Flame normalizing-induced robust and oriented metallic layer for stable Zn anode

Flame normalizing is innovatively applied to enrich the preferential crystal plane of Zn-affinitive Sn layer on Zn anode and enhance Sn/Zn interaction concurrently, thus resulting in robust and stable Zn metal anodes. Theoretical calculations and experimental results reveal that such Sn layers effectively inhibit parasitic reactions and dendrite growth, lower Zn nucleation/deposition energy barriers, enable sufficient contact with electrolytes, and have fast reaction kinetics. Interestingly, we find that flame normalizing treatment increases Sn (200) facet which has high surface energy, thus further improving surface wettability and homogenizing Zn2+ flux. In addition, the strengthened Sn/Zn interaction enhances the structural integrity of electrodes to withstand harsh conditions. These features ensure flame normalized Sn layer covered Zn anode to deliver low Zn plating/stripping overpotential and polarization, together with a long cycling lifetime over 1200 h. The resulting Zn-based anode also significantly improves the performance of Zn//MnO2 full cells. Overall, this work provides insights for crystal plane engineering towards stable Zn anodes.