Thermal Effects on Electrochemical Performance of Copper Oxide Nanoparticles Decorated Amine-Functionalized Graphene Oxide for Ultrahigh Energy Density Supercapacitor with Real-Life Application

The article describes the synthesis of copper oxide decorated amine functionalized graphene oxide (AGO) composites at four different temperatures, i.e., 50, 85, 120, and 155 °C. The process involves the generation of AGO by chemical functionalization and using −NH2 groups to anchor Cu2+ ions via coordinate bonds. Reduction of Cu2+ results in Cu+ on the surface of AGO, which is confirmed by XRD and TEM. The surface composition and amine functionalization of nanocomposites were confirmed by XPS and FTIR analyses. The dielectric measurements display a decrease in dielectric constant with an increase in frequency, for all nanocomposites, signifying better capacitive behavior owing to better polarization. AGC85 displays ultrahigh specific capacitance and energy density values of ∼3890 F/g and 540.71 Wh·kg–1 at 2.0 A/g current density. Interestingly, after 10000 cycles, AGC85 shows excellent capacitance retention of about 85.6%. A solid state supercapacitor device was fabricated with AGC85 (active material), which can supply power for running an LED bulb for 60 min prior to a few minutes of charging. The low-temperature synthesized copper nanoparticle intercalated on amine-functionalized graphene oxide can be scaled up and used in high-performance supercapacitors for real-life applications in energy systems.