V₂O₃–Li₃PO₄ Composite: A New Type of Cathodic Active Material for Li‐Ion Batteries

Abstract A new type of cathodic active material for lithium‐ion batteries based on a composite of Li₃PO₄ and V₂O₃ is proposed in this work. Although the V₂O₃ component is almost inactive in the voltage range of 2–4.5 V versus Li⁺/Li, the mixture of the two components can deliver a larger reversible specific capacity of ≈190 mA h g⁻¹ in the voltage range of 2–4.5 V at a current density of 15 mA g⁻¹. X‐ray photoelectron spectroscopy data and cyclic voltammetry data suggest that the vanadium ions are probably oxidized and reduced repetitively upon cycling and that the V³⁺ ions are partially oxidized to V⁴⁺ and even V⁵⁺ ions during charging to 4.5 V. This distinctive lithium‐ion uptake and release phenomenon, in which Li₃PO₄ functions as a lithium source of surface conversion reaction, will introduce a new path for designing unique cathodic active materials for lithium‐ion batteries.