Anticorrosion of hydrophobic membrane on aluminum electrode for alkaline quasi solid Al-air batteries

Primary quasi-solid Al-air batteries with hydrogel have attracted increasing research attention owing to their high energy density, ionic conductivity, good handling and safety. However, a severe corrosion at open-circuit potential destroy the lifespan and performance of discharge. Suppressing the corrosion of Al anode at standby is of great importance. Here, we present a coating hydrophobic membrane on Al surface to restrain open-circuit corrosion, where the hydrophobic property of the protective membrane is analyzed by contact angle test, changing from 22.48 to 149.48°. The results of electrochemical polarization measurement demonstrate that the corrosion inhibition efficiency of the hydrophobic membrane are 81.6%. Also, the discharge performance of assemble quasi solid Al-air batteries are revealed, and compared with pure Al electrode, the lifetime and special capacity of coated Al electrode is enhanced, expressing special capacity of 1126 mA h g⁻¹ at 10 mA cm⁻² and a power density of 36.3 mW cm⁻². Meanwhile, the lifespan of coated Al electrode is approximately prolonged by 34% at interval discharge mode. This work demonstrates a hydrophobic membrane on Al-electrode opens up a prospect of a corrosion inhibition for Al-air batteries.