Bioinspired conductive-catalytic network accelerates rate-determining steps at cathode-electrolyte interface for high-loading Li-S batteries

Lithium‑sulfur batteries demonstrate substantial promises for evolving into next-generation energy storage systems, but sluggish kinetics of LiPSs conversion and poor interfacial stability at the cathode-electrolyte interface remain critical challenges. Biowaste carbon as hosts is a cost-effective strategy to improve the electrical conductivity of Li-S batteries. However, limited polar sites in raw biowaste carbon restrict the capacity to anchor LiPSs. Herein, we propose a bio-derived hybrid host (PANI@GC) synthesized from waste grapefruit peels and polyaniline to address the rate-determining steps in sulfur electrochemistry. The grapefruit-derived carbon establishes an excellent conductive network that enables rapid electron transfer, while the PANI-integrated numerous polar sites (aromatic amine groups, conjugated π-π stacking) create a catalytically active interface to anchor and accelerate LiPSs conversion kinetics. Due to the conductive-catalytic network, the PANI@GC/S cathode delivers exceptional performance of 1190 mAh g −1 at 0.2C and maintains 779.8 mAh g −1 under stringent conditions (5 mg cm −2 sulfur loading, 8 μL mg −1 E/S ratio). Remarkably, the catalytic interface minimizes capacity fading, exhibiting only 28.9 mAh g −1 loss after 7-day rest, compared to Pure S (152.83 mAh g −1 ). This research pioneers a sustainable strategy to engineer conductive-catalytic networks at cathode-electrolyte interfaces, providing fundamental insights into biowaste utilization for high-energy-density battery systems.