In-situ Study of Solid-Liquid Interface Structure of Zinc-anode Battery by X-ray Total Reflection

Abstract

X-ray reflectivity (XRR) was applied to in-situ measurements of the interface of liquid electrolytes and electrodes of rechargeable batteries. Here, we report the in-situ XRR measurements during the charge and discharge of the zinc-anode battery. The combination of physical and chemical polishing of the Zn plate gave a flat surface, enough to produce the total reflection. Changes in the reflectivity curves during discharge and charge indicated that the Zn density decreased during discharge and increased during charge. This suggests that the uneven structure grew by Zn dissolution and decreased by Zn precipitation. This uneven surface becomes the starting point for dendrite growth. Using this method will make it possible to evaluate what kind of electrolyte to use for a more uniform reaction, which is expected to lead to the development of batteries with good cycle characteristics.