Fabrication and Electrochemical Behavior of a Pure-Phase Li<sub>2</sub>MnO<sub>3</sub> Thin Film for Cathode Material of Li-Ion Batteries

Abstract

Li2MnO3 materials were synthesized by solid state reactions. A series of Li2MnO3 thin films were fabricated at different temperatures under O-2 by pulsed laser deposition (PLO) using a home-made Li2MnO3 target. The structure and morphology of the as-prepared Li2MnO3 thin films were characterized by X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). Their electrochemical performance was also investigated. The results show that the crystallinity of the thin films increased with an increase in deposition temperature, and the thin film electrode prepared at lower than 25 degrees C did not work well. The highest electrochemical activity was achieved by the thin film deposited at 400 degrees C, and this result is consistent with our previous report on powder materials. The Li2MnO3 thin film electrodes deposited at 400 and 600 degrees C exhibited lower discharge voltage decay upon cycling compared with the powder electrode.