Electrochemical behavior of α-MoO3 nanobelts as cathode material for lithium ion batteries

Abstract

α-MoO3 nanobelts were synthesized by simple hydrothermal method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Cyclic voltammogram (CV) and galvanostatic charge/discharge testing techniques were employed to evaluate electrochemical behaviors of α-MoO3 materials. Results showed that α-MoO3 nanobelts with about 80 nm in diameter and 5–12 μm in length were grown in the orthorhombic system. Electrochemical characterisation confirmed that in lithium ion insertion/extraction process, the first intercalation of lithium ion in α-MoO3 at about 2.8 V was irreversible, corresponding to Li x MoO3 (0 < x ≤ 0.25) and the parent MoO3 materials coexisting, the second lithium ion inter-calation was reversible at the potential range of 2.2–2.4 V followed by Li x MoO3 (0.25 < x ≤ 0.5), and below 1.0 V the mechanism of lithium ion storage changed from lithium ion intercalation reaction into lithium alloying reaction. The α-MoO3 nanobelts showed better electrochemical performance, 319 mA h g−1 initial discharge capacity, around 52% capacity retention after 20 cycles than that of α-MoO3 bulk.