The design and fabrication of ultrahigh-performance supercapacitor electrodes from bimetallic PBA/Ni(OH)2/Co3O4/NF quaternary hybrid nanocomposites

This is the first case in which quaternary hybrid nanocomposites, NiMPBA/Ni(OH)2/Co3O4/NF (M = Co, Fe), were designed to be fabricated successfully via a step-by-step synthetic strategy. They, as freestanding supercapacitors, exhibit excellent electrochemical performance with a remarkable specific capacitance (643.6 C g−1 at 1 mA cm−2) and cycling stability. In addition, asymmetric supercapacitor (ASC) systems with as-prepared NiFePBA/Ni(OH)2/Co3O4/NF as the positive electrode and active carbon (AC) as the negative electrode were also successfully fabricated and delivered an energy density of 23.4 W h kg−1 and power density of 570 W kg−1. This work highlights the design strategy of quaternary hybrid nanocomposite materials for efficient energy storage devices.