Multifunctional Interlayer Based on Molybdenum Diphosphide Catalyst and Carbon Nanotube Film for Lithium–Sulfur Batteries

A multifunctional interlayer, composed of molybdenum diphosphide (MoP2) nanoparticles and a carbon nanotube (CNT) film, is introduced into a lithium–sulfur (Li–S) battery system to suppress polysulfide migration. Molybdenum diphosphide acts as the catalyst and can capture polysulfides and improve the polysulfide conversion activity during the discharge/charge processes. The CNT film acts as a conductive skeleton to support the MoP2 nanoparticles and to ensure their uniform distribution. The CNT film physically hinders polysulfide migration, acts as a current collector, and provides abundant electron pathways. The Li–S battery containing the multifunctional MoP2/CNT interlayer exhibits excellent electrochemical performance. It delivers a reversible specific capacity of 905 mA h g−1 over 100 cycles at 0.2 C, with a capacity decay of 0.152% per cycle. These results suggest the introduction of the multifunctional CNT/MoP2 interlayer as an effective and practical method for producing high‐performance Li–S batteries. A multifunctional interlayer, composed of molybdenum diphosphide (MoP2) nanoparticles and carbon nanotube (CNT) films, is incorporated into lithium–sulfur batteries to enhance their electrochemical performance. The MoP2 nanoparticles act as a catalyst to capture the polysulfides and improve their conversion. The CNT films act as a current collector for the electrodes, and also physically suppress the migration of polysulfides.