Two-dimensional materials towards separator functionalization in advanced Li-S batteries.

Functional separators have played important roles in improving the electrochemical performance of lithium-sulfur batteries by addressing the key issues of both sulfur cathode and lithium anode. Compared with other materials that used for separator functionalization, two-dimension (2D) materials with atomic layer thickness and infinite lateral dimensions feature several advantages of ultra-thin laminate structure, remarkable physical properties and tunable surface chemistry, which show potential applications in separator functionalization towards addressing the issues of both shuttle effect and lithium dendrite in Li-S battery. In this review, the unique advantages of 2D materials for separator functionalization in Li-S battery and their common construction methods are introduced. Then, recent progress and advances in the construction of 2D materials functional separators are summarized in detail towards inhibiting shuttle effect of polysulfide and suppressing lithium dendrite growth in Li-S batteries. Finally, some opportunities and challenges of 2D materials for constructing high-performance functional separators are proposed. We anticipate this review will provide new insights into separator functionalization for developing advanced Li-S batteries.