Vertically Oxygen-Incorporated MoS2 Nanosheets Coated on Carbon Fibers for Sodium-Ion Batteries.

Developing a high-performance anode with high reversible capacity, rate performance, and great cycling stability is highly important for sodium-ion batteries (SIBs). MoS2 has attracted extensive interest as the anode for SIBs. Herein, the vertically oxygen-incorporated MoS2 nanosheets/carbon fibers are constructed via a facile hydrothermal method and then by simple calcination in air. Oxygen incorporation into MoS2 can increase the defect degree and expand the interlayer spacing. Vertical MoS2 nanosheet array coated on carbon fibers not only can expose rich active sites and reduce the diffusion distance of Na+, but also improve the electronic conductivity and enhance structural stability. Meanwhile, interlayer-expanded MoS2 can decrease Na+ diffusion resistance and increase accessible active sites for Na+. In this work, the electrode combining the oxygen-incorporated strategy with vertical MoS2 nanosheet-integrated carbon fibers displays high specific capacities of 330 mAh g-1 over 100 cycles at a current density of 0.1 A g-1 together with excellent rate behavior as the anode for SIBs. This strategy offers a helpful way for improving the electrochemical performance.