Self-assembled Li4Ti5O12/rGO nanocomposite anode for high power lithium-ion batteries

Abstract

• 20–100 nm Li 4 Ti 5 O 12 nanomaterials were prepared on the surface of graphite oxide (GO) using a simple and controllable self-assembly method. • The synergistic effect of rGO and Li 4 Ti 5 O 12 shows good cycle performance, the capacity retention rate is as high as 97.2% after 1000 cycles even at the higher rate of 10C. • Compared with the performance of previously reported LTO-based electrodes, this work shows remarkable rate performance. Although Li 4 Ti 5 O 2 (LTO) exhibits excellent cycling stability and high safety, the poor electronic conductivity and slow ion diffusion kinetics largely limit its practical applications. Herein, LTO/reduced graphite oxide (rGO) composite anodes have been fabricated via a simple and controlled self-assembly method. LTO nanoparticles with diameters ranging from 20 to 100 nm are tightly anchored on the rGO to form a unique hierarchical structure. Compared with pure LTO material, the ultrathin rGO film and nanoparticles endow LTO higher electronic conductivity, shorten Li + diffusion paths and provide more active sites for lithium storage. As a result, the synergistic effect of rGO and unique morphology play a dominant role in high specific discharge capcacity, excellent cycling life and high-capacity retention at high-rate discharging for the LTO/rGO composite electrode. Specifically, large specific discharge capacity of 129 mAh g −1 can be delivered at a high current rate of 20C, as well as good capacity retention at 40C. Furthermore, the composite exhibited excellent cycling performance with superior capacity retention of 97.2% even at high rate of 10C after 1000 cycles.