fig2

Figure 2. Mechanism of the CE-EDL framework. (A) Electron cloud model for contact electrification between two materials: (i) before contact, (ii) in contact, (iii) after contact, and (iv) charge release. Adapted with permission^[31], Copyright 2018 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim; (B) Microscopic CE-EDL process: (i) before contact, (ii) contact and electron transfer, (iii) electrons charge the surface, and (iv) EDL formation. Adapted from^[32], licensed under CC BY 4.0. CE: Electrification; EDL: electrical double layer.