A minky-dot-fabric-shaped composite of porous TiO2 microsphere/reduced graphene oxide for lithium ion batteries

Abstract

We describe a novel strategy for fabrication of a unique minky-dot-fabric-shaped composite of well-organized porous TiO₂ microspheres and reduced-graphene-oxide (rGO) sheets used as an anode material in lithium-ion batteries. In this composite, the porous TiO₂ microspheres act as hosts for fast and efficient lithium storage while the rGO sheets serve as highly conductive substrates. Such unique structural features assure a large contact area between the electrolyte and the electrode, favorable for the diffusion of electrons and Li⁺ ions. Moreover, they can accommodate volume changes of the electroactive TiO₂ materials readily so as to improve the overall electrical conductivity between the electrodes during electrochemical processes. In electrochemical tests, the TiO₂–rGO composites used as anodes in lithium-ion batteries exhibited superior performance with a reversible capacity of 100 mA h g⁻¹ at 10 C for up to 100 cycles, as compared to 58 mA h g⁻¹ at 10 C for up to 100 cycles from pure TiO₂, suggesting great potential of this unique composite to function as high-rate lithium-ion battery materials.