Syntheses and Electrochemical Characterization of Li-Rich Li2Mn1-xTixO3 Layered Materials Used for Lithium Ion Batteries

Ti-doped Li2MnO3 is synthesized by a conventional solid-state reaction. Scanning electron microscopy, X-ray diffraction and X-ray photoelectric spectroscopy analyses indicate Ti is successfully doped into Li2MnO3 structure and the doping could suppress agglomeration of primary particlesis efficiently. Electrochemical impedance spectroscopy and galvanostatic charge/discharge results show that, in the voltage window of 2.0 similar to 4.6 V (vs Li/Li+), doped sample Li2Mn0.97Ti0.03O3 delivers an initial discharge capacity of 209 mAh center dot g(-1) with 99.5% coulombic efficiency; after 40 cycles the capacity retention is 94%. Even the current density increases to 400 mA center dot g(-1), the doped sample could still deliver 120 mAh center dot g(-1) capacity, which is more than twice of that of undoped Li2MnO3 (52 mAh center dot g(-1)). Ti-doped Li2MnO3 show greatly improved cycling stability and rate performance, which is beneficial for promoting the commercial application of Li2MnO3 material.