Prussian‐Blue Analogue‐Derived Hollow Structured Co3S4/CuS2/NiS2 Nanocubes as an Advanced Battery‐Type Electrode Material for High‐Performance Hybrid Supercapacitors

The facile and cost-effective fabrication of hybrid nanostructures comprised of hollow mixed metallic chalcogenides has attracted growing interest in the development of high-performance energy storage devices. Herein, multi-component (nickel-cobalt-copper-sulfides/selenides (NCCS/NCCSe)) hollow nanocubes (HNCs) are prepared via a single-step sulfurization/selenization process. The NCCS material shows interior HNCs, and the NCCSe material exhibits slightly formed porous cubes. Both the prepared materials demonstrate higher charge storage performance than the precursor NCC NCs owing to the improved surface morphology and addition of sulfur and selenium ions. Particularly, the NCCS HNCs electrode reveals superior specific capacity (capacitance) (70.32 mAh g-1 (666.20 F g-1 ) at 5 mA cm-2 ) along with excellent cycling stability of 108.6% even after 10 000 cycles. Interestingly, the electrode delivers a good rate capability of 83.5% at a high current density of 20 mA cm-2 . The feasibility of the battery-type NCCS HNCs as a positive electrode is explored by constructing an aqueous electrochemical hybrid capacitor (AEHC). The AEHC exhibits maximum energy and power densities of 23.15 Wh kg-1 and 7899.08 W kg-1 , respectively. Remarkably, it demonstrates superior long-life cycling stability even after 10 000 cycles (120.6% retention). The suitability of AEHC for practical application is also tested by driving electronic devices.