Multi-Scale Functionally Designed ZnWO4 Artificial Interphase for Ultra-Stable Aqueous Zn Metal Anodes Under High Current Rates

Abstract

Aqueous zinc ion batteries have received unprecedented attention owing to their superior safety and sustainability, yet their cycling stability especially at high current rates is greatly limited by the poor reversibility of Zn metal anodes, due to the delayed ion transport, severe water-induced side reactions, and uncontrollable dendrites growth at electrolyte/electrode interface. Herein, a robust and multi-scale functionally designed amorphous ZnWO4 (ZWO) artificial interphase that fully addresses the aforementioned issues, is proposed. The modified Zn anodes deliver remarkable stability, surpassing 3000 h of operation at a high current density of 20 mA cm−2 in symmetrical cells. Even under harsh conditions of 20 mA cm−2 and 10 mAh cm−2, the electrode demonstrates steady cycling for over 600 h with low overpotential. The excellent cycling stability and rate performance are mainly attributed to a range of collective functionalities of ZWO interphase, including short-range and isotropic ion migration, superior ion-screening capability, and a thermodynamically enhanced energy barrier for hydrogen evolution reaction (HER) during Zn plating. These findings highlight the significance of the multi-scale functional interphase in overcoming key barriers associated with zinc anodes under high current density, offering a facile and insightful approach for achieving high-performance Zn metal anodes.