Structural changes in electrochemically cycled LiMn^sub 0.7^Fe^sub 0.3^PO^sub 4

Li(1−x)Mn0.7Fe0.3PO4 (0.00 ≤ x ≤ 1.0) samples, obtained by electrochemical cycling, were investigated by powder X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The purpose of this work is to map phase transition information for samples at quasi equilibrium i.e. after a long relaxation time. The required high accuracy solid Li+ content was determined by atomic emission using the standard addition method. From XRD analysis of the charging cycle samples, the phase diagram was shown to exhibit a solid solution (0 ≤ x ≤ 0.42), followed by a two phases system exhibiting both olivine and heterosite structures (0.42