Electrochemical characteristics of lithium ion battery anode materials of graphite/SiO2

Abstract

The graphite/SiO2 composites as anode materials for lithium-ion batteries were prepared by sol-gel method to improve the graphite’s electrochemical characteristics. The prepared graphite/SiO2 composites were analysed by XRD, FE-SEM and EDX. The graphite surface modified by silicon dioxide showed several advantages to stabilize SEI layer. The electrochemical characteristics were investigated for lithium ion battery using graphite/SiO2 as the working electrode and Li metal as the counter electrode. Electrochemical behaviors using organic electrolytes (LiPF6, EC/DMC) were characterized by charge/discharge, cycle, cyclic voltammetry and impedance tests. The lithium ion battery using graphite/SiO2 electrodes had better capacity than that of using graphite electrodes and was able to deliver a discharge capacity with 475 mAh/g at a rate of 0.1 C. Also, the capacity retention ratio of the modified graphite reaches 99% at a rate of 0.8 C.