Lithium–sulfur batteries (LSBs) have received substantial interest because their theoretical energy density is considerably

higher than that of conventional lithium-ion batteries. However, the diffi culty in confi ning the soluble intermediate polysulfi

de (PS) species of LSBs hinders the prolonged cycling of the cell. In this study, a Spartina anglica -derived carbon-coated

polyethylene (PE) separator (SC-coated PE separator), which can confi ne the PS species on the cathode side, is developed

to improve the cycling retention of LSBs. Spartina anglica , which is considered a predominant marine waste, is converted

to task-specifi c carbon materials via size-controlled milling and carbonization, and is embedded on a PE separator through

a simple casting process. The SC-coated PE separator improves the electrolyte affi nity, which is characterized by measuring

the contact angle, electrolyte uptake, and transference number of Li + ; consequently, the migration of Li + is undisturbed in

the cell, even if an additional layer is formed on the PE separator. Based on the electrochemical performance, the SC-coated

PE separator exhibits a higher initial specifi c capacity than the PE separator, in addition to a remarkably increased cycling

retention (65.3% vs. 27.7%) after 100 cycles. The SC-coated PE separator eff ectively inhibits the PS species through physical

absorption, thereby increasing the utilization of the active sulfur species. Moreover, the SC-coated PE separator presents a

relatively stable interfacial morphology of the cycled Li anode, revealing that the comprehensive interfacial stability of the

Li–S cell is enhanced by eff ectively confi ning the PS species in the cell.