Hydrogen storage in nano-structured graphite: a solution for economic energy storage for low-carbon vehicles and the buffering of renewable energy?

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Hydrogen storage in nano-structured graphite a
solution for economic energy storage for
low-carbon vehicles and the buffering of
renewable energy?

• Yinghe Zhang, Dr David Book, Prof. Rex Harris
• School of Metallurgy and Materials,
• University of Birmingham, UK

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Outline

• Hydrogen as a fuel for the future
• Nanostructured carbon-based materials for
  hydrogen storage

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1.1 Hydrogen economy
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1.2 Ways to store hydrogen
4 kg hydrogen

• Compressed hydrogen
• Liquid hydrogen
• Solid-state hydrogen storage materials

110l
57l
33l
26l
H2 (liquid)
Mg2FeH6
LaNi5H6
H2 (200 bar)
Issues weight, cost, reaction kinetics and
reversibility
Ref. Louis Schlapbach Andreas Züttel, NATURE,
414, p.353, (2001)
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2.1 Nanostructured graphite made by ball-milling
H atoms
d-space
d-space

• Particle size
• Specific surface area
• Interlayer distance (d-space)
• Defects- intermediate state for H2 storage

(a)
(b)
Ref. 1 Shunsuke MUTO, Japanese Journal of
Applied Physics, 44,2005 2 Scanning
Electron Microscopy secondary mode micrographs
of (a) as-received graphite (b)graphite milled
for 40 hours (3 bar H2). 2007
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(b) Milling pot and balls
(a) Retsch PM400 Planetary Ball Mill.
(c) Schematic depicting the ball motion inside
the ball mill.
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2.2 Previous Work on Graphite
Graphite milled in a hydrogen atmosphere
(10 bar) in a ball-mill for 80 hours can absorb
7.4 wt hydrogen1.

• However,
• release hydrogen at 600 K
• it was not reversible
• So additions (e.g. LiH, Fe) were introduced2,3

Ref. 1. S. Orimo, et al, Applied physics
letters, (1999) 75, 20, 3093 2. T.
Ichikawa, et al, Materials Science and
Engineering B108 pp138142 (2004) 3. T.
Ichikawa, et al, Appl. Phys. Lett.86, 241914
(2005)
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2.3 Results and discussion
10 hours
Amount of hydrogen and methane desorbed
from graphite milled in hydrogen (3 bar) for
various times (040 hours). Calculated from
Thermal Gravimetric Analysis-Mass spectrometer
(TGA-MS) measurement. (WC milling pot, 3bar H2)
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The relationship between milling time and average
graphene interlayer space
(c)
(a)
(b)
High Resolution Transmission Electron
Microscopy image of (a) as-received graphite
(b) graphite milled for 10 hours and (c) graphite
milled for 40 hours (3 bar H2).
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2.4 Conclusion

• Hydrogen is a clean and sustainable energy
• Nanotechnology is being used to develop graphite
  for storing hydrogen
• Under the conditions used in this study, it was
  found that the optimum milling time (to maximize
  the amount of hydrogen stored and minimise
  methane release) was 10 hours. It was shown that
  the interlayer distance can be related to the
  hydrogen storage properties of the milled
  graphite.

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2.5 Future work

• The relationship between the structure of
  milled graphite and hydrogen storage properties
  (Raman, EELS)
• The effect of additions
• The function of impurity

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Thank you !

• Yinghe Zhang
• E-mail zhangyinghe_at_gmail.com
• Group Website http//www.hydrogen.bham.ac.uk

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• Introduction of Hydrogen Materials Group
• Head of Group

Major research areas1) development of novel materials for solid-state hydrogen storage2) fabrication of dense-metal membranes for hydrogen purification3) use of hydrogen in the microstructural processing of materials4) H2 energy demonstration projects (e.g. PROTIUM Hydrogen Canal Boat)
Dr David Book Email D.Book_at_bham.ac.uk
www.hydrogen.bham.ac.uk
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PROTIUM Project Hydrogen Canal Boat
Professor Rex Harris FREng
The "Ross Barlow", was officially
launched on 21 September 2007 at the Mailbox in
the centre of Birmingham
BBC Midlands Today http//tinyurl.com/2hatjh
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(a) Effect of Fe1
(b) Effect of Lithium Hydride additions to
milled graphite2
Hydrogenation 10bar, H2, milled grapihte
LiH21 milled for 2 hrs Rehydrogenation
10bar, H2, for 8 hrs
10bar, H2 , graphiteFe power 1 atom milled
for 80hrs
1 T. Ichikawa, et al, Materials Science and
Engineering B108 pp138142 (2004) 2 T.
Ichikawa, et al, Appl. Phys. Lett.86, 241914
(2005)
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3.3 Conclusions

• Ball milling of graphite under a hydrogen
  atmosphere is an effective method of producing
  nanostructured graphite which is able to store an
  appreciable amount of hydrogen.
• Under the conditions used in this study, it was
  found that the optimum milling time (to maximize
  the amount of hydrogen stored and minimise
  methane release) was 10 hours. It was shown that
  the interlayer distance can be related to the
  hydrogen storage properties of the milled
  graphite.
• Nanostructured graphite has potential for use as
  a low-cost in energy store, for vehicles and
  stationary hydrogen-energy applications.