Metal Hydride Storage – Future Technologies and New Advancements

Matthew Baxley3 December 2012

NPRE 498baxley2@illinois.edu

Overview of Metal Hydrides

-Potentially reversible storage medium for hydrogen

-Generally have good energy density, but specific energy is less than conventional hydrocarbons

- A variety of different materials-MgH

2

-LaNi5H

6

-NaAlH4

-Many others

Mechanism of Action

Mechanism of Action

2/nM + H2 <=> 2/nMHn +ΔH Changing pressure and temperature will

cause the hydrogen to either be adsorbed or desorbed

Under low temperature or high pressure the hydrogen atoms can enter the gaps in the parent metal, forming a solid solution

Goals for a Hydrogen Storage Medium in Fuel Cell Vehicles

Yang, Wolverton, and Siegel, 2009

Note: Old targets (2003) were developed before widespread research into fuel cell vehicles and therefore necessitated assumptions

Goals for a Hydrogen Storage Medium in Fuel Cell Vehicles

Yang, Wolverton, and Siegel, 2009

Note: Old targets (2003) were developed before widespread research into fuel cell vehicles and therefore necessitated assumptions

Capacity of Metal Hydrides to be used in Fuel Cell Vehicles

Yang, Wolverton, and Siegel, 2009

Advances and Future Technologies

Proton Flow Battery

Metal Hydride-Carbon Compounds

Nanoconfinement of Light Metal Hydrides

Additional Uses

The “Proton Flow Battery”

Integrates a composite metal hydride with a reversible proton exchange membrane

Energy efficiency near that of a lithium-ion battery, but provides a hydrogen storage capacity of about 0.6% H2 (significantly more energy per unit mass).

Removes the need for an H2

gas intermediate

Andrews and Mohammadi (2014)

Metal Hydride-Carbon Compounds

Typical metal hydrides are a lattice of metal ions which form ionic bonds with hydrogen

Complex metal hydrides contain additional compounds and cause the hydrogen form covalent bonds with molecular anions containing the hydride

Complex metal hydrides provide additional options for metal hydride storageLiBH

4

NaAlH4

Excellent gravimetric storage capacity, but the kinetics of hydrogen release are too slow for practical applications

Metal Hydride-Carbon Compounds

Study performed by Lin et al. explores improving the complex hydride

NaAlH

4 with

Co/Carbon catalysts This Co/Carbon mixture is an effective catalyst

for the dehydrogenation of metal hydrides. Hydrogen spillover Nano-confinement Metal catalyzed hydrogen dissociation and

recombination

Nanoconfinement of Light Metal Hydrides

Jongh et al. investigate the applications of nano-sizing and scaffolding of light metal hydrides

Reducing the size of light metal hydride compounds to a nanometer range allows for much faster hydrogen adsorption and desorption

This relatively speedy reversibility is due to the nanoconfining of the metal hydride materials in a metal-organic scaffold

Additional Interesting Uses

Kim et al. - Metal hydride storage as a means to power cell phones – 22 L battery

Reissner et al. - Development of metal hydrides as a mean to power telecommunications satellites during the typical eclipse length of 72 minutes

Miura et al. - Hydrogen storage system using a CO adsorbant to significantly reduce potential incidental CO

2 emissions from fuel cells

References

Yang, J., Sudik, A., Wolverton, C., & Siegel, D. (2009). High capacity hydrogen storage materials: Attributes for automotive applications and techniques for materials discovery. Chemical Society Reviews, 656-656. Retrieved December 3, 2014, from http://www-personal.umich.edu/~djsiege/Energy_Storage_Lab/Publications_files/CSR_H2_storage.pdf

http://www.pragma-industries.com/products/hydrogen-storage/

Andrews, J., & Mohammadi, S. (2014). Towards a ‘proton flow battery’: Investigation of a reversible PEM fuel cell with integrated metal-hydride hydrogen storage. International Journal of Hydrogen Energy, 1740-1751. Retrieved December 1, 2014, from http://www.sciencedirect.com/science/article/pii/S0360319913027341

Lin, S., Yang, J., Kung, H., & Kung, M. (2013). Hydrogen Storage Properties of Complex Metal Hydride-Carbon Materials. Topics in Catalysis, 1937-1943. Retrieved December 1, 2014, from http://link.springer.com/article/10.1007/s11244-013-0130-2#page-2

Liu, J., & Zhang, W. (n.d.). Improvement on Hydrogen Storage Properties of Complex Metal Hydride. Retrieved from http://cdn.intechopen.com/pdfs-wm/38716.pdf

Jongh, P., Allendorf, M., Vajo, J., & Zlotea, C. (2013). Nanoconfined light metal hydrides for reversible hydrogen storage. MRS Bulletin, 488-494. Retrieved December 1, 2014, from http://onlinedigeditions.com/display_article.php?id=1422992