The increase in conductivity of polymer electrolytes on the addition of nanocrystalline materials has been investigated via the local dynamics of diglyme with two different salts: LiCF3SO3 and NH4I. Local dynamics can be used as a diagnostic tool of changes to backbone conformations of the diglyme and the dynamics of the NH4 ion of the added salt, these being measured using inelastic neutron scattering (INS) and analyzed with the assistance of density functional theory (DFT) calculations. It is shown that the backbone conformation of the diglyme is little changed by the addition of salts and/or TiO2 nanoparticles. The potential energy landscape of the cation (NH4+) becomes smoother as interactions with the diglyme, and probably the anion, are reduced on the addition of nanoparticles. Anion diglyme interactions seem to be weakened by TiO2, and the cation remains coupled to diglyme.