Highly stable zinc anode enabled by a Zn-ion-regulating interface for Zn metal batteries

Abstract

Multifunctional interfacial construction of zinc metal anodes is a crucial measure to surmount the uncontrolled dendrite growth and intricate side reactions. Herein, an organic polymer film formed by the complexation effect between polyacrylonitrile (PAN) and zinc acetate is introduced on a zinc metal to prepare zinc complex polyacrylonitrile@Zn electrode (PANA@Zn). This PANA layer functions as a stretchy barrier to restrain the side reaction and repress zinc dendrites. More importantly, the zinc ion kinetics of PANA layer can be controlled by the complexation states between Zn species and C=N bond along with the heating time, which can regulate the zinc ion flux distribution, resulting in fast and uniform zinc deposition. Thanks to this multifunction protective layer, the obtained PANA@Zn electrode is given a stable cycling lifespan of 3000 h at 1 mA cm⁻² (polarization voltage of 46 mV). Furthermore, the convincing performances are also displayed in full cells, which involves 179 mAh g⁻¹ after 700 cycles at 1 A g⁻¹ for CNT/MnO₂||PANA@Zn full cell, indicating the feasibility of this multifunction shielded layer for the application in zinc metal anode.