Nitrogen and oxygen co-doped porous biocarbon@sulfur/carbon nanotubes as cathodes for high-performance lithium-sulfur batteries

Abstract

Practical applications of lithium-sulfur batteries (LSBs) are limited due to the shuttle effect and the low conductivity of sulfur (S) and lithium polysulfide (LiPS). Currently, porous carbon materials doped with heteroatoms show extraordinary potential in this regard. Therefore, using KOH activation, we successfully prepared porous London Plane seed stems biochar (LPSC) with nitrogen and oxygen co-doping as the S carrier. We used carbon nanotubes (CNTs) as electrode coatings to improve the conductivity and suppress the shuttle effect. The results showed that the LPSC@S/CNTs composite electrode had an initial discharge capacity of 1090.4 mAh g−1 at 0.05 C. Furthermore, the capacity remained at 86.0 % after 300 cycles. This study provides a promising and sustainable approach to high-performance energy storage solutions.