Decoupling Redox Kinetics with Complementary d-Band Catalysis for High-Performance Lithium–Sulfur Batteries

Advancing our understanding of heterogeneous catalysis is critical for resolving the kinetic challenges in lithium-sulfur batteries (LSBs). Herein, we propose a theoretical framework: the dual d-band model, which extends the classical d-band center theory by introducing two distinct catalytic sites with complementary d-band centers. Specifically, by strategically integrating two distinct catalytic sites with complementary d-band centers, where one aligns with the lowest unoccupied molecular orbital (LUMO) of sulfur species to optimize the sulfur reduction reaction (SRR) and the other aligns with the highest occupied molecular orbital (HOMO) to accelerate the sulfur evolution reaction (SER), the redox kinetics of sulfur species is effectively balanced. To verify this hypothesis, we developed a dual-site catalyst, Mn-RuO2 (MRO), featuring Ru sites tailored for SRR and the supplementary Mn sites optimized for SER. Leveraging this dual-site synergy, the MRO-based cell achieved superior performance under limited electrolyte conditions. This work presents a promising strategy to regulate sulfur redox reactions for high-performance LSBs.