Fig. 3From: Amorphous Vanadium Oxide Thin Films as Stable Performing Cathodes of Lithium and Sodium-Ion BatteriesHigh-resolution XPS spectra of a-VOx films (a) O 1s and V 2p core level; V 2p3/2 of (b) a-VOx-6 Pa, (c) a-VOx-13 Pa and (d) a-VOx-30 PaBack to article page