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High temperature metal hydrides as heat storage materials for solar and related applications.

Felderhoff M, Bogdanović B - Int J Mol Sci (2009)

Bottom Line: High temperature metal hydrides offer high heat storage capacities around this temperature.Based on Mg-compounds, these hydrides are in principle low-cost materials with excellent cycling stability.Relevant properties of these hydrides and their possible applications as heat storage materials are described.

View Article: PubMed Central - PubMed

Affiliation: Max-Planck Institut für Kohlenforschung, Mülheim/Ruhr, Germany. felderhoff@mpi-muelheim.mpg.de <felderhoff@mpi-muelheim.mpg.de>

ABSTRACT
For the continuous production of electricity with solar heat power plants the storage of heat at a temperature level around 400 degrees C is essential. High temperature metal hydrides offer high heat storage capacities around this temperature. Based on Mg-compounds, these hydrides are in principle low-cost materials with excellent cycling stability. Relevant properties of these hydrides and their possible applications as heat storage materials are described.

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Related in: MedlinePlus

Left: HR-TEM-pictures of Mg2FeH6 (top) and dehydrogenated material (2Mg + Fe) (bottom); right: TEM micrographs of different steps of Mg2FeH6 formation are recorded. Dark regions of the particles are Fe regions and the lighter consist of Mg2FeH6. (a) Initial stage of the Mg2FeH6 formation; (b) vermicular excresence of Mg2FeH6 out of the surface of an iron seed; (c) final stage of the Mg2FeH6 formation [22].
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f11-ijms-10-00325: Left: HR-TEM-pictures of Mg2FeH6 (top) and dehydrogenated material (2Mg + Fe) (bottom); right: TEM micrographs of different steps of Mg2FeH6 formation are recorded. Dark regions of the particles are Fe regions and the lighter consist of Mg2FeH6. (a) Initial stage of the Mg2FeH6 formation; (b) vermicular excresence of Mg2FeH6 out of the surface of an iron seed; (c) final stage of the Mg2FeH6 formation [22].

Mentions: The cause for the improvement of thermochemical storage properties of the Mg-Fe-H system with respect to the MgH2 system could be partially elucidated via electron microscopy investigations on Mg-Fe-H samples in the hydrogenated and dehydrogenated state. Raster electron- microscopy images of the starting Fe and Mg powders (Fe 5–10 μm and Mg particles 50–100 μm) and of Mg2FeH6 after 600 hydrogenation/dehydrogenation cycles at high temperatures are shown in Figures 10a–c. A high resolution transmission electron microscopy (TEM) micrograph of Mg2FeH6 is reproduced in Figure 11 (top). At 1:500,000 magnification one can already perceive the atomic net plains of the crystalline magnesium-iron hydride. The material is perfectly homogeneous. On the lower part of the Figure (Figure 11, bottom) can be seen a TEM photo of the dehydrogenated material: in this case black and colorless regions can be discerned. By energy dispersive X-ray (EDX) analyses it could be proved that the black regions are almost pure iron and the colorless transparent ones are pure magnesium. Upon each dehydrogenation the two metals separate from each other.


High temperature metal hydrides as heat storage materials for solar and related applications.

Felderhoff M, Bogdanović B - Int J Mol Sci (2009)

Left: HR-TEM-pictures of Mg2FeH6 (top) and dehydrogenated material (2Mg + Fe) (bottom); right: TEM micrographs of different steps of Mg2FeH6 formation are recorded. Dark regions of the particles are Fe regions and the lighter consist of Mg2FeH6. (a) Initial stage of the Mg2FeH6 formation; (b) vermicular excresence of Mg2FeH6 out of the surface of an iron seed; (c) final stage of the Mg2FeH6 formation [22].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2662468&req=5

f11-ijms-10-00325: Left: HR-TEM-pictures of Mg2FeH6 (top) and dehydrogenated material (2Mg + Fe) (bottom); right: TEM micrographs of different steps of Mg2FeH6 formation are recorded. Dark regions of the particles are Fe regions and the lighter consist of Mg2FeH6. (a) Initial stage of the Mg2FeH6 formation; (b) vermicular excresence of Mg2FeH6 out of the surface of an iron seed; (c) final stage of the Mg2FeH6 formation [22].
Mentions: The cause for the improvement of thermochemical storage properties of the Mg-Fe-H system with respect to the MgH2 system could be partially elucidated via electron microscopy investigations on Mg-Fe-H samples in the hydrogenated and dehydrogenated state. Raster electron- microscopy images of the starting Fe and Mg powders (Fe 5–10 μm and Mg particles 50–100 μm) and of Mg2FeH6 after 600 hydrogenation/dehydrogenation cycles at high temperatures are shown in Figures 10a–c. A high resolution transmission electron microscopy (TEM) micrograph of Mg2FeH6 is reproduced in Figure 11 (top). At 1:500,000 magnification one can already perceive the atomic net plains of the crystalline magnesium-iron hydride. The material is perfectly homogeneous. On the lower part of the Figure (Figure 11, bottom) can be seen a TEM photo of the dehydrogenated material: in this case black and colorless regions can be discerned. By energy dispersive X-ray (EDX) analyses it could be proved that the black regions are almost pure iron and the colorless transparent ones are pure magnesium. Upon each dehydrogenation the two metals separate from each other.

Bottom Line: High temperature metal hydrides offer high heat storage capacities around this temperature.Based on Mg-compounds, these hydrides are in principle low-cost materials with excellent cycling stability.Relevant properties of these hydrides and their possible applications as heat storage materials are described.

View Article: PubMed Central - PubMed

Affiliation: Max-Planck Institut für Kohlenforschung, Mülheim/Ruhr, Germany. felderhoff@mpi-muelheim.mpg.de <felderhoff@mpi-muelheim.mpg.de>

ABSTRACT
For the continuous production of electricity with solar heat power plants the storage of heat at a temperature level around 400 degrees C is essential. High temperature metal hydrides offer high heat storage capacities around this temperature. Based on Mg-compounds, these hydrides are in principle low-cost materials with excellent cycling stability. Relevant properties of these hydrides and their possible applications as heat storage materials are described.

Show MeSH
Related in: MedlinePlus