Hierarchically Interconnected 3D Catalyst Structure of Porous Multi-Metal Oxide Nanofibers for High-Performance Li-O₂...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Non-aqueous lithium-oxygen batteries (LOBs) offer high theoretical energy density but face challenges with high overpotential and poor cycling stability.
• Difficulties in decomposing lithium peroxide (Li2O2) discharge products limit LOB performance.

Purpose of the Study:

• To develop a novel catalyst structure for enhancing the electrochemical performance of LOBs.
• To improve the kinetics of Li2O2 formation and decomposition in LOBs.

Main Methods:

• Fabrication of highly-thin and porous multi-metal oxide nanofibers (MMONFs) using electrospinning and heat treatment.
• Assembly of a 3D open network catalyst structure using MMONFs.
• Electrochemical characterization of the developed cathode materials in LOBs.

Main Results:

• The 3D porous MMONFs catalyst exhibited a high specific surface area and porosity, enhancing electrochemical reaction kinetics.
• Achieved 82% energy efficiency at 50 mA g⁻¹ and over 100 cycles at 200 mA g⁻¹ with 500 mAh g⁻¹ cut-off capacity.
• Demonstrated a remarkable energy density of 1013 Wh kg⁻¹ at the 100th cycle, significantly outperforming current electric vehicle cathode materials.

Conclusions:

• The proposed 3D MMONFs catalyst structure effectively improves Li2O2 decomposition and formation kinetics.
• The novel cathode materials show promising potential for next-generation high-energy-density lithium-oxygen batteries.
• This advancement addresses critical stability and efficiency issues in LOB technology.