Cage‐confinement synthesis of MoC nanoclusers as efficient sulfiphilic and lithiophilic regulator for superior Li–S batteries

Abstract High‐energy‐density Li‐S batteries are subjected to serious sulfur deactivation and short cycle lifetime caused by undesirable polysulfide shuttle effect and frantic lithium dendrite formation. In this work, a controllable cage‐confinement strategy to fabricate molybdenum carbide (MoC) nanoclusters as a high‐efficient sulfiphilic and lithiophilic regulator to mitigate the formidable issues of Li‐S batteries is demonstrated. The sub‐2 nm MoC nanoclusters not only guarantee robust chemisorption and fast electrocatalytic conversion of polysulfides to enhance the sulfur electrochemistry, but also homogenize Li + flux to suppress the lithium dendrite growth. As a consequence, the MoC‐modified separator endows the batteries with boosted reaction kinetics, promoted sulfur utilization, and improved cycling stability. A reversible capacity of 701 mAh·g −1 at a high rate of 5.0C and a small decay rate of 0.076% per cycle at 1.0C over 600 cycles are achieved. This study offers a rational route for design and synthesis of bifunctional nanoclusers with both sulfiphilicity and lithiophilicity for high‐performance Li‐S batteries.