Dynamic Ni–N ₄ centers enable concurrent polysulfide catalysis and Li ⁺ flux control for high‐performance Li–S batteries

Abstract This work introduces nickel (II) tetraphenylporphyrin (NiTPP) as a multifunctional electrolyte additive to simultaneously address polysulfide shuttle and uncontrolled lithium dendrite growth in lithium–sulfur (Li–S) batteries. Mobile NiTPP species act as homogeneous catalysts with Ni–N 4 centers for rapid polysulfide redox mediation to suppress migration, while planar molecules featuring lithium‐affinity capability migrate to the lithium metal surfaces, enabling uniform lithium flux and anode protection. NiTPP‐modified electrolytes significantly enhance Li–S battery performance, demonstrated by 634.9 mAh g −1 at 4C, 758.3 mAh g −1 after 100 cycles at 0.2 C (83.4% retention), and 757.5 mAh g −1 under high sulfur loading (2.9 mg cm −2 ) with lean electrolyte ( E / S = 5 μL mg −1 ), all with high Coulombic efficiency. Crucially, NiTPP, acting as a soluble dual‐functional mediator enabling homogeneous operation in electrolytes, simplifies Li–S battery fabrication while demonstrating the commercial viability of molecularly engineered mobile active sites for stabilizing both electrodes in high‐energy‐density Li–S batteries.