Copper-doped dual phase Li4Ti5O12-TiO2 nanosheets as high-rate and long cycle life anodes for high-power lithium-ion batteries

Abstract

Cu-doped Li4 Ti5 O12 -TiO2 nanosheets were synthesized by a facile, cheap, and environmentally friendly solution-based method. These nanostructures were investigated as an anode material for lithium-ion batteries. Cu doping was found to enhance the electron conductivity of the materials, and the amount of Cu doped controlled the crystal structure and content of TiO2 . In addition, the samples, which benefit from multiphases and doping, exhibited much improved capacity, cycle performance, and high rate capability over Cu-free Li4 Ti5 O12 -TiO2 . The discharge capacity of the 0.05 Cu-doped sample was 190 mAh g(-1) at 1C, and even 144 mAh g(-1) was obtained at 30C after 100 cycles. Moreover, after 500 cycles at 30C, the discharge capacity remained at approximately 130 mAh g(-1) . The excellent electrochemical performance of the cell demonstrated that Cu-doping was able to adjust and control the Li4 Ti5 O12 -TiO2 system appropriately.

Keywords: anodes; copper; electrochemistry; lithium-ion batteries; nanostructures.