Sol-gel synthesis of nanocomposite Cu-Li4Ti5O12 structures for ultrahigh rate Li-ion batteries

Abstract

In this study, spinel Li4Ti5O12 materials were successfully synthesized by a simple and facile sol-gel process and electroless copper deposition techniques. The characteristics of the as-prepared Li4Ti5O12 and Cu-Li4Ti5O12 were examined by X-ray diffraction and scanning electronic microscopy, while the electrochemical performances including charge/discharge and rate performance tests were also investigated. Cu-Li4Ti5O12 electrode demonstrated the superior initial discharge capacity and rate capability to Li4Ti5O12 electrode, cycled between 1.0 and 2.5 V. The enhanced rate capability can be attributed to the higher Li+ diffusivity and lower charge-transfer resistance due to the electroless deposition of copper. Moreover, when both electrodes discharged with 80 C state of discharge conditions, the reversible capacities were further increased ∼70 mAh g.-1 with excellent cycling stability and almost no irreversible capability was observed during cycling.