Lithium diffusion in a new cathode material Li0.8[Ni0.6Sb0.4]O2 studied by 7Li NMR

A rhombohedral layered α-NaFeO2-type compound, Lix[Ni(1+x)/3Sb(2-x)/3]O2 (x=0.8) has been prepared from the sodium analogue by ion exchange at 570 K. In contrast to the stoichiometric composition Li3Ni2SbO6, it shows considerable Li/Ni inversion and no long-range Ni/Sb ordering. The temperature dependence of the 7Li NMR spin-lattice relaxation rate and linewidth data measured at temperature range from 30-450 K show the sharp increase of lithium ions mobility comparing to the stoichiometric compound Li3Ni2SbO6. From the NMR data the activation energy was estimated by different methods.