Residual Li 2 O degrades PVdF during the preparation of NMC811 slurries for Li-ion batteries.

7 Li MAS NMR quantification of lithiated species at the surface of aged NMC811 industrial powders and slurries shows that the electrode preparation process exacerbates Li extraction. A combination of 7 Li MAS NMR and XPS suggest a new reaction for the PVdF binder degradation, involving in fact Li 2 O as the reagent and the formation of LiF.