Electrochemical and spectroscopic characterization of an alumina-coated LiMn2O4 cathode with enhanced interfacial stability

The cycling performances of pristine and modified materials are investigated by galvanostatic cycles at several charge/discharge rates. A detailed analysis of the interfacial properties, and of their impact toward cycling behavior, is carried out by combining galvanostatic cycles at 1C and electrochemical impedance spectroscopy at T = 25 °C and T = 50 °C. The results show that the electrode/electrolyte interface of Al2O3-modified LiMn2O4 is stabilized by suppressing Mn dissolution, resulting in improved cycleability, especially at high temperatures. These results are corroborated by X-ray photoelectron spectroscopy studies, which confirm the suppression of Mn dissolution for the Al2O3-coated material.