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Journal ArticleDOI

Effect of substitutional elements on hydrogen absorption properties in Mm-based AB5 alloys

28 Jan 2004-Journal of Alloys and Compounds (Elsevier)-Vol. 363, Iss: 1, pp 275-291
TL;DR: In this paper, the authors studied the hydrogen absorption isotherms for the CaCu5 hexagonal structured alloys MmNi3.4, Mm Ni3.8Al 0.368Mn0.5Fe0.4Co 0.333V0.333Al0.3Fe0,4Fe 0.5Co 0,5Fe 0,6Al 0,7Al 0 0,8Al0 0.4Fe0 0,4Co0.
About: This article is published in Journal of Alloys and Compounds.The article was published on 2004-01-28. It has received 48 citations till now. The article focuses on the topics: Hydrogen & Hydrogen storage.
Citations
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TL;DR: In this paper, the performance of the CeY2Ni9 negative electrode, at a room and different temperatures, was compared with the parent alloy LaY 2Ni9, which exhibits an easy activation and good reaction reversibility.
Abstract: For the purpose of lowering the cost of metal hydride electrode, the La of LaY2Ni9 electrode was replaced by Ce. The electrochemical performances of the CeY2Ni9 negative electrode, at a room and different temperatures, were compared with the parent alloy LaY2Ni9. At room temperature during a long cycling, the evolution of the electrochemical capacity—the diffusivity indicator ( $$ \frac{D_{\mathrm{H}}}{a^2} $$ )—the exchange current density, and the equilibrium potential were determined. At different temperatures, the electrochemical characterization of this alloy allowed the estimation of the enthalpy, the entropy, and the activation energy of the hydride formation. The evolution of the high-rate dischargeability was also evaluated at different temperatures. Compared with the parent LaY2Ni9 alloy, CeY2Ni9 exhibits an easy activation and good reaction reversibility. This alloy also conserves a good lifetime during a long-term cycling. A lower activation energy determined for this alloy corresponds to an easy absorption of hydrogen into this new alloy.

17 citations

Journal ArticleDOI
TL;DR: In this paper, the gas phase and electrochemical properties of the quinary alloy Ti 1.5 Zr 5.5 V 0.2 are studied and compared to the structural properties reported in Part 1.

17 citations

Journal ArticleDOI
TL;DR: In this article, the dependence of the thermodynamics of dissolved hydrogen in these alloy hydrides on the hydrogen concentration has been studied and the results showed that hydrogen induced amorphization (HIA) at higher hydrogen concentration is observed.

16 citations

Journal ArticleDOI
TL;DR: The kinetic behavior of the LaNi3.55Mn0.4Al0.3Co 0.4Fe0.35 metal hydride, used as a negative electrode in the nickel/metal-hydride (Ni/MH) batteries, was investigated using electrochemical impedance spectroscopy (EIS) at different state of charge (SOC) as mentioned in this paper.

16 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of micro-encapsulation on the surface morphology and kinetics of hydrogen charging was investigated and it was found that palladium-nickel (Pd-Ni) co-deposition by electroless plating significantly improved the hydrogen charging of the AB 5 -type intermetallides at low hydrogen pressure and temperature, after long-term pre-exposure to air.
Abstract: Surface engineering approaches were adopted in the preparation of advanced hydrogen sorption materials, based on ‘low-temperature’, AB 5 -type intermetallides. The approaches investigated included micro-encapsulation with palladium and mixed-metal mantles using electroless plating. The influence of micro-encapsulation on the surface morphology and kinetics of hydrogen charging were investigated. It was found that palladium-nickel (Pd-Ni) co-deposition by electroless plating significantly improved the kinetics of hydrogen charging of the AB 5 -type intermetallides at low hydrogen pressure and temperature, after long-term pre-exposure to air. The improvement in the kinetics of hydrogen charging was credited to a synergistic effect between the palladium and nickel atoms in the catalytic mantle and the formation of an ‘interfacial bridge’ for hydrogen diffusion by the nickel atoms in the deposited layer. The developed surface-modified materials may find application in highly selective hydrogen extraction, purification, and storage from impure hydrogen feeds.

