Cobalt-based zeolitic imidazolate frameworks modified separator as efficient polysulfide adsorbent for high...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Polypropylene (PP) films are widely used but require modification for advanced energy storage applications.
• Lithium-sulfur (Li-S) batteries offer high theoretical energy density but suffer from polysulfide dissolution and poor cycling stability.
• Zeolitic imidazolate frameworks (ZIFs) are promising porous materials for electrochemical applications.

Purpose of the Study:

• To develop a novel strategy for modifying polypropylene films using cobalt-based zeolitic imidazolate framework-67 (ZIF-67).
• To investigate the structural and morphological properties of the synthesized ZIF-67.
• To evaluate the electrochemical performance of ZIF-67 modified polypropylene (ZIF-67/PP) films in lithium-sulfur batteries.

Main Methods:

• Synthesis and characterization of ZIF-67 using powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM).
• Nitrogen (N2) absorption-desorption analysis to confirm mesoporosity.
• Fabrication of ZIF-67/PP films and their integration into Li-S battery test cells.
• Electrochemical testing, including capacity measurements and cycling stability at various C-rates.

Main Results:

• ZIF-67 was successfully synthesized with a cubic structure (80-100 nm) and confirmed mesoporosity.
• Li-S batteries utilizing ZIF-67/PP films demonstrated a high initial specific capacity of 1365 mAh g⁻¹ at 0.1C.
• Superior cycling stability was observed, with a capacity of 816 mAh g⁻¹ retained after 300 cycles at 2C.

Conclusions:

• The ZIF-67/PP film exhibits strong adsorption capabilities for polysulfides, mitigating their negative impact on Li-S battery performance.
• The developed modification strategy offers a promising route for enhancing the commercial viability of Li-S batteries.
• This work highlights the potential of ZIF-based materials in advanced energy storage solutions.