Download Allan Walton - University of Warwick

Dr Allan Walton
SCIRA - Senior Research Fellow
Energy Theme
Hydrogen Storage Materials and Hydrogen
Processing of Materials
Solid State Hydrogen
Storage
Schlapbach and Züttel, Nature, 15 Nov 2001 (modified)
4 kg H2

At STP 1 mole of gas occupies 22.4 litres.

1 kg H2 occupies ~11 m3 at STP.

4-5kg of H2 would be required for a 400km car journey.

The hydrogen storage problem is essentially one of gas compression.


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Mg2NiH4 LaNi5H6 H2 (liquid) H2 (200 bar)
In solid state hydrogen storage, H2 is captured within the crystal structure
of a material such as LaNi5.
Solid state materials can offer a safe, low pressure solution for hydrogen
storage.
However a material has not yet been found which offers the correct wt% H2
at the correct pressure, temperature and price to meet the requirements for
an automotive application.
Overview of Solid State Hydrogen Storage Materials
Adsorbents
Observed H2 weight fraction (%)
14
12
US DOE
system target
2010
10
AlH3
8
Absorbents
LiBH4
Ca(BH4)2
Bridged carbon foam
spillover material
MOFs
MgH2
LiNH2/MgH2
6
Activated carbons
4
2
Bridged IRMOF 8
Polymers of Intrinsic
Microporosity (PIMS)
Zeolites
LaNi5
Pd
Carbon nanotubes
-200
-100
Mg2Ni
0
100
200
Temperature for significant hydrogen release oC
300
400
Equipment in the Hydrogen Materials Laboratory
Bruker D8- XRD
• 3 Gravimetric balance systems
• 2 Volumetric sieverts systems
• XRD with 10/100 bar gas cells and gas
dosing system
• Dispersive Raman spectrometer with gas
cells and cryostat
• Membrane testing facility
• 3 mass spectrometers
Gas reaction cell 10bar and 100 bar H2
Dispersive Raman
Spectrometer
• High Pressure reaction vessels >700bar H2
• Hydrogen processing furnaces
• Resistivity measurements
• Melt spinner
• Magnetron sputtering system with inert
sample transfer
• 3 gloveboxes
• Flowing gas measurements
• Reactive planetary and freezer milling
Gas reaction cell 1bar/100bar H2
• Confocal laser microscope with gas cells
Melt Spinning of Magnesium Alloys
Production of rapidly solidified amorphous
and metastable ribbons in high vacuum or inert
gas

Slit nozzle
Boron Nitride furnace tube

Thickness: 20-60 µm, 10mm

Sample size 5 – 10 grams

Cooling rates 105 – 106 K/sec

Wheel surface velocity 60m/sec

5kW induction heater
Melt Spinning Facility in Metallurgy and
Materials at the University of Birmingham
Inert sample loading
Inert sample transfer
Automatic sample
positioning
Confocal Laser Microscopy
Graph showing optical transparency vs
pressure for a 65nm Pd film.
Pd film
valves
Sample cell
77K – 873K, 10-6mBar – 100 bar H2
Pressure transducer
Anti-vibration table
Confocal Laser Microscopy
3-D map of a 65nm Pd film deposited
onto glass . Fully de-hydrided in air 9th
cycle
3-D map of a 65nm Pd film deposited
onto glass . Fully Hydrided 10th cycle at 1
bar
Y.Pivak, R.Gremaud, K.Gross, M. Gonsalez-Silveira, A.Walton, H.Schreuders, B.Dam and R.Griessen.
‘Effect of the film substrate on the thermodynamic properties of the PdHx studied by
hydrogenography’, submitted to the Scripta Materialia August 2008.
65nm Pd hydride film on exposure to air