Improving the Reaction Kinetics by Annealing MoS2/PVP Nanoflowers for Sodium-Ion Storage.

ABSTRACT

Under the ever-growing demand for electrochemical energy storage devices, developing anode materials with low cost and high performance is crucial. This study established a multiscale design of MoS2/carbon composites with a hollow nanoflower structure (MoS2/C NFs) for use in sodium-ion batteries as anode materials. The NF structure consists of several MoS2 nanosheets embedded with carbon layers, considerably increasing the interlayer distance. Compared with pristine MoS2 crystals, the carbon matrix and hollow-hierarchical structure of MoS2/C exhibit higher electronic conductivity and optimized thermodynamic/kinetic potential for the migration of sodium ions. Hence, the synthesized MoS2/C NFs exhibited an excellent capacity of 1300 mA h g-1 after 50 cycles at a current density of 0.1 A g-1 and 630 mA h g-1 at 2 A g-1 and high-capacity retention at large charge/discharge current density (80% after 600 cycles 2 A g-1). The suggested approach can be adopted to optimize layered materials by embedding layered carbon matrixes. Such optimized materials can be used as electrodes in sodium-ion batteries, among other electrochemical applications.