Alkaline Metal Intercalates of VSe₂ by Electrochemical Intercalation

We report on the series of the alkali metal intercalates of VSe2 synthesised by electrochemical means in an aqueous environment. For all alkali metals we find water-conintercalated structures (stage I and stage II), of which only the sodium structure had been reported so far. The new structures are analyzed by powder X-ray diffraction and Rietveld refinement. Their (meta-)stability is investigated in terms of the open circuit potential, revealing the sensitivity towards oxygen. Except for the lithium intercalate these structures transform into water-free alkali metal intercalates under vacuum. In addition, scanning electron microscopy reveals the impact of different electrochemical intercalation techniques yielding different intercalation rates. This paves the way for future single crystal investigations.