Fig. 3: Zn plating dynamics on 3D Zn-Mn alloy imaged by in-situ optical microscope.

a Schematic illustration of the experimental setup. b SEM image of 3D Zn-Mn alloy. c–e The early stage of Zn plating. Images were taken with a ×20 water immersion objective at 25 frames per second, and the experiment was performed at a current density of 80 mA cm⁻². c shows the 3D Zn-Mn alloy before the experiment. d, e show the differential images at 10 s and 30 s, respectively, after the start of the experiment. f–h Zn plating on 3D Zn-Mn alloy. The experiment was performed at a current density of 80 mA cm⁻² for 320 s. f, g are the images of 3D Zn-Mn alloy before and after Zn plating. h was calculated by (g–f)/f = (∆I/I). i–q Evolution of Zn plating on the 3D Zn-Mn alloy. i–q are from the three different regions of interest labeled in f, where i–k, l–n, and o–q correspond to regions E, F, and G in f, respectively. The images were taken at 0 s (i, l, o), 160 s (j, m, p), and 320 s (k, n, q). The black dashed lines in (i–q) circle out the trench regions (i–n) and the protruding regions (o–q). Scale bars: 10 μm.