Fig. 3. (a) Schematic showing ZnO nanoparticles coated with an ion-sieving carbon nanoshell; (b) specific capacity and coulombic efficiency of bare ZnO, ZnO@C, and bulk Zn foil anodes during discharge; (c and d) SEM images of the bare ZnO anode (c) before and (d) after cycling; (e and f) SEM images of the ZnO@C anode (e) before and (f) after cycling, ref. 65, copyright© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.