Sr1−xNa2xLi2Ti6O14 (0≤x≤1) as anode materials for rechargeable Li-ion batteries

In order to further expand the application of lithium titanate anode materials for lithium ion batteries (LIBs), a series of Sr1−xNa2xLi2Ti6O14 (x=0, 0.25, 0.5, 0.75, 1) have been synthesized by the solid-state method. The structure, morphology and their electrochemical properties have been investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM), high-resolution transmission electron microscope (HRTEM), galvanostatic charge-discharge tests and electrochemical impedance spectroscopy (EIS) measurements. Electrochemical analysis suggests Sr0.5NaLi2Ti6O14 to show the better cycling stability, delivering a charge capacity of 184 mA h g−1 at the current density of 50 mA g−1 for the first cycle, and to exhibit reversible capacity of 176.8 mA h g−1 after 50 cycles corresponding to 0.0782% capacity decrease per cycle. Besides, Sr0.5NaLi2Ti6O14 also has the highest lithium-ion diffusion coefficient among all the examined samples.