Activated carbon with hierarchical porosity derived from biomass for lithium sulfur batteries

Abstract

Highly porous activated carbon (RHAC) with micro/meso porosity has been synthesized through carbonizing rice husk and activaling by K₂CO₃. Elemental sulfur has been loaded to the micropores through a solution infiltration method to form RHAC@S nanocomposite. The resulted RHAC@S nanocomposite with 0.25 and 0.38 mg.cm⁻¹ of sulfur loading have been tested as novel cathodes for Li-S batteries. The 0.25 mg.cm⁻¹ sulfur loading sample shows an initial discharge capacity of 1080 mA.h.g⁻¹ at 167.5 mA g⁻¹. After 50 cycles of charge/discharge test at the current density of 0.2C, the reversible capacity maintains at 312 mA.h.g⁻¹. The material has delivered a capacity of more than 300 mA.h.g⁻¹ at 284.75 mA g⁻¹. These results suggest that the rice husk is a good candidate for large-scale production of activated carbon, which is a promising material for cathode of Li-S batteries.