Lithium-free transition metal phosphate cathode for Li secondary batteries

Li atoms can be inserted electrochemically into the vacant sites in the host framework structure of hexagonal Cr0.5Nb1.5(PO4)(3) (an analog of Nasicon). Intercalation of lithium into this compound is achieved electrochemically at room temperature. The compound, Cr0.5Nb1.5(PO4)(3), is used as a cathode of a secondary battery without any lithium initially present in the starting material. The performance of this material is discussed in view of its discharge. XRD, SEM and ESCA spectral studies are carried out on electrode surfaces before and after the insertion/extraction reactions and the results are presented. (C) 2002 Elsevier Science B.V. All rights reserved.