Interface Engineering of Branched PdCoP_x Nanostructures for High-Performance Lithium-Oxygen Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Advanced cathode materials are crucial for improving lithium-oxygen battery (LOB) charge/discharge efficiency and cycle life.
• Developing novel nanostructures can enhance catalytic activity for oxygen reduction reactions (ORR).

Purpose of the Study:

• To develop a novel, high-dimensional branched PdCoP_x cathode material for enhanced LOB performance.
• To investigate the catalytic activity and structural properties of PdCoP_x for ORR and LOB applications.

Main Methods:

• Direct synthesis of high-dimensional branched PdCoP_x nanostructures.
• Electrochemical testing of PdCoP_x for oxygen reduction reaction (ORR) in alkaline media.
• Assembly and testing of LOBs using PdCoP_x cathodes.
• Density Functional Theory (DFT) calculations to understand reaction mechanisms.

Main Results:

• Pd₁Co₂P_x demonstrated superior ORR mass activity (1.46 A mg_Pd^-1) compared to commercial Pd/C and Pt/C catalysts.
• LOBs with Pd₁Co₂P_x cathodes exhibited an ultralow discharge/charge overpotential (0.40 V) and stable cycling for over 240 cycles.
• DFT calculations confirmed enhanced ORR kinetics due to dispersed Pd atoms and facilitated Li₂O₂ decomposition via Pd─Co─P interfaces.

Conclusions:

• The synthesized Pd₁Co₂P_x nanostructures serve as highly effective cathode materials for LOBs.
• The unique Pd─Co─P interfaces and ligand effects promote efficient ORR and Li₂O₂ decomposition, boosting battery performance and stability.