Comparison between Mg/Cu Super-Laminates and Mg2Cu Powder in Microstructure and Hydrogen Storage Properties

Super-laminates have been attracting attention since co-authors Ueda et al. reported that Mg/Cu super-laminates showed reversible hydrogenation and dehydrogenation at 473K. The Mg/Cu super-laminates were prepared by a repetitive fold and roll method. Initial activation at 573 K led the super-laminates to absorb hydrogen at 473K. TEM observations of micro/nano-structures in the super-laminates and Mg2Cu powder were performed in order to clarify the process of hydrogenation and dehydrogenation at 473K. The as-rolled Mg/Cu super-laminates have laminated structures in size of sub-micrometer thickness composed of Mg and Cu layers with dense lattice defects. The super-laminates after initial activation keep laminated structure and have uniformly distributed pores with a sub-micrometer diameter. It is considered that these micro/nano-structures of Mg/Cu super-laminates lead to lower dehydrogenation temperature and better kinetics.

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Micro/Nano-Structures and Hydrogen Absorption/Desorption Properties of Mg/Cu Super-Laminates

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.1143 ◽

2010 ◽

Vol 638-642 ◽

pp. 1143-1147 ◽

Cited By ~ 1

Author(s):

Koji Tanaka ◽

Tetsu Kiyobayashi ◽

Nobuhiko Takeichi ◽

Hiroshi Miyamura ◽

Shiomi Kikuchi

Keyword(s):

Hydrogen Absorption ◽

Lattice Defects ◽

Laminated Structure ◽

Dense Lattice ◽

Nano Structures ◽

Initial Activation ◽

Laminated Structures

Super-laminates have been attracting attention since co-authors Ueda et al. reported that Mg/Cu super-laminates showed reversible hydrogenation and dehydrogenation at 473K. The Mg/Cu super-laminates were prepared by a repetitive fold and roll method. Initial activation at 573 K led the super-laminates to absorb hydrogen at 473K. TEM observations of micro/nano-structures in the Mg/Cu super-laminates and Mg2Cu powder were performed in order to clarify the process of hydrogenation and dehydrogenation at 473K. The as-rolled Mg/Cu super-laminates have laminated structures sub-micrometer thick composed of Mg and Cu layers with dense lattice defects. The super-laminates after initial activation keep laminated structure and have uniformly distributed pores sub-micrometer in diameter. It is considered that these micro/nano-structures of Mg/Cu super-laminates lead to lower dehydrogenation temperature and better kinetics.

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Relations between Microstructure of Mg/Cu Super-laminates and Kinetics of Hydrogen Absorption/desorption

MRS Proceedings ◽

10.1557/proc-0971-z07-06 ◽

2006 ◽

Vol 971 ◽

Author(s):

Koji Tanaka ◽

Nobuhiko Takeichi ◽

Hideaki Tanaka ◽

Nobuhiro Kuriyama ◽

Tamotsu T. Ueda ◽

...

Keyword(s):

Hydrogen Storage ◽

Hydrogen Absorption ◽

High Performance ◽

Hydrogen Storage Materials ◽

Laminated Structure ◽

Dense Lattice ◽

Nano Structures ◽

Initial Activation ◽

Laminated Structures ◽

Kinetics Of

ABSTRACTSuper-laminates have been attracting attention since co-authors Ueda et al. reported that Mg/Cu super-laminates showed reversible hydrogenation and dehydrogenation at 473K. The Mg/Cu super-laminates were prepared by a repetitive fold and roll method. Initial activation at 573 K led the super-laminates to absorb hydrogen at 473K. TEM observations of micro/nano-structures in the super-laminates were performed in order to clarify the process of hydrogenation and dehydrogenation at 473K, The as-rolled Mg/Cu super-laminates have laminated structures in size of sub-micrometer thickness composed of Mg and Cu layers with dense lattice defects. The super-laminates after initial activation keep laminated structure and have uniformly distributed pores with a sub-micrometer diameter. It is considered that these micro/nano-structures of Mg/Cu super-laminates lead to lower dehydrogenation temperature and better kinetics, which would contribute to achieve high performance hydrogen storage materials.

