Effect of Mo–Ni treatment on electrochemical kinetics of La–Mg–Ni-based hydrogen storage alloys

In order to obtain a nanocrystalline and amorphous structure in the Mg2Ni-type alloy, the Ni in Mg2Ni alloy has been partially substituted by M (M=Co, Cu), and the melt spinning has been used to fabricate the Mg20Ni10-xMx (M=Co, Cu; x=0-4) hydrogen storage alloys. The microstructures of the alloys were characterized by XRD, SEM and HRTEM. The effects of substituting Ni with M (M=Co, Cu) on the gaseous and electrochemical hydrogen storage kinetics of the as-spun alloys were investigated. The results indicate that the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure, while the as-spun (M=Cu) alloys hold an entire nanocrystalline structure, suggesting that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The substitution of M (M=Co, Cu) for Ni exerts a trifling impact on the hydriding kinetics of the alloys, but it renders a marked enhancement of dehydriding capacity and kinetics. Furthermore, the measurements of the high rate discharge ability (HRD) and the hydrogen diffusion coefficient (D) as well as the electrochemical impedance spectra (EIS) of the alloys exhibit that the electrochemical kinetics of the as-spun (30 m/s) alloys is significantly ameliorated by substituting Ni with M (M=Co, Cu).

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Mechanical alloys Mg-Me (Me: Ti, Fe, Ni, Al) & Mg-Me1-Me2(Ме1:Al, Me2: Ti, Fe, Ni) with low resistance and improved kinetics of hydrogenation/dehydrogenation for hydrogen storage applications

French-Ukrainian Journal of Chemistry ◽

10.17721/fujcv6i1p31-55 ◽

2018 ◽

Vol 6 (1) ◽

pp. 31-55 ◽

Cited By ~ 1

Author(s):

O. Ershova ◽

V. Dobrovolsky ◽

Y. Solonin

Keyword(s):

Thermal Stability ◽

Hydrogen Storage ◽

Sorption Capacity ◽

Hydrogen Pressure ◽

Hydrogen Desorption ◽

Decomposition Kinetics ◽

Hydrogen Storage Alloys ◽

Mechanically Alloyed ◽

Kinetics Of ◽

Complex Doping

Changes in MgH2 decomposition kinetics were investigated in dependence on complex doping of MgH2 by Al, Ti, Ni, and Fe. Reactive mechanochemical alloying method (RMA) was applied in the temperature descending regime. It was found that addition of Al+Ni+Ti, Al+Ti, Fe+Ti (see below) and Al+Fe elements combinations led to a lower thermal stability and, consequently, to a lowering of the temperature of hydrogen desorption onset. Whereas desorption began at temperature of 320 °C from the pure MgH2, the aditions of Al, Ni, Ti and Fe lowered the start of the desorption down to 250°C (at hydrogen pressure 0.1 MPa in the reactor). Very fast desorption kineticsprecize at 300 0C and PH 2= 0.1 MPa were observed for Mg+Me mixture in comparison with the pure Mg. Sorption capacity of investigated mechanically-alloyed composites varied from 5 to 6.5 wt. % H2. The tested materials showed a high potential as hydrogen storage alloys especially for stationary application.

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The Hydriding and Dehydriding Kinetics of Some AB 5 Type Hydrogen Storage Alloys Presented at the International Symposium on Metal–Hydrogen Systems, Fundamentals and Applications, Uppsala, Sweden, June 8–12, 1992.

ENERGYO ◽

10.1515/energyo.0092.00016 ◽

2018 ◽

Author(s):

J. Cimato ◽

W. Zhang ◽

A. J. Goudy ◽

K. R. Singleton

Keyword(s):

Hydrogen Storage ◽

International Symposium ◽

Hydrogen Storage Alloys ◽

Hydrogen Systems ◽

Kinetics Of

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