Multifunctional Polypropylene Separator via Cooperative Modification and Its Application in the Lithium–Sulfur Battery

The continuous shuttling of dissolved polysulfides between the electrodes is the primary cause for the rapid decay of lithium–sulfur batteries. Modulation of the separator–electrolyte interface through separator modification is a promising strategy to inhibit polysulfide shuttling. In this work, we develop a graphene oxide and ferrocene comodified polypropylene separator with multifunctionality at the separator–electrolyte interface. The graphene oxide on the functionalized separator could physically adsorb the polysulfide while the ferrocene component could effectively facilitate the conversion of the adsorbed polysulfide. Due to the combination of these beneficial functionalities, the separator exhibits an excellent battery performance, with a high reversible capacity of 409 mAh g^–1 after 500 cycles at 0.2 C. We anticipate that the combinatorial separator functionalization proposed herein is an effective approach for improving the performance of lithium–sulfur batteries.