Kinetic Monte Carlo simulations of proton conductivity

TL;DR

This paper uses kinetic Monte Carlo simulations to analyze proton diffusion mechanisms, emphasizing the importance of reorientation and diffusion process frequencies, and applies the model to proton transport in polymer membranes.

Contribution

It introduces a detailed microscopic model of proton conductivity that highlights the role of process frequencies and tests it on polymer electrolyte membranes.

Findings

Reorientation and diffusion frequencies are crucial for conductivity.

Proton concentration affects transport properties.

Model successfully applied to polymer electrolyte membranes.

Abstract

The kinetic Monte Carlo method is used to model the dynamic properties of proton diffusion in anhydrous proton conductors. The results have been discussed with reference to a two-step process called the Grotthuss mechanism. There is a widespread belief that this mechanism is responsible for fast proton mobility. We showed in detail that the relative frequency of reorientation and diffusion processes is crucial for the conductivity. Moreover, the current dependence on proton concentration has been analyzed. In order to test our microscopic model the proton transport in polymer electrolyte membranes based on benzimidazole C7H6N2 molecules is studied.