Remarkable hydrogen storage properties at low temperature of Mg–Ni composites prepared by hydriding combustion synthesis and mechanical milling
Remarkable hydrogen storage properties at low temperature of Mg–Ni composites prepared by hydriding combustion synthesis and mechanical milling
复制标题
氢化燃烧合成机械球磨制备Mg-Ni复合材料具有优异的低温储氢性能
DOI：
10.1039/c5ra09754a
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发表时间：
2015
期刊：
影响因子：
3.9
通讯作者：
Liquan Li
中科院分区：
文献类型：
--
作者：
Yajun Tan;Qifeng Mao;Wei Su;Yunfeng Zhu;Liquan Li
采用燃烧合成-机械球磨（HCS + MM）法制备了主颗粒尺寸小于400 nm的Mg 100 −xNix（x = 0、5、10和20）复合材料。XRD和TEM结果表明，Mg 100 −xNix复合材料中存在MgH 2、Mg 2NiH 4、Mg2NiH0.3和Mg（x = 0和5时为Mg）等相，Mg-Ni颗粒在复合材料中分布均匀。Mg 100 −xNix复合材料的DSC结果表明，Mg 80 Ni 20复合材料中MgH 2的脱氢峰降低至223.9/247.3 °C。添加5at%Ni时，Mg 95 Ni 5合金在473 K下100 s内达到饱和吸氢容量5.80wt%。Mg 80 Ni 20在313 K时的吸氢量为3.70wt%，在473 K时的放氢量为1.84wt%。Mg 2Ni在Mg-Ni复合材料中的均匀分布显著促进了氢的扩散，提高了Mg-Ni复合材料的吸放氢动力学和低温储氢性能。Mg 100 −xNix的吸放氢性能与Ni的含量密切相关，因此其储氢量和吸放氢动力学显著。此外，通过等温脱氢/加氢循环动力学测试，也获得了优异的循环稳定性。
Mg100−xNix (x = 0, 5, 10 and 20) composites with the main particle size below 400 nm were synthesized by hydriding combustion synthesis followed by mechanical milling (HCS + MM). XRD and TEM results of Mg100−xNix revealed that the products had the phases of MgH2, Mg2NiH4, Mg2NiH0.3 and Mg (Mg just for x = 0 and 5), with Mg–Ni hydrides distributing uniformly in the composites. DSC results of Mg100−xNix composites demonstrated that the hydrogen desorption peak for MgH2 in the Mg80Ni20 composite was decreased to 223.9/247.3 °C. With 5 at% Ni added, the Mg95Ni5 reached its saturated hydrogen absorption capacity of 5.80 wt% within 100 s at 473 K. As for Mg80Ni20, a hydrogen absorption of 3.70 wt% at 313 K and a desorption capacity of 1.84 wt% at 473 K could be obtained. The Mg2Ni distributing uniformly in Mg–Ni composites significantly facilitates hydrogen diffusion and improves the hydriding/dehydriding kinetics and hydrogen storage capacity at low temperature. The amount of Ni is related greatly to the hydriding/dehydriding properties of Mg100−xNix, which makes the hydrogen storage capacity and hydriding/dehydriding kinetics remarkable. Besides, the excellent cycling stability was also obtained through the isothermal de/hydrogenation cycling kinetics measurement.