CoTe nanorods/rGO composites as a potential anode material for sodium-ion storage

Abstract

Transition-metal sulfides and selenides have been widely studied as sodium ion batteries anode materials owing to large theoretical capacity. Nevertheless, tellurides in the same chalcogen group with higher densities and better conductivity are scarcely investigated as an electrode material for sodium ion batteries. In this work, CoTe with different morphologies were synthesized by a facile one-pot solvothermal method. Both the CoTe nanorods/reduced graphene oxide (CTNRs/rGO) composites and the CoTe nanotubes (CTNTs) exhibit an advanced performance for Na-ion storage when used as anode materials for sodium-ion batteries. The electrochemical reaction mechanism of the electrode was revealed by ex-situ X-ray diffraction, high resolution transmission electron microscopy and electron diffraction methods. Particularly, the CTNR/rGO has better performance with specific capacity of 306 mA h g−1 at 50 mA g−1 after 100 cycles and capacity of 200 mA h g−1 even after 200 cycles at 0.1 A g−1, which attribute to enlarged contact surface area, improved electrical conductivity and higher mechanical strength by hybridizing with rGO. Accordingly, the CTNR/rGO can be considered as promising anode materials for sodium-ion batteries.