Flexible NiCo2S4-hollow carbon nanofibers electrocatalytic membrane as an advanced interlayer for lithium-sulfur batteries

Abstract

Lithium-sulfur (Li-S) batteries have been recognized to be one of the most promising devices for next-generation energy storage devices. However, the severe lithium polysulfides (LiPSs) shuttle effect and torpid redox kinetics hinder their practical application. To solve these issues, a flexible NiCo2S4-hollow carbon nanofibers (NiCo2S4@HCNF) electrocatalytic membrane for Li-S batteries interlayer is fabricated by combining coaxial electrospinning and hydrothermal methods. On the one hand, the conductive framework of HCNF with hollow structure can buffer more electrolytes, which provides fast electron transport pathways and shortens the diffusion distance of ions. On the other hand, the dense NiCo2S4 nanowires uniformly grow on the surface of the HCNF, which can adsorb and catalyze LiPSs conversion. Due to the structural advantage of the NiCo2S4@HCNF, the Li-S batteries exhibit excellent cycling stability (only 0.06% decay per cycle in 500 cycles at 1 C) and high specific capacity (607.6 mA h g−1 at 3 C). This research illustrates that the NiCo2S4@HCNF composite has extensive application prospects in high-performance Li-S batteries.