▎ 摘　　要

As a novel anode material for lithium-ion batteries, graphene has a higher theoretical capacity than graphite. However, the practical application of graphene suffers from a low coulombic efficiency and poor cycle stability due to the unstable solid electrolyte interphase layer. In this work, ultrathin amorphous TiO2 nanofilm-coated graphene is fabricated by controlled hydrolysis of tetrabutyl titanate on the surface of graphene, and shows superior cycle and rate performance compared to uncoated graphene because amorphous TiO2 nanofilms can prevent the detachment of graphene nanosheets and avoids the formation of thick and unstable solid-electrolyte interphase layers during cycling. Moreover, the electrochemical performance of TiO2-coated graphene can be further improved by controllable calcination of TiO2-coated graphene under a N-2 atmosphere. The produced porosity of TiO2 nanofilms after calcination can improve both Li+ and electron transport, leading to the further improved lithium storage performance of graphene. This novel synthesis strategy may be employed in other graphene-based anode materials for high-performance lithium-ion batteries and other electrochemical devices. (C) 2017 Elsevier B.V. All rights reserved.