Special Issue "Functional Materials Based on Metal Hydrides"

A special issue of Inorganics (ISSN 2304-6740). This special issue belongs to the section "Inorganic Solid-State Chemistry".

Deadline for manuscript submissions: closed (30 September 2017)

Special Issue Editors

Guest Editor
Prof. Dr. Torben R. Jensen

Center for Materials Crystallography, Interdisciplinary Nanoscience Center and Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
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Interests: synthesis and characterization of inorganics; structural; chemical and physical properties
Guest Editor
Associate Prof. Dr. Hai-Wen Li

International Research Center for Hydrogen Energy, Kyushu University, Fukuoka 819-0395, Japan WPI International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
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Interests: hydrogen storage; ionic conductivity; rechargeable battery; functional materials
Guest Editor
Prof. Dr. Min Zhu

School of Materials Science and Engineering, Key Laboratory of Advanced Energy Storage Materials of Guangdong Province, South China University of Technology, Guangzhou 510641, China
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Interests: hydrogen storage; microstructure characterization; electrode materials for batteries; materials synthesis by plasma milling
Guest Editor
Prof. Dr. Craig Buckley

Department of Imaging & Applied Physics, Faculty of Science & Engineering, Curtin University of Technology, GPO Box U 1987, Perth 6845, WA, Australia
Website | E-Mail
Interests: solar heat storage; thermodynamic properties; nanoconfinement

Special Issue Information

Dear Colleagues,

Our extreme and growing energy consumption, based on fossil fuels, has significantly increased the levels of carbon dioxide, which may lead to global and irreversible climate changes. We have plenty of renewable energy, e.g., sun and wind, but the fluctuations over time and geography call for a range of new ideas, and possibly novel technologies. The most difficult challenge appears to be the development of efficient and reliable storage of renewable energy. Hydrogen has long been considered as a potential means of energy storage; however, storage of hydrogen is also challenging. Therefore, a wide range of hydrogen-containing materials, with energy-related functions, has been discovered over the past few decades. The chemistry of hydrogen is very diverse, and so also are the new hydrides that have been discovered, not only in terms of structure and composition, but also in terms of their properties. This has led to a wide range of new possible applications of metal hydrides that permeate beyond solid-state hydrogen storage. A variety of new hydrides, proposed as battery materials, has been discovered. These can exploit properties as fast ion conductors or as conversion-type electrodes with much higher potential energy capacities, as compared to materials currently used in commercial batteries. Solar heat storage is also an area of great potential with metal hydrides, in principle offering orders of magnitude better storage performance than phase change materials. Recently, hydrides with optical and superconducting properties have also been investigated. This Special Issue of Inorganics, entitled “Functional Materials Based on Metal Hydrides”, is dedicated to the full range of emerging electronic, photonic, and energy-related inorganic hydrogen-containing materials.

Prof. Dr. Torben R. Jensen
Associate Prof. Dr. Hai-Wen Li
Prof. Dr. Min Zhu
Prof. Dr. Craig Buckley
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Inorganics is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 350 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Hydrides
  • Synthesis
  • Structural, chemical and physical properties
  • Functional energy materials
  • Hydrogen Storage
  • Ionic Conductivity
  • Battery Electrode
  • Metal hydride based batteries
  • Heat Storage
  • Optical Switch
  • Superconductivity

Published Papers (10 papers)

