Unlocking Cryogenic Zinc-ion Batteries with a Glycerol Monoallyl Ether-Modulated Aqueous Electrolyte

Abstract

Aqueous zinc-ion batteries (AZIBs) face critical challenges including zinc anode/electrolyte interfacial instability inducing capacity fade and cycle life degradation, and operational failure at sub-zero temperatures due to electrolyte freezing. To address these limitations, we employed 3-allyloxy-1,2-propanediol (AP) as a multifunctional electrolyte cosolvent. The AP synergistically depresses the electrolyte freezing point via disruption of water hydrogen-bonding network. Concurrently, alcoholic hydroxyl groups in AP preferentially absorb onto the zinc anode, directing oriented Zn(002) plane growth to enable uniform and dendrite-free zinc deposition. Furthermore, oxygen atoms of AP restructure Zn 2+ solvation sheaths, weakening H2O-Zn 2+ coordination bonds while suppressing water activity. Through systematic optimization of the water-to-AP ratio and combined experimental-theoretical analysis, we elucidated Zn 2+ behavior from solvation thermodynamics to deposition kinetics. The optimized AP-10% electrolyte enables a Zn||Zn symmetric cell to achieve exceptional cycling stability (4500 h at 1.0 mA cm -2 /1.0 mAh cm -2 , 25 o C). The Zn||NVO full cells with AP-10% electrolyte retain capacity 1650 cycles at 2.0 A g -1 .The electrolyte also exhibits sustained operation for 2500 h in Zn||Zn symmetric cells at -20 o C. This work establishes an integrated electrolyte design strategy that simultaneously addresses dendrite suppression, parasitic reaction mitigation, and low-temperature cryogenic operation, advancing practical AZIBs for cryogenic energy storage applications.