Assessing the oxidation behavior of EC:DMC based electrolyte on non-catalytically active surface

Iban Azcarate, Wei Yin, Christophe Methivier, François Ribot, Christel Laberty-Robert, Alexis Grimaud
2020 Journal of the Electrochemical Society  
The race for developing Li-ion batteries positive electrodes with always greater energy density has recently renewed interest towards understanding the formation of the so-called cathode electrolyte interface (CEI) forming upon cycling at high potential. In this work, we used an approach combining electrochemical measurements with physical characterizations to study the different anodic events occurring for the state-of-the-art EC:DMC 1M LiPF 6 (LP30) electrolyte. Doing so, we could find that
more » ... -related species are first oxidized before the oxidation of DMC-related species at greater potential which forms a film relatively rich in organic polycarbonates species. Using a soluble redox probe, we could then demonstrate that while this organic layer is partially passivating, it is unstable with time and cycling. In fact, only reaching a potential as high as 5.4 V vs Li + /Li for several hours leads to the formation of a perfectly stable and passivating CEI.
doi:10.1149/1945-7111/ab8f57 fatcat:ndv6hdtjlbeh3g3bk4ulrpuv7y