An Environmental‐Friendly and Sustainable Ramie‐Derived Co/N‐Doped Carbon With Dual Function for Synergistic Polysulfide Regulation in Li‐S Batteries

ABSTRACT The dual challenges of environmental sustainability and rising energy needs underscore the necessity for high‐energy‐density batteries, making lithium–sulfur (LSB) systems with their high theoretical capacity highly attractive. However, the polysulfide shuttle, coupled with inherent kinetic limitations in the sulfur reduction reaction, significantly compromises the battery's commercialization. Utilizing biomass‐derived materials presents a sustainable and cost‐effective approach to mitigating these issues. Therefore, in this study, a series of cobalt–nitrogen co‐doped porous carbon materials (Co,N‐C) were prepared from ramie waste glue by adjusting the cobalt source content, and their electrochemical properties as sulfur hosts were systematically investigated. Among them, Co,N‐C‐2 exhibits the best performance. The three‐dimensional (3D) porous architecture promotes electrolyte penetration and lithium–ion mobility, whereas the Co,N co‐doping sites effectively adsorb lithium polysulfides, markedly reducing the shuttle effect and improving conversion kinetics. The Co,N‐C‐2/S cathode has an initial discharge capacity of 1274.2 mAh g −1 at 0.2C and sustains a reversible capacity of 540.6 mAh g −1 after 350 cycles at 1C, demonstrating a minimal degradation rate of 0.11% each cycle. This study offers a sustainable and cost‐effective design strategy for high‐performance LSBs.