Coralline‐Like N‐Doped Hierarchically Porous Carbon Derived from Enteromorpha as a Host Matrix for Lithium‐Sulfur Battery

Coralline‐like N‐doped hierarchically porous carbon (CNHPC) was prepared through a hydrothermal carbonization process using a sea pollutant enteromorpha as the starting material. The addition of a small amount of glucose during carbonization improved the yield of carbon, and the inherent N contents, especially for pyrrolic N and pyridinic N atoms. After loading 40 wt. % sulfur, the CNHPC/S composite, as a cathode in a Li‐S battery, exhibited an initial discharge capacity of 1617 mAh g−1 (96.5 % of theoretical capacity) at 0.1 C and a capacity loss of 0.05 % per charge‐discharge cycle after 500 cycles at 0.5 C with a stable Coulombic efficiency of 100 % in carbonate based electrolyte. Such a great performance can be attributed to the coralline‐like hierarchically porous infrastructure and inherently abundant N doping. Given the conversion of waste pollutants into valuable energy‐storage materials and the easy process, this work features a promising approach to prepare C/S cathodes for Li‐S batteries. The special structural and textural characteristics of CNHPC might be attractive to other practical applications such as supercapacitors and catalysis. Green batteries: A coralline‐like N‐doped hierarchically porous carbon was fabricated through hydrothermal carbonization of a sea pollutant enteromorpha, which shows excellent electrochemical performance as a cathode material in Li‐S batteries. The special structural and textural characteristics are promising to other practical applications such as supercapacitors and catalysis.