Multi-channel sulfurized polyacrylonitrile with hollow structure as cathode for room temperature sodium–sulfur batteries

Abstract

Sulfurized polyacrylonitrile (SPAN) has been comprehensively studied as a promising electrode material for sodium–sulfur batteries. However, problems such as low capacity and poor cycle stability still exist in room temperature sodium–sulfur batteries (RT-Na/S batteries). Here, a multi-channel sulfurized polyacrylonitrile (MSPAN) with hollow structure prepared by electrospinning technology was combined with polystyrene (PS) acting as a pore-forming agent, which not only provided a larger specific surface area and enlarged contact between electrode and electrolyte, but also limited the shuttling of polysulfides effectively, thereby improving the reversible specific capacity and rate performance of the electrodes. Through comparing the electrochemical performances of MSPAN on different current collectors, it was found that copper foil as the current collector favored the electrochemical performances of the materials. As a result, the MSPAN-2 used as the cathode for RT-Na/S batteries exhibited a high discharge specific capacity of 314.2 mAh g−1 at a current density of 2 ​A ​g−1. The fabrication of MSPAN provides a good example for improving the electrochemical performance of RT-Na/S batteries.