Effects of Additional Elements on Hydrogen Storage Properties for Vanadium Alloys

2016 ◽  
Vol 879 ◽  
pp. 885-890
Author(s):  
Atsunori Kamegawa ◽  
Ryoichi Namba ◽  
Masuo Okada
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Content ◽  
Vanadium Alloys ◽  
High Hydrogen ◽  
Hydrogen Storage Properties ◽  
Hydrogen Capacity ◽  
Cr Content ◽  
Cr Addition ◽  
Storage Properties ◽  
Hydride Phases

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.

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
Keyword(s):  
Hydrogen Storage ◽  
Milling Process ◽  
Practical Application ◽  
High Hydrogen ◽  
Hydrogen Storage Properties ◽  
Hydrogen Capacity ◽  
Co Addition ◽  
Storage Properties ◽  
Insight Into

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.

scholarly journals The Crystal Structures in Hydrogen Absorption Reactions of REMgNi4-Based Alloys (RE: Rare-Earth Metals)

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8163
Author(s):  
Toyoto Sato ◽  
Shin-ichi Orimo
Keyword(s):  
Rare Earth ◽  
Hydrogen Storage ◽  
Crystal Structures ◽  
Hydrogen Absorption ◽  
Rare Earth Metals ◽  
Hydrogen Storage Properties ◽  
Hydride Formation ◽  
Storage Properties ◽  
Type Crystal ◽  
Hydride Phases

REMgNi4-based alloys, RE(2−x)MgxNi4 (RE: rare-earth metals; 0 < x < 2), with a AuBe5-type crystal structure, exhibit reversible hydrogen absorption and desorption reactions, which are known as hydrogen storage properties. These reactions involve formation of three hydride phases. The hydride formation pressures and hydrogen storage capacities are related to the radii of the RE(2−x)MgxNi4, which in turn are dependent on the radii and compositional ratios of the RE and Mg atoms. The crystal structures formed during hydrogen absorption reactions are the key to understanding the hydrogen storage properties of RE(2−x)MgxNi4. Therefore, in this review, we provide an overview of the crystal structures in the hydrogen absorption reactions focusing on RE(2−x)MgxNi4.

scholarly journals Roles of Ti-Based Catalysts on Magnesium Hydride and Its Hydrogen Storage Properties

Inorganics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 36
Author(s):  
Chengshang Zhou ◽  
Jingxi Zhang ◽  
Robert C. Bowman ◽  
Zhigang Zak Fang
Keyword(s):  
Hydrogen Storage ◽  
Fundamental Principle ◽  
Magnesium Hydride ◽  
Elemental Abundance ◽  
High Hydrogen ◽  
Hydrogen Storage Properties ◽  
The Past ◽  
Kinetic Mechanisms ◽  
Kinetics Of ◽  
Storage Properties

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.

Hydrogen Storage Properties of a Combined Li3AlH6-LiBH4 System

2008 ◽  
Vol 1098 ◽  
Author(s):  
Young Joon Choi ◽  
Jun Lu ◽  
Hong Yong Sohn ◽  
Zak Fang
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Release ◽  
Lithium Aluminum ◽  
Combined System ◽  
High Hydrogen ◽  
Lithium Borohydride ◽  
Hydrogen Storage Properties ◽  
Complex Hydrides ◽  
Aluminum Hydrides ◽  
Storage Properties

AbstractLithium based complex hydrides, including lithium aluminum hydrides and lithium borohydride (LiAlH4, Li3AlH6 and LiBH4), are among the most promising materials due to their high hydrogen contents. In the present work, we investigated the hydrogen storage properties of a new combined system of Li3AlH6-LiBH4. The samples were made with small amounts of catalyst under low energy milling conditions. Thermogravimetric analysis (TGA) of a Ti-doped Li3AlH6/2LiBH4 indicated that the degree of hydrogen release reached 7.3 wt. % by the time the sample reached 450iÆc under a heating rate of 2iÆC/min. This increased to 8.8 wt. % when the sample was held at 450iÆCfor additional 8 hours minutes under this condition. The dehydrogenation product was a mixture of LiH and AlB2. This product could be rehydrogenated up to 3.8 wt. % under 24.1 MPa hydrogen pressure and 450iÆC.

