Dandelion-shaped TiO2/multi-layer graphene composed of TiO2(B) fibrils and anatase TiO2 pappi utilizing triphase boundaries for lithium storage

A three-dimensional dandelion-shaped TiO2/multi-layer graphene compound (TiO2/MLG) composed of TiO2(B) fibrils and anatase pappus structures has been synthesized as a potential anode material for Li storage. Electron microscopy indicates that the composite contains triphase boundaries between anatase, TiO2(B) and graphene, which are responsible for the enhancement of energy storage and the decrease of electrode polarization. Cyclic voltammetric investigations indicate that both Li+ insertion and pseudocapacitance contribute to charge storage. Ultrahigh specific capacities of 243 and 182 mA h g(-1) have been obtained at 0.1 and 1 A g(-1), respectively. Moreover, the excellent capacity retention can reach 99.6% after 100 cycles with almost 100% coulombic efficiency at 0.1 A g(-1). The importance of the triphase boundary in enhancing the storage of charge and transport of Li+ is demonstrated.