Fabrication of NiCoAl-layered double hydroxide/N-GO for high energy all-solid-state asymmetric supercapacitors

Abstract Herein, the NiCo2Al-LDH/N-GO electrode was first and successfully synthesized by a simple and environmental-friendly method. The NiCo2Al-LDH/N-GO electrode has a high specific capacitance of 1136.67F g−1 at a current density of 1 A g−1, and the specific capacitance retention rate maintained 90.10% after 5000 cycles at a current density of 10 A g−1. The prepared NiCo2Al-LDH/N-GO electrode has excellent electrochemical performance and cycle performance. In addition, the ASC device was assembled using NiCo2Al-LDH/N-GO as the positive electrode and activated carbon as the negative electrode with KOH/PVA as gel electrolyte. The NiCo2Al-LDH/N-GO//AC asymmetric capacitor exhibits a high energy density of 42.25 Wh kg−1 at a power density of 800 W kg−1 and 11.39 Wh kg−1 at a power density of 8 kW kg−1. Thus, NiCo2Al-LDH/N-GO electrode shows the potential application in energy storage device.