Low-temperature tolerant poly(acrylic acid) (PAA) gel polymer electrolytes for rechargeable zinc-air batteries

Gel polymer electrolytes (GPEs) are emerging materials for Zn-air batteries (ZABs), since the GPE can act as a combined electrolyte and separator in the battery. GPE-KOH was fabricated through the polymerization of poly(acrylic) acid in the presence of KOH and ZnO. GPE-KOH-KI was fabricated following a similar procedure, followed by immersion in a solution containing KOH, KI, and ZnO. The addition of KI to the electrolyte changed the conventional charging reaction to a reaction with a lower thermodynamic barrier, which improved the battery efficiency with a maximum increase of 36% relative to ZABs without KI. This work focused on extending the working temperature range of the ZAB to low temperatures (as low as -41 degrees C) as well as exploring the reaction mechanism for ZABs using KI as an additive. It is proposed that the discharging reaction at the air electrode is a combination of the oxygen reduction reaction and iodate reduction reaction.

Automated summary

In this study, gel polymer electrolytes (GPEs) were prepared via polymerization of poly(acrylic) acid in the presence of KOH and ZnO, and GPE-KOH-KI was fabricated by immersing GPE-KOH in a solution containing KOH, KI, and ZnO. The addition of KI to the electrolyte improved the battery efficiency and extended the working temperature range to as low as -41 degrees C. The reaction mechanism for ZABs using KI as an additive was found to involve a combination of oxygen reduction and iodate reduction reactions.