton conductivity of Nafion/Ti3C2Tx composite membrane is im-proved significantly compared with that in pure Nafion.However,the microscopic mechanism of doping on the enhancement of membrane per-formance is remain unclear now.In this work,molecular dynamics simulation was used to investigate the microscopic morphology and proton transport behaviors of Nafion/Ti3C2Tx composite membrane at the molecular level.The results shown that there were significant differences about the diffusion kinetics of water molecules and hydroxium ions in Nafion/Ti3C2Tx at low and high hydration levels in the nanoscale region.With the increase of water content,Ti3C2Tx in membrane was gradually surrounded by ambient water molecules to form a hydration layer,and forming a relatively continuous proton transport channel between Nafion polymer and Ti3C2Tx monomer.The continuous proton transport chan-nel could increase the number of binding sites of proton and thus achieving high proton conductivity and high mobility of water molecules at higher hydration level.The current work can provide a theoretical guidance for designing new type of Nafion composite membranes.
基金项目
National Key R&D Program of China(2020YFB1505500)
National Key R&D Program of China(2020YFB1505503)
万方数据