Intermetallic Compounds Synthesized by Mechanical Alloying for Solid-State Hydrogen Storage: A Review

Abstract

Hydrogen energy is a very attractive option in dealing with the existing energy crisis. For the development of a hydrogen energy economy, hydrogen storage technology must be improved to over the storage limitations. Compared with traditional hydrogen storage technology, the prospect of hydrogen storage materials is broader. Among all types of hydrogen storage materials, solid hydrogen storage materials are most promising and have the most safety security. Solid hydrogen storage materials include high surface area physical adsorption materials and interstitial and non-interstitial hydrides. Among them, interstitial hydrides, also called intermetallic hydrides, are hydrides formed by transition metals or their alloys. The main alloy types are A2B, AB, AB2, AB3, A2B7, AB5, and BCC. A is a hydride that easily forms metal (such as Ti, V, Zr, and Y), while B is a non-hydride forming metal (such as Cr, Mn, and Fe). The development of intermetallic compounds as hydrogen storage materials is very attractive because their volumetric capacity is much higher (80–160 kgH2m−3) than the gaseous storage method and the liquid storage method in a cryogenic tank (40 and 71 kgH2m−3). Additionally, for hydrogen absorption and desorption reactions, the environmental requirements are lower than that of physical adsorption materials (ultra-low temperature) and the simplicity of the procedure is higher than that of non-interstitial hydrogen storage materials (multiple steps and a complex catalyst). In addition, there are abundant raw materials and diverse ingredients. For the synthesis and optimization of intermetallic compounds, in addition to traditional melting methods, mechanical alloying is a very important synthesis method, which has a unique synthesis mechanism and advantages. This review focuses on the application of mechanical alloying methods in the field of solid hydrogen storage materials.

Nanoparticle and Nanostructure Synthesis and Controlled Growth Methods

“…The particle shape cannot be fully controlled by this method [99]. Mechanical alloying and reactive milling are simple, require few machines, and the material is easy to handle [100]. Their main advantage is that no waste is released into the environment.…”

Heat Capacity Function, Enthalpy of Formation and Absolute Entropy of Mg(AlH4)2

“…Solid-state hydrogen storage appears beneficial in cases that require high volumetric density, but all types of materials investigated, be it classical or complex metal hydrides, light element hydrides and others, come with their specific issues. [1][2][3][4][5][6] Light metal complex hydrides have been intensively investigated with respect to their suitability to store hydrogen ever since Bogdanović and Schwickwardi [7] discovered the reversible hydrogenation in a complex metal hydride system based on Ti doped NaAlH 4 . These studies were mainly focused on NaAlH 4 and LiAlH 4 , leaving the alanates of the alkaline earth metals less explored.…”

“…However, hydrogen is not yet widely used for energy storage or supply because its storage in many technical settings remains a challenge. Solid‐state hydrogen storage appears beneficial in cases that require high volumetric density, but all types of materials investigated, be it classical or complex metal hydrides, light element hydrides and others, come with their specific issues [1–6] . Light metal complex hydrides have been intensively investigated with respect to their suitability to store hydrogen ever since Bogdanović and Schwickwardi [7] discovered the reversible hydrogenation in a complex metal hydride system based on Ti doped NaAlH 4 .…”

A Computational Investigation of Lithium‐Based Metal Hydrides for Advanced Solid‐State Hydrogen Storage

“…[35,36] The future of hydrogen storage will likely consist of a combination of different techniques. The solid-state hydrogen storage method utilizes materials such as complex hydrides, [37] chemical hydrides, [38] magnesium-based alloys, [39] and intermetallic compounds [40] to store hydrogen. Solid-state hydrogen storage technologies have comparable high storage capacity and can be utilized in industrial sectors.…”