An apatite for fuel cells
16 February 2012
CSCT member Professor Saiful Islam, with collaborators at the Universities of Birmingham and Warwick, have published key new results in the search for new oxide ion conductors for clean energy applications.
The viability of low carbon energy technologies such as fuel cells is crucially dependent on the fundamental advances in the component materials.
Si- and Ge-apatite compounds are attracting considerable interest as new fast oxide-ion conductors for use in solid oxide fuel cells (SOFCs).
Professor Islam (Bath), Dr Peter Slater (Birmingham) and Professor Mark Smith (Warwick) utilised a powerful combined nuclear magnetic resonance (NMR) and computational approach to elucidate, for the first time, the oxygen defect sites and conductivity mechanisms in the novel apatite compound La8Y2Ge6O27, which exhibits high oxide-ion conductivity.
Through large-scale simulations and solid-state NMR studies they show that interstitial oxygen leads to five-coordinate Ge, and that oxide-ion migration occurs via cooperative mechanisms with evidence of a novel “SN2-like” conduction mechanism.
Panchmatia, P.M., Orera, A., Rees, G.J., Smith, M.E., Hanna, J., Slater, P.R., Islam, M.S., 2011. Elucidation of Oxygen Defects and Novel Transport Mechanisms in Apatite Ionic Conductors: Combined 17O NMR and Modeling Studies. Angew. Chemie., 50(40), pp. 9328-9333.