In Situ Embedding of Mg2NiH4 and YH3 Nanoparticles into Bimetallic Hydride NaMgH3 to Inhibit Phase Segregation for Enhanced Hydrogen Storage

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• 作者：Yongtao Li ; Luxing Zhang ; Qingan Zhang ; Fang Fang ; Dalin Sun ; Kongzhai Li ; Hua Wang ; Liuzhang Ouyang ; Min Zhu
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：October 16, 2014
• 年：2014
• 卷：118
• 期：41
• 页码：23635-23644
• 全文大小：832K
• ISSN：1932-7455

文摘

For the first time, component segregation during cycling was demonstrated to be responsible for the deterioration in the kinetics of bimetallic hydride NaMgH₃. To solve this problem, we propose a method involving in situ embedding of Mg₂NiH₄ and YH₃ into NaMgH₃, which is accomplished with a solid-phase reaction using amorphous Mg₁₂YNi alloy and NaH as starting materials under a H₂ atmosphere. Using this novel method, 12 wt % of the Mg₂NiH₄ phase and 11 wt % of the YH₃ phase were homogeneously embedded in the NaMgH₃ matrix. In comparison to those of pure NaMgH₃, this composite material exhibits no change in thermodynamics but shows greatly enhanced kinetics for hydrogen absorption and desorption cycling. In addition, reasonable mechanisms for the enhanced kinetics have been proposed including the prevention of macroscopic segregation of metallic Na, grain refinement, and a synergistic catalytic effect. All of these mechanisms rely on the intimately interdispersed Mg₂NiH₄ and YH₃ nanoparticles embedded in the NaMgH₃ matrix.