Self-breathing ternary nanocomposite based on nitrogen-doped graphene aerogel/polyaniline/sulfur as a cathode material for lithium-sulfur (Li-S) batteries

Abstract

Li-S batteries are one of exciting new technologies in high energy density storage devices. But, their widespread commercialization has been limited by several obstacles. Elemental sulfur is not conductive electrically and electrochemical conversion during cycles causes intense change in volume. In this work, a sulfur/polyaniline/nitrogen-doped graphene aerogel (S@PANi-NGA) nanocomposite synthesized through a facile chemical procedure. Nitrogen-doped amino functionalized graphene aerogel (NGA) used as cross-linker for polyaniline to improve the stability of the entire cathode framework. Also, NGA possesses porous structure, high surface area, and enhances electronic conductance due to the nitrogen atoms doped into graphene sheets. As a result, S@PANi-NGA delivered an initial discharge capacity of 1332 mAh g−1 at a scan rate of 0.2 C and 872 mAh g−1 of the capacity retained after 100 cycles. The performance was clearly superior to the sulfur/PANi binary composite, in which pure polyaniline used as accommodator.