Improving self-discharge and anti-corrosion performance of Zn-air batteries using conductive polymer-coated Zn active materials

The corrosion and hydrogen evolution reactions of Zn anodes accelerate the self-discharge of a Zn-air battery. To suppress the corrosion reaction and improve the self-discharge behavior of a Zn-air battery, polyaniline (PANI) is synthesized with different amounts of 0.1 M sulfuric acid and coated on a Zn surface. The PANI-coated materials effectively suppress the corrosion reaction, and the Zn-air cells prepared with PANI-coated Zn materials exhibit enhanced self-discharge behavior. The specific discharge capacity after 24 h storage and capacity retention of Zn were 520.2 mA h/g and 74.4%, respectively. Whereas the PANI-coated Zn (100 ml sulfuric acid) shows 565.3 mA h/g of specific discharge capacity after 24 h storage, 75.8% corrosion inhibition efficiency and 96.9% capacity retention. Therefore, PANI-coated Zn materials are effective in suppressing the corrosion reaction and improving self-discharge behaviors in Zn-air batteries.