Synthesis and Performance of Nano MnO as an Anode Material for Lithium-Ion Batteries

Abstract

Transition metal oxides,especially manganese monoxide(MnO),are being intensively studied as candidate anode materials for next generation lithium-ion batteries in high efficiency energy storage applications such as portable electronics,electric vehicles,and stationary electricity storage.In this paper, the MnC_2O_4·2H_2O precursor,prepared from KMnO_4 and ascorbic acid,was heat-treated to synthesize nano MnO by a solid-state reaction approach.X-ray diffraction(XRD) showed that the so-obtained MnO had a rock-salt structure with good crystallinity,and scanning electron microscopy(SEM) indicated that the primary particle size was about 50-100 nm,while the secondary particle size was about 400-600 nm.As an active material for lithium-ion batteries,the nano MnO material delivered a reversible capacity of 679.7 mAh ? g~(-1) with an initial columbic efficiency of 68.9%at a current density of 46.3 mA ? g~(-1).The specific discharge capacity slightly decreased from 584.5 to 581.5 mAh ? g~(-1) with a retention of 99.5%after 50 cycles at a current density of 141.1 mA·g~(-1).Moreover,the material was able to release a capacity of 290 mAh ? g~(-1) at current densities as high as 494.7 mA ? g~(-1)(corresponding to ~2C),which demonstrates reasonable rate performance and moderately fast charge/discharge capabilities.All of the above characteristics make nano MnO promising anode materials for developing high-capacity,long-life,low-cost, and environmentally-friendly lithium-ion batteries.