Zhang Jianfeng, Li Zhinian, Wu Yuanfang, Guo Xiumei, Ye Jianhua, Yuan Baolong, Wang Shumao, Jiang Lijun
General Research Institute for Nonferrous Metals 2 Xinjiekou Wai Street Beijing 100088 China
RSC Adv. 2019 Jan 2;9(1):408-428. doi: 10.1039/c8ra05596c. eCollection 2018 Dec 19.
Magnesium hydride and its compounds have a high hydrogen storage capacity and are inexpensive, and thus have been considered as one of the most promising hydrogen storage materials for on-board applications. Nevertheless, Mg/MgH systems suffer from great drawbacks in terms of kinetics and thermodynamics for hydrogen uptake/release. Over the past decades, although significant progress has been achieved with respect to hydrogen sorption kinetics in Mg/MgH systems, their high thermal stability remains the main drawback, which hinders their practical applications. Accordingly, herein, we present a brief summary of the synthetic routes and a comprehensive overview of the advantages and disadvantages of the promising strategies to effectively tune the thermodynamics of Mg-based materials, such as alloying, nanostructuring, metastable phase formation, changing reaction pathway, and nano Mg-based composites. Among them nanostructuring and metastable phase formation, which have the superiority of changing the thermodynamics without affecting the hydrogen capacity, have attracted increasing interest in this field. To further optimize the hydrogen storage performance, we specially emphasize novel nanostructured materials, which have the advantage of combining alloy engineering, nanostructuring and the synergistic effect to change the thermodynamics of Mg/MgH to some extent. Furthermore, the remaining challenges and the directions of further research on MgH, including the fundamental mechanism of the Mg-H bond instability, advanced synthetic routes, stabilizing nanostructures, and predicting novel composite materials, are proposed.
氢化镁及其化合物具有高储氢容量且价格低廉，因此被认为是车载应用中最具潜力的储氢材料之一。然而，Mg/MgH体系在氢吸收/释放的动力学和热力学方面存在很大缺陷。在过去几十年里，尽管Mg/MgH体系在氢吸附动力学方面取得了显著进展，但其高热稳定性仍然是主要缺点，这阻碍了它们的实际应用。因此，在本文中，我们简要总结了合成路线，并全面概述了有效调控镁基材料热力学的几种有前景策略的优缺点，如合金化、纳米结构化、亚稳相形成、改变反应途径以及纳米镁基复合材料。其中，纳米结构化和亚稳相形成在不影响储氢容量的情况下具有改变热力学的优势，在该领域引起了越来越多的关注。为了进一步优化储氢性能，我们特别强调新型纳米结构材料，其优点是结合了合金工程、纳米结构化以及协同效应，能在一定程度上改变Mg/MgH的热力学。此外，还提出了MgH研究中 remaining challenges以及进一步研究的方向，包括Mg - H键不稳定性的基本机制、先进的合成路线、稳定的纳米结构以及新型复合材料的预测。 （注：原文中“remaining challenges”直接保留英文未翻译，疑为有误，若改为“剩余挑战”之类表述会更通顺，但按要求未添加其他解释说明。）
