Figure illustrates the correlations between ionic conductivity and ionic radius in bulk and under vibrational strong coupling. The plot includes the ionic conductivity of electrolyte solutions with and without a cavity. Firstly, it should be noted that the slight increase in ionic conductivity can be attributed to the higher transport number of the counter anion, Cl -. Alkylammonium cations exhibit a linear relationship with the cation's ionic radius, Ri. This behavior is consistent with Stokes' law, where the viscosity of water plays a significant role in the modifications. The hydrodynamic friction (𝜁 ! " = 4𝜋𝜂𝑅 ! ) is minimally affected by vibrational strong coupling, indicating that the modification of water viscosity is negligible. Alkali cation species display an inflection in their ionic conduction behavior based on the ionic radius. This is attributed to the dynamic hydration process, which is described by the component in the relaxation time of dielectric friction