Enhancing lithium-sulfur battery performance with biomass-derived graphene-like porous carbon and NiO nanoparticles composites

Abstract

Despite the promising specific discharge capacity and energy density, lithium-sulfur batteries (LSBs) encounter challenges related to the lithium polysulfides (LiPSs) shuttle effect and volume expansion during extended cycling. A pivotal aspect of this research lies in the strategic synthesis of a hybrid of non-polar and polar compounds, creating an effective host and separator modifier tailored for LSBs for improvement of their electrochemical characteristics. Precisely, high-specific surface area graphene-like porous carbon (GPC) was successfully synthesized from inexpensive and abundant rice husk (RH) waste via step-by-step carbonization and thermo-chemical activation, and subsequently used as a porous matrix for sulfur cathode preparation using the melt-diffusion technique. Furthermore, composites based on GPC decorated with NiO nanoparticles were synthesized with varying GPC to Ni(NO3)2 ratios and utilized as an efficient separator modifier. The obtained results revealed that the cell consisting of GPC@S cathode and GPC-NiO-20 modified separator exhibited accelerated LiPSs redox reactions and suppressed the shuttle effect. In particular, the GPC@S/GPC-NiO-20 cell demonstrated excellent initial discharge capacity (1519 mAh g−1 at 0.2 C), promising long-term cycling performance (capacity decay of 0.091 % per cycle over 400 cycles at 1 C), and remarkable rate performance (568 mAh g−1 at 2 C).