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

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).