Steaming inspired 3D porous architecture for improving the capability and stability of sulfurized polyacrylonitrile cathode

Abstract

Sulfurized polyacrylonitrile (SPAN) is a promising cathode candidate for lithium sulfur batteries based on the short sulfur chain in the backbone. Herein, to further boost electrochemical performance, the three-dimensional porous SPAN (TPSPAN) is constructed via a steaming method using sodium bicarbonate as a space-holder. Benefiting from the structure advantages of TPSPAN, the shuttle effect of polysulfides is restrained by the covalent molecular interactions and highly efficient channels are provided for electron transport and ionic diffusion. As cathode material, TPSPAN exhibits high reversible capacity of 1304 mAh g−1 at 0.1 A g−1 and superb rate capability of 986 mAh g−1 at 2.0 A g−1. Furthermore, the cathode can deliver outstanding long cycle stability with a higher capacity retention of about 94.6% after 1000 cycles at 2.0 A g−1. This work provides a prolongable strategy for developing electrode materials with porous architecture.