One-dimensional architecture with reduced graphene oxide supporting ultrathin MoO2 nanosheets as high performance anodes for lithium-ion batteries

Abstract

Two-dimensional (2D) materials have been widely studied and used as anode materials for lithium ion batteries (LIBs) because of their high specific surface area and intrinsic mechanical flexibility which could offer numerous active sites and protect effect for LIBs. However, 2D nanosheets are easy to stack and partially lose surface area for Li-ion storage thus greatly affecting their electrochemical performance. Here, we develop a simple strategy to obtain a nanosheets-based one-dimensional structure hybrid by in situ reduction from MoO3 nanorods to MoO2 nanosheets and nanoparticles which are anchored on a 1D reduced graphene oxide skeleton (MoO2-rGO). It was demonstrated that the primary MoO2 nanosheets and nanoparticles are uniformly dispersed on the reduced graphene oxide nanosheets, which are further assembled into a 1D loosened nanostructure. The loosened nanosheets offer more accessible surface area and facilitate transport of electrons and Li-ions. Moreover, MoO2 nanoparticles effectively avoid agglomeration from nanosheets. Results show that MoO2-rGO hybrid demonstrates an enhanced cyclic life, high stability and prominent rate performance when evaluated as anode material for LIBs. The first discharge capacity can reach 1256.4 mAh g−1 and provide a highly reversible capacity of 1003.7 mA h g−1 after 100 cycles at 0.1 A g−1, which makes MoO2-rGO a promising candidate for LIBs. The excellent performance can be attributed to the unique 1D loosened structure consists of MoO2 and conducting rGO nanosheets, which facilitates fast transfer of Li-ion and electron, and the reduced graphene oxide nanosheets acting as a skeleton provide a continuous conductive network and simultaneously strengthen the structural stability.