Electrocatalytic MOF‐Carbon Bridged Network Accelerates Li+‐Solvents Desolvation for High Li+ Diffusion toward Rapid Sulfur Redox Kinetics

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Abstract
Lithium‐sulfur batteries are famous for high energy density but prevented by shuttling effect and sluggish electrochemical conversion kinetics due to the high energy barriers of Li+ transport across the electrode/electrolyte interface. Herein, the Li+‐solvents dissociation kinetics is catalyzed and stimulated by designing a carbon bridged metal‐organic framework (MOF@CC), aimed at realizing increased bare Li+ transport for the rapid conversion kinetics of sulfur species. Theoretical simulations and spectroscopic results demonstrate that the bridged MOF@CC well grants a special transport channel for accelerating Li+ benefited from aggregated anion/cation clusters. Moreover, the CN bridge between ‐NH2 ligand in MOF and carbon shell enhances electron exchange, and thus promotes polysulfide catalytic efficiency and hinder polysulfide aggregation and accumulation. With the MOF@CC‐modified separators, the assembled Li/S batteries deliver a reversible capability of 1063 mAh g‐1 at 0.5 C, a capacity retention of 88% after 100 cycles, and a high‐rate performance of 765 mAh g−1 at 5 C. Moreover, the large areal pouch cell with 100 µm Li foil and lean electrolyte is capable of stabilizing 855 mAh g−1 after 70 cycles. These results well demonstrate the efficiency of catalyzing desolvation for fast Li+ transport kinetics and the conversion of polysulfides.
Funding Information
  • National Natural Science Foundation of China
  • Natural Science Foundation of Jiangsu Province

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