Structure and electrochemical properties of Sc3+-doped Li4Ti5O12 as anode materials for lithium-ion battery

Spinel Li4Ti5−xScxO12(x=0, 0.05, 0.10, 0.15) anode materials were successfully synthesized by a facile solid state reaction. The structure, morphology and electrochemical performance in a broad voltage window were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge–discharge tests in sequence. Li4Ti4.95Sc0.05O12 material exhibits excellent cycling stability and rate capability in relevant lithium-ion batteries, which can retain a capacity of 138.6 mAh g−1 after 80 cycles at 2 C charge–discharge rate. This performance is much better than that of pristine Li4Ti5O12 (121 mAh g−1), whose capacity fades seriously. The improved electrochemical performance of Sc3+-doped Li4Ti5O12 can be ascribed to the reduction of charge transfer resistance, increase of electronic conductivity, and fast lithium ion diffusion behavior. Hence, Li4Ti4.95Sc0.05O12 can be considered as an economical and potential candidate as anode material for power lithium-ion batteries.