In Situ Synchrotron X-Ray Diffraction Investigations of LiCu[sub x]Mn[sub 2−x]O[sub 4] Surface Coated LiMn[sub 2]O[sub 4] Spinel Cathode Material during Charge with Various Rates

Abstract

The precursor of was calcined at for to form the semicrystallite and mixed with in deionized water. The mixture powders were then calcined at for to synthesize -coated composite. The phase transformation of both base and -coated during charging at 0.1, 0.5, and rate from 3 to was confirmed by the in situ synchrotron X-ray diffractometer. The plateau potential difference between the base and -coated composite was . The decrease of the plateau can be related to the fact that the kinetics of the -coated composite cathode material was faster than that of the uncoated material. The cyclic voltammograms of two cells using the -coated composite and the base composite as the working electrodes and lithium metal as the counter electrode was applied to measure the oxidation and reduction reaction of the 2016 coin cell during charge and discharge with a rate of from 3 to . Both uncoated and -coated composite displayed two pairs of well-separated redox peaks, corresponding to two voltage plateaus.