Tuneable graphite intercalates for hydrogen storage

The development of hydrogen as an energy transfer mechanism is of great importance to alleviate environmental damage and economic destabilisation caused by over-reliance on oil, as long as the hydrogen can be generated renewably. To be suitable for road transport applications, safe and compact hydrogen storage systems need to be developed, the primary technological motivation for this PhD project which investigates hydrogen absorbed into graphite intercalation compounds (GICs), to gain a fundamental physical understanding of the sorption processes to improve such materials' capacity for hydrogen storage. Literature searching has led to a principal investigation, primarily using neutron scattering and thermogravimetry, of potassium and calcium-GICs with hydrogen. Inelastic neutron scattering on hydrogenated KC24 has shown hydrogen sorption in this system to be quantitatively different from its analogues RbC24 and CsC24. A consistent model of the H2 sites and dynamics has been proposed. Time-resolved structural data on the hydriding phase transition in KC8Hx have been obtained. A calcium-ammonia intercalate has shown most promise for hydrogen storage, with uptake of 3.2 wt.% H2 at 77 K and 2 bar, a signifcant amount of the 6 wt.% target set by the US DoE. It is concluded that available internal volume and donor charge in GICs are critical parameters for optimising hydrogen uptake.

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of London

Year dc:date.issued

2007

Author dc:creator

• Lovell, A.

• Department of Physics and Astronomy

Language dc:language

en, eng