A new squaraine-triazine based covalent organic polymers as electrode material with long life and high performance for supercapacitor

A new two- dimensional covalent organic polymers material (ST-1) was synthesized by the condensation of squaric acid and melamine. The preparation is simple and cheap. Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption, powder X-ray diffraction (XRD), scanning electron microscopy(SEM) and thermogravimetric analysis(TGA) were employed to characterize the structure and properties of ST-1. This material presents the highest specific capacitance value of 177.6 F∙g-1 at current density of 0.3 A g-1 in three electrode configuration in the 6 M potassium hydroxide electrolyte. Retention rate of specific capacitance can be maintained about 60.24 % when the current density was increased by 50 times. It is worth mentioning that ST-1 also demonstrates about 94 % capacitance retention after 10000 galvanostatic charge-discharge cycles.