Single Atom‐Particle Tandem Catalysis Enables Enhanced Desolvation Kinetics for Low‐Temperature Li‐S Batteries

Abstract The commercial implementation of lithium‐sulfur (Li‐S) batteries is plagued by the sluggish kinetics of interfacial Li(solvent) _x ⁺ desolvation and successive redox conversions of sulfur species, exhibiting high tandem barriers. Herein, the tandem catalyst consisted of single Fe atom and Fe ₃ C nanoparticles on porous carbon sheet (SAPTC@PCS) is initially proposed and developed. As illustrated in theoretical simulation, the neighboring Fe ₃ C further tunes the electronic density and affects related coordination structure of atomically distributed iron for reinforcing catalytic efficiency. The as‐prepared SAPTC@PCS facilitates the dissociation of Li(solvent) _x ⁺ to release more isolated Li ⁺ to participate in the subsequent polysulfide redox conversions by decreasing the desolvation/diffusion barriers, as revealed by in‐situ Raman, time‐of‐flight second ion mass spectroscopy, electronic microscope and X‐ray measurements. Consequently, the cell with SAPTC@PCS delivers a high capacity‐retention over 1000 cycles and high rate up to 3 C. Impressively, under the practical mass loading of 6 mg cm ⁻² , the cell stabilizes the capacity of 4.59 mAh cm ⁻² after 90 cycles, and a desirable capacity of 804.8 mAh g ⁻¹ after 100 cycles is achieved even being exposed to low temperature of 0 °C, demonstrating the feasibility of single atom‐particle catalysts for tandem catalysis in Li‐S batteries.