Hydrogen energy, economy and storage: Review and recommendation

A review on the current progress of metal hydrides material for solid-state hydrogen storage applications

Review of hydrogen storage techniques for on board vehicle applications

Materials, technological status, and fundamentals of PEM fuel cells – A review

Hydrogen is a promising alternative energy carrier that can potentially facilitate the transition from fossil fuels to sources of clean energy because of its prominent advantages such as high energy density (142 MJ kg(-1); ref. 1), great variety of potential sources (for example water, biomass, organic matter), light weight, and low environmental impact (water is the sole combustion product). However, there remains a challenge to produce a material capable of simultaneously optimizing two conflicting criteria--absorbing hydrogen strongly enough to form a stable thermodynamic state, but weakly enough to release it on-demand with a small temperature rise. Many materials under development, including metal-organic frameworks, nanoporous polymers, and other carbon-based materials, physisorb only a small amount of hydrogen (typically 1-2 wt%) at room temperature. Metal hydrides were traditionally thought to be unsuitable materials because of their high bond formation enthalpies (for example MgH(2) has a ΔHf~75 kJ mol(-1)), thus requiring unacceptably high release temperatures resulting in low energy efficiency. However, recent theoretical calculations and metal-catalysed thin-film studies have shown that microstructuring of these materials can enhance the kinetics by decreasing diffusion path lengths for hydrogen and decreasing the required thickness of the poorly permeable hydride layer that forms during absorption. Here, we report the synthesis of an air-stable composite material that consists of metallic Mg nanocrystals (NCs) in a gas-barrier polymer matrix that enables both the storage of a high density of hydrogen (up to 6 wt% of Mg, 4 wt% for the composite) and rapid kinetics (loading in <30 min at 200 °C). Moreover, nanostructuring of the Mg provides rapid storage kinetics without using expensive heavy-metal catalysts.

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Air-stable magnesium nanocomposites provide rapid and high-capacity hydrogen storage without using heavy-metal catalysts

Irradiation induced effects on Ni3N/Si bilayer system

Structural, magnetic and electrical properties of Fe/Si system

Structural and optical properties of AlN/Si system

Ion beam induced mixing at Co/Si interface

The high de-/hydrogenation temperature of magnesium hydride is still a challenge in solid-state hydrogen storage system for automobiles applications. To improve the hydrogenation properties of MgH2, we select activated carbon/charcoal (AC) as a catalyst. A systematic investigation was performed on the hydrogen storage behaviors of MgH2 and MgH2 - 5 wt% AC nanocomposites, which were prepared by a high-energy planetary ball mill. These synthesized nanocomposites were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM) for phase identification, surface morphology and microstructural analysis. The pressure-composition-temperature (PCT) isotherm investigation shows the maximum hydrogen storage capacity ~ 6.312 wt% for MgH2-AC nanocomposites, while 3.417 wt% for MgH2 at 300 °C. The onset temperature for MgH2-AC nanocomposites is shifted towards lower side than the 50 h milled MgH2. The HRTEM study show the activated carbon helps to reduce oxygen from MgO phase in MgH2, so that significantly improvement achieved in the absorption capacity and kinetics also for the MgH2-AC nanocomposites. The presence of β- and γ-phases of MgH2 in MgH2-AC nanocomposites also supports the high hydrogenation properties and with the support of XRD data.

Chhagan Lal

Papers

Irradiation induced effects on Ni3N/Si bilayer system

Structural, magnetic and electrical properties of Fe/Si system

Structural and optical properties of AlN/Si system

Ion beam induced mixing at Co/Si interface

Hydrogenation properties and kinetic study of MgH2 - x wt% AC nanocomposites prepared by ball milling