Improvement of natural graphite as a lithium-ion battery anode material, from raw flake to carbon-coated sphere

Natural graphite is a promising candidate for the anode material in lithium-ion batteries. To enhance its electrochemical performance, raw natural graphite flakes have been rolled into spheres by impact milling and then coated with carbon by thermal vapor decomposition (TVD). The obtained spherical graphite samples show excellent performance in terms of high rate capacity, high reversible capacity, high coulombic efficiency and low irreversible capacity. The improvements in performance have been mainly correlated with the morphologies of carbon-coated spherical graphite.