Boosting Li-ion storage kinetics via constructing layered TiO2 anode

Abstract

Due to the typical intercalation-deintercalation mechanism, TiO₂ holds great promise as a sustainable anode for next-generation lithium-ion batteries (LIBs). However, commercial TiO₂ (C–TiO₂) is granular and shows slow ionic conductivity, which greatly hinders its development due to sluggish kinetics, leading to low reversible capacity and inferior rate capability. In this study, a two-dimensional layered TiO₂ (L-TiO₂) anode is prepared via a one-step calcination process, which can effectively shorten the lithium ions diffusion path and improve its lithium ions conductivity. We elucidated the enhanced electrochemical performance of L-TiO₂ as an anode in LIBs through pseudocapacitive acceleration of lithium ions intercalation and deintercalation using various characterization techniques, including different scan rate cyclic voltammetry tests, in situ electrochemical impedance spectroscopy, in situ Raman spectroscopy, and in situ X-ray diffraction. In comparison to C–TiO₂ material, L-TiO₂ material showcases remarkable electrochemical performance, achieving a capacity of 166 mAh/g after 100 cycles at 0.1 C. Additionally, the lithium-ion diffusion coefficient calculated for the L-TiO₂ is two orders of magnitude greater, underscoring its potential as a negative electrode material for LIBs.