Design strategies for low temperature aqueous electrolytes

Abstract

Low temperature aqueous batteries (LT-ABs) have attracted extensive attention recent years. The LT-ABs suffer from electrolyte freezing, slow ionic diffusion and sluggish interfacial redox kinetics at low temperature. In this review, we discuss physicochemical properties of aqueous electrolytes in terms of phase diagram, ion diffusion and interfacial redox kinetics to guide the design of low temperature aqueous electrolytes (LT-AEs). Firstly, the characteristics of equilibrium and non-equilibrium phase diagrams are introduced to analyze the antifreezing mechanisms and propose design strategies for LT-AEs. Then, the temperature/concentration/charge carrier dependence conductivity characteristics in aqueous electrolytes are reviewed to comprehend and regulate the ion diffusion kinetics. Moreover, we introduce interfacial studies in aqueous and non-aqueous batteries and propose potential improvement strategies for interfacial redox kinetics in LT-ABs. Finally, we summarize design strategies of LT-AEs for developing high performance LT-ABs.