High performance of MoS2 microflowers with a water-based binder as an anode for Na-ion batteries

Abstract

Na-ion batteries have risen as an alternative system to current Li-ion batteries due to the wide range of availability and low price of sodium resources. Here we report the binder effect on sodium storage properties of MoS₂ microflowers with nano-sized petals which are prepared by a combination of a hydrothermal reaction and solid-state reaction. The electrochemical performance of MoS₂ microflowers with different binders is evaluated against pure Na metal in a half-cell configuration through a conversion reaction. Especially, the electrode of MoS₂ microflowers with a Na-alginate binder shows an excellent cycling stability, delivering a high discharge capacity of 595 mA h g⁻¹ after 50 cycles. The MoS₂ microflowers with the Na-alginate binder also exhibit high rate capability, retaining a capacity of 236 mA h g⁻¹ at 10C without any carbonaceous materials. The improved electrochemical performance was mainly attributed to the synergetic effect of the morphology of the MoS₂ microflowers and good adhesive capabilities of the alginate binder. Furthermore, we report a Na-ion fuel cell using the MoS₂ microflower anode with Na₃V₂O_2x(PO₄)₂F_3−2x/C as a cathode material.