Enhancement of electrochemical properties of MoO3 nanobelts electrode using PEG as surfactant for lithium battery

Molybdenum trioxide (MoO3) has attracted considerable attention due to their typical two-dimensional layered structure consisting of double layers of edge- and vertex-sharing MoO6 octahedral being weakly held together by van der Waals bonds. These MoO3 nanostructures and their polymer composites are currently drawing interest for the potential applications of Li batteries, supercapacitors, and other electrochemical as well as electrochromic display devices. In this paper, we report the synthesis of MoO3 nanobelts and polyethylene glycol (PEG) surfactant MoO3 nanobelts by hydrothermal method. Structure and morphology of the samples were investigated by X-ray diffraction, Fourier transform spectroscopy, scanning electron microscopy, and transmission electron microscopy (TEM). The pure MoO3 nanobelts show an initial specific capacity of 275 mAh g(-1), whereas the 0.5 mol% PEG surfactant MoO3 nanobelts show 307 mAh g(-1) at constant current density of 30.7 mA g(-1) with the 1.0-3.0 V vs. Li/Li+ potential range. It was found that PEG surfactant MoO3 nanobelts show not only a high initial specific capacity but also show better cyclic performance compared with that of pure MoO3 nanobelts. The PEG surfactant MoO3 nanobelts show stability and improvement of the specific capacity due to decreasing the length, width, and thickness of the nanobelts by surface reaction. Electrochemical impedance spectroscopy reveals that the PEG surfactant MoO3 nanobelts exhibit low electrode resistance compared with pure MoO3 nanobelts.