Residual Li2O degrades PVdF during the preparation of NMC811 slurries for Li-ion batteries

⁷Li 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 ⁷Li MAS NMR and XPS suggest a new reaction for the PVdF binder degradation, involving in fact Li₂O as the reagent and the formation of LiF.