Synergistic Chaotropic Effect and Cathode Interface Thermal Release Effect Enabling Ultralow Temperature Aqueous Zinc Battery.

Abstract

Although rechargeable zinc-ion batteries are promising candidates for next-generation energy storage devices, their inferior performance at subzero temperatures limits their practical application. Here, a strategy to destroy the H-bond network by adding synergistic chaotropic regents is reported, thus reducing the freezing point of the aqueous electrolyte below -90°C. Owing to the synergistic chaotropic effect between urea and Zn(ClO4 )2 and the thermal release effect on the cathode interface during charging, Zn//VO2 batteries feature a specific capacity of 111.4mAhg-1 and stability after ≈1000 cycles with 81.9% capacity retention at -40°C. This work demonstrates that the synergistic chaotropic effect and the thermal effect on the interface can effectively widen the operation range of temperature of aqueous electrolytes and maintain fast kinetics, which provides a new design strategy for all-weather aqueous zinc batteries.