Energetic evaluation of possible insertion sites of Li into La3Ni2Sn7 using a first principle calculation

Electronic energy calculations of Li-inserted La3Ni2Sn7, an expected anode material for Li-ion battery, have been performed by a density-functional theory assuming several possible insertion sites. Twelve sites of 2d (0, 0, 0.5), 2b (0.5, 0, 0), 4i (0, 0.0873, 0) and 4i (0, 0.2964, 0) are found to be inserted more favorably than other sites from the energetic consideration. This was understood by a simple consideration based on the pair-potential between Li and Sn or La. However, estimated potential of Li-inserted La3Ni2Sn7 with reference to Li is higher than the observed values.