Cerium/Ascorbic Acid/Iodine Active Species for Redox Flow Energy Storage Battery

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Redox flow batteries (RFBs) are crucial for grid-scale energy storage.
• Developing cost-effective and efficient RFB systems remains a key challenge.
• Cerium and iodine redox couples offer potential for low-cost RFB electrolytes.

Purpose of the Study:

• To design and develop a novel cerium/ascorbic acid/iodine active species for a redox flow battery.
• To enhance electrochemical activity and prevent ion cross-contamination through electrode and membrane modification.
• To evaluate the performance and potential of this new RFB system.

Main Methods:

• Development of a novel Ce/ascorbic acid/I active species using cerium nitrate and potassium iodate with ascorbic acid.
• Modification of carbon paper electrodes and Nafion 117 membranes using electroless plating and sol-gel methods.
• Electrochemical characterization using cyclic voltammetry (CV) with methanesulfonic acid as a supporting electrolyte.

Main Results:

• The Ce³⁺/Ce⁴⁺ redox couple exhibited symmetric oxidation/reduction on the C-TiO₂-PdO composite electrode (ratio 1.09).
• Ascorbic acid addition to the iodine solution ensured a reversible oxidation/reduction reaction.
• The developed Ce/ascorbic acid/I RFB with modified electrodes and membrane achieved approximately 72% energy efficiency.

Conclusions:

• A novel and potentially low-cost cerium/ascorbic acid/iodine RFB system has been successfully developed.
• Electrode and membrane modifications are effective in improving electrochemical performance and preventing cross-contamination.
• This system demonstrates significant development potential as a cost-effective alternative to traditional all-vanadium RFBs.