Bimetallic-synergistic 3D tetraaminophthalocyanine/CNTs conductive network enabling superior cycling stability in lithium-sulfur batteries

Efficient lithium polysulfides (LIPSs) conversion is essential for enhancing the kinetics and suppressing the shuttle effect in lithium-sulfur (Li-S) batteries. Metal tetraaminophthalocyanines (TaPcM), with abundant amino functional groups and stable metal-centered sites, exhibit remarkable catalytic activity and strong LIPSs adsorption capability in Li-S systems. In this study, nickel and copper atoms were individually anchored at the central coordination sites of tetraaminophthalocyanine (TaPc) molecules. The amino groups of TaPc served as branching points to establish chemical cross-linking bonds and π-π interactions with the surface of carbon nanotubes, thereby forming robust and stable cross-linking junctions. Electrochemical evaluations reveal that the as-designed S/TaPcNiCu/CNTs composite cathode delivers an impressive initial discharge capacity of 1139.7 mAh g −1 at 0.2C and retains 600.6 mAh g −1 after 500cycles at 1.0C, demonstrating excellent catalytic conversion of LIPSs and outstanding cycling stability. Furthermore, density functional theory (DFT) calculations elucidate the synergistic roles of Ni and Cu active centers in LIPSs adsorption and catalytic conversion. This work highlights the promising potential of bimetallic TaPc for Li-S cathode applications, paving a new pathway for advancing Li-S battery technologies.