ISOMORPHIC PHASE TRANSITIONS IN Li_xV₂O₅ INTERCALATION COMPOUNDS. H. Katzke, W. Depmeier, Mineralogical Institute, University of Kiel, Olshausenstr. 40, D-24098 Kiel, Germany

The intercalation of lithium ions into the layered structure of V₂O₅ is within certain stoichiometry ranges the result of a topotactic electron/cation-transfer reaction which is used in high density/high capacity solid state batteries operating at ambient temperature.

The intercalation leads in dependence of the external conditions to a series of composition and temperature induced structural phase transitions. These structural phase transitions can be understood by consideration of the symmetry relations between the various phases. They can be described in terms of group-subgroup relationships, despite the fact that most of the phase transitions are first order and several transitions are even isomorphous.