Corrosion inhibition of polyelectrolytes to the Al anode in Al-air battery: A comparative study of functional group effect

• Published in: Journal of power sources 2024-02, Vol.592, p.233907, Article 233907
• Main Authors: Wu, Guang-Xu, Wei, Ze-Song, Li, Shuo-Qi, Cui, Lan-Yue, Zhang, Guo-Xin, Zeng, Rong-Chang
• Format: Article
• Language: English
• Subjects: Al-air battery; Corrosion inhibitors; Polyelectrolytes; Self-corrosion
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2023.233907

Al-air battery is a promising alternative to electrochemical storage systems because of their high energy density and low cost. However, the hydrogen evolution corrosion in alkaline electrolytes is a major obstacle before this technology can be commercially viable. In this paper, three polyelectrolytes as corrosion inhibitors for pure Al anodes in KOH electrolytes are investigated by electrochemical methods, hydrogen evolution rate (HER) tests, weight loss measurements, and surface characterization. The Attenuated Total internal Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and theoretical simulation results show that all the polyelectrolytes can be adsorbed on Al to form a protective barrier against the corrosive species. In particular, poly(allylamine) (PAH) exhibits the highest corrosion inhibition efficiency. Furthermore, galvanostatic discharge measurement reveals that the Al-air battery in PAH electrolyte exhibits the highest specific discharge capacity (1495.2 mA h g−1). Computational analysis shows that the inhibition performance depends on the frontier molecular orbital energy and adsorption energy. [Display omitted] •Polyelectrolytes are assessed as corrosion inhibitors for the Al-air battery.•The anticorrosion efficiency follows the order of PAH > PAA > PSS.•PAH would form the most compact protective layer in the near-surface region.•The adsoption energy rather than ΔE would determine the anti-corrosion efficiency.