Hydrogen bubble template fabricated nano-architecture quaternary dendritic sulfide as cathode and electro-etched carbon fiber paper as anode electrode for total novel binder-free asymmetric supercapacitors

Abstract

A novel electrode consisting of 3D porous nickel‒cobalt‒copper sulfide dendritic structures is synthesized, in which, for the first time ternary Ni–Co–Cu foam is constructed through hydrogen bubble template and followed by sulfidization via a hydrothermal reaction in thiourea. The 3D, porous Ni–Co–Cu dendritic sulfide electrode exhibits a high specific capacitance of 1203.75 F g−1 (0.963 F cm−2) at current of 1.0 mA and excellent cycling stability, excellent ratability along with high cycle stability. An asymmetric supercapacitor (ASC) using dendritic sulfide structures and reduced electro-etched carbon fiber paper (RECF) as the positive and negative electrodes, respectively is developed. RECF is prepared through electrochemical oxidation process in acidic solution followed by electrochemical reduction, which exhibits a high areal capacitance of 695 mF cm−2 at current of 1.0 mA. The assembled device can be operating reversibly between 0 and 1.6 V and provides high specific capacitance of 178.5 mF cm−2 and an excellent cycling stability of 97.3% after 1000 cycles. This work exploits a pathway to construction of dendritic sulfides of quaternary metal foams that could be used for any flat metal substrate and open a new doorway to quaternary transition metal sulfides electrode materials in energy storage and conversion devices.