Synthesis of nickel-cobalt-aluminum/graphene nanocomposite and its electrochemical performance as supercapacitor

In this study, using Hydrothermal method, electrodes were synthesized to be used as supercapacitors. Using the alteration ratio of Al+3/Co+2/Ni+2 metal ions, Al0.5Co0.5Ni2O4 electrode with a molar ratio of 1:1:2 for Al+3/Co+2/Ni+2 ions, the highest capacitance was obtained, which was called the NiCoAl electrode. With the change of time (2, 5 and 20 hours) and the temperature of the hydrothermal process (150 and 180 °C), the performance of the manufactured electrodes changed, and as a result, the NiCoAl electrode synthesized at 150 °C for a period of 5 h, the capacity of 1473 F g-1 in the current density of 8 A g-1 was obtained as the best electrode made. By adding graphene to the electrode's constituent materials, the NiCoAl-rGO electrode, synthesized at 150 °C showed a maximum capacity of 2364 F g-1 at a current density equal to 8 A g-1. With the help of structural analysis of X-ray diffraction test (XRD) and infrared spectrum (FTIR), the presence of constituent materials in the structure was confirmed, and the presence of graphene in the NiCoAl-rGO electrode structure was observed. In order to determine how electrochemical performance works, the electrodes were subjected to cycles (CV), Galvanostatic charge and discharge (CD), and electrochemical impedance (EIS) tests.