Effect of CO₂ temperature on porous textures and electrochemical performance of N-C composite carbon aerogels

The physical structure of N-doped carbon aerogel(N-CA) is modified with CO2 technology. The effect of activation temperature on the porous texture and the electrochemical performance of activated N-doped carbon aerogel(N-ACA) as electrode material of supercapacitors are investigated. The porous structure and elemental composition of the N-doped aerogels are tested by nitrogen adsorption at 77 K, X-ray photoelectron spectroscopy (XPS) and elemental analysis. With further increasing of the activation time,the surface area of N-ACA increases, and the concentration of nitrogen decreases continually but not the pyrrolic. The electrochemical performance of N-doped carbon aerogels is confirmed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that the appropriate porous texture and the concentration of pyrrolic have crucial effect on the electrochemical performance of the electric double-layer capacitors. The specific capacitance of the 950-N-ACA electrode obtained from cyclic voltammetry measurement in 6 molL-1 KOH aqueous solution at a scan rate of 5 mVs-1 is up to 267.4 Fg-1 and loses about 1.5% after 1000 charge-discharge cycles.