Study on the enhancement of flexible zinc-air battery performance with polyethylene glycol and nano SiO2 composite hydrogel

Flexible zinc-air batteries have garnered significant attention due to their high energy density, low cost, and environmental friendliness. However, issues such as poor cycle life and anode dendrite growth severely hinder their practical application. This study introduces polyethylene glycol (PEG) as a pore-forming agent and incorporates nano SiO₂ into a polyacrylamide/carboxymethyl cellulose (PAM/CMC) composite hydrogel, resulting in a PAM/CMC/PEG/SiO₂ (PCPS) composite hydrogel. Phase analysis and electrochemical characterization of PCPS were conducted. The hydrogel electrolyte formed in an alkaline KI environment, when assembled into a battery, achieved a capacity of 494.6 mAh/g and maintained a low potential range of 0.36 V for over 40 h, with an energy efficiency of 86.3 % for the first 60 cycles. To address the issue of dendrite growth in alkaline environments, this study also explores the performance of PCPS composite hydrogel in near-neutral environments.