Facile Synthesis of Polymeric Schiff Base Metal Complex as Electrode for High-performance Supercapacitors

Abstract

This research presents a simple method for preparing poly Schiff base ligand (L) and its metal complex (M–L, M = Al3+, Cr3+, Zn2+) as electrode materials for supercapacitors, which is derived from mixing terephthalaldehyde, m-phenylenediamine and metal nitrate in ethanol at room temperature. Compared with L, M–L combine the advantages of larger surface area, appropriate mesopore diameter, unique morphology and suitable conductivity. The electrochemical properties of the materials are assessed by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) analysis in 6 M KOH electrolyte. The results show that the electrochemical performance of M–L significantly improve compared with L, especially when the current density is 0.5 A g−1, Al–L displays a superior specific capacitance of 608.6 F g−1. Moreover, the specific capacitance of Al–L still reaches 299.1 F g−1 after 1000 GCD cycles at 10 A g−1, which is higher than the initial capacitance of Cr–L and Zn–L. Moreover, the electrochemical resistance of Al–L is smaller than that of others. Therefore, Al–L will become an attractive material in supercapacitors, and opens the door for further research on various poly Schiff base metal complexes (poly[M(Schiff)]) as electrode materials for supercapacitors.