Reversible, stable Li-ion storage in 2 D single crystal orthorhombic α–MoO3 anodes

Abstract

Engineering two dimensional (2D) materials at atomic level is a key factor to achieve enhanced electrochemical Li-ion storage properties. This work demonstrates that single crystals of orthorhombic α–MoO3 phase can preferentially grow with a 2D nanoarchitecture via a ball-milling process, followed by heat treatment at elevated temperature. Detailed FE-SEM and TEM micrographs proved the 2D architecture of α–MoO3 nanoparticles and Raman spectroscopy evidenced the active vibration modes that correspond to the orthorhombic α-MoO3 phase. Single crystalline MoO3 belts depicted high intensity of (0 2 0) and (0 4 0) indexed planes indicating a preferential arrangement. As Li-ion host anode, the 2D α–MoO3 nanostructure delivered high reversible specific discharge capacity of ~540 mA h g−1 at 0.2 C-rate with 99.9% coulombic efficiency as well as 63% capacity retention after 200 charge-discharge cycles. An excellent reversible Li-ion storage performance (high capacity, longer cycle life and good rate capability) was attributed to the 2D α–MoO3 arrangement consists of MoO6 octahedron by corner sharing chains.