Triazine based polyimide framework derived N-doped porous carbons: a study of their capacitive behaviour in aqueous acidic electrolyte

Nitrogen-doped porous carbon materials have been synthesized from nitrogen and oxygen rich triazine based polyimide (TPI-P/TPI-N) frameworks using ZnCl2 as an activating agent at different temperatures (600 and 700 degrees C) for electrochemical energy storage applications. The morphology and structural features of the materials were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), N-2 adsorption/desorption isotherms, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopic techniques. The resultant carbon materials possess large specific surface area and rich nitrogen contents. In particular, the material obtained at 700 degrees C (TPI-P-700) exhibits a surface area of up to 1650 m(2) g(-1) and a nitrogen content of up to 6.3%, and shows an excellent specific capacitance of 423 F g(-1) in an aqueous acid electrolyte (1 M H2SO4) in a three electrode system. Moreover, the material also demonstrates nearly 100% capacitance retention up to 10000 charge-discharge cycles. A symmetrical supercapacitor device assembled using TPI-P-700 as an active material delivered an energy density of 10.5 W h kg(-1) at 0.5 A g(-1).