Enhanced reversible sodium storage by thin carbon layer encapsulated MoS2 nanospheres on interwoven carbon nanotubes

Abstract

Here, an effective approach to obtain controllable thin carbon layer encapsulated MoS2 nanospheres on the surface of interwoven carbon nanotubes to form interconnected network structure of C-MoS2/CNTs composites is presented by a facile hydrothermal method. The remarkable electrochemical performance of the resulting composites as anode electrode materials are achieved for Na-ion energy storage systems, such as excellent capacity (~468 mA h g−1 at 1.0 A g−1), high rate capability (capacity retention of ~72.8% from 0.1 A g−1 to 5.0 A g−1) and long cycling stability (100.0% capacity remaining after 1000 cycles). Systematic characterizations reveal that the outstanding performance is mainly attributed to the unique and robust composite architecture, such as, improvement the conductivity of the whole electrode material, preventing the aggregation of C-MoS2 during cycles, large atomic interface contact for Na+ storage, and providing a dense porous space to alleviate volume expansion during cycling.