Nickel‐Functionalized Porous Carbon for Catalytic Polysulfide Conversion in Li–S Batteries

Lithium–sulfur (Li–S) batteries are widely recognized for their high theoretical energy density and cost‐effective sulfur cathodes; however, their commercial application remains limited due to challenges such as the polysulfide shuttle effect, poor conductivity of sulfur, and sluggish redox kinetics. To address these issues, we present a sustainable strategy that utilizes pine needle biomass to engineer an advanced sulfur host material. The biomass undergoes a supercritical water gasification process in the presence of a nickel precursor, enabling simultaneous carbonization and in situ nickel impregnation. This is followed by chemical activation using KOH, which significantly enhances the porosity and surface area of the resulting carbon materials. The synthesized materials were then subjected to detailed spectroscopic analyses to elucidate their structural and chemical characteristics. Based on these insights, Li–S cells were assembled using the developed carbon materials as cathodes. Notably, the Ni‐doped, KOH‐activated porous carbon demonstrates superior electrochemical performance, delivering an initial discharge capacity of approximately 1302 mAh g −1 . This exceptional behavior arises from the synergistic combination of the catalytic activity of nickel and the well‐developed porous architecture, which together accelerate redox kinetics and effectively mitigate the polysulfide shuttling.