The Influence of Morphology on the Hydrogen Storage Properties of Magnesium Based Materials Processed by Cold Rolling

2014 ◽  
Vol 922 ◽  
pp. 400-405 ◽  
Author(s):  
Julien Lang ◽  
Alexandre Asselli ◽  
Nicolas Hebert ◽  
Jacques Huot
Keyword(s):  
Cold Rolling ◽  
Hydrogen Storage ◽  
Hydrogen Absorption ◽  
Low Cost ◽  
Volume Ratio ◽  
Desorption Kinetics ◽  
Small Surface ◽  
High Hydrogen ◽  
Hydrogen Storage Properties ◽  
Storage Properties

In this communication we report the effect of macro and microstructure on the hydrogen storage properties of magnesium based materials. Magnesium hydride is an attractive material for hydrogen storage applications since it has a high hydrogen volumetric density. Furthermore, the high enthalpy of hydride formation makes it attractive for thermal energy storage applications. Besides, magnesium is an abundant and low cost material. However, the Mg/MgH2 system requires high operating temperatures due to its thermodynamic stability and slow hydrogen absorption and desorption kinetics. Magnesium’s first hydrogenation is a very long and costly process. This work aims to ameliorate this process which would effectively reduce the cost of MgH2. Commercial pure magnesium samples were processed by cold rolling. After processing, the samples presented limited hydrogen absorption due to their small surface area to volume ratio. To overcome this problem the samples were then reduced to powder using a bastard file. The samples were characterized by scanning electron microscopy and presented different morphology. Hydrogen storage properties and morphology are discussed and correlated. Results show an important improvement on the hydrogen absorption and desorption kinetics for the comminuted samples.

scholarly journals Enhanced Hydrogen Storage Properties of Li-RHC System with In-House Synthesized AlTi3 Nanoparticles

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7853
Author(s):  
Thi-Thu Le ◽  
Claudio Pistidda ◽  
Julián Puszkiel ◽  
María Victoria Castro Riglos ◽  
David Michael Dreistadt ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogenation Reaction ◽  
Kinetic Behavior ◽  
High Hydrogen ◽  
Hydrogen Storage Properties ◽  
Storage Performance ◽  
Dehydrogenation Kinetics ◽  
Hydrogen Storage Performance ◽  
Kinetics Of ◽  
Storage Properties

In recent years, the use of selected additives for improving the kinetic behavior of the system 2LiH + MgB2 (Li-RHC) has been investigated. As a result, it has been reported that some additives (e.g., 3TiCl3·AlCl3), by reacting with the Li-RHC components, form nanostructured phases (e.g., AlTi3) possessing peculiar microstructural properties capable of enhancing the system’s kinetic behavior. The effect of in-house-produced AlTi3 nanoparticles on the hydrogenation/dehydrogenation kinetics of the 2LiH + MgB2 (Li-RHC) system is explored in this work, with the aim of reaching high hydrogen storage performance. Experimental results show that the AlTi3 nanoparticles significantly improve the reaction rate of the Li-RHC system, mainly for the dehydrogenation process. The observed improvement is most likely due to the similar structural properties between AlTi3 and MgB2 phases which provide an energetically favored path for the nucleation of MgB2. In comparison with the pristine material, the Li-RHC doped with AlTi3 nanoparticles has about a nine times faster dehydrogenation rate. The results obtained from the kinetic modeling indicate a change in the Li-RHC hydrogenation reaction mechanism in the presence of AlTi3 nanoparticles.

Hydrogen Storage Properties of Mg76Ti12Ni12-xCrX(x=0,3,6,9) Alloys by Mechanical Alloying

2010 ◽  
Vol 156-157 ◽  
pp. 1146-1150
Author(s):  
Zhi Qiang Lan ◽  
Shu Bo Li ◽  
Zhao Lu ◽  
Jin Guo
Keyword(s):  
Hydrogen Storage ◽  
Mechanical Alloying ◽  
Storage Capacity ◽  
X Ray Diffraction ◽  
Hydrogen Storage Capacity ◽  
Hydrogen Storage Properties ◽  
X Ray ◽  
Cr Content ◽  
Ti2ni Phase ◽  
Storage Properties

Mg76Ti12Ni12-xCrx(x=0,3,6,9) alloys were synthesized by mechanical alloying(MA) approach and hydrogen storage properties of the alloys were investigated by X-ray diffraction, thermal analysis and pressure-composition isotherm measurement. It is found that Ti2Ni phase and Mg2Ni phase exist as the main phases in Mg76Ti12Ni12-xCrx(x=0,3,6,9) alloys. The Mg76Ti12Ni12-xCrx(x=0,3,6,9) alloys exhibit the hydrogen storage capacity of 4.61,4.30,4.21 and 4.12wt%, and the decomposition enthalpies of the alloy hydrides are 928.4, 898.3, 831.2 and 851.4J/g H2, respectively. Mg76Ti12Ni6Cr6 alloy shows small hysteresis and fast hydrogen absorption rate. Proper Cr content can improve the performance of the Mg76Ti12Ni12-xCrx(x =0,3,6,9) alloys.

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