Effect of lanthanum hydride on microstructures and hydrogen storage performances of 2LiNH₂-MgH₂ system

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• 作者：Xilin ZHU ((鏈辨儨鏋?)^a ; Shumin HAN ((闊╂爲姘?)^a ; ^b ; ^{hanshm@ysu.edu.cn" class="auth_mail} ; Xin ZHAO ((璧?閼?)^a ; Yuan LI ((鏉?濯?)^a ; Baozhong LIU ((鍒樺疂蹇?)^b ; ^c ; ^{bzliu@hpu.edu.cn" class="auth_mail}
• 关键词：hydrogen storage performances ; Li-Mg-N-H system ; lanthanum hydride ; kinetics ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：May 2014
• 年：2014
• 卷：32
• 期：5
• 页码：429-433
• 全文大小：850 K

文摘

Hydrogen storage properties of 2LiNH₂-MgH₂ system were improved by adding lanthanum hydride (LaH₃), and the role of LaH₃ in hydrogen sorption process of Li-Mg-N-H system was investigated. Temperature programmed sorption results showed that the addition of lanthanum hydride reduced the dehydriding/hydriding onset temperature of 2LiNH₂-MgH₂ system by at least 15 K. Moreover, A 0.053 wt.%/min average rate was determined for the hydrogen desorption of 2LiNH₂-MgH₂-0.05LaH₃ composite, while it was only 0.035 wt.%/min for 2LiNH₂-MgH₂ system. Hydrogen absorption capacity increased from 1.62 wt.% to 2.12 wt.% within 200 min by adding LaH₃ into 2LiNH₂-MgH₂ system at 383 K. In the dehydrogenation of 2LiNH₂-MgH₂-0.05LaH₃ composite, LaH₂ transferred to LaN phase, which reversed to LaH₂ in the following hydrogen adsorption process. The reversible reaction of LaH₂ effectively promoted the hydrogen sorption of Li-Mg-N-H system. Moreover, the homogenous distribution of fine La hydride was favorable to improving effect of lanthanum hydride.