Department of Chemical & Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur-Sultan 010000, Kazakhstan.
Laboratory of Advanced Materials and Systems for Energy Storage, Center for Energy and Advanced Materials Science, National Laboratory Astana, Nazarbayev University, Nur-Sultan 010000, Kazakhstan.
Molecules. 2022 Jun 2;27(11):3574. doi: 10.3390/molecules27113574.
Anion Exchange Membrane (AEM) fuel cells have attracted growing interest, due to their encouraging advantages, including high power density and relatively low cost. AEM is a polymer matrix, which conducts hydroxide (OH-) ions, prevents physical contact of electrodes, and has positively charged head groups (mainly quaternary ammonium (QA) groups), covalently bound to the polymer backbone. The chemical instability of the quaternary ammonium (QA)-based head groups, at alkaline pH and elevated temperature, is a significant threshold in AEMFC technology. This review work aims to introduce recent studies on the chemical stability of various QA-based head groups and transportation of OH- ions in AEMFC, via modeling and simulation techniques, at different scales. It starts by introducing the fundamental theories behind AEM-based fuel-cell technology. In the main body of this review, we present selected computational studies that deal with the effects of various parameters on AEMs, via a variety of multi-length and multi-time-scale modeling and simulation methods. Such methods include electronic structure calculations via the quantum Density Functional Theory (DFT), ab initio, classical all-atom Molecular Dynamics (MD) simulations, and coarse-grained MD simulations. The explored processing and structural parameters include temperature, hydration levels, several QA-based head groups, various types of QA-based head groups and backbones, etc. Nowadays, many methods and software packages for molecular and materials modeling are available. Applications of such methods may help to understand the transportation mechanisms of OH- ions, the chemical stability of functional head groups, and many other relevant properties, leading to a performance-based molecular and structure design as well as, ultimately, improved AEM-based fuel cell performances. This contribution aims to introduce those molecular modeling methods and their recent applications to the AEM-based fuel cells research community.
阴离子交换膜（AEM）燃料电池由于其高功率密度和相对低成本等优势，引起了越来越多的关注。AEM 是一种聚合物基质，它传导氢氧根（OH-）离子，防止电极物理接触，并具有带正电荷的头基（主要是季铵（QA）基团），与聚合物主链共价结合。在碱性 pH 值和高温下，基于季铵（QA）的头基的化学不稳定性是 AEMFC 技术的一个重要门槛。本综述工作旨在介绍通过建模和模拟技术，在不同尺度上研究各种基于 QA 的头基在 AEMFC 中 OH-离子的输运和化学稳定性的最新研究进展。首先介绍了基于 AEM 的燃料电池技术的基本理论。在本综述的主体部分，我们介绍了通过各种多长度和多时间尺度的建模和模拟方法处理各种参数对 AEM 影响的选定计算研究。这些方法包括通过量子密度泛函理论（DFT）、从头算、经典全原子分子动力学（MD）模拟和粗粒化 MD 模拟进行电子结构计算。所研究的处理和结构参数包括温度、水合水平、几种基于 QA 的头基、各种类型的基于 QA 的头基和主链等。如今，有许多用于分子和材料建模的方法和软件包。这些方法的应用可能有助于理解 OH-离子的输运机制、功能头基的化学稳定性以及许多其他相关性质，从而实现基于性能的分子和结构设计，最终提高基于 AEM 的燃料电池性能。本贡献旨在向基于 AEM 的燃料电池研究界介绍这些分子建模方法及其最近在该领域的应用。
