Island-like mesoporous amorphous Fe2O3 layer: surface disorder engineering for enhanced lithium-storage performance

Abstract

Molybdenum trioxide (MoO3) nanobelt is very attractive anode electrode for LIBs because of their high theoretical capacity. To enhance the capacity and cyclic performance of MoO3-based electrode materials of lithium ion battery (LIB), here, as a proof of concept, we report in this work a novel surface disordered engineering strategy of fabrication of island-like mesoporous amorphous Fe2O3 layer on MoO3 nanobelts (a-Fe2O3@MoO3). The island-like mesoporous amorphous Fe2O3 layer is obtained by direct hydrolysis of FeCl3.6H2O on MoO3 nanobelts assisted by low-temperature heat treatment. Here, the FeCl3.6H2O plays a multifunctional role of the formation of amorphous Fe2O3 layer, disordering MoO3 nanobelts and increasing the specific surface area and porosity of MoO3 nanobelts. The as-formed amorphous Fe2O3 layer is demonstrated to significantly improve the kinetics behavior of lithium-ion diffusion and electronic transport due to its isotropic feature during cycling. As a result, the designed anode exhibits dramatically enhanced electrochemical properties compared with individual MoO3 nanobelts and physical mixture of Fe2O3 powdes and MoO3 nanobelts: a high initial discharge capacity of 1523mAhg⿿1 at 50mAg⿿1, remarkable rate capability (386mAhg⿿1 at 500mAg⿿1) and outstanding cycling performance. Our results reveal new possibilities of designing amorphous oxides layer of anode electrodes by surface disorder engineering on achieving enhanced LIBs performance.