Electrochemical Characteristics of Silicon/Carbon Composites for Anode Materials of Lithium Ion Batteries

Abstract

Silicon/carbon composites as anode materials for lithium-ion batteries were examined to find the cycle performance and capacity. Silicon/carbon composites were prepared by a two-step method, including the magnesiothermic reduction of SBA-15 (Santa Barbara Amorphous material No. 15) and carbonization of phenol resin. The electrochemical behaviors of lithium ion batteries were characterized by charge/discharge, cycle, cyclic voltammetry and impedance tests. The improved electrochemical performance attributed to the fact that silicon/carbon composites suppress the volume expansion of the silicon particles and enhance the conductivity of silicon/carbon composites (30 ohm) compared to that of using the pure silicon (235 ohm). The anode electrode of silicon/carbon composites showed the high capacity approaching 1,348 mAh/g and the capacity retentio