Bio-mass derived hierarchically porous and high surface area carbon as an efficient sulfur host for lithium-sulfur batteries

Abstract

Lithium–sulfur (Li-S) batteries are attractive candidates for electric vehicles and grid storage applications due to their high energy density than Li-ion batteries. Development of high energy Li-S batteries employing eco-friendly, and bio-waste derived materials will further increase the sustainability of the energy storage devices. Herein, we utilize porous carbon derived from waste watermelon rind for Li-S battery application. The porous carbon with hierarchal architecture, and functional heteroatoms can efficiently infiltrate the sulfur cathode and overcomes the major challenges in the Li-S battery, namely (i) poor electronic conductivity of sulfur cathode, and (ii) dissolution of long-chain polysulfides. The Li-S cell with a sulfur-infiltrated porous carbon delivered a high initial discharge capacity of 1176 mAh g−1 at 0.5C rate with a low capacity fading rate of 0.057% over 500 cycles. The strong carbon framework can accommodate the volume changes during the sulfur conversion reaction, and the unoccupied pores in porous carbon can function as polysulfide reservoir to efficiently trap polysulfide migration to achieve a high stability. The highly inter-connected hierarchical pores further facilitated a faster electronic and ionic transport to achieve a high rate performance, higher than pristine sulfur cathode. These results demonstrate the potential to develop high-performance energy storage devices using eco-friendly and renewable materials for electric vehicles and other energy storage systems.