Scaling-Up Insights for Zinc-Air Battery Technologies Realizing Reversible Zinc Anodes.

Zinc-air battery (ZAB) technology is considered one of the promising candidates to complement the existing lithium-ion batteries for future large-scale high-energy-storage demands. The scientific literature reveals many efforts for the ZAB chemistries, materials design, and limited accounts for cell design principles with apparently superior performances for liquid and solid-state electrolytes. However, along with the difficulty of forming robust solid-electrolyte interphases, the discrepancy in testing methods and assessment metrics severely challenges the realistic evaluation/comparison and commercialization of ZABs. Here, strategies to formulate reversible zinc anodes are proposed and specific cell-level energy metrics (100-500 Wh kg -1 ) and realistic long-cycling operations are realized. Stabilizing anode/electrolyte interfaces results in a cumulative capacity of 25 Ah cm -2 and Coulomb efficiency of >99.9% for 5000 plating/stripping cycles. Using 1-10 Ah scale (≈500 Wh kg -1 at cell level) solid-state zinc-air pouch cells, scale-up insights for Ah-level ZABs that can progress from lab-scale research to practical production are also offered.