Ultrathin TiO2 Coating on LiCoO2 for Improved Electrochemical Performance as Li-Ion Battery Cathode

摘要

Surface modification of LiCoO2 (LCO) gained much attention as it could play a prominent role in improving electrochemical performance and structural stability. Herein, we report an ultrathin TiO2 coating on LiCoO2 (LCO-TiO2) as a potential candidate to overcome the electrochemical, structural instability and interface issues of the bare-LCO. The structural properties as well as electrochemical performances of bare-LCO and LCOTiO2 were investigated by X-Ray diffraction, Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). At the end of 100 cycles, 1C rate capacity retention was about 50% and 90% for bare-LCO and LCO-TiO2 respectively. Rate studies showed that the bare LCO exhibited a specific capacity of ~120 mAh/g and only 16 mAh/ g at 1C and 60 discharge rates respectively whereas, the TiO2 coated LCO showed a capacity of ~132 mAh/g and nearly 98 mAh/g at 1C and 60C discharge rates respectively. The implementation of TiO2 coating over LiCoO2 enhanced the electrochemical performance, cell stability as well as efficien