Lithium insertion behavior of ε-Cu0.9V2O5

Copper vanadium oxide bronze ε-Cu0.9V2O5 has been synthesized and its lithium insertion behavior has been investigated. Insertion and extraction of lithium in this bronze occur up to about 2 mol per formula unit while maintaining its layered structure. Reversible reduction of VV to VIV up to VV/VIV=1, interlayer Cu1 to Cu0 followed by crystallization, and further reduction of VV to VIV occur successively in the course of lithium insertion. The opposite lithium extraction processes occur reversibly with corresponding oxidation processes. This behavior is similar to that in δ-AgyV2O5, with the typical double-layer structure.