Regulated Ion/Electron‐Conducting Interphase Enables Stable Zinc‐Metal Anodes for Aqueous Zinc‐Ions Batteries

Abstract

Abstract Metallic Zinc (Zn) is considered as a remarkably promising anode for aqueous Zn‐ion batteries due to its high volumetric capacity and low redox potential. Unfortunately, dendritic growth and severe side reactions destabilizes the electrode/electrolyte interface, and ultimately reduce the electrochemical performance. Here, an artificial protective layer (APL) with a regulated ion and electron‐conducting interphase is constructed on the Zn‐metal anode to provide excellent interfacial stability in high‐rate cycling. The superior ionic and moderate electronic conductivity of the APL derives from the co‐embedding of MXene and Zn(CF 3 SO 3 ) 2 salts into the polyvinyl alcohol hydrogel, which enables a synergistic effect of local current density reduction during plating and ion transport acceleration during stripping for Zn anode. Furthermore, the high Young's modulus of the protective layer and dendrite‐free deposition morphology during cycling suppresses hydrogen evolution reactions (2.5 mmol h −1 cm −2 ) and passivation. As a result, in symmetrical cell tests, the modified battery presents a stable life of over 2000 cycles at ultra‐high current density of 20 mA cm −2 . This research presents a new insight into the formation and regulation of stable electrode‐electrolyte interface for the Zn‐metal anode.