Effect of Thermal Treatment Temperature on Electrochemical Behaviors of Ni/trimesic Acid-based Metal Organic Frameworks Electrodes for Supercapacitors

Ni-benzene-1,3,5-tricarboxylic acid based metal organic frameworks were successfully synthesized by hydrothermal method and thermally treated at various temperature. The electrochemical performance of composites was investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. Among all prepared composites, the samples annealed at 250 degrees C showed the highest capacitance with a low resistance, and high cycle stability. It was possible to obtain the low electrical resistance and high electric conductivity of the electrode by improved microstructure and morphology after the thermal annealing at 250 degrees C. The samples annealed at 250 degrees C also displayed the maximum specific capacitance with a value of 953 Fg(-1) at a current density of 0.66 A/g(-1) in 6 M KOH electrolyte. Moreover, a 86.4% of the initial specific capacitance of the composite was maintained after 3,000 times charge-discharge cycle tests. Based on these properties, it can be concluded that the composite could be applied as potential supercapacitor electrode materials.