Facile Preparation and Lithium Storage Properties of TiO 2 @Graphene Composite Electrodes with Low Carbon Content

Over the past decade, TiO 2 /graphene composites as electrodes for lithium ion batteries have attracted a great deal of attention for reasons of safety and environmental friendliness. However, most of the TiO 2 /graphene electrodes have large graphene content (9–40 %), which is bound to increase the cost of the battery. Logically, reducing the amount of graphene is a necessary part to achieve a green battery. The synthesis of TiO 2 nanosheets under solvothermal conditions without additives is now demonstrated. Through mechanical mixing TiO 2 nanosheets with different amount of reduced graphene (rGO), a series of TiO 2 @graphene composites was prepared with low graphene content (rGO content 1, 2, 3, and 5 wt %). When these composites were evaluated as anodes for lithium ion batteries, it was found that TiO 2 +3 wt % rGO manifested excellent cycling stability and a high specific capacity (243.7 mAh g −1 at 1 C; 1 C=167.5 mA g −1 ), and demonstrated superior high‐rate discharge/charge capability at 20 C.