One-step for in-situ etching and reduction to construct oxygen vacancy modified MoO2/reduced graphene oxide nanotubes for high performance lithium-ion batteries

Abstract Rational design of nanostructure and improved Li-ion diffusion kinetics is of significant in pursuit stable electrode architecture and high performance lithium-ion batteries. Here we report a one-step self-templated method to simultaneously accomplish in-situ etching and reduction with the assistant of thiourea to fabricate one-dimensional hollow MoO2/reduced graphene oxide nanotubes (denote as H-MoO2@rGO nanotubes) from MoO3@reduced graphene oxide (MoO3@rGO). The functionalization of MoO3 surface is of significant for etching to keep the architecture integrity during the preparation process. At the same time, the introduced oxygen vacancy cause a lopsided charge distribution around the vacancy to generate a foreign coulomb force for facilitating the Li-ion migration. The fabricated 1D H-MoO2@rGO nanotubes not only offer direct electron pathways, greatly shorten ion diffusion length, facilitating electrical transport, but also effectively buffer large volume change during cycling. The as prepared H-MoO2@rGO nanotubes deliver enhanced Li-ion diffusion kinetics and reliability for long cycle life. Thus, 1D H-MoO2@rGO nanotubes exhibit superior stability (1078 mAh g−1 after 200 cycles at 0.1 A g−1), rate performance and high specific capacity (798 mAh g−1, 0.5 A g−1). This work shows a feasible method to simplify the procedures to get access to steady hollow structure with abundant oxygen vacancies, which is of important to meet the demand of lithium-ion batteries for practical application.