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Research

Jump to: Review

Open AccessArticle Lewis Base Complexes of Magnesium Borohydride: Enhanced Kinetics and Product Selectivity upon Hydrogen Release
Inorganics 2017, 5(4), 89; doi:10.3390/inorganics5040089
Received: 3 November 2017 / Revised: 27 November 2017 / Accepted: 28 November 2017 / Published: 6 December 2017
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Abstract
Tetrahydofuran (THF) complexed to magnesium borohydride has been found to have a positive effect on both the reactivity and selectivity, enabling release of H2 at <200 °C and forms Mg(B10H10) with high selectivity. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Open AccessArticle Microstructure and Hydrogen Storage Properties of Ti1V0.9Cr1.1 Alloy with Addition of x wt % Zr (x = 0, 2, 4, 8, and 12)
Inorganics 2017, 5(4), 86; doi:10.3390/inorganics5040086
Received: 4 October 2017 / Revised: 28 November 2017 / Accepted: 28 November 2017 / Published: 3 December 2017
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Abstract
The effect of adding Zr on microstructure and hydrogen storage properties of BCC Ti1V0.9Cr1.1 synthesized by arc melting was studied. The microstructures of samples with Zr were multiphase with a main BCC phase and secondary Laves phases C15
[...] Read more.
The effect of adding Zr on microstructure and hydrogen storage properties of BCC Ti1V0.9Cr1.1 synthesized by arc melting was studied. The microstructures of samples with Zr were multiphase with a main BCC phase and secondary Laves phases C15 and C14. The abundance of secondary phases increased with increasing amount of zirconium. We found that addition of Zr greatly enhanced the first hydrogenation kinetics. The addition of 4 wt % of Zr produced fast kinetics and high hydrogen storage capacity. Addition of higher amount of Zr had for effect of decreasing the hydrogen capacity. The reduction in hydrogen capacity might be due to the increased secondary phase abundance. The effect of air exposure was also studied. It was found that, for the sample with 12 wt % of Zr, exposure to the air resulted in appearance of an incubation time in the first hydrogenation and a slight reduction of hydrogen capacity. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Open AccessArticle Investigation of the Reversible Lithiation of an Oxide Free Aluminum Anode by a LiBH4 Solid State Electrolyte
Inorganics 2017, 5(4), 83; doi:10.3390/inorganics5040083
Received: 19 September 2017 / Revised: 21 November 2017 / Accepted: 21 November 2017 / Published: 23 November 2017
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Abstract
In this study, we analyze and compare the physical and electrochemical properties of an all solid-state cell utilizing LiBH4 as the electrolyte and aluminum as the active anode material. The system was characterized by galvanostatic lithiation/delithiation, cyclic voltammetry (CV), X-ray diffraction (XRD), energy
[...] Read more.
In this study, we analyze and compare the physical and electrochemical properties of an all solid-state cell utilizing LiBH4 as the electrolyte and aluminum as the active anode material. The system was characterized by galvanostatic lithiation/delithiation, cyclic voltammetry (CV), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Constant current cycling demonstrated that the aluminum anode can be reversibly lithiated over multiple cycles utilizing a solid-state electrolyte. An initial capacity of 895 mAh/g was observed and is close to the theoretical capacity of aluminum. Cyclic voltammetry of the cell was consistent with the constant current cycling data and showed that the reversible lithiation/delithiation of aluminum occurs at 0.32 V and 0.38 V (vs. Li+/Li) respectively. XRD of the aluminum anode in the initial and lithiated state clearly showed the formation of a LiAl (1:1) alloy. SEM-EDS was utilized to examine the morphological changes that occur within the electrode during cycling. This work is the first example of reversible lithiation of aluminum in a solid-state cell and further emphasizes the robust nature of the LiBH4 electrolyte. This demonstrates the possibility of utilizing other high capacity anode materials with a LiBH4 based solid electrolyte in all-solid-state batteries. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Open AccessArticle Dehydrogenation of Surface-Oxidized Mixtures of 2LiBH4 + Al/Additives (TiF3 or CeO2)
Inorganics 2017, 5(4), 82; doi:10.3390/inorganics5040082
Received: 28 September 2017 / Revised: 9 November 2017 / Accepted: 16 November 2017 / Published: 21 November 2017
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Abstract
Research for suitable hydrogen storage materials is an important ongoing subject. LiBH4–Al mixtures could be attractive; however, several issues must be solved. Here, the dehydrogenation reactions of surface-oxidized 2LiBH4 + Al mixtures plus an additive (TiF3 or CeO2
[...] Read more.
