Synergistic Catalytic Effect of Ion Tunnels with Polar Dopants to Boost the Electrochemical Kinetics for High‐Performance Sulfur Cathodes

Rechargeable lithium−sulfur (Li−S) batteries with high areal capacity are hindered by the ion/electron pathway and sluggish reaction kinetics of sulfur species, resulting from high energy barriers. Inspired by the nature of biomass and efficient nutrition transfer, we present a high‐performance sulfur cathode based on nanocarbon tunnels with natural polar catalytic sites. The inherited tunnels can propel lithium‐ion transport across the interface to reach the active materials and the interior heteroatom dopants provide abundant catalytic sites to further reduce the energy barriers. The as‐fabricated sulfur cathode displays much higher rate performance of 565 mA h g−1 at 6 C and a low decay rates of 0.029 % per cycle for 2000 cycles at 3 C. Most importantly, a high initial areal capacity of 5.1 mA h cm−2 with enhanced loading up to 5.8 mg cm−2 at 1 C is achieved, corresponding to volumetric capacity of 638 A h L−1.