Honeycomb-like N-doped porous carbon derived from poly(Schiff-base) as an electrode material for high-performance supercapacitor

In the design of carbon-based electrode materials, the introduction of heteroatoms and fabrication of the hierarchical porous structures are two important strategies to improve the performance of supercapacitors. In this investigation, based on the dispersion polymerization of 1,2,4,5-benzenetetramine tetrahydrochloride and terephthalaldehyde in ethanol, followed by etching with KOH and carbonizing at 500–800 °C of the resulting microspheric poly(Schiff-base), a honeycomb-like N-doped porous carbon material (N-PCMs) was synthesized. The specific surface area of porous N-PCMs was measured as higher as 1164 m²·g⁻¹. In 1 M Na₂SO₄ electrolyte, N-PCM-7 (sample carbonized at 700 °C) showed higher specific capacitance and good rate performance (297 F·g⁻¹ at 0.5 A·g⁻¹, and 186 F·g⁻¹ at 20 A·g⁻¹). To get closer to the practical application, the button-type symmetrical supercapacitors (N-PCM-7D) have made from the N-PCM-7, for this supercapacitor, its specific capacitance was determined to be up to 158 F·g⁻¹ under the condition of 0.5 A·g⁻¹. Furthermore, the supercapacitor still has a capacitance retention rate of 89.4% after 10,000 cycles at 1 A·g⁻¹, indicating higher-performance for energy storage and the potential applications.