Revealing the plating/stripping processes on Zn anodes in Zn metal batteries via in situ AFM

Mechanistic insights into the interfacial evolution are essential for advancing rechargeable zinc metal batteries (RZMBs). Employing in situ atomic force microscopy (AFM), we observed the Zn plating and stripping processes on the Zn metal anode and investigated the effect of initial stripping over the interfacial evolution. During the initial stripping process, the interfacial evolution is uneven, and by-products form at the Zn anode, which contributes to the heterogeneous nucleation and quick dendrite growth during the subsequent plating, causing performance fading. In contrast, uniform Zn deposition and reversible dissolution can be achieved during the initial plating and following stripping processes. The Zn substrate remains flat without evident cracks or pits, which ensures the interfacial stability of the Zn metal anode during cycling. This work provides direct insights into the morphological evolution and interfacial mechanism of Zn metal anode, promoting the optimal design of advanced RZMBs.