The effect of lithium salts (LiBF4, LiPF6, and LiClO4) on the crystalline to amorphous transition in the poly(ethylene oxide) (PEO):LiX (8:1)–Al2O3 (20 wt.%, 24 nm) system was investigated and analyzed. Differential scanning calorimetry (DSC) and impedance measurements were conducted to characterize the transition. It was determined that among the three salts, lithium perchlorate (LiClO4) was the most effective in producing and stabilizing the amorphous structure. Long-term stabilization of the specimens, predominantly in an amorphous state around ambient temperature, leads to a significant conductivity enhancement.