Revealing the Impact of Hierarchical Pore Organization in Supercapacitor Electrodes by Coupling Ionic Dynamics at Micro? and Macroscales

The rate of charging supercapacitors depends on how quickly ions can reach and accommodate the surface electrodes. Diffusivity, a parameter reflecting speed ions’ migration, is believed to be crucial in designing supercapacitor Herein, this belief questioned, shedding light puzzling potentially critical feature ionic dynamics denoted as confinement-induced ion–solvent separation. This effect lead strong slowdown ion mobility inside hierarchical pore networks. Explanations for when such an occurs it circumvented are provided. Furthermore, microscopic picture diffusion seen by NMR bridged with macroscopic behavior investigated impedance spectroscopy. Quantifying average residence time within carbon particles shows that nanopore environment may not rate-limiting factor overall thus performance cell—as commonly expected. Combining direct studies performed neat solvated liquids those organic electrolytes, so far lacking criteria rational selection electrolyte–carbon systems developed recommendations preparation transport-optimized materials minimize limitations given.