A 3D porous architecture composed of TiO2 nanotubes connected with a carbon nanofiber matrix for fast energy storage

Abstract

To develop high-power and fast energy storage devices, electrode materials with superior ionic and electronic transport properties should be developed. Herein, a novel composite electrode with TiO2nanotubes connected onto a conductive carbon nanofiber network is designed and realized through a general route. The carbon matrix is first synthesized using an electrospinning technique and heat treatment, and the embedded rutile TiO2 nanoparticles are formed in situ as the starting materials for the hydrothermal reaction. After hydrothermal treatment, a three-dimensional (3D) porous architecture is developed. The mechanistic analysis demonstrates that the raw embedded rutile TiO2 nanoparticles react with NaOH solution and go out around the carbon nanofiber matrix to form a well-connected 3D porous nanotube/nanofiber architecture. By using the as-prepared films as electrodes for lithium-ion batteries (LIBs) without the application of any additional conductive agent or binder, high initial capacity and excellent rate performance (214 mA h g-1 at 5 C rate, 180 mA h g-1 at 10 C rate, 138 mA h g-1 at 20 C rate and 112 mA h g-1 at 30 C rate) are achieved. Moreover, the electrode shows stable cycling performance, especially at a high rate of 30 C, without undergoing decay after 1000 cycles.