Synergistic Regulation of Al Alloy Anode/Electrolyte Interface Layer in Al-Air Battery by Composite Inhibitor HEC-K2SnO3

Abstract

The extreme corrosion reaction of the Al anode in alkaline electrolyte is the biggest challenge for the industrialization of Al-air batteries (AABs). This article proposes a composite corrosion inhibitor composed of hydroxyethyl fiber and potassium stannate to weaken the corrosion reaction of Al anodes. The results showed that the hydrogen evolution rate suddenly decreased from 0.47 to 0.08 mL·cm^–2·min^–1 with the addition of composite corrosion inhibitors. The AABs with composite inhibitors exhibit a high energy density of 3311.26 mWh·g^–1 and a power density of 75.0 mW·cm^–2. Introducing hydroxyethyl cellulose (HEC) into an electrolyte containing K₂SnO₃, its rich O heteroatoms will adjust the growth state of Sn through adsorption, resulting in uniform deposition on the Al alloy anode. In addition, the polar hydroxyl groups in HEC are prone to forming organic Al salts (RO-Al) with Al³⁺ in solution, greatly activating the Al alloy anode. In summary, this review elaborates on the corrosion inhibition mechanisms of HEC, K₂SnO₃, and composite corrosion inhibitors, opening up prospects for the subsequent development of simple and effective organic, inorganic corrosion inhibitors.