Facile synthesis and enhanced electrochemical performances of Li2TiO3-coated lithium-rich layered Li1.13Ni0.30Mn0.57O2 cathode materials for lithium-ion batteries

Li2TiO3-coated Li-rich layered Li1.13Ni0.30Mn0.57O2 (0.3Li(2)MnO(3)center dot 0.7LiNi(0.5),Mn0.5O2) compound has been successfully synthesized for the first time through a syn-lithiation strategy. In this approach, Ni0.35Mn0.65C2O4 center dot xH(2)O precursor is first prepared by a co-precipitation method, then it is coated with TiO2 through a reaction between Ni0.35Mn0.65C2O4 center dot xH(2)O and Ti(OC4H9)(4), and finally Ni0.35Mn0.65C2O4 center dot yH(2)O@TiO2 is simultaneously lithiated to form Li2TiO3-coated Li-rich layered oxide. Both the cyclability and high-rate capability of Li-rich layered cathode materials have been greatly improved by Li(2)TiO(3)coating. Meanwhile, the Li2TiO3 coating layer also reduces the polarization of the electrode and retards voltage drop during cycling. The reversible capacity of the 3 mol% Li2TiO3-coated Li-rich layered cathode material at the 100th cycle at a large current density of 100 mA/g is significantly enhanced to 105 mAh/g from 78 mAh/g of the un-coated sample. The enhancements of the electrochemical performance can be largely attributed to the stabilization of the interface between the cathode and electrolyte, the three-dimensional path for Lit-ion and better conductivity after Li2TiO3 coating. It is also disclosed that the amount of Li(2)TiO(3)coating also has a large influence on the electrochemical performances and it is necessary to optimize the specific capacity, cycling stability and rate capability through tuning the content of Li2TiO3 coating. (C) 2015 Elsevier B.V. All rights reserved.