Ionic conductivity enhancement by particle size reduction in Li2FeSiO4

Li2FeSiO4 is an important alternative cathode material for the next generation Li-ion batteries due to its high theoretical capacity (330 mA h/g). However, its development has faced great challenges arising from its structural complexity and its poor ionic conductivity. In the present study, the energetics of surface structures and nano particles of the Pmn21 polymorph of Li2FeSiO4 are studied by means of first-principles calculations based on density functional theory. The present study demonstrates that, by tailoring the particle size of the Li2FeSiO4, one can increase the diffusion coefficient above 10−8 cm2/s, which is comparable to the the typical one reported for the current generation state-of-the-art material.