Island-like mesoporous amorphous Fe₂O₃layer: Surface disorder engineering for enhanced lithium-storage performance

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 Fe2O3layer on MoO3nanobelts (a-Fe2O3@MoO3). The island-like mesoporous amorphous Fe2O3layer is obtained by direct hydrolysis of FeCl3.6H2O on MoO3nanobelts assisted by low-temperature heat treatment. Here, the FeCl3.6H2O plays a multifunctional role of the formation of amorphous Fe2O3layer, disordering MoO3nanobelts and increasing the specific surface area and porosity of MoO3nanobelts. The as-formed amorphous Fe2O3layer 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 MoO3nanobelts and physical mixture of Fe2O3powdes and MoO3nanobelts: a high initial discharge capacity of 1523 mAh g-1at 50 mA g-1, remarkable rate capability (386 mAh g-1at 500 mA g-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.