Research for suitable hydrogen storage materials is an important ongoing subject. LiBH4–Al mixtures could be attractive; however, several issues must be solved. Here, the dehydrogenation reactions of surface-oxidized 2LiBH4 + Al mixtures plus an additive (TiF3 or CeO2) at two different pressures are presented. The mixtures were produced by mechanical milling and handled under welding-grade argon. The dehydrogenation reactions were studied by means of temperature programmed desorption (TPD) at 400 °C and at 3 or 5 bar initial hydrogen pressure. The milled and dehydrogenated materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transformed infrared spectroscopy (FT-IR) The additives and the surface oxidation, promoted by the impurities in the welding-grade argon, induced a reduction in the dehydrogenation temperature and an increase in the reaction kinetics, as compared to pure (reported) LiBH4. The dehydrogenation reactions were observed to take place in two main steps, with onsets at 100 °C and 200–300 °C. The maximum released hydrogen was 9.3 wt % in the 2LiBH4 + Al/TiF3 material, and 7.9 wt % in the 2LiBH4 + Al/CeO2 material. Formation of CeB6 after dehydrogenation of 2LiBH4 + Al/CeO2 was confirmed. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Open AccessArticle Thermodynamic Properties and Reversible Hydrogenation of LiBH4–Mg2FeH6 Composite Materials
Inorganics 2017, 5(4), 81; doi:10.3390/inorganics5040081
Received: 8 October 2017 / Revised: 2 November 2017 / Accepted: 2 November 2017 / Published: 16 November 2017
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Abstract
In previous studies, complex hydrides LiBH4 and Mg2FeH6 have been reported to undergo simultaneous dehydrogenation when ball-milled as composite materials (1 − x)LiBH4 + xMg2FeH6. The simultaneous hydrogen release led to a
[...] Read more.
In previous studies, complex hydrides LiBH4 and Mg2FeH6 have been reported to undergo simultaneous dehydrogenation when ball-milled as composite materials (1 − x)LiBH4 + xMg2FeH6. The simultaneous hydrogen release led to a decrease of the dehydrogenation temperature by as much as 150 K when compared to that of LiBH4. It also led to the modified dehydrogenation properties of Mg2FeH6. The simultaneous dehydrogenation behavior between stoichiometric ratios of LiBH4 and Mg2FeH6 is not yet understood. Therefore, in the present work, we used the molar ratio x = 0.25, 0.5, and 0.75, and studied the isothermal dehydrogenation processes via pressure–composition–isothermal (PCT) measurements. The results indicated that the same stoichiometric reaction occurred in all of these composite materials, and x = 0.5 was the molar ratio between LiBH4 and Mg2FeH6 in the reaction. Due to the optimal composition ratio, the composite material exhibited enhanced rehydrogenation and reversibility properties: the temperature and pressure of 673 K and 20 MPa of H2, respectively, for the full rehydrogenation of x = 0.5 composite, were much lower than those required for the partial rehydrogenation of LiBH4. Moreover, the x = 0.5 composite could be reversibly hydrogenated for more than four cycles without degradation of its H2 capacity. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Open AccessArticle Unique Hydrogen Desorption Properties of LiAlH4/h-BN Composites
Inorganics 2017, 5(4), 71; doi:10.3390/inorganics5040071
Received: 30 September 2017 / Revised: 19 October 2017 / Accepted: 23 October 2017 / Published: 25 October 2017
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Abstract
Hexagonal boron nitride (h-BN) is known as an effective additive to improve the hydrogen de/absorption properties of hydrogen storage materials consisting of light elements. Herein, we report the unique hydrogen desorption properties of LiAlH4/h-BN composites, which were prepared by ball-milling. The
[...] Read more.
Hexagonal boron nitride (h-BN) is known as an effective additive to improve the hydrogen de/absorption properties of hydrogen storage materials consisting of light elements. Herein, we report the unique hydrogen desorption properties of LiAlH4/h-BN composites, which were prepared by ball-milling. The desorption profiles of the composite indicated the decrease of melting temperature of LiAlH4, the delay of desorption kinetics in the first step, and the enhancement of the kinetics in the second step, compared with milled LiAlH4. Li3AlH6 was also formed in the composite after desorption in the first step, suggesting h-BN would have a catalytic effect on the desorption kinetics of Li3AlH6. Finally, the role of h-BN on the desorption process of LiAlH4 was discussed by comparison with the desorption properties of LiAlH4/X (X = graphite, LiCl and LiI) composites, suggesting the enhancement of Li ion mobility in the LiAlH4/h-BN composite. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Open AccessArticle Hydrogen Storage Stability of Nanoconfined MgH2 upon Cycling
Inorganics 2017, 5(3), 57; doi:10.3390/inorganics5030057
Received: 4 July 2017 / Revised: 18 August 2017 / Accepted: 18 August 2017 / Published: 23 August 2017
