Synthesis of multinary composite (NiMnCuCoS) electrodes: Aqueous hybrid supercapacitors

Supercapacitors can upgrade their energy storage performance through a smart design of the electrode material. The long cyclic life achieved by a synergistic effect of multinary compositions, multinary electroactive composites, has fascinated the interest of researchers in the energy dilemma. This study endeavors the facile solvothermal synthesis of multinary Ni-rich NiMnCuCoS composites at different solvothermal reaction times for end use as a cathode material in aqueous hybrid supercapacitors (HSCs). Among a series of NiMnCuCoS composites, the NiMnCuCoS-4 electrode exhibits a significantly high specific capacity and areal capacitance of 201.64 mAh g−1 and 4.355 F cm−2 at 7 mA cm−2, respectively, and an excellent cycling life (76% capacitance preserved after 10,000 cycles). Furthermore, the as-fabricated aqueous NiMnCuCoS@NF// AC@NF HSC device demonstrates superior energy and power densities of 19.67 Wh kg−1 and 2951.50 W kg−1, respectively, with impressive stability (80% capacitance retention over 10,000 charge–discharge cycles). Therefore, encouraging energy storage performance with innovative pathways allows new possibilities for synthesizing multinary composites as promising candidates for next-generation HSCs.