Structure and Electrochemical Properties of LiFe[sub x]Mn[sub 2−x]O[sub 4] (0≤x≤0.5) Spinel as 5 V Electrode Material for Lithium Batteries

An electroactive spinel solid solution, was prepared and investigated. X-ray Rietveld refinements showed a small amount of transition metal ions in tetrahedral sites in Fe-substituted samples. The Mössbauer spectrum of at 300 K is composed of two doublets and attributed to trivalent Fe. In the voltage range 3.0 and 5.3 V vs. two reversible plateaus appeared at 4.9 and 3.9 V during discharge. Combined data of X-ray diffraction, Mn K-edge X-ray absorption near-edge structure (XANES), and Mössbauer spectroscopy obtained in situ during charge and discharge demonstrate that the plateau around 4 V on charging is associated with the oxidation of to and the plateau around 5 V with the partial oxidation of to © 2001 The Electrochemical Society. All rights reserved.