基于耗散粒子动力学的Nafion膜内质子扩散行为

Study of Proton Diffusion Behavior in Nafion Membrane Based on Dissipative Particle Dynamics

目的研究质子在Nafion117膜内的扩散行为及其最优水合形式.方法采用耗散粒子动力学(DPD)方法,利用Materials Studio软件构建质子在Nafion117膜内传递模型,通过介观模拟获取径向分布函数和扩散系数.结果当Nafion117膜含水量达到一定程度时,水通道相互连通,构成水合质子的传递通道;增加Nafion117膜的水含量和提高温度,有利于水合质子的扩散.结论质子在Nafion117膜内传递最优水合形式为H3O+(H2O)2,研究成果为全钒液流电池性能的提升提供了重要依据.

The purpose of this paper is to study the diffusion behavior of protons in Nafion 117 membrane and its optimal hydrated form.Based on the dissipative particle dynamics(DPD),the mesoscopic model of proton transfer in Nafion 117 membrane is built by Materials Studio software.The radial distribution function and diffusion coefficient are obtained by the mesoscopic simulation method.The results show that the water channels are interconnected to form a transfer channel of hydrated proton if the water content of Nafion 117 membrane reaches a certain degree.Increasing the water content of Nafion 117 membrane and increasing the temperature are conducive to the diffusion behavior of hydrated protons.The optimal transfer form of the hydrated form is H3O+(H2O)2 in Nafion 117 membrane.The results provide an important basis for improving the performance of all vanadium flow batteries.