Interplay of the functional units of a binder in the oxygen reduction process of zinc-air battery.

[Display omitted] • Functionalised Polystyrene-Block-Poly(ethylene-ran-butylene)-Block-Polystyrene (f-SEBS) is developed and used as binder. • Anionic binders, Fumion and f-SEBS substitutes the expensive Nafion binder in alkaline ZAB. • Hydrophobic filament, hydrophilic branching with ionic conductivity formulates an effective cathodic binder. • Fumion is the most suitable binder for the state-of-art Pt/C catalyst. Zinc-air battery (ZAB) technology is a strong competitor in the automobile sector for powering automotive. Alas, there are a few issues that restrain them from being commercialized. One prominent issue which has not been discoursed thus far in alkaline ZAB is the impact of the type and content of the binder. The present work incorporates a study conducted to get insights on the impact of eleven different polymeric binders in the air electrode of an alkaline zinc-air battery. They include anion and cation conducting polymers, hydrophilic and hydrophobic polymers. The galvanostatic polarisation curves reveal a huge variation depending on the type of binder. Fumion ionomer, an anion conducting material, shows the highest current density of about 163 mA cm−2 at 0.6 V owing to the right proportion of hydrophilic-hydrophobic segments and ion-conducting nature. A specific capacity of 770 mA h g−1 was obtained when Fumion was employed as a binder with 1 mg Pt cm−2. Eventually, the upshot of the experiment motivated us to try a home-made less commonly known anionic binder, functionalised-Polystyrene-Block-Poly(ethylene-ran-butylene)-Block-Polystyrene, which performed on par with Nafion™ and Fumion at a practical operating voltage of ∼1.2 V. [ABSTRACT FROM AUTHOR]