Effect of Li3N additive on the hydrogen storage properties of Li-Mg-N-H system

2009 ◽  
Vol 24 (6) ◽  
pp. 1936-1942 ◽  
Author(s):  
Lai-Peng Ma ◽  
Zhan-Zhao Fang ◽  
Hong-Bin Dai ◽  
Xiang-Dong Kang ◽  
Yan Liang ◽  
...  
Keyword(s):  
Hydrogen Desorption ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Hydrogen Storage Properties ◽  
Capacity Enhancement ◽  
Ammonia Release ◽  
Screening Study ◽  
Practical Capacity ◽  
Combined Structure ◽  
Storage Properties

The effect of Li3N additive on the Li-Mg-N-H system was examined with respect to the reversible dehydrogenation performance. Screening study with varying Li3N additions (5, 10, 20, and 30 mol%) demonstrates that all are effective for improving the hydrogen desorption capacity. Optimally, incorporation of 10 mol% Li3N improves the practical capacity from 3.9 wt% to approximately 4.7 wt% hydrogen at 200 °C, which drives the dehydrogenation reaction toward completion. Moreover, the capacity enhancement persists well over 10 de-/rehydrogenation cycles. Systematic x-ray diffraction examinations indicate that Li3N additive transforms into LiNH2 and LiH phases and remains during hydrogen cycling. Combined structure/property investigations suggest that the LiNH2 “seeding” should be responsible for the capacity enhancement, which reduces the kinetic barrier associated with the nucleation of intermediate LiNH2. In addition, the concurrent incorporation of LiH is effective for mitigating the ammonia release.

scholarly journals Dehydrogenation/rehydrogenation mechanism in aluminum destabilized lithium borohydride

2009 ◽  
Vol 24 (8) ◽  
pp. 2720-2727 ◽  
Author(s):  
Xuebin Yu ◽  
Guanglin Xia ◽  
Zaiping Guo ◽  
Huakun Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrogen Desorption ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Lithium Borohydride ◽  
Hydrogen Storage Properties ◽  
X Ray ◽  
Before And After ◽  
Storage Properties ◽  
Desorption Cycle

LiBH4/Al mixtures with various mol ratios were prepared by ball milling. The hydrogen storage properties of the mixtures were evaluated by differential scanning calorimetry/thermogravimetry analyses coupled with mass spectrometry measurements. The phase compositions and chemical state of elements for the LiBH4/Al mixtures before and after hydrogen desorption and absorption reactions were assessed via powder x-ray diffraction, infrared spectroscopy, and x-ray photoelectron spectroscopy. Dehydrogenation results revealed that LiBH4 could react with Al to form AlB2 and AlLi compounds with a two-step decomposition, resulting in improved dehydrogenation. The rehydrogenation experiments were investigated at 600 °C with various H2 pressure. It was found that intermediate hydride was formed firstly at a low H2 pressure of 30 atm, while LiBH4 could be reformed completely after increasing the pressure to 100 atm. Absorption/desorption cycle results showed that the dehydrogenation temperature increased and the hydrogen capacity degraded with the increase of cycle numbers.

Crystal Structure and Hydrogen Storage Properties of novel Mg-Zr-(Li, Na, K) Hydrides Prepared by Gigapascal Hydrogen Pressure Method

2011 ◽  
Vol 1334 ◽  
Author(s):  
Nobuhiko Takeichi ◽  
Kenji Shida ◽  
Xiao Yang ◽  
Tetsuo Sakai
Keyword(s):  
Crystal Structure ◽  
Hydrogen Pressure ◽  
Hydrogen Desorption ◽  
X Ray Diffraction ◽  
Hydrogen Storage Properties ◽  
X Ray ◽  
Pressure Method ◽  
Xrd Patterns ◽  
Storage Properties ◽  
Fcc Structure

