Li2Ti6O13 and H2Ti6O13 were easily synthesized from Na2Ti6O13 by successive Na+–Li+–H+ ion exchange. The crystal structures of Na2Ti6O13, Li2Ti6O13 and H2Ti6O13 were investigated using neutron powder diffraction. Monovalent A+ cations (Na, Li and H) have been located using difference Fourier analysis. Although monoclinic lattice parameters (space group C2/m) of the three titanates remain almost unchanged with retention of the basic [Ti6O132−] network, monovalent Na, Li and H cations occupy different sites in the tunnel space. By comparing the structural details concerning the A+ oxygen coordination, i.e. NaO8 square prismatic coordination, LiO4 square planar coordination and covalently bond H atoms, with results from 23Na, 7Li and 1H NMR spectroscopy we were able to obtain a more detailed insight into the respective local distortions and anharmonic motions. We were able to show that the site that the A+ cation occupies in the hexatitanate channel structure strongly influences the lithium insertion properties of these compounds and therefore their usefulness as electrode materials for energy storage.
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