Nanoarchitectonics of high-microporosity carbon from light bio-oil via ultralow K+ template-mediated liquid-liquid interfacial activation for high-rate supercapacitors

The precise manipulation of the pore structure of carbon electrode materials at the atomic level is crucial for achieving ultra-fast charge and discharge in high-power supercapacitors. In this study, a novel strategy based on a trace amount of potassium ion (K + ) template-mediated liquid-liquid interface activation is developed. Using light bio-oil as the precursor, this method exploits the directional aggregation effect of its oxygen-rich macromolecules on the K + activating agent surface, successfully producing carbon materials with a high specific surface area (2044.4 m 2 /g), large pore volume (1.13 cm 3 /g), and high microporosity (97 %). The optimal carbon material demonstrates excellent electrochemical performance in aqueous supercapacitors: specific capacitances of 234.4 F/g and 434.5 F/g are achieved at 0.1 A/g in 6 M KOH and 0.25 M K 2 SO 4 electrolytes, respectively. Even after a 1000-fold increase in current density, 63.2 % of the initial capacitance is retained, demonstrating exceptional rate capability. Notably, the amount of activator used in this method is reduced by 27 times compared to traditional processes (activator/precursor ratio decreased from 3:1 to 1:9). Furthermore, comprehensive characterization techniques are employed to elucidate the chemical properties of light bio-oil and the pore-forming mechanism through activation with a low ratio of K + templates. The transport properties of different electrolyte ions within the pore structure of the synthesized carbon materials are also revealed. Particularly, the carbon electrode materials demonstrate exceptional cycling stability, maintaining nearly 100 % of their initial specific capacitance after 51,000 charge-discharge cycles at 10 A/g. This innovative liquid-liquid activation strategy, which achieves both high porosity and outstanding electrochemical performance in carbon materials using minimal activating agents, holds significant implications for the valorization of bio-oils.