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 via 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 Li-S battery, exhibited an initial discharge capacity of 1617 mAh g-1 (96.5% of theoretical capacity) at 0.1C and a capacity loss of 0.05% per charge-discharge cycle after 500 cycles at 0.5C 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 that converting the waste pollutants into valuable energy-storage materials and easy processes, 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.