Li ions are strongly hydrated by water molecules, leading to the formation of a structured network of hydrogen bonding between water molecules. On the other hand, due to the low charge density of Cs ions, water molecules are weakly hydrated, resulting in unstable water networks. Under vibrational strong coupling, an enhancement in the ionic conductivity of Cs ions is observed. Notably, the enhancement of Cs + , Rb + , and K + ions exceeds that predicted by the Hubbard-Onsager model. The enhancement of ionic conductivities gradually decreases with an increase in the ionic radius. The demonstrated modification of ionic conductivity can be explained by the nature of the hydration modifications. Hubbard-Onsager model. Finally, we discuss the effect of thermodynamic parameters on the modifications of ionic conductivities. Figure illustrates the correlation between thermodynamic parameters reported in the literature and the observed modifications in ionic conductivities and activation energies. The observed modifications in ionic conductivities can be correlated with hydration entropies. Hydration entropy is associated with the solvation of ions from