Flexible rechargeable photo-assisted zinc-air batteries based on photo-active pTTh bifunctional oxygen electrocatalyst

Abstract

Photo-assisted zinc-air batteries have gained attention for incorporating solar energy, reducing reliance on non-renewable sources, and promoting clean energy adoption. However, currently, the efficiency of the photo-assisted cathode for oxygen reduction/evolution reactions (ORR/OER) remains low, and its application is limited to aqueous zinc-air batteries. Therefore, it is highly necessary to develop bifunctional cathodes with high photo-assisted ORR/OER efficiency and to expand the application of aqueous zinc-air batteries to flexible zinc-air batteries, providing efficient, flexible, and portable power solutions. In this study, we employed pTTh as a bifunctional catalyst in rechargeable zinc-air batteries (RZABs) and utilized solar energy to address the issues of high polarization and low round-trip efficiencies. For photo-assisted pTTh cathode, the Eonset is 0.910 V vs. RHE, E1/2 is 0.831 V vs. RHE, and E10 is 1.99 V vs. RHE. The power density of pTTh cathode-based ZABs is enhanced 56.25 % under illumination. Furthermore, we have pioneered the application of photo-assisted strategy in flexible zinc-air batteries. This photo-assisted pTTh cathode based flexible zinc-air batteries showing the discharge potential of ca. 1.2 V, and the charge potential of ca. 1.8 V at 0.1 mA cm−2 under illumination. Further, under illumination a single photo-assisted flexible zinc-air battery can light up a diode and propel a toy car, and four photo-assisted rechargeable flexible Zn-air pouch batteries (FZAPBs) in series can charge a smartphone.