Enabling Wide‐Temperature Range Li‐S Batteries via Asymmetric‐Coordinated Titanium Sites‐Implanted Graphene Single‐Atom Electrocatalysts

ABSTRACT High‐performance lithium‐sulfur batteries capable of operating under harsh environmental conditions have garnered significant attention, yet they still confront two critical challenges: sluggish polysulfide redox reaction kinetics at low temperatures and the persistent shuttle effect of lithium polysulfides at elevated temperatures. Herein, a single‐atom catalyst featuring an asymmetric Ti ₁ ‐O ₅ configuration (Ti‐rGO) supported by reduced graphene oxide is designed to act as an efficient host catalyst for lithium‐sulfur batteries. Experimental and theoretical calculations reveal that the Ti ₁ ‐O ₅ configuration in Ti‐rGO is capable of tuning the electronic properties of rGO. Such a tailored electronic structure with an optimized Fermi level accelerates charge transfer and further enhances adsorption energy and conversion kinetics for lithium polysulfides. The 2D porous nanostructure of Ti‐rGO provides a physical barrier for the shuttle effect and an open framework to efficiently boost the utilization of sulfur species. Lithium‐sulfur batteries employing Ti‐rGO/S cathodes demonstrate exceptional rate capability (761 mAh g ⁻¹ at 5 C) and cycling stability (low capacity decay of 0.018% per cycle over 1000 cycles at 2 C) under ambient conditions. With a high sulfur loading of 9.2 mg cm ⁻² and lean electrolyte usage of 5.8 μL mg ⁻¹ , the Ti‐rGO/S cathodes still achieve a remarkable areal capacity of 10.65 mAh cm ⁻² . Notably, even over a wide temperature range (−25°C–70°C), the lithium‐sulfur batteries based on Ti‐rGO/S cathodes still maintain stable cyclic performance at 2 C. This research demonstrates that Ti‐rGO‐based electrocatalyst systems can facilitate the realization of temperature‐resilient lithium‐sulfur batteries capable of withstanding both cryogenic and elevated temperature conditions.