Defect-Engineered MOF for Wide-Temperature Quasi-Solid-State Electrolyte with High Comprehensive Electrochemical...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) are promising for lithium metal batteries.
• Defect engineering can improve MOF electrolyte performance.
• Optimizing active sites is key for electrochemical applications.

Purpose of the Study:

• To engineer defects in Ni-MOF(II) for enhanced lithium metal battery electrolytes.
• To investigate the impact of defect concentration on electrochemical properties.
• To develop high-performance quasi-solid-state electrolytes.

Main Methods:

• Synthesized a 3D cluster-based Ni-MOF(II) framework.
• Employed a ligand defect strategy to create defective Ni-MOF(II)-X materials (X=30, 50, 70).
• Evaluated electrochemical performance, including ionic conductivity, Li+ transference number, and electrochemical stability window.

Main Results:

• Defective Ni-MOF(II)-50 exhibited excellent ionic conductivity (1.25 × 10^-3 S cm^-1 at 25°C) and a high Li+ transference number (0.83).
• Achieved a broad electrochemical stability window (5.1 V at 25°C, 5.0 V at -30°C).
• Demonstrated stable cycling in a Li|Ni-MOF(II)-50|Li symmetric cell for over 800 hours.

Conclusions:

• Defect engineering creates open metal sites, facilitating ion transport and anion immobilization.
• Ni-MOF(II)-50 shows potential as a high-performance quasi-solid-state electrolyte for lithium metal batteries.
• The study presents a viable defect-engineering pathway for advanced MOF-based electrolytes with wide operational temperature ranges.