Atomic layer deposition derived amorphous TiO2 thin film decorating graphene nanosheets with superior rate capability

Composites consisting of graphene nanosheets (GNSs) decorated with amorphous TiO2 thin films were synthesized by an atomic layer deposition (ALD) technique. It was revealed that the TiO2 thin films were uniformly deposited onto the worm-like GNSs. When used as anode materials in lithium ion batteries (LIBs), the TiO2-GNS composites deliver a stable capacity of similar to 140 mAh g(-1) after 100 cycles at a specific current of 100 rnA g(-1) as well as superior rate capability, accounting for a sustainable 95 mAh g(-1) capacity at a specific current of 1200 mA g(-1). It is believed that the remarkable electrochemical performance lied in the unique features of the composites, i.e., the amorphous nature of the TiO2 films and the large surface area of GNSs. The former rendered short Li+ diffusion pathways in TiO2 thin film, while the latter offered excellent electronic conductivity as well as a large intimate contact area between the electrolyte and TiO2. This work laid a venue for designing new electrodes for high-performance LIBs. (C) 2015 Elsevier B.V. All rights reserved.