Mo2N Quantum Dots Decorated N‐Doped Graphene Nanosheets as Dual‐Functional Interlayer for Dendrite‐Free and Shuttle‐Free Lithium‐Sulfur Batteries

Abstract

AbstractThe industrialization of lithium–sulfur (Li–S) batteries is simultaneously impeded by the shuttle effect of lithium polysulfides and dendrites growth on lithium anode. To address both issues, a novel sulfiphilic and lithiophilic interlayer of Mo2N quantum dots decorated N‐doped graphene‐nanosheet (Mo2N@NG) are presented on polypropylene separator via a facile scalable method. Benefiting from the strong chemisorption ability, eminent electrocatalysis for LiPSs, and high chemical affinity with lithium‐ion (Li+), Mo2N@NG can efficiently catalyze the rapid transformation of LiPSs and induce uniform deposition of Li+. Theoretical calculation and in situ Raman synergistically elucidate the inhibition of shuttle effect and alleviation of dendrite growth. As a result, the assembled Li–S cell with Mo2N@NG/PP separator exhibits remarkable rate performance (860.2 mA h g–1 at 4 C), good cycling stability (0.039% capacity decay per cycle after 800 cycles at 2 C), a high areal capacity of 3.89 mA h cm–2 of Li–S pouch cell (4.5 mg cm–2 and 6 µL mg–1 at 0.2 C), and steady performance in protecting the lithium anode (at 5 mA cm–2 for 1500 h). This present strategy of quantum dots in a hybrid framework has great potential to be generalized to other transition metal‐based catalysts for advanced Li–S batteries.