Texturing In-Situ: N/F Dual-Doped hollow porous carbon nanospheres for advanced Li-S batteries

Heteroatom-doped hollow carbon nanostructures are one of the most promising sulfur hosts for high-performance lithium-sulfur (Li-S) batteries. However, finding a facile and controllable synthesis and enhancing their immobilization effect on polysulfides have been challenging. Herein, we propose a one-step in-situ reaction approach to synthesize N/F dual-doped hollow micro/mesoporous carbon nanospheres (NFHCs) as multifunctional sulfur host, which integrates the physical confinement of hollow porous structure and chemical adsorption/catalytic ability of N/F active sites to realize strong anchoring and accelerated conversion of polysulfides. This sulfur cathode based on NFHCs host with a high sulfur content of 80 wt% enables a superior high-rate capacity of 689 mAh g −1 at 3C, accompanied by outstanding cycle life over 500 cycles at 2C with a capacity decay of only 0.05% per cycle and nearly 100% Coulombic efficiency. This work opens up new horizons to design nanostructured functional hollow carbons for advanced Li-S batteries.