AlF3 coated LiV3O8 nanosheets with significantly improved cycling stability as cathode material for Li-ion battery

In this study, AlF3 was successfully coated on the surface of LiV3O8 nanosheets, as verified by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). AlF3 coated LiV3O8 exhibited the significantly improved cycling stability with the capacity retention of ca. 91% over 50 cycles at 150 mA g− 1, while that of the bare one was only 61%. When cycling at 55 °C, the bare electrode delivered a much larger capacity loss (44.8%) in comparison with that (19.1%) of the coated one. On the basis of the XRD, CV and EIS results, it was suggested that the AlF3 coating layer could protect the bulk material well and facilitate the kinetics of Li-ion diffusion, leading to smaller electrochemical impedance, thus resulted in improvement of cycling stability for LiV3O8.

► AlF3 was successfully coated on the surface of LiV3O8 nanosheets. ► AlF3 coated LiV3O8 exhibited the significantly improved cycling stability. ► Electrochemical property of the coated one at elevated temperature was improved. ► AlF3 layer could protect the bulk material well.