Electrochemical lithium insertion in (PO2)4(WO3)2m (2 ≤ m ≤ 10): Relation among the electrochemical insertion process and structural features

In this work it is presented a review of the main results obtained during the electrochemical lithium insertion in the family of monophosphate tungsten bronzes (PO2)4(WO3)2m (2 ≤ m ≤ 10). This family of oxides is a good system in order to study the relation among the electrochemical processes observed in the course of lithium insertion and the changes of bronzes structures. By means of X-ray diffraction experiments, the nature of Lix(PO2)4(WO3)2m phases has been elucidated and a correlation with the reversible/irreversible processes observed during the electrochemical insertion has been established. The electrical properties of the inserted Lix(PO2)4(WO3)2m phases were measured and a relation with the amount of lithium inserted and m was also found.