Unveiling the Nanoarchitectonics of Interfacial Electronic Coupling in Atomically Thin 2D WO₃/WSe₂ Heterostructure for Sodium‐Ion Storage in Aqueous System

Abstract

Aqueous sodium (Na+) ion storage systems face challenges due to sluggish adsorption and diffusion of Na+ ions with larger size, hindering their potential for stationary applications. This issue is addressed by evolving the interfacial electronic coupling in atomically thin 2D WO3/WSe2 heterostructure for efficient Na+ ion storage. Density functional theory (DFT) analysis elucidates the superior charge storage capability for the WO3/WSe2 heterostructure facilitated by the charge transfer from the WO3 – WSe2 (002). The charge transfer from the W‐5d and O‐2p orbitals of WO3 to the valence W‐5d and Se‐4p orbitals of the WSe2 (002) surface boosts the electronic conductivity. As a result, the WO3/WSe2 electrode demonstrates exceptional Na+ ion storage, with a specific capacitance of 378.1 F g−1 at 1 A g−1, excellent rate capability, and long‐lasting cycling durability. The full cell comprising WO3/WSe2 as the negative and MnSe/MnSe2 as the positive electrode achieved a peak energy density of 82.1 Wh kg−1 at a power density of 1873.5 W kg−1, along with high rate capability and long‐cycle durability. Insights gained from this study pave the technique for the rational design and optimization of the interfacial electronic features in 2D heterostructures for next‐generation energy storage devices with enhanced performance and stability.