Nitrogen-doped carbon derived from composite of phenolic and amino foam: Effect of synthesis processes on physicochemical properties and super-capacitive performances

Phenolic resin was thermally cured on the melamine-based amino foam fiber to construct a nitrogen-containing composite. By employing the composite as the precursor, nitrogen doped microporous carbons were synthesized by two process schemes. One process was two-step of pre-carbonization and further activation (TNC). Another route was one-step of simultaneous activation and carbonization (ONC). Physicochemical properties of resulting carbons were characterized, and super-capacitive performances were also examined. Specific surface area of TNC and ONC were 1657 and 1223 m2 g−1, respectively. The doped nitrogen in the corresponding carbons were determined to be 2.6 and 3.1 at.%. Using the TNC and ONC as electroactive materials, in a three-electrode test configuration in 6.0 M KOH aqueous electrolyte, the electrode harvests the specific capacitance of 316.4 and 303.8 F g−1 at 1.0 A g−1 current density, respectively. When the current density increased to 10 A g−1, retention rates of the corresponding specific capacitance were 88.7 and 85.9%, respectively. In the symmetric-electrode system in aqueous electrolyte, an electrode enclosed the TNC exhibited a specific capacitance of 269.7 F g−1 at the current density of 0.5 A g−1. The assembled simulated supercapacitor delivered an energy density of 9.6 W h kg−1 with the power density of 124.9 W kg−1. The purpose of the present work was to clarify the effect of preparation procedures on the physicochemical properties and super-capacitive performances of porous carbons. Findings demonstrated that the porous carbon prepared by two-step of pre-carbonization and then reactivation showing larger specific surface area and better super-capacitive performance than that of synthesized via one-step of in situ carbonization and activation.