Sol-Gel Synthesis of Nanocomposite $Cu-Li_4Ti_5O_{12}$ Structures for Ultrahigh Rate Li-Ion Batteries

In this study, spinel $Li_4Ti_5O_{12}$ materials were successfully synthesized by a simple and facile sol-gel process and electroless copper deposition techniques. The characteristics of the as-prepared $Li_4Ti_5O_{12}$ and $Cu-Li_4Ti_5O_{12}$ were examined by X-ray diffraction and scanning electronic microscopy, while the electrochemical performances including charge/discharge and rate performance tests were also investigated. $Cu-Li_4Ti_5O_{12}$ electrode demonstrated the superior initial discharge capacity and rate capability to $Li_4Ti_5O_{12}$ electrode, cycled between 1.0 and 2.5 V. 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 ım70 mAh $g^{-1}$ with excellent cycling stability and almost no irreversible capability was observed during cycling.