Enhanced Ion/Electron Migration and Sodium Storage Driven by Different MoS_2-ZnIn_2S_4 Heterointerfaces

摘要

Constructing hierarchical structures with heterointerfaces is an effectiveapproach for developing high-efficiency energy-storage anodes for sodium-ionbatteries. In this study, MoS_2@ZnIn_2S_4 nanorods are designed and fabricatedfor structural improvement. Theoretical calculations reveal that there are twodifferent MoS_2-ZnIn_2S_4 heterointerfaces formed by MoS_2 with the Zn and Infacets of ZnIn_2S_4, which generate directional built-in electric fields that provideadditional driving forces for facilitating electron transfer. These two heterojunctioninterfaces, especially the MoS_2-In facet, exhibit enhanced Na~+ adsorptionenergies and reduce Na+ diffusion energy barriers. The multistep reactions ofMoS_2 and ZnIn_2S_4 reveal a synergistic effect that promotes the entire electrochemicalprocess. Furthermore, the synthesized hierarchical nanorods composedof nanosheets offer abundant Na~+-storage sites and multidirectionalmigration pathways and, importantly, accommodate the excessive volumechange. Benefiting from the heterointerfaces and hierarchical structure, thecomposite electrode exhibits excellent electrochemical performance, with highreaction activity and rapid electron/ion diffusion kinetics.