Sulfur‐Immobilized Nitrogen and Oxygen Co–Doped Hierarchically Porous Biomass Carbon for Lithium‐Sulfur Batteries: Influence of Sulfur Content and Distribution on Its Performance

Abstract

Abstract Hierarchically porous carbon with inherently doped heteroatoms and the quantity of active material (sulfur) confined within this carbon matrix play a major role for the high performance of Li−S batteries. Herein, we discuss the influence of sulfur content and distribution onto the N and O co‐doped hierarchically porous biomass carbon matrix (PC) to achieve high specific capacitance and cycling stability. Sulfur encapsulated PC was prepared from an eco‐friendly source with a high surface area of 2065 m 2 g −1 and a pore volume of 1.5 cm 3 g −1 . PC with 54, 68 & 73% of sulfur content (PCSCs) have been investigated as cathode materials for Li−S battery. PC with 54% sulfur displayed better performance with an initial discharge capacity of 1606 mA h g −1 and a cycling stability of 1269 mA h g −1 at 0.1C rate after 100 cycles due to better dispersion of sulfur in the porous architecture. The higher cycling stability of PCSC (54%) is due to the N and O co‐doped hierarchical porous carbon layers, enhancing the sulfur utilization ratio and mitigating the polysulfide shuttle during the cycling process.