Effect of mechanical grinding under Ar and H2 atmospheres on structural and hydriding properties in LaNi5

Fujii, H.; Munehiro, Shuko; Fujii, Keiji; Orimo, Shin Ichi

doi:10.1016/s0925-8388(01)01508-0

Cited by 29 publications

(20 citation statements)

References 17 publications

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“…The plateau pressure increases for nanocrystalline materials with a reduction in hydrogen capacity and a sloping plateau [152,154,155]. In reference [154] a high energy shaker mill (SPEX 8000) was used, while for references [152,155] milling was performed on a Fritsch P7 planetary mill.…”

Section: Abmentioning

confidence: 99%

“…In reference [154] a high energy shaker mill (SPEX 8000) was used, while for references [152,155] milling was performed on a Fritsch P7 planetary mill. However, because of batch sizes, grinding balls and milling speed, the milling in [155] was more energetic than in [152]. This explains why in [155] the loss of capacity is more important and the plateau slope is greater than in [152].…”

Section: Abmentioning

confidence: 99%

“…However, because of batch sizes, grinding balls and milling speed, the milling in [155] was more energetic than in [152]. This explains why in [155] the loss of capacity is more important and the plateau slope is greater than in [152]. Fujii et al concluded that no improvement in hydrogen sorption properties is expected from nanocrystalline LaNi 5 because of the formation of a too stable hydride in the grain boundaries [155].…”

Section: Abmentioning

confidence: 99%

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Metal Hydrides

Huot

2010

Handbook of Hydrogen Storage

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Metal hydrides are promising candidates for many stationary and mobile hydrogen storage applications. Presently, the most common use of metal hydrides is as anode material in commercial nickel-metal hydrides (Ni-MH) rechargeable batteries which have replaced conventional nickel-cadmium batteries in many applications. A wide variety of Ni-MH batteries are now on the market with cell sizes ranging from 30 mAh to 250 Ah [1,2]. Some other applications are: hydrogen compression [3], aircraft fire-detectors [4], isotope separation [5], and hydrogen getters for microelectronic packages. Hydride formation is also used in the HDDR process (hydrogenation-disproportionation-desorption-recombination) for the synthesis of magnetic materials such as Nd 2 Fe 14 B [6]. A striking application is as a component of cryocoolers for the ESA Planck mission [7]. Another exciting new application is the use of metal hydrides for switchable mirrors [8]. As we can see, metal hydrides have a wide range of applications. However, most research and development is targeted towards two applications: batteries and hydrogen storage. The former is now widely exploited but the latter is still facing many technical problems. The main advantages of storing hydrogen in a metal hydride are the high hydrogen volumetric densities (sometimes higher than in liquid hydrogen) and the possibility to absorb and desorb hydrogen with a small change in hydrogen pressure [9].The physics of hydrogen in elemental metals was reviewed at the end of the 1970s in thebooksHydrogeninMetals,volumesIandII [10,11].The1970s alsosawtheemergence of the important field of intermetallic compounds as hydride materials. An in-depth review of this field can be found in Hydrogen in Intermetallic Compounds volumes I, and II [12,13]. A review of the propertiesand applications of hydrogen in metals can befound in the third volume of Hydrogen in Metals [14]. The basic properties of the metal-hydrogen system are discussed from a fundamental point of view by Fukai [15]. Although initial studies on nanocrystalline and amorphous metal hydrides were initiated around the 1980s [16], the real emergence of nanocrystalline metal hydrides as a new class of Handbook of Hydrogen Storage. Edited by Michael Hirscher

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Section: Abmentioning

confidence: 99%

Section: Abmentioning

confidence: 99%

Section: Abmentioning

confidence: 99%

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Metal Hydrides

Huot

2010

Handbook of Hydrogen Storage

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“…The partial amorphization of LaNi 5 is not unexpected in the light of the observations of Fujii et al [18] who were able to induce glass transformation of this phase by ball milling. According to their findings, ball milled LaNi 5 begins to lose the crystal order immediately, so that the amorphous fraction is notable even after 1 h of processing.…”

Section: Structural and Morphological Analysesmentioning

confidence: 62%

“…1 where an X-ray diffractogram relative to the sample MgH 2 + 30 wt.% LaNi 5 milled for 5 h is reported. The diffractogram evidences four main features: (a) a partial modification of MgH 2 from a tetragonal to an orthorhombic phase; (b) a small shift to low angle of the peaks belonging to the LaNi 5 phase which can suggest the formation of a LaNi 5−x H 0.15 phase [18]; (c) the presence of a broad peak characteristic of an amorphous phase; (d) peaks characteristic of fcc Ni.…”

Section: Structural and Morphological Analysesmentioning

confidence: 97%

Hydrogen Release and Microstructure of MgH₂Based Composite Powders Containing a Relevant Amount of LaNi₅

et al. 2010

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Micro-composite materials based on MgH 2 with the addition of a relevant amount of LaNi 5 have been synthesized by reactive ball milling. The powder microstructure has been studied by a combination of X-ray diffraction and scanning electron microscopy, while the decomposition behaviour and the hydrogen release properties have been obtained by differential thermal analysis and thermo-gravimetric measurements. Both temperature scans and constant temperature isotherms have been used to this purpose. Experimental results allow identifying optimum processing condition for synthesis of material that shows the onset of hydrogen release at temperatures as low as 450 K. The decomposition kinetics has been studied by isothermal measurements which show that the whole process cannot be described by just one mechanism limiting the reaction velocity. In fact in the first decomposition step the reaction is kinetically limited by the second phase nucleation, while, for partially decomposed samples the bulk diffusion appears to limit the process. On the basis of the experimental results we propose a mechanism of phase transformation where a percolating network of the two phases is formed.

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How to Design Hydrogen Storage Materials? Fundamentals, Synthesis, and Storage Tanks

Lai

Sun

Wang

et al. 2019

Advanced Sustainable Systems

116

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Effect of mechanical grinding under Ar and H2 atmospheres on structural and hydriding properties in LaNi5

Cited by 29 publications

References 17 publications

Metal Hydrides

Metal Hydrides

Hydrogen Release and Microstructure of MgH₂Based Composite Powders Containing a Relevant Amount of LaNi₅

How to Design Hydrogen Storage Materials? Fundamentals, Synthesis, and Storage Tanks

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Effect of mechanical grinding under Ar and H2 atmospheres on structural and hydriding properties in LaNi5

Cited by 29 publications

References 17 publications

Metal Hydrides

Metal Hydrides

Hydrogen Release and Microstructure of MgH2Based Composite Powders Containing a Relevant Amount of LaNi5

How to Design Hydrogen Storage Materials? Fundamentals, Synthesis, and Storage Tanks

Contact Info

Product

Resources

About

Hydrogen Release and Microstructure of MgH₂Based Composite Powders Containing a Relevant Amount of LaNi₅