Contribution of the oxygen extracted from overlithiated layered oxidesn at high potential to the formation of the interphase

摘要

Li-rich (1-x)LiMO2 center dot xLi(2)MnO(3) layered oxides materials have been proposed recently as an attractive alternative to LiCoO2 Their electrochemical performance is greatly improved by charging above the 4.5 -4.6 V voltage plateau during the first oxidation. The associated reaction mechanism has been assigned to a transformation from layered to spinel, accompanied a partial oxygen removal process from the surface. Nevertheless, many questions are still unanswered concerning the influence