Corrosion behavior of Zn alloy anodes in rechargeable Zn-Air batteries: A characterization review

The corrosion behavior of Zn and Zn alloy anodes in Zn-air batteries (ZABs) requires the use of advanced characterization techniques to understand surface degradation, dendrite formation, and the effectiveness of alloying strategies for corrosion mitigation. A comprehensive discussion is conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorbance spectroscopy (XAS) to evaluate surface morphological, structural, and elemental changes before and after electrochemical cycling. SEM provides visual evidence of corrosion morphologies and dendritic growth, XRD identifies phase transformations and oxide formation, while XPS and XAS reveal oxidation states, elemental distributions and electronic configuration. Alloyed anodes exhibit compact surface layers with fewer defects, enhanced passivation, and improved cycling stability compared to pure Zn, validating the benefits of strategic alloying. This review presents an integrated multi-technique framework combining morphological, phase, and surface science analyses to elucidate corrosion mechanisms at both morphological and atomic levels. This approach facilitates a comprehensive understanding of structure-performance correlations in Zn alloy anodes for better rechargeable ZABs.