In situ converting the native passivation layer into a fast ion transport interphase to boost the stability of zinc anodes

Aqueous zinc batteries offer significant potential for large-scale energy storage, wearable devices, and medium-to low-speed transportation due to their safety, affordability, and environmental friendliness. However, the uneven zinc deposition at the anode side caused by localized reaction activity from the passivation layer presents challenges that significantly impact the battery's stability and lifespan. In this study, we have proposed an expandable and maneuverable gel sustained-release (GSR) treatment to polish the Zn metal, which in situ converts its native passivation layer into a composite interphase layer with nanocrystal zinc phosphate and flexible polyvinyl alcohol. Such a thin and uniform interface contributes to fast and homogeneous Zn ion transport and improved anti-corrosion ability, enabling uniform zinc deposition without dendrite growth and thereby improving the battery performance with high-rate ability and long cycle life. This GSR treatment method, characterized by its simplicity, low cost, and universality, facilitates the widespread application of aqueous zinc batteries.