Improved electrochemical performance of Li₄Ti₅O₁₂by reducing rutile TiO₂phase impurity and particle size

Abstract

Pure lithium titanate (Li4Ti5O12) powder having particle size of 100 (±38) nm has been prepared by solid-state synthesis method, using planetary ball milling at lower speed of 900 rpm as compared to high energy ball milling (3000 rpm) and characterized by X-ray diffractometer, field emission scanning electron microscopy and thermogravimetric analysis. Electrochemical performance of Li-ion battery cells is determined by charging–discharging and cyclic voltammetry tests. The material has shown very high discharge capacity of 171 and 108 mAhg−1 measured at current rates of 0.1C and 5C, respectively, as compared to 160 and 71 mAhg−1 for impure Li4Ti5O12 material (containing rutile phase of TiO2) having particle size 213 (±45) nm. Capacity retention of pure Li4Ti5O12 was 91% after 100 cycles, whereas the impure Li4Ti5O12 has shown the retention ability of 85%.