Abstract: Strategic design and synergistic interactions between the electrodes and electroactive materials profoundly influence the energy storage efficiency of supercapacitor devices. Herein, we present the interfacial engineering of CoMoS₄-NiS₂ with a well-defined construction of amorphous/crystalline hetero-phases deposited on carbon cloth using a hydrothermal technique. The optimal in-situ growth of CoMoS₄-NiS₂@CFC boasts an impressive areal capacity of 1341 mC cm^-2 and retains ∼91 % capacity after 5000 cycles, attributed to the synergy effect and improved conductivity of multi-metallic sulfide ions over the CFC substrate. Density functional theory (DFT) reveals the metallic nature of CoMoS₄-NiS₂@CFC and favorable OH^- ion adsorption energy of -4.35 eV, enhancing its charge storage capabilities. Furthermore, a hybrid supercapacitor (HSC) and Pouch HSC are assembled utilizing the CoMoS₄-NiS₂@CFC as a positrode and marine waste jellyfish-derived AC as a negatrode with an aqueous electrolyte. The HSC and PHSC demonstrate superior specific energies of 51.99 and 58.4 W h kg^-1, respectively, along with corresponding specific powers of 800 and 780 W kg^-1, maintaining robust stability of ∼90 % stability over 10000 cycles. Additionally, the HSC and PHSC have successfully illuminated several light-emitting diodes (LEDs) demonstrating superior energy storage performance. This work advances the design of hetero-phase multi-metal sulfides, paving the way for high-performance supercapacitor devices.

Key words: Heterostructure, Multi-metal sulfide, Density functional theory, Marine waste Jellyfish activated carbon, Pouch hybrid supercapacitor