Surface layer formation on Li1 + xMn2O4 − δ thin film electrodes during electrochemical cycling

A surface layer formation on positive Li1 + xMn2O4 − δ thin film model electrodes as a result of electrochemical cycling procedures has been detected and characterized by scanning electron microscopy and X-ray photoemission spectroscopy. These thin film spinel electrodes, prepared by pulsed laser deposition, were cycled in 1 M LiClO4 in propylene carbonate between 3.5 and 4.4 V vs. Li/Li+ at 40 °C and stopped at defined potentials and cycle numbers. The observed surface layers show, depending on the cycling conditions, a spotty and/or layered appearance and the fraction of this layer covering the cycled electrode depends on the charge potential and the number of electrochemical cycles.

► The spinel LiMn2O4 is a promising candidate for future battery applications.
► Good electrochemical properties of LiMn2O4 films grown on p-Si.
► Spinel thin films are used as model system to study the solid electrolyte interphase formation.
► SEI formation depends on the charge potential and the number of electrochemical cycles.