Multiscale sulfur particles confined in honeycomb-like graphene with the assistance of bio-based adhesive for ultrathin and robust free-standing electrode of Li–S batteries with improved performance

Carbon/sulfur composites are attracting extensive attention due to their improved performances for Li–S batteries. Herein, a hierarchical ultrathin but robust graphene composite membrane, which includes an inherent carbon framework and the embedded sulfur multi-sized particles, is facilely in situ and one-pot synthesized with the assistance of bio-based surfactant/adhesive for flexible cathode without current collectors. It shows better cycling stability and higher specific capacity of 823 mA h g−1 over 100 cycles at 0.5C with a high sulfur content of ∼61 wt% in the electrode. The introduction of biosurfactant and interfacial adhesion enhanced the flexibility and strength of the thinner composite membrane in addition to the increased specific capacity, which may show promising potential for better flexible and wearable electronic devices.