English
The shuttle of polysulfides and the growth of lithium dendrites greatly limit the practical application of lithium sulfur batteries (LSB). A well-designed diaphragm combined with polysulfide catalyst and lithium regulator can achieve a win-win effect. Here, organic-inorganic hybrid materials were designed to construct complementary interfaces for LSB. Specifically, two covalent organic frameworks (COFs) with different pore sizes are grown in situ on the surface of MXene by forming Ti-N bonds. The high electronic conductivity and rich surface functional groups of MXene make it an effective catalyst to accelerate the conversion of polysulfides, while COF can serve as an ion calibrator to guide uniform lithium deposition. As expected, MXene@COF The MCOF integrated separator achieves complementary advantages, enabling Li | | Li symmetric batteries to achieve a surprisingly stable lithium deposition/stripping process of up to 4750 hours at 10 mA cm-2. In addition, the assembled LSB exhibits a high capacity of 584/563 mAh g-1 at 3 C, and the capacity decay rate after 1000 cycles at 1 C is only 0.042%/0.048%/cycle. This work proposes a complementary strategy based on interface layer MXene and COF composite materials, which is of great significance for the construction of high-performance LSB membranes.
