Effect of the lactate precursor on the microstructure of Li1+xMn 2−xO4 with 0≤x≤0.33

Using EPR of Mn4+, the microstructure of Li1+xMn2−xO4 with 0≤x≤0.33 obtained from lactate precursors and by a solid state reaction has been compared. It has been shown that the microstructure of ex-lactate Li4Mn5O12 is similar to that of the sample obtained by a solid state reaction at 400°C: in addition to the statistically distributed Mn4+ and Li+, there are regions where Li+ ions tend to segregate. For 0≤x≤0.1, thermal decomposition of Li–Mn lactate precursors at 450°C in air yields vacancy-rich spinels, in which the excess Mn4+ and the corresponding metal vacancies are randomly distributed. For annealed at 750°C ex-lactate Li1+xMn2−xO4, the spinel microstructure depends on the temperature regime of sample cooling and on the lithium content x. The procedure for the preparation of stoichiometric Li1+xMn2−xO4 with 0≤x≤0.1 and a homogeneous cation distribution from lactate precursors has been specified.