Hydrogen storage properties of 2LiNH2+LiBH4+MgH2

Yang, Jun; Sudik, Andrea; Siegel, Donald J.; Halliday, Devin; Drews, A. R.; Carter, Roscoe O.; Wolverton, Christopher; Lewis, Gregory J.; Sachtler, J.W.A.; Low, John J.; Faheem, Syed A.; Lesch, David A.; Ozoliņš, Vidvuds

doi:10.1016/j.jallcom.2007.03.145

Cited by 44 publications

(27 citation statements)

References 11 publications

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“…In the last years, many efforts have been made to improve both the thermodynamic and the kinetic characteristics of LiBH 4 desorption by addition of suitable catalyzing/destabilizing agents. A promising solution seems the preparation of the so called "reactive hydrides composites" (RHC) systems (Barkhordarian et al [11], Vajo et al [12]), made of the borohydride, the light hydride MgH 2 (Dornehim et al [13], Vajo et al [14,15]), and eventually other complex hydrides such as LiAlH 4 and/or LiNH 2 (Pinkerton et al [16], Sudik et al [17], Yang et al [18,19]). The borohydride reacts with the destabilizing hydride or with its dehydrogenation product, leading to the formation of a stable discharged compound (the general reaction scheme being AH + MBH → AB + MH).…”

Section: Introductionmentioning

confidence: 99%

H₂sorption performance of NaBH₄–MgH₂composites prepared by mechanical activation

Milanese¹,

Girella²,

Mulas³

et al. 2009

WIT Transactions on Ecology and the Environment

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The current research on solid state hydrogen storage materials for on-board applications is focused on reactive hydrides composites (RHC), i.e. systems based on the improvement of the dehydrogenation thermodynamic of a complex hydride when one (generally the light hydride MgH 2 ) or more hydrides take part to the reaction. The extent of the destabilization, as well as the sorption characteristics of the composites, strongly depends on the structural and nanostructural properties of the constituent hydrides, which are in turn affected by the preparation route. The aim of this work is to evaluate the influence of different mechanical activation conditions on the storage properties of NaBH 4 -MgH 2 composites, up to now scarcely explored in literature. The first results regard composites with 2:1 and 1:2 stoichiometry milled under different atmosphere (Ar or H 2 ). X-ray powders diffraction analysis shows that milling does not lead to the formation of any new phase, but it reduces the average crystallite size of the powders down to nanometric scale. All the mixtures release an H 2 amount close to the theoretical value expected for the full dissociation of both the hydrides and much higher than the target fixed by the US Department of Energy for on-board application. The thermal programmed desorption profiles of the mixtures clearly show two steps, with MgH 2 dissociating first and with higher rate and NaBH 4 gradually dehydrogenating at temperatures close to 400°C. Concerning the 2:1 stoichiometry, when the samples are processed under Ar the two dehydrogenation processes are characterized by a lower starting temperature but also by a lower average rate with respect to the sample milled in H 2 . The 1:2 sample milled under Ar shows the best kinetic performance. Unfortunately, also for this mixture more than 10 h are required to obtain full desorption at a temperature as high as 450°C.

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Section: Introductionmentioning

confidence: 99%

H₂sorption performance of NaBH₄–MgH₂composites prepared by mechanical activation

Milanese¹,

Girella²,

Mulas³

et al. 2009

WIT Transactions on Ecology and the Environment

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“…In these experiments, the difference in the absorption rates of the doped and undoped systems is particularly noticeable at 180 • C and 115 bar, while it becomes less pronounced at higher temperature and pressure (i.e., 200 • C and 155 bar, respectively) [73]. The studies conducted separately by Yang [75] and Sudik [76] proved that the addition in stoichiometric amount of LiBH 4 has a significant impact on the hydrogen storage properties of the Li-Mg-N-H system. Ulmer et al [71] verified that co-doping with LiBH 4 and KH can significantly improve the de/absorption kinetics of the 2LiNH 2 + MgH 2 system.…”

Section: Li-mg-n-h Systemmentioning

confidence: 83%

“…In fact, the use of borohydrides as additives alters not only the kinetics but also the thermodynamics of Li-Mg-N-H system. Inspired by the richness of the chemistry observed in the binary systems 2LiBH 4 [75]. In their following works [114,115], an optimum composition of this ternary system was found to be 6LiNH 2 + 3MgH 2 + LiBH 4 by combinatorial synthesis and screening techniques.…”

