Nanowires-Assembled TiO Nanorods Anchored on Multilayer Graphene for High-Performance Anodes of Lithium-Ion Batteries.

Multilayer graphene (MLG) prepared via ultrasonic exfoliation has many advantages such as its low-cost and defect-free nature, high electronic conductivity, and large specific surface area, which make it an apt conductive substrate for TiO composites. To synthesize graphene/TiO hybrids, traditional methods that greatly depend on the chemical bond of oxygen-containing functional groups on graphene with titanium cations are not applicable due to the absence of these functional groups on MLG. In this work, a facile chemical method is developed to directly deposit TiO on the MLG surface without the introduction of chemically active groups. With this method, four types of TiO materials, that is pure anatase TiO nanoparticles, a mixture of anatase TiO nanoparticles and rutile TiO nanoflowers, pure rutile TiO nanoflowers, and pure rutile TiO nanorods, are homogeneously anchored on the MLG surface by controlling the amount of HCl in the reactant. Interestingly, the rutile TiO nanorods in the TiO/MLG composite are assembled by many TiO nanowires with an ultra-small diameter and ultra-long length, which provides a better synergetic effect for high performances as LIB anodes than other composites. A specific capacity of 631.4 mAh g after 100 cycles at a current density of 100 mA g is delivered, indicating it to be a valuable LIB anode material with low cost and high electrochemical performances.