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Abstract
It is of utmost importance to optimise and stabilise hydrogen storage capacity during multiple cycles of hydrogen release and uptake to realise a hydrogen-based energy system. Here, the direct solvent-based synthesis of magnesium hydride, MgH2, from dibutyl magnesium, MgBu2,
[...] Read more.
It is of utmost importance to optimise and stabilise hydrogen storage capacity during multiple cycles of hydrogen release and uptake to realise a hydrogen-based energy system. Here, the direct solvent-based synthesis of magnesium hydride, MgH2, from dibutyl magnesium, MgBu2, in four different carbon aerogels with different porosities, i.e., pore sizes, 15 < Davg < 26 nm, surface area 800 < SBET < 2100 m2/g, and total pore volume, 1.3 < Vtot < 2.5 cm3/g, is investigated. Three independent infiltrations of MgBu2, each with three individual hydrogenations, are conducted for each scaffold. The volumetric and gravimetric loading of MgH2 is in the range 17 to 20 vol % and 24 to 40 wt %, which is only slightly larger as compared to the first infiltration assigned to the large difference in molar volume of MgH2 and MgBu2. Despite the rigorous infiltration and sample preparation techniques, particular issues are highlighted relating to the presence of unwanted gaseous by-products, Mg/MgH2 containment within the scaffold, and the purity of the carbon aerogel scaffold. The results presented provide a research path for future researchers to improve the nanoconfinement process for hydrogen storage applications. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Open AccessArticle Synthesis of LiAlH4 Nanoparticles Leading to a Single Hydrogen Release Step upon Ti Coating
Inorganics 2017, 5(2), 38; doi:10.3390/inorganics5020038
Received: 20 May 2017 / Revised: 3 June 2017 / Accepted: 3 June 2017 / Published: 7 June 2017
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Abstract
Lithium aluminum hydride (LiAlH4) is an interesting high capacity hydrogen storage material with fast hydrogen release kinetics when mechanically activated with additives. Herein, we report on a novel approach to produce nanoscale LiAlH4 via a bottom-up synthesis. Upon further coating
[...] Read more.
Lithium aluminum hydride (LiAlH4) is an interesting high capacity hydrogen storage material with fast hydrogen release kinetics when mechanically activated with additives. Herein, we report on a novel approach to produce nanoscale LiAlH4 via a bottom-up synthesis. Upon further coating of these nanoparticles with Ti, the composite nanomaterial was found to decompose at 120 °C in one single and extremely sharp exothermic event with instant hydrogen release. This finding implies a significant thermodynamic alteration of the hydrogen properties of LiAlH4 induced by the synergetic effects of the Ti catalytic coating and nanosizing effects. Ultimately, the decomposition path of LiAlH4 was changed to LiAlH4 → Al + LiH + 3/2H2. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Open AccessArticle Hydrogen Sorption in Erbium Borohydride Composite Mixtures with LiBH4 and/or LiH
Inorganics 2017, 5(2), 31; doi:10.3390/inorganics5020031
Received: 27 March 2017 / Revised: 19 April 2017 / Accepted: 20 April 2017 / Published: 26 April 2017
Cited by 1 | PDF Full-text (2214 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Rare earth (RE) metal borohydrides have recently been receiving attention as possible hydrogen storage materials and solid-state Li-ion conductors. In this paper, the decomposition and reabsorption of Er(BH4)3 in composite mixtures with LiBH4 and/or LiH were investigated. The composite
[...] Read more.
Rare earth (RE) metal borohydrides have recently been receiving attention as possible hydrogen storage materials and solid-state Li-ion conductors. In this paper, the decomposition and reabsorption of Er(BH4)3 in composite mixtures with LiBH4 and/or LiH were investigated. The composite of 3LiBH4 + Er(BH4)3 + 3LiH has a theoretical hydrogen storage capacity of 9 wt %, nevertheless, only 6 wt % hydrogen are accessible due to the formation of thermally stable LiH. Hydrogen sorption measurements in a Sieverts-type apparatus revealed that during three desorption-absorption cycles of 3LiBH4 + Er(BH4)3 + 3LiH, the composite desorbed 4.2, 3.7 and 3.5 wt % H for the first, second and third cycle, respectively, and thus showed good rehydrogenation behavior. In situ synchrotron radiation powder X-ray diffraction (SR-PXD) after ball milling of Er(BH4)3 + 6LiH resulted in the formation of LiBH4, revealing that metathesis reactions occurred during milling in these systems. Impedance spectroscopy of absorbed Er(BH4)3 + 6LiH showed an exceptional high hysteresis of 40–60 K for the transition between the high and low temperature phases of LiBH4, indicating that the high temperature phase of LiBH4 is stabilized in the composite. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)
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Review

