we describe a modified activated expanded graphite chitosan (AEG/CH) coated separator for Li–S batteries in which the shuttling phenomenon of the lithium polysulfides is restrained through two types of interactions: activated expanded graphite (AEG) flakes having a high surface area of 368 m²g^-1interacted physically with the lithium polysulfides, while chitosan (CH), was used to bind the AEG flakes on the separator, interacted chemically through its abundance of amino and hydroxyl functional groups. Moreover, the AEG flakes facilitated ionic and electronic transfer during the redox reaction. Live H-cell discharging experiments revealed that the modified separator was effective at curbing polysulfide shuttling; moreover, XPS analysis of the cycled separator confirmed the presence of lithium polysulfides in the AEG/CH matrix. Using this dual functional interaction approach, the lifetime of the pure sulfur-based cathode was extended to 1000 cycles at 1C-rate (1C = 1670 mA/g), decreasing the decay rate to 0.021% per cycle—a value that is among the best reported to date. A flexible battery based on this modified separator exhibited stable performance and could turn on multiple light emitting diodes. Such modified membranes with good mechanical strength, high electronic conductivity, and anti-self-discharging shield appear to be a scalable solution for future high-energy battery systems.