Rambutan peel derived porous carbons for lithium sulfur battery

Porous carbons were prepared from the biomass waste rambutan peels using hydrothermal carbonization followed by the KOH activation process. Rambutan peel derived porous carbons (RPC) with high surface area of 2104 m2 g−1 and large pore volume of 1.2 cm3 g−1 were obtained at KOH/carbon ratio of 4 and activation temperature of 900 °C. The as-obtained porous carbons were capable of encapsulating sulfur with a high loading of 68.2 wt% to form RPC/S composite cathode for lithium sulfur (Li–S) battery. High specific discharge capacities of about 1275 mAh g−1 were demonstrated by the RPC/S composites at 0.1 C. After 200 cycles at 0.1 C, a high specific capacity of 936 mAh g−1 was maintained, showing an excellent capacity retention of about 73%.