2D-on-2D Mott–Schottky 1T-MoS2 Heterostructure with Rich Defects and an Expanded Interlayer for Enhanced Zn-Storage

Abstract

Layered transition metal dichalcogenides, especially MoS₂, have great potential as cathodes for aqueous zinc ion batteries (AZIBs) due to their flexible interlayer structural characteristics. However, the unsatisfactory diffusion efficiency of Zn²⁺ in pristine MoS₂ severely restricts its application. Herein, a strategy of interfacial heterostructure construction and surface defect fabrication is employed to introduce metallic VS₂ with matchable formation energies into MoS₂ (designated as HD-MVS), thereby exposing active interfaces, increasing the 1T-phase proportion, and expanding interlayer spacing. The GITT, rate-scan CV, and multiple ex situ characterizations confirm that HD-MVS possesses a rapid and reversible Zn²⁺ insertion/extraction ability. Therefore, HD-MVS exhibits satisfactory rate performance (265 mA h g^–1 at 0.1 A g^–1 and 116 mA h g^–1 at 6.0 A g^–1), long cycle durability (92.47% capacity retention over 5000 cycles at 1.0 A g^–1), and stable flexible electrochemistry (91.68% capacity retention after 2000 cycles under 180°), providing assistance for the widespread application of AZIBs in the future.