Anti‐corrosive additives for alkaline electrolyte in Al‐air batteries: NH<sub>4</sub>VO<sub>3</sub> and polyoxometalates
Anyie P. Atencio, Juan Ramón Aviles, Dayatri Bolaños, Roberto Urcuyo, Mavis L. Montero, Diego González‐Flores, P. Ocón
Abstract
Abstract Aluminum‐air batteries are a promising alternative for portable energy storage. However, one of the significant issues in this technology is the corrosion of aluminum in alkaline electrolytes. In this study, we explored heteropolyacids (HPAs) H 5 PMo 11 Al 0.5 V 0.5 O 40 and H 6 PMo 11 AlO 40 as possible anti‐corrosive additives in Al7475, Al6062, and Al5052 commercial alloys. We also investigated the anti‐corrosive properties of commercial NH 4 VO 3 and ZnO. Concerning HPAs, only H 6 PMo 11 AlO 40 in combination with Al5052 showed anti‐corrosive activity. However, ZnO did not present anti‐corrosive properties in Al6062 alloy, while NH 4 VO 3 presented anti‐corrosive properties for all three alloys. The combination of carboxymethylcellulose with NH 4 VO 3 further improved the anti‐corrosive properties in the Al7475 alloy. We observed by using 2D Raman imaging the formation of polymeric forms of tetrahedral V +5 O 4 over the surface of three alloys. The main conclusion of our studies is that NH 4 VO 3 combined with carboxymethylcellulose is a promising anti‐corrosive in the alkaline electrolyte of aluminum‐air batteries.