Comparative study of ternary metal chalcogenides (MX; M= Zn–Co–Ni; X= S, Se, Te): Formation process, charge storage mechanism and hybrid supercapacitor

In the recent past, metal chalcogenides are achieving predominance as potential electrode materials in energy storage devices. Despite that, trimetallic lower chalcogenides (selenides and tellurides) are barely retrieved and their inherent charge-storage mechanism is still far from deep understanding. Herein, a hydrothermal/solvothermal strategy is formulated to successfully fabricate the highly efficient Zn–Ni–Co sulfide/selenide/telluride (Zn–Ni–Co–S/Se/Te) electrode materials. Inherent development of Zn–Ni–Co–S/Se/Te is cautiously set forth with parallel structure-evolution examinations. With systematic electrochemical and physicochemical investigations, inherent energy storage mechanism of trimetallic chalcogenides is persuasively disclosed in the aqueous KOH electrolyte. Zn–Ni–Co–Se electrode material exhibits competitive high specific capacity of 1239.7 C g⁻¹ at a current density of 1 A g⁻¹. Moreover, the hybrid supercapacitor (HSC) device is designed and delivers a high energy density and power density. More remarkably, the new perceptions and electrode layout hold profound agreement in material synthesis approaches and deep insight of charge-storage process of the novel promising capacitive materials for the next-generation energy storage devices.