N-doped hollow carbon nanoparticles encapsulated fibers derived from ZIF-8 self-sacrificed template for advanced lithium–sulfur batteries

Abstract

Abstract The facile synthesis of sulfur scaffold with high electrical conductivity and strong polysulfide immobilization capability plays an important role in developing high-performance lithium sulfur batteries. Here a new type of porous N-doped carbon fiber consisting of hollow carbon nanoparticles (9 wt%-CF) is designed as sulfur scaffold through electrospinning and carbonization processes with ZIF-8 and polyacrylonitrile as precursors. The carbon fiber skeleton can provide high electrical conductivity, and interconnected hollow particles provide ample space to host active materials and to immobilize polysulfides. Moreover, the N-doping further improves the interaction between 9 wt%-CF and polysulfides. Consequently, the as-prepared 9 wt%-CF/S cathode delivers an initial discharge capacity of 1524 mAh g−1 at 0.1 C and high capacity retention of 83% after 200 cycles charge/discharge at 0.5 C with a sulfur loading of 1.9 mg cm−2.