Initial stage of the delithiation of Li_(1.2-x)Mn_(0.4)Fe_(0.4)O_2 positive electrode material for lithium-ion batteries studied by electron energv-loss spectroscopy

摘要

We have investigated initial stage of the delithiation of Li_(1.2-x)Mn_(0.4)Fe_(0.4)O_2 nanoparticles by means of transmission electron microscopy and electron energy-loss spectroscopy. It was found that depletion areas with diameters of less than 10 nm are preferentially formed at Fe-rich regions on the particle surfaces. Correlations between redox reactions of transition metal ions and formation of the depletion areas are discussed.