A glutamate anion boosted zinc anode for deep cycling aqueous zinc ion batteries

Abstract

Due to the low reduction potentials of conventional additives, in situ construction of appropriate solid electrolyte interphases (SEIs) in aqueous batteries has never been properly explored, although they play a critical role in governing the metal anode surface electrochemistry. Herein, we reveal new insight into the role of Glu⁻ as an enabling player in the in situ construction of a robust SEI, thereby achieving impressive Zn²⁺ electrochemical kinetics and effectively mitigating the unwanted Zn dendrites and parasitic reactions. By virtue of the protective SEI layer, we demonstrate a symmetric Zn//Zn (asymmetric Zn//Cu) cell exhibiting a long cycle lifespan (up to 4000 h), high reversibility (99.35% over 1350 cycles), and outstanding stability (running at up to 20 mA cm⁻²). As a demonstration of establishing aqueous zinc ion batteries for practical applications, a full cell with a MnO₂ cathode shows a higher specific capacity of 108.7 mA h g⁻¹ after 1300 cycles.