Synthesis and characterization of spinel Li1.05Cr0.1Mn1.9O4-zFz as cathode materials for lithium-ion batteries

Samples with the nominal stoichiometry LiCrMnOF(z=0,0.05,0.1,0.15,and 0.2) were synthesized via the solid-state reaction method and characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),galvanostatic charge/discharge, and slow rate cyclic voltammetry(SSCV) techniques.The results show that the pure spinel phase indexed to Fd3m can be obtained when z=0, 0.05,and 0.1.The substitution of F for O with z≤0.1 contributes to the increase of initial capacity compared with LiCrMnOspinels. However,when the F-dopant content is designed to be 0.15 and 0.2,the LiCrMnOFsamples deliver relatively low capacity and poor cycling properties at 55℃.