Ultralong-Lifespan and Low-Temperature Zinc Metal Batteries Enabled by a Propylene Glycol-Modified Electrolyte

Aqueous zinc-ion batteries (AZIBs) hold great promise for next-generation large-scale energy storage owing to their safety, environmental friendliness, and low cost. However, their practical application is severely hindered by unstable Zn stripping/plating behavior, which often results in dendrite growth, side reactions, and poor reversibility, particularly under high current densities and low-temperature conditions. Here, we report the introduction of propylene glycol (PG) as a multifunctional electrolyte additive to fundamentally stabilize Zn anodes. PG molecules adsorb onto the Zn surface, regulating surface energy and lowering nucleation barriers to promote uniform Zn deposition. In parallel, PG participates in Zn²⁺ solvation by partially replacing H₂O molecules in the inner solvation shell. This dual regulation reduces H₂O activity and tailors both the inner and outer solvation structures, thereby optimizing Zn²⁺ transport. Furthermore, COMSOL simulations reveal that PG effectively suppresses the hydrogen evolution reaction. Benefiting from these synergistic effects, Zn||Zn symmetric cells exhibit prolonged cycling lifetimes of up to 4000 h, while Zn||V₂O₅ full cells maintain stable operation over 3000 cycles at high current densities. It is worth noting that the system can also be used normally at low temperatures, and the Zn||Zn battery can be stably cycled for more than 100 h at -30 °C. This work provides a simple yet effective strategy for constructing high-performance AZIBs with enhanced interfacial stability and wide temperature adaptability.