To further investigate the difference in the morphology evolution of the Zn surface during the discharge process in different gas environments, discharge experiments are conducted by controlling at different intervals (Fig. ) and the respective Zn electrodes are characterized using field emission scanning electron microscopy (FESEM). Herein, five sets of Zn electrodes, discharged up to different intervals (t = 30 mins, 2 h, 5 h, 6 h and 7.5 h i.e. failed) in N2 supplied electrolytes, are analyzed using FESEM imaging. As shown in Fig. B to 3 F, a slow evolution of dendritic oxides (ZnO, as verified in the later part) is evident from the initial stage of nodular to flaky and again to nodular oxides. Similarly, electrodes with O2 supplied condition are also analyzed at different discharge time intervals (t =s, 30 mins, and 50 mins i.e. failed) as shown in 20 min Fig. G to 3 I (detailed data in SI Appendix, Fig. ). Zinc electrodes, during the discharge in O2 environment, is led to early passivation and has dominant dendritic features even in the initial stages. The vigorous dendritic growth can be correlated to the early passivation and the formation of irreversible ZnO.