Bio-inspired poly(3,4-ethylenedioxythiophene): Poly(styrene sulfonate)-sulfur@polyacrylonitrile electrospun nanofibers for lithium-sulfur batteries

Abstract

The drive for commercializing high energy density lithium-sulfur batteries is leading to the development of various material architectures for suppressing the notorious “shuttle effect” of intermediate polysulfides and improve cycle life. Inspired by the structural features of plant roots protecting soil erosion, herein, we report a novel strategy to use poly(3,4-ethylenedioxythiophene):polystyrene sulfonate-sulfur@polyacrylonitrile electrospun nanofibers as flexible additives in the cathode of lithium-sulfur batteries to trap lithium polysulfides and suppress their dissolution into liquid electrolyte. The nanofibers consist of in-situ grown sulfur particles, embedded inside porous polyacrylonitrile shell and coated with poly(3,4-ethylenedioxythiophene):polystyrene sulfonate. The electrochemical performance of lithium-sulfur batteries using poly(3,4-ethylenedioxythiophene):polystyrene sulfonate-sulfur@polyacrylonitrile nanofiber incorporated sulfur hybrid cathode shows a significantly better cycle stability and excellent rate capability compared to the bare sulfur cathode owing to the adsorption effect of the nanofibers. Even after 500 cycles at a high rate of 0.5 C, the capacity retention is approximately 41% of the initial capacity with average columbic efficiency above 94%. This work offers a novel approach to fabricate viable lithium-sulfur batteries and possibly pave the way to further develop innovative flexible additives for practically applicable lithium-sulfur batteries.