Electron Localization in Rationally Designed Pt₁Pd Single-Atom Alloy Catalyst Enables High-Performance Li-O₂...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Lithium-oxygen batteries (LOBs) offer high energy density but suffer from slow cathode reaction rates.
• Sluggish oxygen reduction and evolution reactions impede LOB efficiency and cycle life.

Purpose of the Study:

• To develop an efficient catalyst for LOBs that overcomes sluggish redox kinetics.
• To investigate the catalytic activity of single-atom alloys in LOBs.

Main Methods:

• Direct synthesis of single-atom alloy catalyst: single-atom platinum precisely dispersed in ultrathin palladium hexagonal nanoplates (Pt1Pd).
• Electrochemical testing of LOBs with Pt1Pd cathodes.
• Density functional theory (DFT) calculations to understand reaction mechanisms.

Main Results:

• The Pt1Pd cathode exhibited an ultralow overpotential of 0.69 V at 0.5 A g⁻¹.
• Negligible activity loss was observed over 600 hours of operation.
• DFT calculations confirmed that Pt1Pd enhances O2/Li2O2 redox couple activation by localizing electrons, reducing energy barriers.

Conclusions:

• The developed Pt1Pd single-atom alloy catalyst effectively addresses sluggish oxygen redox kinetics in LOBs.
• This catalytic design strategy is promising for improving LOB performance and can be applied to other energy storage and conversion devices.