Electrochemical performance of Li1.2Ni0.2Mn0.6O2 coated with a facilely synthesized Li1.3Al0.3Ti1.7(PO4)3

Abstract In this work, a facile method has been developed to synthesize Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) coated Li 1.2 Ni 0.2 Mn 0.6 O 2 and its electrochemical properties have been optimized through tuning the LATP content and heating temperature. Electrochemical tests indicate that 3wt% LATP-coated sample (heated at 575 °C) shows the best performance with a discharge specific capacity of 264.7 mAh∙g −1 at 0.1 C in first cycle and the capacity retention of 94.3% after 80 cycles at 0.2 C. Furthermore, the voltage decay of Li 1.2 Ni 0.2 Mn 0.6 O 2 is restrained significantly after 3wt% LATP coating. The high structure stability of LATP is beneficial to restrain the side reactions and results in enhanced cycle performances Li 1.2 Ni 0.2 Mn 0.6 O 2 . The electrochemical impedance spectroscopy (EIS) analysis shows that the charge transfer impedance for Li 1.2 Ni 0.2 Mn 0.6 O 2 is reduced and the lithium ion diffusion coefficient has increased significantly by more than four times after LATP-coating. The low charge transfer impedance and high ion diffusion coefficient are responsible for the better rate capability of LATP-coated Li 1.2 Ni 0.2 Mn 0.6 O 2 .