Synthesis of Nitrogen Doped Porous Carbons from Sodium Carboxymethyl Cellulose and the Capacitive Performance

We demonstrate a direct carbonization method to prepare porous carbons as electrode materials without an activation process, using sodium carboxymethyl cellulose (NaCMC) as the carbon source, which are further doped with varying mass ratios of nitrogen. From X-ray photoelectron data, the nitrogen species include pyridinic N, graphitic N, and pyrrolic N. The relative mass ratios of NaCMC and CO(NH2)(2) affect the nature of the nitrogen species, dopant dosages as well as specific surface areas and pore structures. The cyclic voltammetry and galvanostatic charge-discharge measurements in 6 mol . L-1 KOH aqueous solutions reveal that the specific surface areas and capacitive performances improve after nitrogen-doping. Taking carbon-N-1:20 as example, its S-BET can reach 858 m(2) . g(-1), which is higher than that of carbon-blank (463 m(2) . g(-1)) and the corresponding specific capacitance greatly improves from 94.0 to 156.7 F . g(-1), respectively. The present carbons are excellent electrode candidates for high-rate electrochemical capacitors.