THERMODYNAMIC AND STRUCTURAL CONSIDERATIONS OF INSERTION REACTIONS IN LITHIUM VANADIUM BRONZE STRUCTURES

Lithium vanadium bronze structures show promise for use as positive electrode materials in advanced lithium batteries. Many studies indicate that the insertion of lithium in these structures is reversible and at high rates. However, the electrochemical behaviors among these phases are quite different and also deviate from that predicted by the high temperature phase diagram. In this paper, a rationalization based on the thermodynamic and structural considerations is proposed. Strikingly, metastable reactions are found during the insertion and metastable allotropes are produced. We call these types of reactions "allotropic insertions" to distinguish from the conventional isomorphic insertion and displacement reactions.