Daikon‐Derived Carbon Materials With Honeycomb Microstructure for Flexible Supercapacitor

Designing carbon‐based electrode materials with excellent performance under high loading to meet the application requirements of lightweight supercapacitors remains a significant challenge. In this study, a honeycomb‐like microstructured carbon material with an appropriate content of heteroatoms (O, S, and N) was synthesized using green radish as the precursor. The prepared activated carbon exhibits a honeycomb‐like structure with a micropore‐mesopore configuration, featuring a specific surface area of 500 m ² /g and a total pore volume of 0.512 cm ³ /g. A detailed investigation was carried out on the material's electrochemical behavior, capacitance sources, and reaction kinetic mechanisms. Benefiting from its structural characteristics: in a three‐electrode system with 6 M KOH as the electrolyte, the activated carbon achieves a high specific capacitance of 221.03 F/g at 0.25 A/g and retains 130.67 F/g at 25 A/g; in the coin‐type supercapacitor, its specific capacitance and energy density reach 221.03 F/g and 7.97 Wh/kg, respectively; in the interdigital flexible device. When the bending angle increases to 180°, the areal specific capacitance still retains 95% of its initial value. After 1000 folding cycles, the areal specific capacitance still maintains 80% of its initial value.