Titre du document / Document title

Application of Mg-x wt% MmNi₅ (x = 10-70) nanostructured composites in a hydrogen storage device

Auteur(s) / Author(s)

VIJAY R. ⁽¹⁾ ; SUNDARESAN R. ⁽¹⁾ ; MAIYA M. P. ⁽²⁾ ; SRINIVASA MURTHY S. ⁽²⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Intemational Advanced Research Centre for Powder Metallurgy and New Materials, Balapur, Hyderabad-500 005, INDE
⁽²⁾ Refrigeration and Air-conditioning Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600 036, INDE

Résumé / Abstract

Large batches (800 g) of nanostructured Mg-xwt% MmNi₅ (x = 10-70) composites were prepared by ball milling elemental Mg with MmNi5 in an attritor for 12h under hydrogen atmosphere. There was no alloy formation between Mg and MmNi₅ within the milling times employed. The grain size of Mg in the composite varied from 28 to 45 nm, increasing with Mg content, whereas that of MmNi₅ was constant at 12nm, irrespective of its concentration in the composite. BET surface area of the milled composites was in the range of 25 to 58m²/g, increased with MmNi₅ content. The absorption kinetics and capacities of these composites were measured at 100, 200 and 300°C under 30 bar hydrogen pressure on a small sample of about 8 g. The samples absorbed at all the temperatures, the absorption rate increases with increase in MmNi₅ content. But the rates decreased marginally with temperature and attained steady state in less than 400s even at 100°C. However, the hydrogen absorption capacity of the composites followed the Mg content at all the temperatures, with Mg-10wt% MmNi₅ showing the highest capacity of 5.1 wt%. MmNi5 has a significant effect on the absorption of hydrogen by Mg at temperatures as low as 100°C, even though hydride of MmNi₅was not present in the hydrogenated composite. The nanostructure of Mg together with distribution of MmNi₅ on grain surface/grain boundary of Mg appears to have enhanced the absorption, with MmNi₅ probably acting as a conduit for hydrogen diffusing into Mg grain. The performance of hydrogen storage device with larger quantities of Mg-MmNi5 composites (350-500 g) was evaluated in the temperature range of 100-150°C with supply pressure of 10-30 bar. The absorption rates and quantity of hydrogen absorbed increased with supply pressure and decreased with temperature. The fraction a was more than 70% in compositions with up to 10-30 wt% MmNi₅, but was much lower at higher MmNi5 content. The absorption behaviour of these composites followed the same trend as in the case of testing on smaller sample size.

Revue / Journal Title

International journal of hydrogen energy    ISSN  0360-3199   CODEN IJHEDX 

Source / Source

2007, vol. 32, n^o13, pp. 2390-2399 [10 page(s) (article)] (18 ref.)

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Kidlington, ROYAUME-UNI  (1976) (Revue)

Mots-clés anglais / English Keywords

Performance

;

Kinetics

;

Magnesium Nickel Alloys

;

Grain size

;

Alloys

;

Misch metal

;

Hydrogen storage

;

Nanostructure

;

Mots-clés français / French Keywords

Performance

;

Cinétique

;

Magnésium Nickel Alliage

;

Grosseur grain

;

Alliage

;

Mischmetal

;

Stockage hydrogène

;

Nanostructure

;

Mots-clés espagnols / Spanish Keywords

Rendimiento

;

Cinética

;

Magnesio Niquel Aleación

;

Grosor grano

;

Aleación

;

Mischmetal

;

Nanoestructura

;

Mots-clés d'auteur / Author Keywords

Hydrogen storage

;

Nanostructured composites

;

Absorption kinetics

;

Localisation / Location

INIST-CNRS, Cote INIST : 17522, 35400014976378.0340