Multistage Template-Oriented\nDesign and Tailoring\nof the Hierarchical Porous Biocarbon Materials for High-Performance\nSupercapacitors

Interfacial regulation is crucial for the enhancement\nof the specific\nsurface area and supercapacitive performance in porous carbon materials.\nHowever, traditional porous carbon obtained through potassium hydroxide\nactivation is confronted with a complicated preparation process. Herein,\nhierarchical porous biocarbons (HPBC) were facilely prepared by using\nthe multiscale template method and wheat flour as a precursor without\nany activation. A spherical SiO<sub>2</sub> template and wheat flour\ncan be closely combined by gelatinization so as to effectively confine\nand spatially orient carbon materials. Benefiting from the hierarchical\nporous structure achieved through the use of templates at different\nsizes, HPBC-3 has the best electrochemical performance of 223.6 F·g<sup>–1</sup> at 1 A·g<sup>–1</sup>. Moreover, the\nassembled HPBC-3//HPBC-3 symmetrical supercapacitor demonstrates a\nremarkable energy density of 15.6 W h·kg<sup>–1</sup> and\nexhibits exceptional cycling performance with a capacitance retention\nrate of 106% after 5000 cycles. The results fully demonstrate the\npromising application of the obtained hierarchical porous carbon in\nsupercapacitors.