MoO2 nanobelts modified with an MOF-derived carbon layer for high performance lithium-ion battery anodes

Abstract

Molybdenum oxide (MoO2) is a promising anode material for use in lithium-ion batteries because of its high theoretical capacity (838 mAh g−1). However, rapid capacity decay seriously restricts its practical application. In this work, MoO2 nanobelts were coated in situ with a metal-organic framework (MOF)-derived carbon layer to construct a MoO2@C composite through a facile solvothermal method combined with an annealing treatment to generate high performance lithium-ion battery anodes. Such a composite has a novel core-shell structure with MoO2 nanobelts as the core and an MOF-derived carbon layer as the shell. The MOF-derived carbon layer, which is composed of numerous N-doping carbon nanoparticles immersed with cobalt monoxide (CoO) nanoparticles, is quite thin, with a thickness of ∼7–8 nm, and it possesses many pores. When evaluated as anode material for lithium-ion batteries, the MoO2@C electrode exhibits outstanding electrochemical performance, including a high specific capacity of 1049 mAh g−1 at 0.1 A g−1 for the 50th cycle, superior rate capability of 710 mAh g−1 at 5 A g−1 (68% retention of the capacity at 0.1 A g−1) and excellent cycling stability of 787.7 mAh g−1 at 1 A g−1 after 300 cycles (96% capacity retention). These results are mainly attributed to the multifunctionality of the MOF-derived carbon layer, which realizes an effective synergistic effect of high conductivity, enhanced reaction kinetics, stable microstructure and extra capacity contribution from the CoO component. Therefore, this work expands the application of MOFs and provides a promising method for developing an MoO2 anode material for next-generation lithium-ion batteries.