Effect of the oxygen functional groups of activated carbon on its electrochemical performance for supercapacitors

By Xiran Li, Yang-hui Jiang, Peijia Wang, Yan Mo, Wende Lai, Zhengjiong Li, Runzhen Yu, Yuting Du, Xin-ren Zhang, Yong Chen. Carbon, 2020

163 citations recorded by the source corpus.

Abstract Oxygen functional groups on a commercial activated carbon were modified by (NH4)2S2O8 oxidation and subsequent annealing at different temperatures. The effects of the surface modification on the electrochemical performance as supercapacitor electrodes were investigated by XPS, FTIR, argon adsorption and electrochemical tests. Results indicate that the oxygen functional groups, especially carboxyl and carbonyl groups improved the wettability of the pore surfaces, increased the electrolyte diffusion rate into the electrode and increased the specific capacitance by an additional pseudo-capacitance in a 6mol/L KOH aqueous electrolyte. An excess oxygen content blocked the pores, leading to poor electrochemical performance, but annealing at 300 °C in an inert atmosphere increased the specific capacitance and improved the rate performance in a 6mol/L KOH aqueous electrolyte. In a 1mol/L Et4NBF4/PC organic electrolyte, however, oxygen functional groups introduced by (NH4)2S2O8 oxidation reduced the specific capacitance and annealing at 700 °C to reduce their content effectively increased the specific capacitance.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/4cc93c8285de58456c9515386bce8acd0815e11f