Nonlinear Correlation of Polyoxyethylene Castor Oil between Dynamic–Static Corrosion Inhibition and Cyclic Stability as Zinc–Air Battery Additives

Zinc-air batteries (ZABs) are hampered by severe zinc anode degradation, encompassing static self-corrosion and dynamic dendrite growth during cycling. To address this dual challenge, four types of polyoxyethylene castor oil (Cremophor EL) were used as electrolyte additives in ZABs. The results show that under static conditions, all four ELs exhibit excellent corrosion inhibition performance with an inhibition efficiency of more than 90%. Among them, EL-10 and EL-60 form dense adsorption films due to their strong adsorption energy, thus achieving an optimal static corrosion inhibition effect. Galvanostatic charge-discharge tests indicate that EL can significantly extend the stable operation time of ZABs, with EL-90 performing the best, enabling about 400 h, in which the blank system is less than 60 h. Interface analysis reveals that EL reagents function through a synergistic mechanism of dynamic interface reconstruction and ion transport optimization. Under static conditions, they form a physical barrier through the collaboration of hydrophobic and hydrophilic groups, blocking the contact with the electrolyte. During dynamic charge-discharge, the ultralong chains construct oriented hydration channels via ether oxygen atoms, reducing the desolvation energy barrier of Zn²⁺ and inhibiting dendrite growth. Meanwhile, they form porous flexible films with uniform pores, balancing corrosion inhibition and ion transport. In addition, the adaptability of EL reagents to intermittent working conditions still needs optimization, but this work provides a new design paradigm for ″dynamic interface reconstruction" for durable ZABs.