High-entropy transition metal disulfide colloid clusters: synergistic atomic scale interaction and interconnected network for ultra-stable potassium ion storage

Abstract

High-entropy metal disulfide (HES2) colloid clusters were synthesized through a two-step templated solvothermal method for used as anode materials for potassium-ion storage devices. HES2’s large configuration entropy stabilizes its crystal structure and promotes chemical diversity by introducing multiple cations, thus reducing the impact of the shuttle effect, retaining active materials and extending cycling life up to 1800 cycles. During cycling, crystalline-amorphous grain boundaries formed in situ enhance electrochemical reaction activities and ensure the exposure of active sites. Elements with lower electronegativity allow S to bring more negative charges, improving the electrostatic force between S and K+ and enabling better anchoring of potassium polysulfide. Meanwhile, the retained close-packed cluster structure of HES2 provides a large contact area to accelerate the reduction reaction of the electrolyte in the sphere during the repeating K+ insertion/extraction. We further demonstrate the excellent performance of HES2 anodes on practical potassium-ion full battery and hybrid capacitor applications. The pioneering concept in atomic compositional engineering and structural design of transition metal sulfide electrodes presented in this work marks a significant step forward in the development of chalcogenide electrode systems for energy storage devices.