Multiscale in Situ Analysis of the Zinc Electrodeposition Process in Aqueous Electrolytes

In the practical applications of rechargeable Zn-anode batteries as leading alternatives for postlithium batteries, the suppression of Zn dendrite formation during charging is a critical challenge. Here, to clarify the correlation between reaction conditions and Zn metal morphology, in situ multiscale observations of the electrodeposition process in liquid electrolytes were conducted using liquid-phase electrochemical transmission electron microscopy, liquid-phase electrochemical scanning electron microscopy (LP-EC-SEM), and in situ optical microscopy. The dependence of Zn morphology on the electrochemical conditions and electrolyte concentration was clarified by using the LP-EC-SEM observations of electrochemical reactions with high reproducibility. During electrodeposition, the Zn diffusion layer in the liquid electrolyte strongly influences the formation of Zn dendrites.