MoTe2 on metal-organic framework derived MoO2/N-doped carbon rods for enhanced sodium-ion storage properties

Abstract

Sodium-ion batteries (SIBs) are highly potential for next-generation electrochemical energy storage because of their abundant resources and low prices. Transition metal dichalcogenides (TMDCs) have an excellent capacity, high electrical conductivity, and diverse structures. However, its volume expansion and tendency to restack during charge/discharge cycles lead to inferior electrochemical properties, limiting its development in the battery field. Herein, we synthesized MoO2/NC rods covered with MoTe2 nanosheets on the surface (MoTe2@MoO2/NC) by a high-temperature solid-phase synthesis method based on Mo-MOF a sacrificial template for sodium-ion batteries. The MoO2 core enhances the electron transfer efficiency as a conductive backbone and prevents the volume expansion of MoTe2 nanosheets. Meanwhile, the MoTe2 nanosheets are tightly wrapped around the MoO2 core, significantly reducing the ion diffusion path. Furthermore, the C and N doped substrates with conductivity ensure the integrity of the structure and enhance the conductivity of the electrodes. Benefiting from these advantages, MoTe2@MoO2/NC delivered a high electrochemical performance with high capacity (∼463.9 mAh g−1), superior fast-charge discharge ability (∼294.7, and 258.3 mAh g−1 at 5, and 10 A g−1, respectively). Even at a high current density of 1 A g−1, the specific capacity was maintained at about 328.3 mAh g−1 after 100 cycles.