A high power flexible Zn-air battery via concurrent PAA modulation and structural tuning

Flexible zinc-air batteries, recognized for their high theoretical energy density, safety, and cost-effectiveness, are promising candidates for next-generation power sources. However, challenges related to gel electrolytes, including low ionic conductivity and inadequate water retention, have impeded their performance and lifespan. In this study, we address these challenges by developing a dual-network gel structure combining 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and polyacrylic acid (PAA), further modified with KCl and KAc. This approach achieves an ionic conductivity of 367.9 mS cm⁻¹ and significantly enhances water retention, extending the battery life to over 55 h. The KAc modification balances ionic conductivity and gel lifespan. Additionally, we introduced a gel with a maximum thickness of 0.5 mm, fabricated using a modified micro-vertical slot coating device, optimized for solid-state zinc-air batteries. This advancement improved the air electrode structure, facilitating better mass and charge transfer, and resulted in a peak power density of 389.1 mW cm⁻². This study provides valuable insights into the development of flexible zinc-air batteries, particularly for wearable electronic devices, and contributes to resolving key limitations in gel electrolytes through both theoretical and experimental validation.