Section: Li-mg-n-h-borohydride Systemsmentioning

confidence: 99%

Recent Progress and New Perspectives on Metal Amide and Imide Systems for Solid-State Hydrogen Storage

et al. 2018

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Hydrogen storage in the solid state represents one of the most attractive and challenging ways to supply hydrogen to a proton exchange membrane (PEM) fuel cell. Although in the last 15 years a large variety of material systems have been identified as possible candidates for storing hydrogen, further efforts have to be made in the development of systems which meet the strict targets of the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) and U.S. Department of Energy (DOE). Recent projections indicate that a system possessing: (i) an ideal enthalpy in the range of 20-50 kJ/mol H 2 , to use the heat produced by PEM fuel cell for providing the energy necessary for desorption; (ii) a gravimetric hydrogen density of 5 wt. % H 2 and (iii) fast sorption kinetics below 110 • C is strongly recommended. Among the known hydrogen storage materials, amide and imide-based mixtures represent the most promising class of compounds for on-board applications; however, some barriers still have to be overcome before considering this class of material mature for real applications. In this review, the most relevant progresses made in the recent years as well as the kinetic and thermodynamic properties, experimentally measured for the most promising systems, are reported and properly discussed.

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“…LiBH 4 seemed to improve reaction rates and thermodynamics, when added in small ratios [13,14]. In 2010, [16].…”

Section: Introductionmentioning

confidence: 98%

Material properties and empirical rate equations for hydrogen sorption reactions in 2 LiNH2–1.1 MgH2–0.1 LiBH4–3 wt.% ZrCoH3

Bürger

Vitillo

et al. 2014

International Journal of Hydrogen Energy

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Abstract2 LiNH 2 -1.1 MgH 2 -0.1 LiBH 4 -3 wt.% ZrCoH 3 is a promising solid state hydrogen storage material with a hydrogen storage capacity of up to 5.3 wt.%. As the material shows sufficiently fast desorption rates at temperatures below 200 °C, it is used for a prototype solid state hydrogen storage tank that is coupled to a HT-PEM fuel cell. In order to perform design simulations for this prototype reactor with a hydrogen capacity of 2kWh el , model equations for the rate of hydrogen sorption reactions are required.Therefore, several material properties, like bulk density and thermodynamic data, have been measured and they are summarized in the present publication. Furthermore, isothermal absorption and desorption experiments are performed in a temperature and pressure range that is in the focus of the coupling procedure. Using this experimental data, two-step model equations have been fitted for the absorption and desorption reaction. These empirical model equations are able to capture the experimentally measured reaction rates and can be used for model validation of the design simulations. KeywordsLi-Mg-N-H hydride, reaction rate, model equations, hydrogen storage IntroductionDue to high theoretical storage densities, complex hydrides show the potential to improve the present state of the art of hydrogen storage for automotive applications [1]. As the hydrogen is strongly bonded to the powdered material, the amount of free gaseous hydrogen in equilibrium at room temperature and pressure is small. Therefore, hydrogen is just released when external heat is provided for the endothermal desorption reactions. In case the storage reactor is coupled to a fuel cell (FC), the required amount of hydrogen can be released by transfer of the waste heat from the FC. This kind of coupled system has already been studied by several simulations and experiments for conventional metal hydrides as well as NaAlH 4 [2,3].The present work has been developed within a framework of activities aiming to realize a hydrogen storage tank that is studied in technically relevant scale, i.e. allowing for 2 h coupled operation with a 1 kW el high temperature proton-exchange membrane (HT-PEM) fuel cell. As for an appropriate tank design modelling and simulation tools are used, reliable information on the properties of the selected

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Hydrogen storage properties of 2LiNH2+LiBH4+MgH2

Cited by 44 publications

References 11 publications

H₂sorption performance of NaBH₄–MgH₂composites prepared by mechanical activation

H₂sorption performance of NaBH₄–MgH₂composites prepared by mechanical activation

Recent Progress and New Perspectives on Metal Amide and Imide Systems for Solid-State Hydrogen Storage

Material properties and empirical rate equations for hydrogen sorption reactions in 2 LiNH2–1.1 MgH2–0.1 LiBH4–3 wt.% ZrCoH3

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Hydrogen storage properties of 2LiNH2+LiBH4+MgH2

Cited by 44 publications

References 11 publications

H2sorption performance of NaBH4–MgH2composites prepared by mechanical activation

H2sorption performance of NaBH4–MgH2composites prepared by mechanical activation

Recent Progress and New Perspectives on Metal Amide and Imide Systems for Solid-State Hydrogen Storage

Material properties and empirical rate equations for hydrogen sorption reactions in 2 LiNH2–1.1 MgH2–0.1 LiBH4–3 wt.% ZrCoH3

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H₂sorption performance of NaBH₄–MgH₂composites prepared by mechanical activation

H₂sorption performance of NaBH₄–MgH₂composites prepared by mechanical activation