Synthesis of ternary transition metal fluorides Li₃MF₆ 𝘷𝘪𝘢 a sol–gel route as candidates for cathode materials in lithium-ion batteries

Abstract

A sol–gel route for ternary lithium fluorides of transition metals (M) is presented allowing the synthesis of Li₃MF₆-type and Li₂MF₅-type compounds. It is based on a fluorolytic process using transition metal acetylacetonates as precursors. The domain size of the obtained powders can be controlled by modifying the conditions of synthesis. ⁶Li and ⁷Li magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy is used to study local environments of the Li ions in orthorhombic and monoclinic Li₃VF₆ as well as Li₂MnF₅. The number of magnetically inequivalent Li sites found by MAS NMR is in agreement with the respective crystal structure of the compounds studied. Quantum chemical calculations show that all materials have high de-lithiation energies making them suitable candidates to be used as high-voltage battery cathode materials.

Dr. Dennis Wiedemann

Technischer Berater für Umweltfragen
Chemiker · Kristallograph

Ich bin promovierter Chemiker und berate zu immissionsschutz- und wasserrechtlichen Genehmigungsfragen.