Ionic Conductor of Li2SiO3 as an Effective Dual-Functional Modifier To Optimize the Electrochemical Performance of Li4Ti5O12 for High-Performance Li-Ion Batteries.

Ionic conductor of Li2SiO3 (LSO) was used as an effective modifier to fabricate surface-modified Li4Ti5O12 (LTO) via simply mixing followed by sintering at 750 °C in air. The electrochemical performance of LTO was enhanced by merely adjusting the mass ratio of LTO/LSO, and the LTO/LSO composite with 0.51 wt % LSO exhibited outstanding rate capabilities (achieving reversible capacities of 163.8, 157.6, 153.1, 147.0, and 137.9 mAh g-1 at 100, 200, 400, 800, and 1600 mA g-1, respectively) and remarkable long-term cycling stability (120.2 mAh g-1 after 2700 cycles with a capacity fading rate of only 0.0074% per cycle even at 500 mA g-1). Combining structural characterization with electrochemical analysis, the LSO coating coupled with the slight doping effect adjacent to the LTO surface contributes to the enhancement of both electronic and ionic conductivities of LTO.