Phase Diagrams and Conductivity Characterization of Some  PEO  ‐ LiX Electrolytes

systems have been characterized by x‐ray diffraction and optical microscopy, and the resulting phase diagrams are taken into account for the interpretation of ac impedance measurements. Eutectic reactions and multiple‐intermediate‐compound formation are characteristic of most systems. Simple phenomenological models do not explain the overall conductivity behavior. The activation energy of ion transport is independent of the anion, and remains mainly constant at 0.7 eV over the concentration range studied for . Ion‐pair formation seems to occur at low salt concentration.