ABSTRACTNovel Mg-Zr-A (A=Na, Li and K) hydrides have been synthesized by the gigapascal hydrogen pressure method. Their crystal structures were analyzed based on synchrotron X-ray diffraction (XRD) patterns. In the Mg-Zr-H system, the Mg-Zr hydride with FCC structure was formed under 8 GPa and 873 K. In the case of Mg-Zr-Li and Mg-Zr-K systems, the quaternary hydrides were formed and these retained the same crystal structure, FCC structure, up to x = 1.0 While in the Mg-Zr-Na system, the quaternary hydrides were formed and these retained the FCC structure, up to x = 0.3. With the addition of 0.5 NaH, a hydride with the Ca7Ge type structure was formed instead of the FCC structure. The Mg-Zr-(Li, Na, K) hydrides can reversibly absorb and desorb hydrogen. The hydrogen desorption temperatures of those hydrides decrease with the increasing ionic radius of the alkali metal.

Synthesis of Quasicrystal Phases by Mechanical Alloying of Ti45+xZr38-XNi17 (-4≤ X ≤16) Powder Mixtures, and Their Hydrogen Storage Properties

2003 ◽  
Vol 805 ◽  
Author(s):  
Akito Takasaki ◽  
Naoki Imai ◽  
Kenneth F. Kelton
Keyword(s):  
Mechanical Alloying ◽  
Hydrogen Desorption ◽  
Lattice Parameter ◽  
Hydrogen Atoms ◽  
Powder Mixtures ◽  
Hydrogen Storage Properties ◽  
Crystal Phases ◽  
Powder Compacts ◽  
Storage Properties ◽  
Type Crystal

ABSTRACTMechanical alloying of Ti45+xZr38-xNi17 (-4 ≤ x ≤ 16) elemental powder mixtures leads to the formation the amorphous phase, but subsequent annealing at 833 K causes the formation of icosahedral (i) quasicrystal and the Ti2Ni-type crystal phases. The α-Ti phase is also produced in Ti-rich powders after annealing. Both the quasilattice constant of the i-phase and the lattice parameter of the Ti2Ni-type crystal phase decrease monotonically with increasing substituted amount of Ti because of the smaller radius of the Ti atom. The maximum hydrogen concentration in the i-phase in all powder compacts, after electrochemical hydrogenation in a KOH solution, is almost the same, about 63 at% ([H] / [M] ≈ 1.7). The onset temperature of hydrogen desorption is about 570 K (at a heating rate of 5 K/min) for all powders, but the temperature for the maximum hydrogen desorption rate increases with increasing Ti concentration in the powders, suggesting that some hydrogen atoms might be more strongly bound in the quasilattice where the original Zr sites become occupied by Ti atoms.

Structural and enhanced hydrogen storage properties of the Li12Mg3Si3Al phase

2021 ◽  
Vol 77 (5) ◽  
pp. 227-234
Author(s):  
Volodymyr Pavlyuk ◽  
Wojciech Ciesielski ◽  
Damian Kulawik ◽  
Nazar Pavlyuk ◽  
Grygoriy Dmytriv
Keyword(s):  
Hydrogen Storage ◽  
Storage Capacity ◽  
Hydrogen Desorption ◽  
Hydrogen Storage Capacity ◽  
Coordination Polyhedra ◽  
Hydrogen Storage Properties ◽  
New Material ◽  
Family Based ◽  
Storage Characteristics ◽  
Storage Properties

The multicomponent alumosilicide Li12Mg3Si3Al (cubic, space group I\overline{4}3d, cI76) belongs to the structural family based on the Cu15Si4 type. The Li atoms are ordered and occupy the site with symmetry 1 and the Mg atoms occupy the site with \overline{4}.. symmetry. The Si/Al statistical mixture occupies the site with .3. symmetry. The coordination polyhedra around the Li atoms are 13-vertex distorted pseudo-Frank–Kasper polyhedra. The environments of the Mg and Si/Al atoms are icosahedral. The hydrogen storage characteristics of Li12Mg3Si3Al were investigated. The reversible hydrogen storage capacity of the title compound is excellent and the gravimetric storage capacity of this new material, corresponding to 9.1 wt% H2, is higher compared to Li12Mg3Si4 (8.8 wt%). The enthalpy of hydrogen desorption is 86 kJ mol−1 and is lower compared to known lithium-based hydrides.

