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

Abstract Molybdenum trioxide (MoO 3 ) nanobelt is very attractive anode electrode for LIBs because of their high theoretical capacity. To enhance the capacity and cyclic performance of MoO 3 -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 Fe 2 O 3 layer on MoO 3 nanobelts (a-Fe 2 O 3 @MoO 3 ). The island-like mesoporous amorphous Fe 2 O 3 layer is obtained by direct hydrolysis of FeCl 3 .6H 2 O on MoO 3 nanobelts assisted by low-temperature heat treatment. Here, the FeCl 3 .6H 2 O plays a multifunctional role of the formation of amorphous Fe 2 O 3 layer, disordering MoO 3 nanobelts and increasing the specific surface area and porosity of MoO 3 nanobelts. The as-formed amorphous Fe 2 O 3 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 MoO 3 nanobelts and physical mixture of Fe 2 O 3 powdes and MoO 3 nanobelts: a high initial discharge capacity of 1523 mAh g ⿿1 at 50 mA g ⿿1 , remarkable rate capability (386 mAh g ⿿1 at 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.