Enhancing the Long-Term Cyclability and Rate Capability of Li4Ti5O12 by Simple Copper-Modification

Cu-modified Li4Ti5O12 (LTO) with various Cu-doping contents was prepared via simple hydrolysis of tetrabutyl titanate in the water solution of LiOH · H2O and Cu(NO3)2 · 3H2O, followed by sintering the dried mixture at 600 °C for 5 h. By virtue of the slightly increased lattice constant, refined grains with relatively large surface area, improved electronic and ionic conductivities, the modified products exhibit excellent long-term cycling stability at a high current rate of 10 C and outstanding rate performance at 0.1–40 C. Particularly, the product with a Cu-doping content of 0.08 demonstrates prominent long-term cycling performance up to 2500 cycles at 10 C and superior capacity retention even at 10–40 C. The Cu-modified LTO could be used as efficient anode materials for long-life and high-rate lithium ion batteries.