RuO_x Quantum Dots Loaded on Graphdiyne for High‐Performance Lithium–Sulfur Batteries

Abstract Here, a strategy to strengthen d–p orbital hybridization by fabricating π backbonding in the catalyst for efficient lithium polysulfides (LiPSs) conversion is reported. A special interface structure of RuO_x quantum dots (QDs) anchored on graphdiyne (GDY) nanoboxes (RuO_xQDs/GDY) is prepared to enable strong Ru‐to‐alkyne π backdonation, which effectively regulates the d‐electron structures of Ru centers to promote the d–p orbital hybridization between the catalyst and LiPSs and significantly boosts the catalytic performance of RuO_xQDs/GDY. The strong affinity with Li ions and fast Li‐ion diffusion of RuO_xQDs/GDY also enable ultrastable Li metal anodes. Thus, S@RuO_xQDs/GDY cathodes exhibit excellent cycling performance under harsh conditions, and Li@RuO_xQDs/GDY anodes show an ultralong cycling life over 8800 h without Li dendrite growth. Lithium‐sulfur (Li–S) full cells with S@RuO_xQDs/GDY cathodes and Li@RuO_xQDs/GDY anodes can deliver an impressive areal capacity of 17.8 mA h cm⁻² and good cycling stability under the practical conditions of low negative‐to‐positive electrode capacity (N/P) ratio (N/P = 1.4), lean electrolyte (E/S = 3 µL mg⁻¹), and high S mass loading (15.4 mg cm⁻²).