Abstract Hydrogen has been considered as a potential candidate for the replacement of fossil fuels in future due to its renewability, abundance, ease in production, environmental friendliness and high energy efficiency. In this regard, chemical storage of hydrogen in solid state of metal hydrides is the safest method for stationary and portable applications since these can be functioned at lower pressure and ambient temperature. Among the desirable metal hydrides, the intermetallic compound TiFe of cubic CsCl-type structure is well known for absorbing hydrogen reversibly up to 1.9 wt.% to form β-FeTiH and γ-FeTiH2 phases. In this paper, we have discussed the historic background outlining the recent developments on the microstructural modifications, activation kinetics and processing routes of TiFe intermetallic alloys toward the improvement of hydrogenation properties. An in-depth microstructural analysis of TiFe alloys has been presented in terms of crystallography, hydride phase formation and hydrogenation mechanisms. The rate-controlling steps for the mechanisms of (de)hydrogenation processes of TiFe intermetallics have been explained in details. It was found that the rate-controlling steps of the hydriding reaction were dependent on the fraction of β-hydride phase. Intensive research activities were carried out to improve the first hydrogenation kinetics that can be categorized into two groups: alloying and mechanical activation. The mechanisms for improved hydrogenation kinetics in both cases have been explained. Lastly, various fabrication processes to produce TiFe alloys have been presented and correlated with cost-effectiveness and hydrogen-storage capability. Therefore, the focus of this article is to present the basic knowledge and recent developments on TiFe intermetallic alloys for future hydrogen-storage applications which will be beneficial to researchers and practitioners in the field of interest.

中文翻译：

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用于固态储氢的 TiFe 金属间化合物概述：微观结构、氢化和制造工艺

摘要 氢因其可再生、储量丰富、易于生产、环境友好和高能效等优点，被认为是未来替代化石燃料的潜在候选者。在这方面，金属氢化物固态氢的化学储存是固定和便携式应用最安全的方法，因为它们可以在较低的压力和环境温度下运行。在理想的金属氢化物中，立方 CsCl 型结构的金属间化合物 TiFe 以可逆地吸收高达 1.9 wt.% 的氢以形成 β-FeTiH 和 γ-FeTiH2 相而闻名。在本文中，我们讨论了历史背景，概述了微观结构修改的最新发展，TiFe金属间合金的活化动力学和加工路线以提高氢化性能。在晶体学、氢化物相形成和氢化机制方面，对 TiFe 合金进行了深入的微观结构分析。详细解释了 TiFe 金属间化合物（脱）氢过程机制的速率控制步骤。发现氢化反应的速率控制步骤取决于β-氢化物相的分数。进行了深入的研究活动以改进可分为两组的第一次氢化动力学：合金化和机械活化。已经解释了两种情况下改进氢化动力学的机制。最后，已经介绍了生产 TiFe 合金的各种制造工艺，并与成本效益和储氢能力相关联。因此，本文的重点是介绍用于未来储氢应用的 TiFe 金属间合金的基础知识和最新进展，这将有利于相关领域的研究人员和从业人员。