Jump to: Research

Open AccessReview Tetrahydroborates: Development and Potential as Hydrogen Storage Medium
Inorganics 2017, 5(4), 74; doi:10.3390/inorganics5040074
Received: 15 September 2017 / Revised: 19 October 2017 / Accepted: 22 October 2017 / Published: 31 October 2017
Cited by 1 | PDF Full-text (329 KB) | HTML Full-text | XML Full-text
Abstract
The use of fossil fuels as an energy supply becomes increasingly problematic from the point of view of both environmental emissions and energy sustainability. As an alternative, hydrogen is widely regarded as a key element for a potential energy solution. However, different from
[...] Read more.
The use of fossil fuels as an energy supply becomes increasingly problematic from the point of view of both environmental emissions and energy sustainability. As an alternative, hydrogen is widely regarded as a key element for a potential energy solution. However, different from fossil fuels such as oil, gas, and coal, the production of hydrogen requires energy. Alternative and intermittent renewable sources such as solar power, wind power, etc., present multiple advantages for the production of hydrogen. On one hand, the renewable sources contribute to a remarkable reduction of pollutants released to the air. On the other hand, they significantly enhance the sustainability of energy supply. In addition, the storage of energy in form of hydrogen has a huge potential to balance an effective and synergetic utilization of the renewable energy sources. In this regard, hydrogen storage technology presents a key roadblock towards the practical application of hydrogen as “energy carrier”. Among the methods available to store hydrogen, solid-state storage is the most attractive alternative both from the safety and the volumetric energy density points of view. Because of their appealing hydrogen content, complex hydrides and complex hydride-based systems have attracted considerable attention as potential energy vectors for mobile and stationary applications. In this review, the progresses made over the last century on the development in the synthesis and research on the decomposition reactions of homoleptic tetrahydroborates is summarized. Furthermore, theoretical and experimental investigations on the thermodynamic and kinetic tuning of tetrahydroborates for hydrogen storage purposes are herein reviewed. Full article
(This article belongs to the Special Issue Functional Materials Based on Metal Hydrides)

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Tentative Title: Improving the reaction reversibility and cyclic performance of Mg2FeH6 as lithium ion battery anode
Type: article
Author: Hui Wang
Abstract: The metal hydride with high hydrogen storage capacity is a potential conversion reaction anode for lithium ion battery, but the reaction reversibility and cyclic performance of hydride anodes need to be improved, which is due to the poor conductivity and the high activity in the electrolyte of hydride. In this work, the Mg2FeH6 was prepared by reactive milling, and its composite with graphite shows greatly enhanced electrochemical performances in comparison with pure Mg2FeH6. The surface coating of SnO2 and Mo on the electrode by magnetron sputtering could further improve the Coulombic efficiency and cyclic stability of hydride anode. Our work demonstrates that the potential of Mg-based hydrides as high-capacity LIB anode.

