Sub-nanopores-containing N,O-codoped porous carbon from molecular-scale networked polymer hydrogel for solid-state supercapacitor

A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole (PPy) hydrogel as a precursor. This design of PPy hydrogel precursor containing molecular-scale grids (diameter similar to 2.0 nm) allows for homogeneous N,O-codoping into the porous carbon scaffold during the pyrolysis process. A subsequent activation step produces activated porous carbons (APCs) with tailored pore structures, which renders the APCs abundant subnanopores on their surface to increase the specific capacitance as extra capacitance sites. Coupled with large specific surface area and abundant heteroatoms, the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor. The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg, which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles. Moreover, this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications. (C) 2020 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

Porous carbons containing sub-nanopores were successfully fabricated using a template-free carbonization-activation route with a novel polypyrrole hydrogel precursor. The resulting activated porous carbons displayed high specific capacitance and energy density, making them suitable for supercapacitors and power sources for electric vehicles.