Structural and Electrochemical Investigation of Li1.02Mn1.92Al0.02Fe0.02Cr0.02O4 - x Fx (x=0, 0.08) Synthesized by Solid-State Method

Abstract

To improve the cycle performance of spinel LiMn2O4 as the cathode of 4-V-class lithium secondary batteries, spinel phases Li1.02Mn1.92Al0.02Fe0.02Cr0.02O4 - xFx (x=0, 0.08) have been successfully prepared by a conventional solid-state method. The structure and physicochemical properties of this as-prepared powder were investigated by powder X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge test in detail. The results reveal that the multiple doping spinel Li1.02Mn1.92Al0.02Fe0.02Cr0.02O4F0.08 have better electrochemical performance than the undoped or only metal-element doped material, which may be contributed to the multiple cation and anion doping to lead to a more stable spinel framework with good capacity retention rate.