Solvation-interface cascade engineering via dual-anion coordination enables ultra-wide-temperature zinc metal...

Aqueous zinc (Zn) metal batteries are promising for sustainable energy storage but suffer from severe temperature sensitivity due to sluggish ion transport at low temperatures and interfacial corrosion at high temperatures. Herein, we propose a solvation-interface cascade engineering strategy that employs a rationally designed dual-anion electrolyte (OTf^-/Ac^-), enabling the stable operation of Zn metal batteries from -60 to 60 °C. The strongly polar Ac^- reconstructs the Zn²⁺ solvation structure, significantly suppressing H₂O activity and reducing the freezing point to -94.1 °C, while accelerating Zn²⁺ desolvation and transport. Simultaneously, Ac^- restructures the electric double layer and cooperates with OTf^- to promote a dense and stable organic-inorganic hybrid solid electrolyte interphase, endowing the Zn metal anode with a stable electrode interface. This cascade regulation, from solvation to electrode interface, suppresses Zn dendrites and side reactions across an ultra-wide temperature range. Consequently, Zn||Zn cells run for 3900 and 2800 h at -25 and 45 °C, respectively. PANI||Zn cells increase 16.0% capacity retention after 120 cycles at 60 °C and maintain stable operation at -60 °C, demonstrating exceptional extreme-temperature potential. This work establishes a generalizable paradigm of anion-mediated solvation-interface cascade regulation for all-climate energy storage systems.