Improved dehydriding property of polyvinylpyrrolidone coated Mg-Ni hydrogen storage nano-composite prepared by hydriding combustion synthesis and wet mechanical milling
Improved dehydriding property of polyvinylpyrrolidone coated Mg-Ni hydrogen storage nano-composite prepared by hydriding combustion synthesis and wet mechanical milling
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氢化燃烧合成湿式机械研磨制备聚乙烯吡咯烷酮包覆镁镍储氢纳米复合材料改善脱氢性能
DOI：
10.1016/j.pnsc.2018.01.011
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Li Liquan
中科院分区：
文献类型：
--
作者：
Yao Linglong;Han Huihui;Liu Yana;Zhu Yunfeng;Zhang Yao;Li Liquan
采用氢化燃烧合成（HCS）和四氢呋喃（THF）湿式机械铣削（WM）法制备了聚乙烯吡罗烷酮（PVP）包覆mg95ni5纳米复合材料，并分别以WM-xwt% PVP （x= 1,3,5和7）为供体。详细研究了PVP和THF的相组成、微观结构和脱氢性能，以及PVP和THF的协同作用。XRD结果表明，在未添加PVP的情况下，mg95ni5中mgh2的平均晶粒尺寸从23 nm减小到1 wt% PVP时的18 nm。mg95ni5中mgh2脱氢峰温度由未加THF时的293.0 °C降至有THF时的250.4 °C。WM-7 wt% PVP分解mgh2的表观活化能为66.94 kJ/mol，比未加THF和PVP的mg95ni5低37.70 kJ/mol。PVP和THF有利于机械磨粉过程中粒度的细化。由于PVP和THF的粒径小，协同作用显著改善了复合材料的脱水性能。
In this work, polyvinylpyrrolidone (PVP) coated Mg95Ni5nano-composites were prepared by hydriding combustion synthesis (HCS) plus wet mechanical milling (WM) with tetrahydrofuran (THF) and donated as WM-xwt% PVP (x= 1, 3, 5 and 7) respectively. The phase compositions, microstructures and dehydriding property, as well as the co-effect of PVP and THF were investigated in detail. XRD results showed that the average crystal size of MgH2in the milled Mg95Ni5decreased from 23 nm without PVP to 18 nm with 1 wt% PVP. The peak temperature of dehydrogenation of MgH2in the milled Mg95Ni5decreased from 293.0 °C without THF to 250.4 °C with THF. The apparent activation energy for decomposition of MgH2in WM-7 wt% PVP was estimated to be 66.94 kJ/mol, which is 37.70 kJ/mol lower than that of milled Mg95Ni5without THF and PVP. PVP and THF can facilitate the refinement of particle size during mechanical milling process. Attributed to small particle sizes and synergistic effect of PVP and THF, the composites exhibit markedly improved dehydriding properties.