Electrochemical Properties of Li4Ti5012/Si Anode Material Prepared by Sol-Gel Method for Lithium Ion Battery

摘要

Spinel Li4Ti5O12 can replace graphite due to zero-strain insertion material, long cycle life, excellent cycle characteristics,and little volume expansion. But this material has low theoretical capacity (175 mAh/g) than graphite (372mAh/g) and low electrical conductivity. In this study, experiments have been done for solving these problems. Li4Ti5O12 was synthesized by sol-gel method. P123 polymer was used as dispersing and pore-forming agency during sol-gel process. Ball-milling and sol-gel methods were used for comparing anode performance. Heat treatment was performed at 750℃ in air. Silicon powder was used to increase the capacity. Li4Ti5O12/Si composite was made by simple mixing, and the capacity was increased from 175 mAh/g to over 300 mAh/g at 0.2 C. The characteristics of anode material were investigated with TGA, XRD, BET, and SEM. The electrochemical properties were measured with battery cycler, electrochemical impedance spectroscopy.