Activated carbon derived from glutinous rice via gamma radiolysis for lithium–sulfur battery cathodes

Abstract

Although lithium-sulfur batteries (LSBs) have high theoretical capacities (1675 mA h g⁻¹), an irreversible charge/discharge process (shuttle effect) due to polysulfide and insulating lithium sulfide (Li₂S) formation causes the death of battery cells. This study aims to solve the shuttle effect by anchoring polysulfide onto porous carbon/sulfur cathodes via chemical interactions. The porous activated carbons were derived from glutinous rice (RAC) and were modified through water (RAC-W) or ammonia radiolysis (RAC-N) using a gamma source (25 kGy). The specific capacities of LSBs obtained from RAC-W and RAC-N are >900 mA h g⁻¹ and they are stable for more than 150 cycles, which is significantly higher than that of unmodified RAC. Furthermore, carbonyl and pyridinic nitrogen moieties formed in RAC-W and RAC-N from gamma radiolysis result in enhanced interactions between polysulfide and the cathode framework.