Inner‐Sphere Penetration and Outer‐Matrix Anchoring: A Biomimetic Compartmentalized Strategy for Sub‐Zero Aqueous Zinc‐Ion Batteries

ABSTRACT Aqueous zinc‐ion batteries (AZIBs) are severely hindered at extremely low temperatures by aqueous electrolyte freezing, sluggish desolvation kinetics, and rampant dendrite growth. Drawing inspiration from biological compartmentalized cryoprotection, a biomimetic binary additive strategy is developed using penetrating dimethyl sulfoxide (DMSO) and non‐penetrating raffinose. DMSO, functioning as a permeable additive, can infiltrate the primary solvation structure of zinc ions, modify the solvation sheath, and disturb the organized configuration of water molecules, thus impeding ice crystal formation. The non‐permeable additive raffinose primarily modifies the surrounding microenvironments of the electrolyte, diminishing the activity of free water molecules, substantially decreasing the freezing point, and facilitating the system's shift to a glassy state. Consequently, the optimized electrolyte enables Zn//Zn symmetric cells to deliver an exceptional lifespan of 1600 h at 10 mA cm −2 , and maintain stable cycling over 600 h even at −30°C (5 mA cm −2 ). Moreover, Zn//Cu half‐cells achieve a high Coulombic efficiency of 99.76%, while Zn//NH 4 V 4 O 10 full cells retain 130 mAh g −1 after 1000 cycles at −30°C and 5 A g −1 . This study breaks the low‐temperature boundaries of AZIBs and offers a universal biomimetic paradigm for wide‐temperature electrolyte engineering.