In-situ polymerization of the electrolyte on the electrode surface: A novel process to eliminate interfacial impedance in flexible Zn-air batteries

Flexible rechargeable quasi-solid-state metal air/O2 batteries are advanced energy sources for wearable and flexible electronic devices. This study proposes an in-situ polymerization of gel electrolyte on the electrode surface (IPEES) technique for the Zn-air battery. The utilization of the IPEES technique for batteries results in superior battery performance as compared to conventional layer-by-layer batteries. The enhanced performance can be credited to several factors, including a reduction in charge transfer resistance and bulk resistance, an increase in ion conductivity, improved water retention, and the establishment of a robust and stable interface between the electrolyte and cathode. The battery with the poly(acrylic acid) gel using the IPEES technique results in a charge-discharge process of 171 h at 1 mA cm−2, while the specific capacity (SC) and power density (PD) of the battery are 72.86 mAh cm−2 and 88.88 mW cm−2, respectively. The novel IPEES method yields an increase of up to 78.6 % in specific capacity compared to the conventional method. At a current density of 10 mA cm−2, the highest values of SC and PD are attained, reaching 83.85 mAh cm−2 and 90.6 mW cm−2, respectively. The novel method exhibits exceptional electrochemical performances and offers additional benefits such as affordability and high mechanical stability.