Construction of interfacial amorphous/crystalline multi-metal sulfide heterostructures and jellyfish-derived activated carbon for high-energy density hybrid pouch supercapacitors

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.