Interconnected nitrogen-doped carbon nanofibers derived from polypyrrole for high-performance Li/S batteries

Interconnected nitrogen-doped carbon nanofibers (INC) prepared through the carbonization of polypyrrole (PPy) precursor is designed as scaffold to load sulfur. The BET measurement showed that INC possessed abundant mesopores with a relatively high specific surface area and a large total pore volume. The sulfur/INC (S/INC) composite was synthesized by a melt-diffusion of sulfur nanoparticle into INC network. Transmission electron microscopy showed the formation of a nanofiber structure with uniform sulfur coating on the surface of INCs. When tested as cathodes for Li/S batteries, a high initial discharge capacity of 1173 mAh g–1 and a reversible capacity of 702 mAh g–1 after 50 cycles at 0.1 C are achieved, which ascribe to the chemical and physical adsorption properties of mesoporous and nitrogen-doped INC.