Reconfiguring\nthe Coordination Structure in Deep Eutectic\nElectrolytes for Enabling Stable Operation of Zinc-Ion Batteries

Highly stable aqueous Zn-ion batteries are of great importance\nfor commercial applications. The challenging issues of interfacial\nside reactions and rampant dendrite growth cause short circuit and\npremature failure of aqueous Zn-ion batteries. Herein, a hydrated\ndeep eutectic electrolyte is formulated to tackle such problems, which\nadopts 1,3-propanediol as a cosolvent. 1,3-Propanediol molecules can\nenter into the Zn<sup>2+</sup> solvation structure to from a lean-water\nelectrolyte and drastically diminish the activity of water molecules\nthrough reinforcing the hydrogen bond network. Meanwhile, PDO molecules\nexclude the neighboring water to modulate the electric double layer\nconfiguration, thus impeding water-mediated side reactions and inducing\nan inorganic-rich interphase. Consequently, this hydrated deep eutectic\nelectrolyte ensures long-term stability of Zn–Zn, Zn–Cu,\nand Zn–I<sub>2</sub> cells. The favorable influence exerted\nby PDO molecules provides the guidance for constructing high-performance\naqueous Zn-ion batteries.