Gel Metal-Organic Frameworks in Highly Concentrated Electrolyte Promote Stable Solid-Electrolyte Interface on Lithium...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Highly concentrated electrolytes (HCEs) are crucial for enhancing lithium-based battery performance by suppressing dendrite formation.
• Developing stable and efficient electrolyte matrices remains a key challenge for advanced energy storage.

Purpose of the Study:

• To investigate the use of gel metal-organic frameworks (g-MOFs) as a component in HCEs for lithium-based batteries.
• To evaluate the impact of g-MOFs on electrolyte properties, including ion conductivity and lithium-ion transference.
• To assess the electrochemical performance and stability of batteries utilizing g-MOF-enhanced electrolytes.

Main Methods:

• Synthesis and characterization of Zr-based g-MOFs.
• Preparation of HCEs incorporating g-MOFs.
• Electrochemical testing of Li-symmetric cells, including cycling stability and rate capability.
• Surface analysis using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM).

Main Results:

• The developed "sandy-slurry" electrolyte, composed of g-MOFs and HCE (4.5 M LiTFSI in acetonitrile), exhibited enhanced ion conductivity (16.0 mS cm⁻¹) and Li⁺ transference number (0.800) compared to HCE alone (8.52 mS cm⁻², 0.511).
• Li-symmetric cells with g-MOF electrolytes demonstrated stable cycling at high charge/discharge rates and reduced overpotential.
• Surface analysis revealed that g-MOFs alter the solid-electrolyte interface (SEI) composition on the Li electrode.

Conclusions:

• Zr-based g-MOFs effectively enhance the performance of HCEs in lithium-based batteries.
• This study pioneers the use of g-MOFs in lithium-based batteries, showcasing their potential as gel electrolyte components for high-density energy storage.
• The findings suggest g-MOFs are promising materials for developing next-generation battery electrolytes.