Mixed-valence induced during the intercalation of lithium ions into uranium fluorides Original Research Article

The mixed-valence in uranium fluorides LiU4F16 and UF4 can be induced (or eliminated) by the intercalation (deintercalation) of lithium ions into these compounds. These processes can be electrochemically performed both with LiU4F16 (or LiTh4F16) and with monoclinic UF4 as starting materials using a liquid electrolyte composed of propylene carbonate as solvent and LiClO4 as salt. In the cases of UF4 and LiU4F16, the electrochemical intercalation of Li+ into the host matrix is reversible and a maximum of three Li+ ions per U4F16 unit can be reversibly intercalated. Additional experimental evidences of the mixed-valence in these fluorides are presented such as the Electron Paramagnetic Resonance characterization of the starting materials and of those electrochemically modified.