Tetra‐Coordinated Zn 2+ with Coordination Number‐Dependent Stacking Behavior of Zn(101) Facets in the DES‐Gel Electrolyte for Wide‐Temperature Zinc‐Ion Batteries

ABSTRACT The typical Zn 2+ solvation structure with six water molecules (Zn 2+ ‐6H 2 O) in the aqueous zinc ion batteries (ZIBs) transports massive H 2 O to the anode, triggering parasitic hydrogen evolution, anode corrosion, and uncontrolled dendrite growth with a loose stacking of Zn(101) facets, leading to the rapid failure of the batteries, especially under harsh working conditions. Herein, in this work, a deeply reconstructed solvation structure of the Zn 2+ with a tetra‐coordination configuration is proposed using the deep eutectic solvent‐based gel (DES‐gel) electrolyte to stabilize the Zn anode in a wide temperature range. The unique solvation structure induces a coordination number‐dependent stacking of the Zn(101) facets with a halogen‐rich solid electrolyte interphase (SEI), which substantially alleviates the undesired side reactions and enhances temperature adaptability. As a result, the Zn||Zn cells using the DES‐gel as electrolyte stably cycle for over 1450 h at the current density of 0.5 mA cm −2 under room temperature. Moreover, the symmetric cells with DES‐gel electrolyte exhibit high temperature adaptability with ultralong cycling stability for 1600 and 980 h at −20°C and 50°C, respectively. Consequently, the full batteries with the DES‐gel deliver ultra‐stable cycling performance over a wide temperature range of 70°C.