A nano-LiBH₄ ​+ ​nano-MgH₂ mixture which can reversibly release and absorb ∼5.0 wt% H₂ at 265 °C is synthesized via a new processing method, termed as Ball Milling with Aerosol Spraying (BMAS) established in this study. The reversible storage capacity of ∼5.0 wt% H₂ is the highest one ever reported for the LiBH₄ + MgH₂ system at temperature ≤265 °C. It is found that the unusually high reversible hydrogen storage is accomplished through two parallel reaction pathways. One is nano-LiBH₄ decomposes to form Li₂B₁₂H₁₂ and H₂ first and then Li₂B₁₂H₁₂ reacts with MgH₂ to form MgB₂, LiH and H₂. The other is nano-MgH₂ decomposes to form Mg and H₂ first and then Mg reacts with LiBH₄ to form MgB₂, LiH and H₂. These reaction pathways become possible because of the presence of nano-LiBH₄ and nano-MgH₂ and their intimate mixing, enabled by the BMAS process. This study unambiguously shows that nano-engineering can overcome kinetics barriers for thermodynamically favorable systems like the LiBH₄ ​+ ​MgH₂ mixture and even provides thermodynamic driving force to enhance hydrogen release at low temperature. The principle established in this study also opens up a new direction for investigating and improving the hydrogenation and dehydrogenation properties of many other systems containing multiple hydride components that have favorable thermodynamic properties for reversible hydrogen storage, but with limited kinetics.

通过一种新的加工方法合成了一种纳米LiBH ₄  +纳米MgH ₂混合物，该混合物可以在265°C下可逆地释放和吸收约5.0 wt％的H ₂，该方法在该方法中被称为球磨与气溶胶喷涂（BMAS）。学习。约5.0 wt％H ₂的可逆存储容量是有史以来报道的LiBH ₄ + MgH ₂系统在≤265°C的温度下的最高存储容量。发现通过两个平行的反应路径实现了异常高的可逆氢存储。一种是纳米LiBH _4先分解形成Li ₂ B ₁₂ H ₁₂和H ₂，然后分解成Li ₂B ₁₂ H ₁₂与MgH ₂反应形成MgB ₂，LiH和H ₂。另一个是纳米MgH _2首先分解形成Mg和H ₂，然后Mg与LiBH ₄反应形成MgB ₂，LiH和H ₂。由于存在纳米LiBH ₄和纳米MgH ₂以及它们的紧密混合（通过BMAS工艺实现），这些反应途径成为可能。这项研究明确表明，纳米工程可以克服热力学上有利的系统如LiBH ₄  + MgH _2的动力学障碍。甚至提供热力学驱动力来增强低温下的氢释放。这项研究中确立的原理也为研究和改善许多其他包含多种氢化物成分的系统提供了可逆储氢的良好热力学性质，但动力学有限的氢化和脱氢性质，也为研究和改善其氢化和脱氢性质开辟了新的方向。