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

Abstract Spinel Li 4 Ti 5− x Sc x O 12 ( 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. Li 4 Ti 4.95 Sc 0.05 O 12 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 Li 4 Ti 5 O 12 (121 mAh g −1 ), whose capacity fades seriously. The improved electrochemical performance of Sc 3+ -doped Li 4 Ti 5 O 12 can be ascribed to the reduction of charge transfer resistance, increase of electronic conductivity, and fast lithium ion diffusion behavior. Hence, Li 4 Ti 4.95 Sc 0.05 O 12 can be considered as an economical and potential candidate as anode material for power lithium-ion batteries.