Electrochemical performance of zinc carbodiimides based porous nanocomposites as supercapacitors

Abstract The low energy densities of supercapacitors are generally limited by the used anodes. To develop supercapacitors with high energy densities, metal–organic framework (TRD-ZIF-8) derived honeycomb-like porous zinc carbodiimide (ZnNCN) based nanocomposites (HPZC) surface loaded with graphitized carbon nitride (g-C3N4) are synthesized. After their detailed characterization by means of electron microscopy, spectroscopy and electrochemical techniques, the materials are used to prepare asymmetric supercapacitor cells (HPZC-4//AC ASCs) with HPZC-4 and active carbon as electrodes, which demonstrate power and energy densities as high as 7839 W Kg−1 and 213 Wh Kg−1, respectively. The unique honeycomb-like porous structure of HPZC loaded with a 2D material (g-C3N4) improves charge/mass transport efficiency and reduces ion diffusion resistance, contributing to a specific capacitance of 779 F g−1 at a current density of 3 A g−1. The study thus presents a new way to design transition metal carbodiimide materials and assesses their potential application as electrodes in asymmetric supercapacitors.