Integrating Effect of Surface Modification of Microporous Carbon by Phosphorus/Oxygen as well as the Redox Additive of p-Aminophenol for High-Performance Supercapacitors

In present work, commercial microporous carbon materials are modified on the surface with phosphorus/oxygen species by using phytic acid as sole dopant, which plays crucial effect on the carbon structure, wettability, electrical conductivity, and capacitive behaviors. It reveals that with increasing the content of heteroatoms, the porosity and contact angle are decreased but the conductivity turns much larger. Furthermore, p-aminophenol is introduced to serve as redox additive, which can produce more active surface sites by forming hydrogen bond and complexation with the surface functional groups, further providing additional pseudo-capacitance. As a result, the energy density of carbon sample by phosphorus/oxygen doping in 1 m H2SO4 electrolyte with p-aminophenol is as high as 9.2 Wh kg(-1), which is 2.6 than that of pristine carbon. What is more, in terms of the simple operation and effective performance, the integration of surface modification toward carbon materials and redox additive can be favorable for largely enhancing the supercapacitor performance.