Exceptional electrochemical performance of porous TiO2-carbon nanofibers for lithium ion battery anodes

摘要

We have developed one-dimensional (1D) porous TiO2-carbon nanofibers (ODPTCNs) by a simple coaxial electrospinning technique combined with subsequent calcination treatment as anode materials for Li-ion batteries. The prepared ODPTCNs contain plentiful surface pores through which lithium ions can transport from outer space into inner space as storage regions, thus activating all the materials. In addition, the high conductivity of the overall electrode and the porous structure aid Li+ access and the rapid transportation of lithium ions, thus reducing the diffusion paths for Li+ and yielding a better rate capability. The novel ODPTCNs show a remarkable specific reversible capacity of ∼806 mA h g-1 and a high volumetric capacity of ∼1.2 A h cm-3, maintain a capacity of ∼680 mA h g-1 after 250 cycles at a current density of 100 mA g-1 and exhibit an exceptional discharge rate capability of 5 A g-1 while retaining a capacity of ∼260 mA h g-1 after 1600 cycles. The ODPTCNs will serve as excellent anode materials for next-generation, high-power, and environmentally benign Li-ion batteries.