A low-cost average valence detector for mixed electrolytes in vanadium flow batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Vanadium redox flow batteries (VFBs) are promising for large-scale energy storage but suffer from capacity decay.
• Electrolyte mixing can partially restore capacity but is limited by increasing average valence due to side reactions.

Purpose of the Study:

• To develop a low-cost optical detector for monitoring the average valence of VFB electrolytes.
• To demonstrate a method for recovering VFB capacity using the developed detector.

Main Methods:

• Fabrication of a low-cost optical average valence detector.
• Experimental validation of the detector's performance in monitoring VFB electrolyte average valence.
• Implementation of electrolyte mixing and online electrolysis guided by the detector for capacity recovery.

Main Results:

• The developed optical detector accurately monitors the average valence of mixed VFB electrolytes.
• Regular capacity recovery of VFBs was achieved using electrolyte mixing and online electrolysis, guided by the detector.
• The proposed method effectively addresses capacity decay issues in VFBs.

Conclusions:

• A low-cost optical average valence detector is a viable tool for VFB monitoring and capacity management.
• This technology holds significant potential for enhancing the long-term performance and reliability of large-scale VFB energy storage systems.
• The developed detector facilitates efficient capacity recovery, overcoming limitations of traditional electrolyte mixing methods.