Mellitic Trianhydride Derived Crystalline and Amorphous Polyimide Networks Exhibit Structure Dependent Electrochemical Properties

The properties and applications of 2D organic materials strongly depend on their structural and morphological features. Herein, under different solvothermal conditions, the reaction is demonstrated between 2,6‐diaminoanthraquinone (ANQ) and mellitic trianhydride (MTA) that results in a thermodynamically‐controlled, mellitic triimide (MTI) based crystalline covalent‐organic framework MTI–ANQ–COF with an ABC‐type interlayer packing and the kinetically‐driven covalent‐organic network MTI–ANQ–CON, which is amorphous. Solid‐state characterization techniques and electrochemical analyses established the structural features of both materials. The symmetric supercapacitors fabricated using crystalline MTI–ANQ–COF exhibited a specific capacitance ( C sp ) of 54 A g −1 , at a constant current density of 1 A g −1 in organic electrolyte, while MTI–ANQ–CON could exhibit nearly half of it (29 A g −1 ). Interestingly, the MTI–ANQ–COF‐based symmetric supercapacitor exhibited relatively better cycling stability (92%) as compared to the MTI–ANQ–CON‐based symmetric supercapacitor (55%) for 10,000 continuous charge–discharge cycles, revealing the fact that crystalline COF exhibits better performance over amorphous CON.