Composite NiCo₂ O₄ @CeO₂ Microsphere as Cathode Catalyst for High-Performance Lithium-Oxygen Battery.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-oxygen batteries (LOBs) face challenges with large overpotential and poor cycle stability due to inactive redox reactions.
• Developing high-performance electrocatalysts is crucial for advancing LOB technology.

Purpose of the Study:

• To synthesize and evaluate a novel NiCo2O4@CeO2 composite microsphere as an electrocatalyst for LOBs.
• To investigate the structural and electronic properties contributing to the enhanced electrochemical performance.

Main Methods:

• Hydrothermal synthesis followed by annealing to create NiCo2O4@CeO2 composite microspheres.
• Electrochemical testing of LOBs using the synthesized catalyst.
• Density Functional Theory (DFT) calculations to analyze electronic structure and reaction kinetics.

Main Results:

• The NiCo2O4@CeO2 microsphere catalyst demonstrated a low overpotential of 1.07 V.
• Achieved remarkable cycling stability of 400 loops at 500 mA g-1.
• The unique structure facilitates oxygen and ion transport, electrolyte penetration, and Li2O2 kinetics.
• CeO2 introduction enhanced oxygen vacancies and optimized NiCo2O4 electronic structure for improved electron transport.

Conclusions:

• NiCo2O4@CeO2 composite microspheres are highly effective electrocatalysts for LOBs.
• The rational design of cathode materials with enhanced structural and electronic properties is key to LOB development.
• This study provides insights into optimizing LOB cathode performance through advanced material design.