A Prussian-Blue Bifunctional Interface Membrane for Enhanced Flexible Al-Air Batteries

Flexible Al-air batteries have attracted widespread attention in the field of wearable power due to the high theoretical energy density of Al metal. However, the efficiency degradation and anodizing retardation caused by Al parasitic corrosion severely limit the performance breakthrough of the batteries. Herein, a Prussian-blue bifunctional interface membrane is proposed to improving the discharge performance of hydrogel-based Al-air battery. When a rational 12 mg center dot cm(-2) membrane is loaded, the effect of anticorrosion and activation is optimal thanks to the formation of a stable and breathable interface. The results demonstrate that a flexible Al-air battery using the membrane can output a high power density of 65.76 mW center dot cm(-2). Besides, the battery can achieve a high capacity of 2377.43 mAh center dot g(-1), anode efficiency of 79.78%, and energy density of 3176.39 Wh center dot kg(-1) at 10 mA center dot cm(-2). Density functional theory calculations uncover the anticorrosion-activation mechanism that Fe3+ with a large number of empty orbitals can accelerate electrons transfer, and nucleophilic reactant [Fe-II(CN)(6)](4-) promotes the Al3+ diffusion. These findings are beneficial to the inhibition of interfacial parasitic corrosion and weakening of discharge hysteresis for flexible Al-air batteries.

Automated summary

Flexible Al-air batteries have attracted attention in wearable power due to high theoretical energy density of Al metal. However, Al parasitic corrosion limits battery performance. In this study, a Prussian-blue bifunctional interface membrane is proposed to improve discharge performance. Results show that the membrane enables a flexible Al-air battery to output high power density, achieve high capacity, anode efficiency, and energy density. Density functional theory calculations reveal the anticorrosion-activation mechanism. These findings benefit the inhibition of parasitic corrosion and discharge hysteresis in flexible Al-air batteries.