scholarly journals Co-Addition of Mg2Si and Graphene for Synergistically Improving the Hydrogen Storage Properties of Mg−Li Alloy

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiantun Huang ◽  
Haizhen Liu ◽  
Xingqing Duan ◽  
Zhiqiang Lan ◽  
Jin Guo

Mg−Li alloy possesses a high hydrogen capacity. However, the hydrogenation and dehydrogenation performances are still far from practical application. In this work, Mg2Si (MS) and graphene (G) were employed together to synergistically improve the hydrogen storage properties of Mg−Li alloy. The structures of the samples were studied by XRD and SEM methods. The hydrogen storage performances of the samples were studied by nonisothermal and isothermal hydrogenation and dehydrogenation, thermal analysis, respectively. It is shown that the onset dehydrogenation temperature of Mg−Li alloy was synergistically reduced from 360°C to 310°C after co-addition of Mg2Si and graphene. At a constant temperature of 325°C, the Mg−Li−MS−G composite can release 2.7 wt.% of hydrogen within 2 h, while only 0.2 wt.% of hydrogen is released for the undoped Mg−Li alloy. The hydrogenation activation energy of the Mg−Li−MS−G composite was calculated to be 86.5 kJ mol−1. Microstructure and hydrogen storage properties studies show that graphene can act as a grinding aid during the ball milling process, which leads to a smaller particle size for the composites. This work demonstrates that coaddition of Mg2Si and graphene can synergistically improve the hydrogen storage properties of Mg−Si alloy and offers an insight into the role of graphene in the Mg−Li−MS−G composite.

2016 ◽  
Vol 879 ◽  
pp. 885-890
Author(s):  
Atsunori Kamegawa ◽  
Ryoichi Namba ◽  
Masuo Okada

The effects of effects of additional elements on hydrogen storage properties and crystal structures for vanadium alloys and their hydrides were investigated in order to obtain high hydrogen capacity. With increasing Cr content in V-xCr binary alloys, fully hydrogen content of the alloys slightly decreased until less than 9 at.%Cr. A clear distinction of the PC isotherm curves between the 15 at.%Cr alloy and the other alloys is observed. V alloys with an excessive Cr addition would come not to form gamma hydride (dihydride). This led the drastic decrement of the hydrogen content in the alloys. Meanwhile, the Cr addition in V alloys was effective to low hydrogen concentration in unstabilizing the beta hydride phases. In addition, it was found that the addition of X elements in V-Cr alloys (X=Al. Mo, Ti, W) was effective to expand the gamma-phase forming range of Cr amounts. As the results, high reversible hydrogen-capacity, 2.68mass% H was obtained in a V-18Cr-2Ti-0.5Al alloy.


Author(s):  
Dong Ju Han ◽  
Sangtae Kim ◽  
Eun Seon Cho

The hydrogen storage properties of magnesium (Mg) considerably rely on the size and morphology of Mg particles that determine the diffusion path for hydrogen atoms. Despite the intensive research on...


2015 ◽  
Vol 40 (39) ◽  
pp. 13506-13517 ◽  
Author(s):  
Luisa Fernández Albanesi ◽  
Sebastiano Garroni ◽  
Pierre Arneodo Larochette ◽  
Pau Nolis ◽  
Gabriele Mulas ◽  
...  

Inorganics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 36
Author(s):  
Chengshang Zhou ◽  
Jingxi Zhang ◽  
Robert C. Bowman ◽  
Zhigang Zak Fang

Magnesium-based hydrides are considered as promising candidates for solid-state hydrogen storage and thermal energy storage, due to their high hydrogen capacity, reversibility, and elemental abundance of Mg. To improve the sluggish kinetics of MgH2, catalytic doping using Ti-based catalysts is regarded as an effective approach to enhance Mg-based materials. In the past decades, Ti-based additives, as one of the important groups of catalysts, have received intensive endeavors towards the understanding of the fundamental principle of catalysis for the Mg-H2 reaction. In this review, we start with the introduction of fundamental features of magnesium hydride and then summarize the recent advances of Ti-based additive doped MgH2 materials. The roles of Ti-based catalysts in various categories of elemental metals, hydrides, oxides, halides, and intermetallic compounds were overviewed. Particularly, the kinetic mechanisms are discussed in detail. Moreover, the remaining challenges and future perspectives of Mg-based hydrides are discussed.


2014 ◽  
Vol 2 (29) ◽  
pp. 11155 ◽  
Author(s):  
Yu Zhang ◽  
Yongfeng Liu ◽  
Yuepeng Pang ◽  
Mingxia Gao ◽  
Hongge Pan

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