Extreme high reversible capacity with over 8.0 wt% and excellent hydrogen storage properties of MgH2 combined with LiBH4 and Li3AlH6
作者:Lin, WP (Lin, Wenping)[ 1 ] ; Xiao, XZ (Xiao, Xuezhang)[ 1,2,3 ] ; Wang, XC (Wang, Xuancheng)[ 1 ] ; Wong, JW (Wong, Jie-Wei)[ 1 ] ; Yao, ZD (Yao, Zhendong)[ 1 ] ; Chen, M (Chen, Man)[ 1 ] ; Zheng, JG (Zheng, Jiaguang)[ 1 ] ; Hu, ZC (Hu, Zhencan)[ 1 ] ; Chen, LX (Chen, Lixin)[ 1,2 ]
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JOURNAL OF ENERGY CHEMISTRY
卷: 50 页: 296-306
DOI: 10.1016/j.jechem.2020.03.076
出版年: NOV 2020
文献类型:Article
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摘要
Magnesium hydride has attracted great attention because of its high theoretical capacity and outstanding reversibility, nevertheless, its practical applications have been restricted by the disadvantages of the sluggish kinetics and high thermodynamic stability. In this work, an unexpected high reversible hydrogen capacity over 8.0 wt% has been achieved from MgH2 metal hydride composited with small amounts of LiBH4 and Li3AlH6 complex hydrides, which begins to release hydrogen at 276 degrees C and then completely dehydrogenates at 360 degrees C. The dehydrogenated MgH2 + LiBH4/Li3AlH6 composite can fully reabsorb hydrogen below 300 degrees C with an excellent cycling stability. The composite exhibits a significant reduction of dehydrogenation activation energy from 279.7 kJ/mol (primitive MgH2) to 139.3 kJ/mol (MgH2 + LiBH4/Li3AlH6), as well as a remarkable reduction of dehydrogenation enthalpy change from 75.1 kJ/mol H-2 (primitive MgH2) to 62.8 kJ/mol H-2 (MgH2 + LiBH4/Li3AlH6). The additives of LiBH4 and Li3AlH6 not only enhance the cycling hydrogen capacity, but also simultaneously improve the reversible de/rehydrogenation kinetics, as well as the dehydrogenation thermodynamics. This notable improvement on the hydrogen absorption/desorption behaviors of the MgH2 + LiBH4/Li3AlH6 composite could be attributed to the dehydrogenated products including Li3Mg7, Mg17Al12 and MgAlB4, which play a key role on reducing the dehydrogenation activation energy and increasing diffusion rate of hydrogen. Meanwhile, the LiBH4 and Li3AlH6 effectively destabilize MgH2 with a remarkable reduction on dehydrogenation enthalpy change in terms of thermodynamics. In particular, the Li3Mg7, Mg17Al12 and MgAlB4 phases can reversibly transform into MgH2, Li3AlH6 and LiBH4 after rehydrogenation, which contribute to maintain a high cycling capacity. This constructing strategy can further promote the development of high reversible capacity Mg-based materials with suitable de/rehydrogenation properties. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
关键词
作者关键词:Magnesium hydride; Complex hydride; Hydrogen storage; High reversible capacity; Synergistic effect
KeyWords Plus:DEHYDROGENATION PROPERTIES; GENERATION PROPERTIES; DESORPTION PROPERTIES; SORPTION PROPERTIES; MAGNESIUM; KINETICS; CARBON; THERMODYNAMICS; TI; NI
作者信息
通讯作者地址:
Zhejiang University Zhejiang Univ, Sch Mat Sci & Engn, State Key Lab Silicon Mat, Hangzhou 310027, Zhejiang, Peoples R China.
通讯作者地址: Xiao, XZ (通讯作者)
显示更多Zhejiang Univ, Sch Mat Sci & Engn, State Key Lab Silicon Mat, Hangzhou 310027, Zhejiang, Peoples R China.
地址:
显示更多[ 1 ] Zhejiang Univ, Sch Mat Sci & Engn, State Key Lab Silicon Mat, Hangzhou 310027, Zhejiang, Peoples R China
[ 2 ] Key Lab Adv Mat & Applicat Batteries Zhejiang Pro, Hangzhou 310013, Zhejiang, Peoples R China
显示更多[ 3 ] South China Univ Technol, Guangdong Prov Key Lab Adv Energy Storage Mat, Guangzhou 510640, Guangdong, Peoples R China
电子邮件地址:xzxiao@zju.edu.cn
基金资助致谢
基金资助机构显示详情授权号
National Basic Research Program of China
2019YFB1505103
National Natural Science Foundation of China (NSFC)
51571179
51671173
Open Fund of the Guangdong Provincial Key Laboratory of Advance Energy Storage Materials
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出版商
ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS
期刊信息
Impact Factor (影响因子): Journal Citation Reports
类别 / 分类
研究方向:Chemistry; Energy & Fuels; Engineering
Web of Science 类别:Chemistry, Applied; Chemistry, Physical; Energy & Fuels; Engineering, Chemical