Electrodeposited CuxFe3-xSe4 nanoheterostructure arrays on carbon cloth as a binder-free faradaic negative electrode for asymmetric supercapacitors

Abstract

Extensive research is being conducted worldwide to design and develop novel high-performance electrodes for supercapacitors (SCs) being a viable alternative to fossil fuels, dealing with the challenges of looming energy crisis and environmental issues globally. Herein, the design and synthesis of novel binder-free CuxFe3-xSe4@carbon cloth (CFS@CC) nanoheterostructure array electrode materials with tunable copper (Cu)/iron (Fe) stoichiometric ratios are demonstrated via a one-step room-temperature chronoamperometric (potentiostatic) electrodeposition process and their electrochemical characteristics as a promising faradaic negative electrode for SCs are explored systematically. The effect of Cu/Fe stoichiometric ratios on the morphological property and electrochemical performance of different CFS@CC array electrodes is thoroughly investigated to realize the sufficiently reaping synergistic benefits of Cu and Fe ions. Moreover, following a kinetic matching strategy, the optimized CFS@CC arrays as a negative electrode are assembled with the faradaic Ni3Se2/NiSe2@CC nanosheet arrays as a positive electrode to fabricate a novel asymmetric supercapacitor (ASC) device (Ni3Se2/NiSe2@CC//CFS-1.5@CC) which is operable in a large and stable potential window of 1.6 V and exhibits a high energy density of 84.8 Wh kg−1 at a power density of 664 W kg−1 with an excellent long-term electrochemical cycling stability. Some real-life applications of the as-fabricated ASC device are displayed to ensure its practicality.