Interface engineering via in situ constructed zincophilic gradient interphases for high-performance zinc-ion batteries in wide temperature ranges

Abstract

With the steadily rising demand for energy storage devices, there is an increasing need for high-performance batteries. Although aqueous zinc-ion batteries (AZIBs) are cost-effective and environmentally friendly, they still encounter challenges including dendrite growth, hydrogen evolution and performance degradation under extreme conditions. Here, a novel hydrated eutectic electrolyte (HEE) including ethylene glycol (EG), SnCl₂ solution and hydrated zinc salt (Zn(ClO₄)₂·6H₂O) successfully prolongs the service life of AZIBs in a range of extreme temperatures. Inspired by the advantageous properties of SnCl₂, this compound was utilized to generate a solid electrolyte interphase layer in situ on the zinc anode. By preventing direct contact between water and the zinc surface, this procedure creates a protective “shielding effect” that reduces the unchecked growth of zinc dendrites over time. Notably, SnCl₂ significantly enhances the cycling stability of the battery. As a result, the Zn||Zn symmetric cells deliver an extra-long cycling performance for 6320 h and a wide temperature tolerance (−30 to 70 °C). Moreover, this work examines the relationship between interfacial chemistry at the electrode–electrolyte interface and the characteristics of liquid eutectic networks. By fine-tuning interfacial chemistry, our findings provide a strategic pathway for optimizing the performance of AZIBs under extreme temperature conditions.