MoF-derived CuCo2S4@FeS2 nanohybrids for supercapacitor applications

Abstract

Metal-organic framework-derived CuCo₂S₄ nanomaterials are a potential target for supercapacitors, because of their structural and electrochemical features. In this study, we constructed nanohybrids of MoF-derived CuCo₂S₄ nanoparticles@FeS₂ nanoplates using a solvothermal method. The presence of conductive carbon in the MoF-derived CuCo₂S₄ nanoparticles increases their electrical conductivity. MoF-derived CuCo₂S₄ exhibited a nanoparticle morphology and FeS₂ exhibited a nanoplate morphology in HR-TEM resutls. The good surface area, porous structure with increseaed pore diameter of the hybrids of the CuCo₂S₄@FeS₂ are offers the good super-capacitor performances. Nanostructured electrode materials have shortened ion diffusion paths and larger the contact areas for electrolyte ions. In a conventional three-electrode system, the hybrids of the CuCo₂S₄@FeS₂ electrode delivered a capacity of 400.10 C g^-1 at 1A g^-1. Even, at a high current density of 10 A g^-1, it delivered 210.19 C g^-1 with an exceptional rate capability. Herein, the long-standing ability study demonstrated good capacity retention of 89.41 % after 5500 cycles. Furthermore, the AC//CuCo₂S₄@FeS₂ device has a working voltage window of 0 - 1.5 V, and delivered the high capacity of 204.77 C g^-1 @ 1 A g^-1. After 10000 cycles, 90.01% capacity was retained at 5 A g^-1 with a coulombic efficiency of 95.63 %. AC//CuCo₂S₄@FeS₂ exhibited a maximum energy density of 63.99 Wh kg^-1 at a power density of 1125 W kg^-1 (1 A g^-1), when increasing the current density to 5A g^-1, the device maintained its energy/power density of 17.61 Wh kg^-1 / 5625 W kg^-1, respectively. Consequently, the exceptional characteristics exhibited by hybrids of CuCo₂S₄@FeS₂ have established them as dependable contenders for implementation in supercapacitors.