Improved pseudocapacitive charge storage in highly ordered mesoporous TiO₂/carbon nanocomposites as high-performance Li-ion hybrid supercapacitor anodes

Abstract

A Li-ion hybrid supercapacitor (Li-HSCs), an integrated system of a Li-ion battery and a supercapacitor, is an important energy-storage device because of its outstanding energy and power as well as long-term cycle life. In this work, we propose an attractive material (a mesoporous anatase titanium dioxide/carbon hybrid material, m-TiO₂-C) as a rapid and stable Li⁺ storage anode material for Li-HSCs. m-TiO₂-C exhibits high specific capacity (∼198 mA h g^-1 at 0.05 A g^-1) and promising rate performance (∼90 mA h g^-1 at 5 A g^-1) with stable cyclability, resulting from the well-designed porous structure with nanocrystalline anatase TiO₂ and conductive carbon. Thereby, it is demonstrated that a Li-HSC system using a m-TiO₂-C anode provides high energy and power (∼63 W h kg^-1, and ∼4044 W kg^-1).