Wet chemical synthesis of Cu/TiO2 nanocomposites with integrated nano-current-collectors as high-rate anode materials in lithium-ion batteries

Abstract

Using a soft-template assisted method, well-organized Cu/TiO₂ nanoarchitectured electrode materials with copper nanowires as their own current collectors are synthesized by controlled hydrolysis of tetrabutyl titanate in the presence of Cu-based nanowires, and investigated by SEM, TEM, XRD, Raman spectroscopy and electrochemical tests towards lithium storage. Two types of Cu/TiO₂ nanocomposites with different TiO₂ grain sizes are obtained by using different thermal treatments. The two types of Cu/TiO₂ nanocomposites show much enhanced rate performances compared with bare TiO₂. A high-rate capability (reversible capacity at 7500 mA g⁻¹ still accounts for 58% of its initial capacity at 50 mA g⁻¹) is observed for the Cu/TiO₂ nanocomposite with smaller TiO₂ grain size. The improvements can be attributed to the integrated Cu nanowires as mechanical supports and efficient current collectors. A cell made from the Cu/TiO₂ nanoarchitectured electrodes exhibits promise as an energy storage device with both high energy and high power densities.