Designing Organic–Inorganic Hybrid Materials to Construct a Complementary Interface with Versatility for Li–S Batteries

Abstract Polysulfides shuttle and lithium dendrites growth greatly restricts the practical application of lithium–sulfur batteries (LSBs). A rational designed separator combined polysulfide catalyst and lithium regulator can achieve the effect of killing two birds with one stone. Herein, organic–inorganic hybrid materials are designed to construct a complementary interface for LSBs. Specially, two kinds of covalent organic frameworks (COF) with different pore size are in situ grown on the MXene surface by forming Ti–N bond. The high electronic conductivity and abundant surface functional groups of MXene allow it to work as a catalyst to effectively accelerate the polysulfides conversion, while COF can be used as an ion calibrator to guide homogeneous lithium deposition. As expected, the MXene@COF (MCOF) integrated separator realizes complementary advantages that enable a Li||Li symmetric cell to achieve a surprisingly stable lithium plating/stripping process up to 4750 h at 10 mA cm⁻². Furthermore, the assembled LSBs exhibit high capacities of 584/563 mAh g⁻¹ at 3 C and low‐capacity decay rates of 0.042%/0.048% per cycle after 1000 cycles at 1 C. This work proposes a strategy of complementary advantages based on the MXene and COF composites in the interface layer, which is of great significance for the separator construction of high‐performance LSBs.