Shield effect of polyaniline between zinc active material and aqueous electrolyte in zinc-air batteries

The self-discharge behavior of zinc-air batteries is a critical issue that is induced by corrosion and hydrogen evolution reaction (HER) of zinc anodes. Polyaniline (PANI) coatings help control the HER and the corrosion reaction. Herein, PANI is synthesized with different amounts of HCl (20, 50, 100 ml). Among these, the PANI synthesized using 20 ml of HCl (20PANI@Zn) is the most effective for reducing the self-discharge behavior because it provides more amount of coating layer on the surfaces of the zinc particles compared to other prepared materials. This layer prevents direct contact between zinc and the aqueous electrolyte and minimize HER. The 20PANI@Zn shows 85% corrosion inhibition efficiency against pure zinc and results in 97.81% capacity retention after 24 h storage against no-storage condition at ambient temperature. (C) 2017 Elsevier B.V. All rights reserved.