In-Situ Ionothermal Synthesis of Nanoporous Carbon/Oxide Composites: A New Key to Functional Separators for Stable Lithium-Sulfur Batteries

Lithium–sulfur batteries (LSBs) are promising high-energy energy storage systems. However, conventional polypropylene-based separator cannot avoid polysulfides shuttling and thus dramatically impedes the practical LSBs. Herein, a novel in-situ ionothermal synthesis strategy that concurrently applies ionic liquid as the solvent, template and high-yield carbon source is proposed for facile preparation of nanoporous carbon/oxides composites. Theoretical and experimental studies suggests that the composites exhibit features of high polarity, Ti 3+ doping, oxygen vacancy, heteroatom doping, abundant defects and high electronic conductivity for fast trapping and conversion of polysulfides in LSBs. As functional materials towards separator modification, the assembled high-loading LSBs deliver enhanced performance due to the suppression of shuttle effects. Furthermore, the proposed strategy exhibits excellent versatility and good practicality.