15 citations

References
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Journal ArticleDOI
TL;DR: A key to pharmaceutical and medicinal chemistry literature and training of literature chemists are discussed in the Advances series as mentioned in this paper, with the focus on the training of chemistry chemists, which is a subject of great interest to the literature chemist.
Abstract: NUMBERS 16 and 17 in the Advances series have made their appearance. The titles are: "A Key to Pharmaceutical and Medicinal Chemistry Literature" and "Training of literature Chemists." The first is a collection of papers presented before the Divisions of Chemical Literature and Medicinal Chemistry; the second consists of papers given before a joint meeting of the Divisions of Chemical Education and Chemical Literature. Glancing at the titles of subjects covered to date in the Advances series, it becomes evident that a substantial literature is being built by literature chemists, largely through the divisions in the AMERICAN CHEMICAL SOCIETY. Number 4, "Searching the Chemical Literature," has been reprinted several times and frequently is referred to as the "bible" of literature chemists. Number 10, "Literature Resources for Chemical Process Industries," is in much demand. Nomenclature is a subject of direct importance to the literature chemist, and Number 8, entitled "Chemical Nomenclature," and ...

3,188 citations

Journal ArticleDOI
Hongge Pan1, Yongfeng Liu1, Mingxia Gao1, Yunfeng Zhu1, Yongquan Lei1, Qidong Wang1 
TL;DR: In this paper, the structural and electrochemical properties of the La0.7Mg0.3(Ni0.85Co0.15)x (x=3.15, 3.30), 3.65,3.50, and 3.80) hydrogen storage electrode alloys have been studied systematically.

146 citations

Journal ArticleDOI
K.H.J. Buschow1
TL;DR: In this paper, the magnetic properties of the hydrides were determined and compared with the original compounds and it was shown that the magnetic moment per Fe atom is much larger in hydride phases.

89 citations

Journal ArticleDOI
TL;DR: In this paper, the authors studied the hydrogen absorption-desorption characteristics of multicomponent alloys such as MmNi5−xAl(Mn)y−zMz and MnNi5 −xMnyM2.
Abstract: In order to reduce the large hysteresis effect in MmNi hydrides (Mm  misch metal) we studied the hydrogen absorption-desorption characteristics of multicomponent alloys such as MmNi5−xAl(Mn)y−zMz and MmNi5−xAl(Mn)yM2 (M = Co, Cr, Cu, Nb, Ti, V, Zr; x = 0.3 − 0.5; y = 0.3 − 0.5; z = 0.05 − 0.1). The substitution or addition of the element M eliminates the large hysteresis effect that occurs during an absorption-desorption cycle. The hysteresis factor (equal to In( P a P d )) for MmNi4.7Al0.3M0.1 hydrides decreased for additives M in the following order: Zr > Co > Cr > Ti,V > Cu. Investigations of the effects of cycling showed that spalling occurred more rapidly for MmNi4.5Mn0.5 than for MmNi4.5Mn0.5Zr0.005 and MmNi4.5Mn0.5Zr0.1.

77 citations

Journal ArticleDOI
TL;DR: The hydrogen absorption and desorption characteristics of mischmetal (Mm)-nickel-aluminum alloys were investigated in this paper, where the same hexagonal structure as LaNi5 and MmNi5 was found to react readily with hydrogen to form the hydrides MnNi4.5Al0.75 Al0.5A10.
Abstract: The hydrogen absorption and desorption characteristics of mischmetal (Mm)-nickel-aluminum alloys were investigated. MmNi5−xAlx (x = 0.25 −0.5) have been found to have the same hexagonal structure as LaNi5 and MmNi5, and they reacted readily with hydrogen to form the hydrides MmNi4.75 Al0.25H5.4, MmNi4.65Al0.35H 5.3H5.3 and MmNi4.5Al0.5H4.9 (hydrogen content: 1.3,1.2 and 1.2 wt.%, respectively) under 60 atm hydrogen pressure at room temperature. The dissociation pressures of these hydrides were dependent on the aluminum content (aluminum partially substitutes for nickel) and the value of log Pbecame lower than the value for MmNi5 hydride as x increased. The enthalpy change on hydride formation as determined from the dissociation isotherms for the MmNi4.5Al0.5-H system was − 5.5 kcal (mol H2)−1; this value was smaller than those for LaNi5 and MmNi5. The dissociation pressure at 30 °C was 3 atm and was nearly the same as that of LaNi5. The desorption rate of hydrogen for MmNi4.5Al0.5 was larger than those for LaNi5 and MmNi5) and a value of 2.1 – 4.3 kcal mol−1 was obtained for the apparent activation energy of hydrogen desorption. For MmNi4.5Al0.5 the hydrogen absorption-desorption cycle was repeated 30 times, but no variation in the hydrogen absorption-desorption capacity was observed. The hydride of MmNi4.5A10.5 proved to be suitable for use as a stationary hydrogen storage material.

66 citations