PFG NMR probes ionic effective diffusion and tortuosity in the carbon nanopore network, offering a more relevant approach by characterizing how electrolyte ions navigate the electrode's meso-and microporous structure under conditions similar to those in actual supercapacitor operation. To measure diffusion within the porosity of nanoporous carbons, here defined as the effective diffusion coefficient over a timescale (and therefore lengthscale) set by the experimental parameters, nanoporous carbons were loaded in an NMR tube and filled with an excess of electrolyte to saturate the carbon pores in the absence of any external potential (Figure ). In the F NMR spectra of activated carbon cloth (ACC) electrode materials soaked in 1 M TEABF4 electrolyte in acetonitrile, two environments are resolved corresponding to the in-pore and ex-pore anionic environments (Figure ). In this context, ex-pore environments refer to anions occupying the interstitial spaces between nanoporous particles and in-pore environments correspond to ions confined within the carbon nanopores.