Fluoro-polyanionic Compounds

In this chapter, we present the progress that allows several lithium-intercalation compounds to become the active cathode element of a new generation of Li-ion batteries, namely the materials with a poly-anion-based structure M x (XO4) y (M is a transition-metal cation and X = P, S), which are promising to improve the technology of energy storage and electric transportation, and address the replacement of gasoline engine by meeting the increasing demand for green energy power sources. The electrode materials considered here are fluorine-containing compounds including fluorophosphates LiMPO4F (M = V, Fe, T), Li2 M′PO4F (M = Fe, Co, Ni), hybrid ion Li x Na1−x VPO4F, and fluorosulfates LiMSO4F; M = Fe, Co, Ni, Mn, Zn, Mg). The electrochemical performance of these materials as the active cathode element of Li-ion batteries is also discussed.