Guiding Uniform Al Stripping with a Polymer Sol Electrolyte for Long-Lasting Al-Air Batteries

Aqueous aluminum-air batteries (AABs) have garnered significant research interest due to their inherent safety, high energy density, and cost-effectiveness advantages. Nevertheless, the widespread application of AABs is constrained by challenges such as undesired parasitic self-corrosion and continuously accumulated byproducts over time. Here, an anticorrosive polyacrylamide (PAM) sol electrolyte is designed to modulate the interfacial reactions at the aluminum (Al) anodes. The PAM sol with a hydrogen bonding network refines the electrolyte’s solvated environment, thus mitigating Al anode corrosion by 56.36% when benchmarked against a 20 wt % sodium chloride (NaCl) electrolyte. Furthermore, this approach ensures uniform Al stripping behavior and manages the generation of aluminum hydroxide at the electrode/electrolyte interface. With respect to the rampant precipitates in pH-neutral electrolytes, the PAM sol assists in facilitating the stable dispersion of aluminum hydroxide (Al(OH) 3 ) and curtailing the excessive buildup of precipitates, thereby prolonging the battery’s operational life. Consequently, the pH-neutral AABs using the PAM sol electrolyte attain a remarkable specific capacity of 2312 mAh g –1, alongside an extended durability of 73.3 h in cyclic on/off testing scenarios. This study offers a viable strategy for regulating interfacial reactions of Al anodes and boosting the long-term stability of AABs.