Regulation Of Release Alkalin At The Interface Of Gel Polyer Electrolytes/Zn Anode For Flexible Zn–air Batteries

Quasi-solid-state flexible Zn–air batteries（QSZABs）will release alkali solutions during cycling,resulting in gradual dehydration and of gel polymer electrolytes（GPEs）.Meanwhile,the leakage of released alkali from GPEs appears at the GPE/Zn anode interface,causing the severe corrosive areas of Zn anode and subsequent Zn dendrites growth,and thus hindering their practical use in wearable electronics.In this work,hollow Sn microspheres were prepared on Zn substrate using colloidal self-assembly technology and thermal evaporation.The inner surfaces of hollow Sn microspheres were then modified with 2 hydroxypropylβ-cyclodextrin（HPβCD）to make the inner surface highly hydrophilicity.The hollow Sn microspheres with the hydrophilic inner surfaces（hollow Sn-inner HPβCD）can regulate the released alkali at the interface of GPEs/Zn anode.Furthermore,We revealed the regulation mechanism of the released alkali in QSZABs by experiments.Concretely,the hollow Sn-inner HPβCD can lessen the leakage of released alkali,mitigate the leakage of the released alkali and the loss of soluble Zn（OH）₄^2-,and hinder the growth of Zn dendrites during the discharging process.Moreover,the alkali solution inside the hollow Sn microspheres can diffuse back into the GPEs during the charging process,making amends for the loss of alkali in the GPEs,which is validated using the NaOD/D₂O as tagged molecules.The GPEs shows high retention capacity of GPEs for alkaline solutions.Finally,the assembled QSZAB exhibits a long cyclic lifespan of 127 h due to the effective regulation of released alkali by hollow Sn-inner HPβCD at the interface,which outperforms QSZAB without hollow Sn-inner HPβCD by 7.94 times.This work rivets the regulation of released alkali at GPE/anode interface,providing a new insight to improve QSZABs’performance.