N/O Co-doped\nPorous Carbon with Controllable Porosity\nSynthesized via an All-in-One Step Method for a High-Rate-Performance\nSupercapacitor

A green\nand economical methodology to fabricate carbon-based\nmaterials\nwith suitable pore size distributions is needed to achieve rapid electrolyte\ndiffusion and improve the performance of supercapacitors. Here, a\nmethod combining <i>in situ</i> templates with self-activation\nand self-doping is proposed. By variation of the molar ratio of magnesium\nfolate and potassium folate, the pore size distribution was effectively\nadjusted. The optimal carbon materials (K<i>x</i>) have\na high specific surface area (1021–1676 m<sup>2</sup> g<sup>–1</sup>) and hierarchical pore structure, which significantly\npromotes its excellent capacitive properties. Notably, K2 shows an\nexcellent mass specific capacitance of 233 F g<sup>–1</sup> at 0.1 A g<sup>–1</sup>. It still retained 113 F g<sup>–1</sup> at 55 A g<sup>–1</sup>. The assembled symmetric supercapacitor\nexhibited an outstanding cyclic stability. It maintains 100% capacitance\nafter 100 000 cycles at 10 A g<sup>–1</sup>. The symmetric\nsupercapacitor demonstrated a maximum power density of 99.8 kW kg<sup>–1</sup>. This study focuses on the preparation of layered\npore structures to provide insights into the sustainable design of\ncarbon materials.