High‐Capacity and Kinetically Accelerated Lithium Storage in MoO₃ Enabled by Oxygen Vacancies and Heterostructure

Abstract

Abstract Molybdenum trioxide (MoO 3 ) has recently aroused intensive interest as a renowned conversion‐type anode of Li‐ion batteries (LIBs). Nevertheless, the inferior rate capability, sluggish reaction kinetics, and fast capacity decay during a long‐term charge/discharge process seriously inhibits large‐scale commercial application. Herein, abundant oxygen vacancies and MXene nanosheets are elaborately introduced into MoO 3 nanobelts through hydrazine reduction and electrostatic assembly to accelerate the ionic and electronic diffusion/transport kinetics for LIBs. Benefitting from the accelerated ion diffusion kinetics, enhanced electrical conductivity, and additional active sites induced by oxygen vacancies as well as the robust interfacial contact, the prepared MoO 3− x /MXene heterostructure exhibits excellent lithium‐ion storage performances. First‐principles calculations indicate that the adsorption of Li + ion and the electrical conductivity are significantly enhanced for the MoO 3− x /MXene heterostructure. Thus, the composite exhibits high reversible capacity of 1258 mAh g −1 at 0.1 A g −1 for Li‐ion storage and retains 474 mAh g −1 at 10 A g −1 , remarkably higher than those of the previously reported MoO 3 ‐based anode materials. More importantly, the composite is fabricated with commercial LiFePO 4 into a full LIB, which displays an unparalleled energy density of 330 Wh kg −1 .