Realizing High-Performance Li/Na-Ion Half/Full Batteries via the Synergistic Coupling of Nano-Iron Sulfide and S-doped Graphene

Abstract

Iron sulfide (FeS) anodes are plagued by severe irreversibility and volume changes that limit cycle performances. Here, a synergistically coupled hybrid composite, nanoengineered iron sulfide/S-doped graphene aerogel, was developed as high-capacity anode material for Li/Na-ion half/full batteries. The rational coupling of in situ generated FeS nanocrystals and the S-doped rGO aerogel matrix boosted the electronic conductivity, Li⁺ /Na⁺ diffusion kinetics, and accommodated the volume changes in FeS. This anode system exhibited excellent long-term cyclability retaining high reversible capacities of 422 (1100 cycles) and 382 mAh g^-1 (1600 cycles), respectively, for Li⁺ and Na⁺ storage at 5 A g^-1 . Full batteries designed with this anode system exhibited 435 (FeS/srGOA||LiCoO₂ ) and 455 mAh g^-1 (FeS/srGOA||Na_0.64 Co_0.1 Mn_0.9 O₂ ). The proposed low-cost anode system is competent with the current Li-ion battery technology and extends its utility for Na⁺ storage.

Keywords: S-doping; batteries; electrode materials; long-term cycling; nanoarchitecture.