Influence of Subnanoporous Carbon with a Customizable Pore Structure on Aqueous Supercapacitors

Abstract

The pore structure of carbon-based materials is one of the determinants of supercapacitor performance. In this paper, a series of subnanoporous carbon materials are prepared by one-step carbonization of interpenetrating polymers, which could not only accurately control the pore size at 0.6 nm but also change the degree of polymerization of dimethylamine formaldehyde resin. The pore structure parameters of the proportion of subnanometer micropores are regulated through carbonization. The pores of the prepared porous carbon are extracted by pyrolysis of sodium polyacrylate, synergistic pore-forming effect of generated gaseous species, and sodium salt etching. Among them, C-IPN3 possesses the highest total specific surface area (575 m2 g–1). The S BET of subnanometer pores is as high as 93.4% with good specific capacitance of 239.1 F g–1 at 0.5 A g–1. In alkaline electrolyte, it shows 82% of capacity retention of its initial capacitance with 20-fold expansion of current density indicating excellent rate capability. In addition, speaking of a symmetric capacitor device, the results show an energy density of 7.57 W h Kg–1 at a power density of 62.5 W Kg–1. This simple and low-cost device, which achieves effective regulation of the pore structure, could also be used as the advanced electrode for supercapacitors.