Microstructure and Hydrogen Storage Properties of Ti-V-Fe Alloys

2016 ◽  
Vol 847 ◽  
pp. 3-7 ◽  
Author(s):  
Gang Fu ◽  
Feng Wang ◽  
Jiang Wang ◽  
Mao Hua Rong ◽  
Zhong Min Wang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Secondary Phase ◽  
Hydrogen Desorption ◽  
Laves Phase ◽  
Thermal Stabilities ◽  
Hydrogen Storage Properties ◽  
Dsc Measurements ◽  
Arc Melting ◽  
Fe Alloys ◽  
Storage Properties

Microstructure, hydrogen storage properties and thermal stabilities of V-Ti-Fe alloys prepared by arc-melting were studied in this work. It was confirmed that V60Ti30Fe10, V70Ti20Fe10 and V80Ti10Fe10 alloys are a body-centered cubic (bcc) single phase, while V75Ti10Fe15 alloy consists of the bcc main phase and C14-typed Laves secondary phase. Experimental results show that the V80Ti10Fe10 alloy reached the largest hydrogen absorption capacities which were about 1.9 wt.% and 1.62 wt.% at 423 K and 473 K, while V75Ti10Fe15 alloy with C14-typed Laves phase showed better hydrogen desorption capacities with 1.31 wt.% at 423 K and 1.35 wt.% at 473 K, respectively. In addition, the DSC measurements indicate that the thermal stability of V75Ti10Fe15 alloy with C14-typed Laves phase decreased, which is very beneficial to the improvement of dehydrogenation rate in the alloy.

Hydrogen Storage Properties of LiNH2/MgH2 Complex Materials with Ti Catalyst by Mechanical Alloying

2014 ◽  
Vol 898 ◽  
pp. 93-97 ◽  
Author(s):  
Zhi Qiang Lan ◽  
Song Liu ◽  
Shu Bo Li ◽  
Wen Lou Wei ◽  
Jin Guo
Keyword(s):  
Hydrogen Storage ◽  
Mechanical Alloying ◽  
Hydrogen Desorption ◽  
Onset Temperature ◽  
Complex Materials ◽  
Mill Time ◽  
Hydrogen Storage Properties ◽  
Hydrogen Saturation ◽  
Saturation Absorption ◽  
Storage Properties

A LiNH2/MgH2 (1:1) complex was prepared by mechanical alloying and the effects of Ti and TiF3 on the characteristics of hydrogen storage were investigated. It was found that LiMgN and Li2NH phases exist as the main phases in the LiNH2/MgH2 (1:1) complex and that Mg (NH2)2 and NH4HF2 phases appear when TiF3 is added. The onset temperature of hydrogen desorption was reduced with increasing mill time, and the hydrogen saturation absorption temperature for the LiNH2/MgH2 complex decreased about 30°C with the addition of Ti and TiF3. Ti and TiF3 as catalysts are favorable for reducing the dehydrogenation temperature. The addition of TiF3 can also facilitate the increase of hydrogen desorption for the LiNH2/MgH2 (1:1) complex.

Microwave Synthesis of MOFs/Graphene Oxide Composites and Hydrogen Storage Properties

2016 ◽  
Vol 852 ◽  
pp. 835-840 ◽  
Author(s):  
Tian Bao Yang ◽  
Li Xian Sun ◽  
Fen Xu ◽  
Zi Qiang Wang
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Hydrogen Storage ◽  
Parent Material ◽  
X Ray Diffraction ◽  
Hydrogen Storage Properties ◽  
Transmission Electron ◽  
Metal Organic ◽  
Oxide Composites ◽  
Storage Properties

Metal-organic frameworks (MOFs: copper containing CuBTC)-graphene oxide (GO) composite (CG) was synthesized using microwave heating. The parent material and the composite were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), nitrogen sorption, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (HRTEM) and Raman spectroscopy. Then their hydrogen storage properties were systematically tested. The composite material CG shows a remarkable H2 capacity up to 2.43 wt% (28.6% increases vs. CuBTC) and higher surface area and pore volume compared to the neat CuBTC. And the particle size of CG is down to nanometer scale.

