Fabrication of Hierarchical MOF-Derived NiCo₂S₄@Mo-Doped Co-LDH Arrays for High-Energy-Density Asymmetric Supercapacitors

Abstract

The rational fabrication of composite structures made of mixed components has shown great potential for boosting the energy density of supercapacitors. Herein, an elaborate hierarchical MOF-derived NiCo2S4@Mo-doped Co-LDH arrays hybrid electrode was fabricated through a step-wise method. By leveraging the synergistic effects of a uniform array of NiCo2S4 nanowires as the core and an MOF-derived porous shell, the NiCo2S4@Mo-doped Co-LDH hybrid electrode demonstrates an exceptional specific capacitance of 3049.3 F g−1 at 1 A g−1. Even at a higher current density of 20 A g−1, the capacitance remains high at 2458.8 F g−1. Moreover, the electrode exhibits remarkable cycling stability, with 91% of the initial capacitance maintained after 10,000 cycles at 10 A g−1. Additionally, the as-fabricated asymmetric supercapacitor (ASC) based on the NiCo2S4@Mo-doped Co-LDH electrode achieves an impressive energy density of 97.5 Wh kg−1 at a power density of 835.6 W kg−1. These findings provide a promising approach for the development of hybrid-structured electrodes, enabling the realization of high-energy-density asymmetric supercapacitors.

Keywords

• asymmetric supercapacitors
• NiCo₂S₄
• Co-LDH
• cross-linked
• Mo-doped
• high energy density