Sol-gel synthesis of aluminum doped lithium titanate anode material for lithium ion batteries

摘要

In this study, spinel Li_4Ti_(5-x)Al_xO_(12) (x = 0, 0.05) materials were successfully synthesized by a simple and facile sol-gel process. The characteristics of the as-prepared Li_4Ti_(5-x)Al_xO_(12) (x=0, 0.05) were examined by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and scanning electronic microscopy, while the electrochemical performances including charge/discharge test, cyclic voltammetry, and electrochemical impedance spectroscopy were also investigated. Li_4Ti_(4.95)Al_(0.05)O_(12) electrode demonstrated the superior initial discharge capacity and rate capability to Li_4Ti_5O_(12) electrode cycled between 1.0 and 2.5 V or between 0 and 2.5 V. The enhanced rate capability can be attributed to the higher Li~+ diffusivity and lower charge-transfer resistance due to the substitution of Al~(3+) for Ti~(4+). Moreover, when both electrodes discharged to 0 V, the reversible capacities were further increased ～50 mAh g~(-1) with excellent cycling stability and almost no irreversible capability was observed during cycling.