Ouma Cecil Naphtaly Moro, Obodo Kingsley Onyebuchi, Bessarabov Dmitri
HySA-Infrastructure, Faculty of Engineering, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
Membranes (Basel). 2022 Oct 27;12(11):1051. doi: 10.3390/membranes12111051.
Anion-exchange membranes (AEMs) are key components in relatively novel technologies such as alkaline exchange-based membrane fuel cells and AEM-based water electrolyzers. The application of AEMs in these processes is made possible in an alkaline environment, where hydroxide ions (OH) play the role of charge carriers in the presence of an electrocatalyst and an AEM acts as an electrical insulator blocking the transport of electrons, thereby preventing circuit break. Thus, a good AEM would allow the selective transport of OH while preventing fuel (e.g., hydrogen, alcohol) crossover. These issues are the subjects of in-depth studies of AEMs-both experimental and theoretical studies-with particular emphasis on the ionic conductivity, ion exchange capacity, fuel crossover, durability, stability, and cell performance properties of AEMs. In this review article, the computational approaches used to investigate the properties of AEMs are discussed. The different modeling length scales are microscopic, mesoscopic, and macroscopic. The microscopic scale entails the ab initio and quantum mechanical modeling of alkaline AEMs. The mesoscopic scale entails using molecular dynamics simulations and other techniques to assess the alkaline electrolyte diffusion in AEMs, OH transport and chemical degradation in AEMs, ion exchange capacity of an AEM, as well as morphological microstructures. This review shows that computational approaches can be used to investigate different properties of AEMs and sheds light on how the different computational domains can be deployed to investigate AEM properties.
阴离子交换膜（AEMs）是相对较新技术中的关键组件，如基于碱性交换的膜燃料电池和基于AEM的水电解槽。AEMs在这些过程中的应用在碱性环境中成为可能，在这种环境中，氢氧根离子（OH⁻）在电催化剂存在的情况下充当电荷载体，而AEM则作为电绝缘体，阻止电子传输，从而防止电路中断。因此，良好的AEM应允许OH⁻的选择性传输，同时防止燃料（如氢气、酒精）渗透。这些问题是AEMs深入研究的主题——包括实验研究和理论研究——特别强调AEMs的离子电导率、离子交换容量、燃料渗透、耐久性、稳定性和电池性能。在这篇综述文章中，讨论了用于研究AEMs性质的计算方法。不同的建模长度尺度有微观、介观和宏观。微观尺度涉及碱性AEMs的从头算和量子力学建模。介观尺度涉及使用分子动力学模拟和其他技术来评估AEMs中的碱性电解质扩散、AEMs中的OH⁻传输和化学降解、AEM的离子交换容量以及形态微观结构。这篇综述表明，计算方法可用于研究AEMs的不同性质，并阐明如何部署不同的计算领域来研究AEMs的性质。
