Supramolecular?mediated ball?in?ball porous carbon nanospheres for ultrafast energy storage

Hierarchical porous carbons are the most viable electrode material for supercapacitors because of their balanced capacitive performance and chemical stability. Their pore connectivity plays a pivotal role in electrolyte transport, which is quantified by new parameter, defined this work as longest possible separation (LPPS). Herein, we report hierarchical carbon nanospheres (HPC-NS) with unique ball-in-ball structure, achieved pyrolysis supramolecular complex ?-cyclodextrin (?-CD)/PEO-PPO-PEO (F127). This approach differs from conventional soft-templating method that, apart assembly monomicelles that leads to host (approximately 300 nm), ?-CD-containing themselves converted small (<10 results an ultralow LPPS 10 nm, representing best-known HPC family. The HPC-NS delivers high specific capacitance (405 F g?1 at 1 A 71% retention 200 g?1), wide voltage window (up 1.6 V), simultaneously energy power densities (24.3 Wh kg?1 density 151 W 9 105 kg?1) aqueous electrolytes. strategy boosts development electrodes densities.