A Self-Sacrifice Template Method to Produce FeS Encapsulated into N, S Co-Doped Carbon for Improved Lithium Storage Performance

The development of high-performance transition metal sulfide (TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries (LIBs). In this study, a facile self-sacrifice template method is developed to prepare FeS encapsulated into N, S co-doped carbon (FeS/NSC) composite using melamine-cyanuric acid (MCA) supermolecule as a multifunctional template precursor. The function of MCA supermolecule for material synthesis is explored, revealing its special function as a dispersant, dopant and pore-forming agent. Furthermore, the effect of Fe source dosage on the morphology, structure and composition of the final products is explored. The resultant FeS/NSC-0.1 (where 0.1 represents the mass of added Fe source) exhibits the most optimal proportion, characterized by a good dispersion status of FeS within the NSC matrix, effective N, S co-doping and ample porosity. Benefiting from these merits, the FeS/NSC-0.1 anode demonstrates significantly improved cycling stability and rate capability when compared to the counterparts. Undoubtedly, this work offers a universal method to produce advanced transition metal sulfide/carbon composite electrodes for energy storage and conversion systems.