Harnessing the synergy in the core-shell architecture of ZIF-derived nanoporous carbon and conducting polymer for supercapacitive aspects

Abstract

The advancement of electrode materials that integrate electrochemical double-layer capacitance and pseudo-capacitance is pivotal for enhancing capacitance output, as it merges the edges of both energy storage mechanisms in a cohesive and efficient system. This study develops a core-shell heterostructure composed of ZIFderived carbon and a conducting polymer, designed to harness the synergistic properties of both materials. Initially, 3D nanoporous carbon (NPC) is synthesized through the pyrolysis of ZIF-67. Subsequently, polyaniline (PANI) is coated onto the surface of the ZIF-derived NPC through a chemical oxidative polymerization process. The core-shell heterostructure of PANI@NPC reveals excellent supercapacitive properties owing to its 3D core-shell structure, where the outer shell of PANI exhibits the redox reaction and easy access of electrolyte ions to the inner core of carbon. Whereas, the carbon core serves as a template for the growth of PANI nanofibers to enhance mechanical strength and chemical stability. The PANI@NPC demonstrates the specific capacitance of 1576 F g-1 at a current density of 4 mA cm-2 in a three-electrode configuration. The fabricated solid-state symmetric supercapacitor device also achieves a remarkable power density of 5.25 kW kg-1 at an energy density of 42.3 Wh kg-1.