ZrO2-Nanoparticle-Modified Graphite Felt: Bifunctional Effects on Vanadium Flow Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Graphite felt (GF) electrodes are crucial for vanadium flow batteries (VFBs).
• Improving GF electrode performance is key to enhancing VFB efficiency and longevity.
• Electrolyte accessibility and active sites limit current GF electrode performance.

Purpose of the Study:

• To synthesize ZrO2-modified GF (ZrO2/GF) electrodes.
• To investigate the effect of ZrO2 content on GF electrode performance in VFBs.
• To enhance the electrochemical activity, reversibility, and stability of GF electrodes.

Main Methods:

• Facile immersion-precipitation approach for ZrO2 nanoparticle synthesis.
• Characterization of ZrO2/GF composite electrodes.
• Electrochemical performance testing of VFBs using modified electrodes.

Main Results:

• Uniform immobilization of ZrO2 nanoparticles on GF.
• Enhanced electrolyte accessibility and increased active sites for redox reactions.
• ZrO2/GF electrodes showed superior electrochemical activity and reversibility compared to bare GF.
• The optimal 0.3 wt% ZrO2/GF composite achieved 71.9% voltage and 67.4% energy efficiency at 200 mA cm(-2).
• ZrO2/GF electrodes demonstrated outstanding stability with negligible activity decay after 200 cycles.

Conclusions:

• ZrO2 modification is an effective strategy to improve GF electrode performance in VFBs.
• The enhanced electrochemical properties and stability of ZrO2/GF electrodes promise advanced VFB technology.
• Optimized ZrO2 loading provides significant improvements in VFB efficiency and cycle life.