 

Tentative Title: Size dependence of hydrogenation of Pd nanoparticles studied by time-resolved X-ray absorption fine structure spectroscopy
Type: article
Author: Daiju Matsumura
Abstract: Expansion of Pd metal nanoparticles during hydrogenation reaction was directly observed by X-ray absorption fine structure spectroscopy with dispersive optics. Nanoparticle size dependence about the elongation of interatomic distance for Pd–Pd bonding was investigated by in situ and time-resolved observation with a rate of 50 Hz. It has been revealed that the reaction quantity of Pd nanoparticles decreases as the particle size decreases, but the reaction rate increases as the particle size decreases. Reaction behavior is discussed from the viewpoints of reaction kinetics and thermodynamics.

Tentative Title: Development and Status of High-Pressure Metal Hydride Compressors for Applications Exceeding 700 Bar
Type: review
Authors: Robert C. Bowman, Jr., Terry A. Johnson, Craig M. Jensen, D. Barton Smith, & Lawrence M. Anovitz
Abstract: This review considers (a) fundamental aspects of materials development with a focus on structure and phase equilibrium of metal hydrogen systems for the hydrogen gas compression; and (b) detailed assessments from a thermal management viewpoint on system design and performance trade-offs for these hydride compressors. The various concepts for metal hydride compressors built for specialized applications at pressures > 200-bar over the past four decades are reviewed.  The prospects for achieving efficient MH compression devices that can be integrated into the gaseous hydrogen refueling stations that can refill the 700-bar gas tanks of fuel cell powered vehicles are addressed.

 

Tentative Title: Tetrahydroborates: development and implementation as hydrogen storage medium
Type: review
Author: Claudio Pistidda
Abstract: Because of their appealing hydrogen content, complex hydrides and complex hydride-based systems attracted considerable attention as potential energy vectors for mobile and stationary applications. In this review, the progresses made over the last century on the development in the synthesis and research on the decomposition reactions of tetrahydroborates is summarized. Furthermore, theoretical and experimental investigations on the thermodynamic and kinetic tuning of tetrahydroborates for hydrogen storage purposes are herein reviewed.

Tentative title: Effect of h-BN Addition on Hydrogen Desorption Process of LiAlH4
Type: article
Author: Yuki Nakagawa
Abstract: Lithium aluminum hydride (LiAlH4) is one of promising candidates for hydrogen storage materials because of its high hydrogen capacity and low desorption temperature. In this work, hydrogen desorption process of LiAlH4/h-BN composites were investigated. The desorption kinetics in the 2nd step was enhanced by h-BN addition, Also, the melting temperature of LiAlH4 was decreased by h-BN addition. These phenomena were not observed in the case of doping graphite. AC impedance measurements revealed that the Li ion conductivity of samples with h-BN was higher than that of LiAlH4. The relationship between Li ion conductivity and the dopant effect on the dehydrogenation is discussed.
 
Tentative title: Microstructure and Hydrogen Storage Properties of Ti1V0.9Cr1.1 alloy with addition of x wt.% Zr (x= 0, 2, 4, 8 and 12)
Type: article
Authors: Salma Sleiman and Jacques Huot
Abstract: The effect of adding Zr on microstructure and hydrogen storage properties of BCC Ti1V0.9Cr1.1 synthesized by arc melting was studied. The microstructures of doped samples were multiphase with a main TiFe phase and secondary Laves phases C15 and C14. The abundance of secondary phases increased with increasing amount of zirconium. We found that addition of Zr greatly enhanced the first hydrogenation kinetics. The addition of 4wt.% of Zr produced fast kinetics and the high hydrogen storage capacity. Addition of higher amount of Zr had for effect of decreasing the hydrogen capacity. The reduction in hydrogen capacity might be due to the increased secondary phase abundance. Effect of air exposure was also studied. It was found that, for the sample with 12 wt.% of Zr exposure to the air resulted in appearance of an incubation time in the first hydrogenation and slight reduction of hydrogen capacity.
Keywords: Hydrogen storage; BCC alloys; Morphology; Kinetics; Air exposure
 
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