Ammonium Vanadium Oxide Nanobelt-Integrated Sulfur Hosts Enabling Enhanced Polysulfide Redox Kinetics in Lithium-Sulfur Batteries

Abstract

Lithium-sulfur (Li-S) batteries are regarded as promising next-generation energy storage systems, but their practical application is limited by the intrinsic insulating nature of sulfur, the dissolution and shuttling of lithium polysulfides, and sluggish redox kinetics. To address these challenges, a multifunctional sulfur host was developed by integrating biomass-derived activated carbon (AC) with ammonium vanadium oxide (NVO) nanobelts, to form an NVO/AC composite. The porous AC framework provides a conductive matrix with high surface area and large pore volume for efficient sulfur encapsulation and physical confinement of polysulfides. Meanwhile, the incorporated NVO introduces abundant polar V-O sites and mixed-valence redox-active centers, enabling strong chemical adsorption of polysulfides and catalyzing their bidirectional redox conversion. Owing to this synergistic design, the NVO/AC cathode delivers a high discharge capacity of 1476.9 mA h g -1 at 0.1 C. These results demonstrate that combining layered ammonium vanadium oxide electrocatalysts with biomassderived porous carbon hosts offers a practical and efficient strategy for improving the electrochemical performance of Li-S batteries.