摘要
Tailoring 1D nanotubes with refined interfacial interactions and optimized adsorption sites presents a highly promising yet challenging strategy for advancing Na/Li-ion batteries(SIBs/LIBs).Herein,the intertwined yardlong bean-like Fe_(9)Ni_(9)S_(16)/FeS heterostructures with sulfur vacancies encapsulated in N-doped carbon nanotubes(3 N-Fe_(9)Ni_(9)S_(16)/FeS-3@CNTs)are controllably synthesized through Fe/Ni-catalyzed pyrolysis of dicyandiamide followed by sulfidation strategies.1D nanotubes with robust outer walls and internal cavity structures shorten the diffusion paths of ions/electrons and buffer volume expansion and aggregation of active materials.The Fe_(9)Ni_(9)S_(16)/FeS heterostructure provides a powerful driving force for charge transfer by forming built-in electric fields,optimizing ion adsorption,while the Fe_(9)Ni_(9)S_(16)features a wider interlayer spacing that allows for frequent Na+/Li+insertion and extraction,thereby enhancing the reaction kinetics within the electrode.Driven by these synergistic factors,the 3 N-Fe_(9)Ni_(9)S_(16)/FeS-3@CNTs demonstrates remarkable electrochemical performance,achieving a substantial reversible capacity of up to 682.1mA h g^(−1)for SIBs at 0.1 A g^(−1)and 782.7 mA h g^(−1)for LIBs at 0.5 A g−1,alongside exceptional cycling stability in SIBs,maintaining 78.7%of its capacity after 1500 cycles at 1 A g^(−1)coupling with the ether-based electrolyte.Employing various electrochemical analyses in conjunction with ex-situ characterization techniques and Density Functional Theory(DFT)calculations,the storage mechanisms and phase transition processes are investigated,elucidating the structure-composition-performance relationships.This work paves the way for a new strategy in designing advanced materials with engineered heterostructures and controllable defects for energy conversion and storage devices.
基金
supported by the program of National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and Future planning(grant number 2022R1A4A1034312,2023R1A2C1007413)
by the Commercialization Promotion Agency for R&D Outcomes(COMPA)grant funded by the Korean Government(Ministery of Science and ICT)(RS-2023-00304764)。
