Wide-Temperature Electrolytes for Aqueous Alkali Metal-Ion Batteries: Challenges, Progress, and Prospects

Aqueous alkali metal-ion batteries (AAMIBs) have been recognized as emerging electrochemical energy storage technologies for grid-scale applications owning to their intrinsic safety, cost-effectiveness, and environmental sustainability. However, the practical application of AAMIBs is still severely constrained by the tendency of aqueous electrolytes to freeze at low temperatures and decompose at high temperatures, limiting their operational temperature range. Considering the urgent need for energy systems with higher adaptability and resilience at various application scenarios, designing novel electrolytes via structure modulation has increasingly emerged as a feasible and economical strategy for the performance optimization of wide-temperature AAMIBs. In this review, the latest advancement of wide-temperature electrolytes for AAMIBs is systematically and comprehensively summarized. Specifically, the key challenges, failure mechanisms, correlations between hydrogen bond behaviors and physicochemical properties, and thermodynamic and kinetic interpretations in aqueous electrolytes are discussed firstly. Additionally, we offer forward-looking insights and innovative design principles for developing aqueous electrolytes capable of operating across a broad temperature range. This review is expected to provide some guidance and reference for the rational design and regulation of wide-temperature electrolytes for AAMIBs and promote their future development.