Synergistic Solvation Strategy for Low-Temperature Alkaline Zinc-Ferricyanide Flow Battery

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Alkaline zinc-ferricyanide flow batteries (AZFFBs) are promising for long-duration energy storage.
• Low-temperature operation faces challenges like electrolyte solidification and capacity decay due to zinc dendrites and ferricyanide precipitation.

Purpose of the Study:

• To develop a synergistic solvation strategy for AZFFBs to improve low-temperature performance and cycle life.
• To address electrolyte solidification, zinc deposition issues, and ferricyanide precipitation at cryogenic temperatures.

Main Methods:

• A synergistic solvation strategy using Li+ and Cl- ions was implemented.
• Li+ and Cl- were used to modify anolyte and catholyte properties, influencing hydrogen bonding, zincate solvation, and ferricyanide solubility.

Main Results:

• The strategy effectively lowered the liquid-solid transition temperature of both electrolytes.
• Optimized AZFFBs demonstrated stable cycling at -20 °C with 99.54% coulombic efficiency.
• Exceptional room-temperature stability was achieved with over 500 cycles (99.79% coulombic efficiency) and robust performance under fluctuating temperatures.

Conclusions:

• The synergistic solvation strategy significantly enhances AZFFB performance in extreme cold and fluctuating temperatures.
• This breakthrough positions AZFFBs as a viable energy storage solution for demanding applications like polar microgrids and subsea power.