Preparation and Hydrogen Storage Properties of Mg-Ni-B BCC Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 1625-1628 ◽  
Author(s):  
Huai Yu Shao ◽  
Kohta Asano ◽  
Hirotoshi Enoki ◽  
Etsuo Akiba
Keyword(s):  
Absorption Capacity ◽  
Nanometer Scale ◽  
Activation Process ◽  
X Ray Diffraction ◽  
Hydrogen Storage Properties ◽  
Transmission Electron ◽  
Two Samples ◽  
Bcc Structure ◽  
Diffraction Patterns ◽  
Storage Properties

Mg-Ni-B system alloys were prepared by the mechanical alloying (MA) method. Body centered cubic (BCC) structure alloys are obtained in some of the Mg-Ni-B compositions after the starting mixtures of raw elements were ball milled for 200 h. Mg50Ni45B5 and Mg48Ni48B4 alloys after ball milling are with single BCC structure, which is confirmed by electron diffraction patterns. From the results of X-ray diffraction and transmission electron microscope, the crystallite size of the alloys is calculated into nanometer scale. Mg50Ni45B5 and Mg48Ni48B4 BCC alloys can absorb hydrogen at 373 K with higher rate than Mg50Ni50 alloy prepared in the same conditions. And these two samples can reach a hydrogen absorption capacity of 1.94 and 1.93 mass%, respectively at 373 K without any activation process.

First-Principles Study on Hydrogen Desorption Properties of Li4BN3H10 Doped by Chlorine Anion

2014 ◽  
Vol 574 ◽  
pp. 363-367
Author(s):  
Cui Cui Du ◽  
Tong Shuo Zhang ◽  
Tian Fu Gao ◽  
Ren Zhong Huang
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Formation Enthalpy ◽  
Hydrogen Desorption ◽  
Main Peak ◽  
Functional Theory ◽  
Hydrogen Storage Properties ◽  
Chlorine Anion ◽  
The Stability ◽  
Storage Properties

The hydrogen storage properties of Li4BN3H10doped by Cl anion are investigated by using first-principles method based on density functional theory. According to the calculated results of formation enthalpy and substitution enthalpy, Cl-doping may result in the substitution of H by Cl-in the hydride lattice and accordingly, a favorable thermodynamics modification. The electronic structure analysis indicates that the main peak of H-1s moves close to Fermi level when substituting H-by Cl-. The stability of hydrogen in the doped hydride is lowered compared with that in the hydride without doping, which improves the hydrogen desorption properties of the hydride.

The synthesis and hydrogen storage properties of Mg2Ni substituted with Cu, Co

2009 ◽  
Vol 24 (4) ◽  
pp. 1311-1316 ◽  
Author(s):  
Yu’an Chen ◽  
Hua Huang ◽  
Jie Fu ◽  
Qing Guo ◽  
Fusheng Pan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrogen Absorption ◽  
Energy Dispersive Spectrometry ◽  
Induction Melting ◽  
X Ray Diffraction ◽  
Hydrogen Storage Properties ◽  
X Ray ◽  
Storage Properties ◽  
Scanning Electron

Mg2Ni1-xCux (x = 0, 0.2, 0.4) and Mg2Ni1-yCoy (y = 0, 0.2, 0.4) were successfully synthesized via two steps: induction melting and then ball milling. The component and microstructure of the alloys were determined with x-ray diffraction (XRD) and scanning electron microscopy/x-ray energy-dispersive spectrometry (SEM/XEDS). Mg2Ni phase was observed in all 5 alloys. When the amount of Cu was increased, it led to the formation of phase from Mg2Cu to Cu11Mg10Ni9. Co2Mg was detected in the Co-containing alloys. The hydrogen absorption/desorption properties were tested with p-C-T measurement apparatus, and the results showed that the gaseous storage properties of the alloys were improved by the addition of Cu or Co.

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