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The Effect of Initial Activation on Microstructures of Mg/Cu Super-laminates and Hydrogen Absorption Properties

MRS Proceedings ◽

10.1557/proc-1042-s03-08 ◽

2007 ◽

Vol 1042 ◽

Cited By ~ 1

Author(s):

Koji Tanaka ◽

Nobuhiko Takeichi ◽

Hideaki Tanaka ◽

Nobuhiro Kuriyama ◽

Tamotsu T Ueda ◽

...

Keyword(s):

Hydrogen Absorption ◽

Diffusion Distance ◽

Absorption Properties ◽

Hydrogen Storage Properties ◽

Fine Grain ◽

Nano Structures ◽

Initial Activation ◽

Micrometer Size ◽

Storage Properties ◽

Short Diffusion Distance

AbstractMicrostructures and hydrogen storage properties of Mg/Cu super-laminates were compared to clarify the effect of initial activation. The initial activation change micro/nano-structures of Mg/Cu super-laminates into Mg2Cu with layered structure in fine grain size of about 1μm and pores highly dispersed between layers in sub-micrometer size. Large surface area, dense defects and short diffusion distance for the reaction enable Mg/Cu super-laminates to absorb hydrogen very quickly.

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Hydrogen Storage Properties, Metallographic Structures and Phase Transitions of Mg-based Alloys Prepared by Super Lamination Technique

MRS Proceedings ◽

10.1557/proc-1128-u01-04 ◽

2008 ◽

Vol 1128 ◽

Cited By ~ 2

Author(s):

Nobuhiko Takeichi ◽

Koji Tanaka ◽

Hideaki Tanaka ◽

Nobuhiro Kuriyama ◽

Tamotsu T Ueda ◽

...

Keyword(s):

Hydrogen Storage ◽

Intermetallic Compounds ◽

Activation Process ◽

Laminate Composites ◽

Hydrogen Storage Properties ◽

In Situ Xrd ◽

Recombination Processes ◽

Initial Activation ◽

Storage Properties

AbstractWe have prepared Mg/Pd laminate composites with (Mg/Pd)=6, 3 and 2.5 atom ratios, by a super lamination technique. The homogeneous Mg-Pd intermetallic compounds, Mg6Pd, Mg3Pd and Mg5Pd2, are formed during the initial activation process. We investigated the hydrogen storage properties of these materials. The compounds can reversibly absorb and desorb a large amount of hydrogen, up to 1.46˜0.9 H/M, at 573 K. Except for the Mg5Pd2-hydrogen system, the pressure composition-isotherms show two plateaux. The mechanism of the phase transition during hydrogenation/dehydrogenation was analyzed by in-situ XRD measurements. These intermetallic compounds absorb and desorb hydrogen through reversible multistage disproportionation and recombination processes.

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Hydrogenation Characteristics of Mg Based Alloy Prepared by Super Lamination Technique

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.1609 ◽

2007 ◽

Vol 561-565 ◽

pp. 1609-1612 ◽

Cited By ~ 19

Author(s):

Ryota Mori ◽

Hiroshi Miyamura ◽

Shiomi Kikuchi ◽

Koji Tanaka ◽

Nobuhiko Takeichi ◽

...

Keyword(s):

Hydrogen Storage ◽

Ambient Conditions ◽

Hydrogen Storage Capacity ◽

Alloy Films ◽

Hydrogen Storage Properties ◽

X Ray ◽

Ni Alloy ◽

Initial Activation ◽

Storage Properties ◽

Activation Property

In order to improve the hydrogenation property of Mg/Ti laminate composite, Ni was added as a third element. Hydrogen storage properties of the laminated Mg/Ti/Ni alloy films were studied. Laminated Mg/Ti/Ni multilayer alloy films were prepared by cold rolling of stacked Mg, Ti and Ni under ambient conditions. The stacked foils were subjected to repetition of rolling and stacking, resulting in super-laminated foils with the thickness less than 0.3mm, containing more than 15000 layers. Microstructures of the super-laminates were studied by scanning electron microscopy and X-ray diffractometry. Their hydrogenation behaviors were investigated by use of a Sieverts type apparatus. The hydrogen storage capacity (H/M) of the laminate with composition Mg/Ti/Ni=9.0/0.9/0.1 amounted H/M=1.6 at 573K, 0.4MPa. Initial activation property was improved by controlling the amount of Ni appropreately.

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