Orange peel derived hierarchical porous carbon/sulfur composite cathode material for Li–S battery.

A hierarchical porous carbon (HPC) structure was developed from the waste orange peel using KOH as an activating agent. In HPC, the carbon has interconnected hierarchical pores size of which lies between 2 nm and 5 μm. HPC/S composite was prepared by melt-diffusion method and analysed for electrochemical performance. HPC/S exhibits a high initial discharge capacity of 870 mAhg−1 at 0.2C and 734 mAhg−1 at 0.4C. The Carbon-black (CB)/Sulfur (S) composite was also prepared and characterized. A comparative study was done with the CB/S composite, which shows poor cyclability and a discharge capacity of 332 mAhg−1 at 0.2C rate considering 1C = 1672 mAhg−1. Sulfur confinement in the HPC structure leads to superior electrochemical performance of the HPC/S composite ensuring a promising cathode material. [Display omitted] • Hierarchical porous carbon (HPC) structure is synthesized by using KOH as an activating agent. • HPC/S composite is prepared by adopting the melt diffusion method. • HPC/S retains 25.5 % more sulfur, addressed as pore-confined sulfur. • Comparative study shows superior electrochemical performance of HPC/S than CB/S composite. [ABSTRACT FROM AUTHOR]