Cofactor‐Assisted Artificial Enzyme with Multiple Li‐Bond Networks for Sustainable Polysulfide Conversion in Lithium–Sulfur Batteries

Abstract Lithium–sulfur batteries possess high theoretical energy density but suffer from rapid capacity fade due to the shuttling and sluggish conversion of polysulfides. Aiming at these problems, a biomimetic design of cofactor‐assisted artificial enzyme catalyst, melamine (MM) crosslinked hemin on carboxylated carbon nanotubes (CNTs) (i.e., [CNTs–MM–hemin]), is presented to efficiently convert polysulfides. The MM cofactors bind with the hemin artificial enzymes and CNT conductive substrates through FeN5 coordination and/or covalent amide bonds to provide high and durable catalytic activity for polysulfide conversions, while π–π conjugations between hemin and CNTs and multiple Li‐bond networks offered by MM endow the cathode with good electronic/Li+ transmission ability. This synergistic mechanism enables rapid sulfur reaction kinetics, alleviated polysulfide shuttling, and an ultralow (