Flexible, Three-Dimensional Ordered Macroporous TiO2 Electrode with Enhanced Electrode–Electrolyte Interaction in High-Power Li-Ion Batteries

Abstract

A simple methodology is developed for the in-situ preparation of flexible, three-dimensional ordered macroporous (3DOM) TiO₂ electrodes with greatly enhanced mass transfer. The 3DOM electrode is fabricated using a polystyrene colloidal crystal templated carbon cloth, and provides significant improvements over conventional nanoparticle electrodes without the use of binder or other additive. When evaluated as an anode in a Li-ion battery, the 3DOM electrode provides outstanding high rate performance. The electrode provides a specific capacity of 174 mAh g-1 at a current density of 2 A g-1, which is 2.6 times greater than that achieved with a nanoparticle electrode (68 mAh g-1). The 3DOM electrode also achieves excellent cycling stability, with a capacity retention of 94.8% (181 mAh g-1) over 1000 cycles at 10C (1.7 A g-1) compared to 93.7% (67 mAh g-1) for the nanoparticle electrode. To the best of our knowledge, the performance of our 3DOM electrode is among the highest of binder-free, flexible TiO₂ electrodes. We believe that this methodology is highly useful and is easily transferable to other materials and applications.