MOF and its derivative materials modified lithium–sulfur battery separator: a new means to improve performance

In recent years, lithium–sulfur batteries (LSBs) are considered as one of the most promising new generation energies with the advantages of high theoretical specific capacity of sulfur (1675 mAh·g−1), abundant sulfur resources, and environmental friendliness storage technologies, and they are receiving wide attention from the industry. However, the problems of the shuttle effect and lithium dendrite growth in LSBs have limited their practical application, so there is a need to find ways to solve these problems. It is an excellent choice to use novel materials to modify battery materials. Among those novel materials, the metal–organic framework (MOF) has the properties of regular pores and controllable structure. When applied as a positive electrode and diaphragm, it can restrain the shuttle effect and lithium dendrite growth, especially since it shows excellent performance in diaphragm modification. Therefore, various design strategies and synthesis methods of MOF-modified separators are reviewed in this paper, and the applications of MOF in LSBs separators in different forms are introduced, including the composite of MOF and carbon-based materials, the compounding of MOF and polymer, self-carbonization to form MOF-derived materials. At the same time, different characterization techniques are systematically reviewed to obtain the physical and chemical properties of MOF particles and the working mechanism of MOF-modified diaphragm, which provides a basis for further research in this field. Finally, some future research trends and directions are put forward to fully tap the future commercial potential of MOF-modified diaphragm in LSBs.