Prussian blue analogue-derived hollow structured CoP/Fe2P nanocubes on Co9S8 nanoarrays as an advanced battery-type electrode material for high-performance hybrid supercapacitors

Abstract

A rationally intended electrode material with evolved structure and composition enrichment is highly essential for optimizing the electrochemical performance for the superior charge storage demand of supercapacitors. In this report, we designed and synthesized cobalt-iron phosphide (CFP) hollow/porous nanocubes anchored on cobalt sulfide (CS) nanosheets (NSs) (i.e., CS@CFP) on nickel foam by a hydrothermal process, followed phosphorylation process, as well as a facile wet chemical route. The hollow/porous nanocube (three-dimensional (3D))-on-NS (2D) hybrid array structure and phosphorous incorporation in CS@CFP could significantly enhance the accessibility of electrolyte ions and the electrochemical kinetics of charge as well as redox-active sites. The resultant CS@CFP electrode demonstrated superior charge storage properties with an areal capacity value of 828.6 µA h cm−2 at 8 mA cm−2 and a better rate performance than the other electrodes. Moreover, its practicability was also verified by fabricating a hybrid electrochemical cell (HEC). The fabricated HEC displayed a notable areal capacity value of 681.4 µA h cm−2 at 10 mA cm−2 with a superior rate performance of 74.6 % even at 70 mA cm−2. Besides, the HEC displayed maximum energy and power density values of 0.528 mW h cm−2 and 60.4 mW cm−2, respectively. Also, the HEC confirmed its charge storage ability by energizing different portable electronic devices. © 2025 Elsevier Inc.