Four activated carbons (ACs), obtained by physical and chemical activation of locally sourced wood charcoal, were evaluated as sustainable and high-performance electrode materials for supercapacitors operating in an organic electrolyte (1M TEABF 4 in acetonitrile). The study provides a systematic comparison of electrode performance under identical testing conditions, including challenging high-current-density regimes often overlooked. The assembled devices demonstrated outstanding electrochemical performance over a wide temperature window (−25 °C to +45 °C). The best material achieved cell capacitances above 30 F g −1 (electrode capacitance, C e , over 120 F g −1 ) and 18 F cm −3 ( C e over 72 F cm −3 ) at 0.5 A g −1 and room temperature, storing up to 49 Wh·kg −1 , and outperforming the commercial reference YP-50F for these specific performance metrics. However, at current densities >20 A g −1 , samples with a predominantly microporous structure and low pore hierarchy experienced a sharp drop in performance, retaining only 11% of their initial capacitance. In contrast, ACs featuring mesopores around 4 nm in diameter showed superior capacitance retention up to 60%. These findings highlight the importance of tailored porous architectures, combining high specific surface area with hierarchical pore structures and well-defined mesopores to facilitate ion transport and ensure robust performance in organic electrolyte systems. • Wood-derived activated carbons were obtained by four different activation routes. • Cells affirms strong potential in organic electrolyte over a wide temperature range. • Top sample delivers 180 F/g and delivers a maximum of 49 Wh kg −1 . • Mesopore size play a key role for performance retention at high current densities.
Blyweert et al. (Thu,) studied this question.