Mimicking the Peptidyl Enzyme Enables Polysulfide Electronic Axial Stretching Catalysis for Lean-Electrolyte Lithium–Sulfur Batteries

Catalysts are effective in mitigating slow sulfur redox reaction (SRR) kinetics in lithium-sulfur (Li-S) batteries. However, ideal battery performance has yet to be achieved under lean-electrolyte conditions due to the massive accumulation of lithium polysulfides in the electrolyte aggravating low ionic conductivity, increased electrolyte viscosity, and sluggish reaction kinetics. Inspired by the thrombolytic and microcirculation improvement functions of peptidyl nattokinase (NK) enzymes, herein, NK and its peptidyl mimicry enzyme (i.e., the serine (Ser)-histidine (His)-aspartate (Asp) triplet active center) are developed to boost lean-electrolyte SRR, featuring electronic axial stretching catalysis of Ser, strongly electronegative adsorption of Asp, and lithiophility of N-rich His synergistically catalyzing tandem sulfur conversions. After optimizing the catalyst formula by machine learning, the resultant Li-S batteries deliver impressive rate capacity (744 mAh g-1 at 5 C), durable cyclability at 0.5 C, and competitive areal capacity (8.87 mAh cm-2 under an electrolyte/sulfur ratio of 4 μL mg-1).