Bismuth nanoparticle decorating graphite felt as a high-performance electrode for an all-vanadium redox flow battery

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• All-vanadium redox flow batteries (VRFBs) are crucial for grid-scale energy storage.
• The sluggish V(II)/V(III) redox reaction kinetics at the negative electrode limit VRFB performance, especially at high power densities.
• Noble metal electrodes are effective but costly.

Purpose of the Study:

• To investigate the electrodeposition of bismuth (Bi) nanoparticles onto graphite felt electrodes in VRFBs.
• To evaluate the impact of Bi nanoparticles on the electrochemical performance of VRFBs.
• To explore Bi nanoparticles as a cost-effective alternative to noble metals for VRFB electrodes.

Main Methods:

• Synchronous electrodeposition of Bi nanoparticles onto graphite felt electrodes during VRFB operation using electrolytes containing Bi(3+).
• Electrochemical performance testing of VRFB cells with and without Bi nanoparticles.
• Analysis of charge transfer kinetics and energy efficiency at various current densities.

Main Results:

• Bi nanoparticles were successfully electrodeposited onto the negative electrode of the VRFB.
• Bi nanoparticles significantly enhanced the kinetics of the V(II)/V(III) redox reaction.
• VRFB cells with Bi nanoparticles showed an 11% increase in energy efficiency at 150 mA·cm(-2) due to faster charge transfer.

Conclusions:

• Bismuth nanoparticles effectively improve the electrochemical performance of all-vanadium redox flow batteries.
• The enhanced kinetics of the V(II)/V(III) redox reaction by Bi nanoparticles are particularly beneficial under high power operation.
• Bismuth nanoparticles present a promising, cost-effective alternative to noble metal electrodes for high-performance VRFB applications.