A New TiO with in-Situ Transformed Rutile TiO2 Nanothorns As a Superb Anode Material for Lithium-Ion Battery

Abstract

Developing high-performance anodes is highly desired to meet the recent ever-increasing demands for lithium-ion battery (LIB). Herein we report a uniquely integrated hybrid structure of rutile TiO2 (r-TiO2) nanothorns in situ grown over a new porous and conductive TiO core, which is generated from pyrolysis of anatase TiO2 with Mg metal at 650℃. The new hybrid exhibits superb LIB performance as an anode with high reversible capacity and almost no capacity decay during 1000 cycles at a high current density of 20 C (4000 mA g-1). Two independent reactions of intercalation and pseudocapacitive interaction are confirmed to occur in the composite of the r-TiO2 and TiO, respectively. In particular, the excellent rate capability along with long cycle life enables the new hybrid to have ultrafast charging of the system. Furthermore, the hybrid with the job-sharing property exhibits stable charge-discharge performance over a wider potential window range of 0.01 to 3.0 V, particularly even in the low potential range of 0.01~1.0 V, which usually causes irreversible Li-intercalation and rapid capacity decay for pristine TiO2. All the properties including the wider potential window allows the hybrid to realize the highest electrochemical performance that titanium oxides have ever achieved so far.