Diffusion pulsed-field gradient (PFG) nuclear magnetic resonance (NMR), is a powerful technique for measuring transport in porous media, and to investigate pore structure . PFG NMR measures self-diffusion coefficients of molecules confined in porosity, characterizing diffusion restrictions due to pore size, interconnectivity, or surface interactions . Widely applied to porous rocks for hydrocarbon and shale gas studies , it has proven valuable for probing transport phenomena and quantifying tortuosity, which describes how twisted and indirect the pathways for diffusion are within a material. In carbon-based EDLCs, in-situ PFG NMR has shown that ion diffusion coefficients are significantly reduced in nanoporous electrodes compared to bulk, modulated by ion population changes at the electrode-electrolyte interface during charging, providing insights into the charging mechanism . Other studies used PFG NMR to investigate electrolyte diffusion in the hierarchical structures of nanoporous carbons, shedding light on the interplay between microporosity, mesoporosity, and hierarchical pore architectures .