Polyelemental Nanoparticles as Catalysts for a Li-O₂ Battery.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Rechargeable lithium-oxygen (Li-O2) batteries offer high energy density but face challenges with cathode catalyst efficiency.
• Polyelemental catalysts, combining multiple elements, show promise for improving oxygen reduction and evolution reactions.

Purpose of the Study:

• To explore the electrochemical performance of Li-O2 batteries using diverse polyelemental catalysts.
• To investigate the impact of catalyst composition (single, binary, ternary, quaternary) on battery performance.

Main Methods:

• Preparation of fourteen different catalyst combinations (Pt, Pd, Au, Ru) on carbon nanofibers (CNFs) using a joule heating route.
• Electrochemical testing of Li-O2 batteries with these catalysts.

Main Results:

• A quaternary catalyst (Pt-Pd-Au-Ru) demonstrated significantly improved Li-O2 battery performance.
• The quaternary catalyst cathode exhibited a reduced overpotential of 0.45 V and a high discharge capacity of 9130 mAh g-1.
• Performance was approximately three times higher than pristine CNF electrodes.

Conclusions:

• Polyelemental catalysts, particularly quaternary combinations, are highly effective for enhancing Li-O2 battery cathodes.
• The superior performance is attributed to increased catalytic activity and improved oxygen adsorption by the quaternary nanoparticles.