Conducting Composite Polymer-Based Solid-State Electrolyte with High Ion Conductivity via Amorphous Condensed...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Traditional polyethylene oxide (PEO) electrolytes suffer from high crystallinity, hindering Li+ ion transport and resulting in poor ionic conductivity and complex processing.
• Limitations in current polymer electrolytes impede efficient ion transmission, impacting overall battery performance and scalability.

Purpose of the Study:

• To design and synthesize an amorphous polymer electrolyte (p-electrolyte) with enhanced ionic conductivity and a wide electrochemical window.
• To construct an in situ curable composite polymer electrolyte (CPE-L) by incorporating Cu-BTC MOF and LLZTO nanoparticles for improved Li+ transport.
• To evaluate the electrochemical performance and stability of the developed polymer electrolyte in lithium-ion batteries.

Main Methods:

• Synthesis of an amorphous polymer electrolyte with a condensed structure.
• Incorporation of Copper(II) benzene-1,3,5-tricarboxylate (Cu-BTC) metal-organic framework (MOF) and lithium lanthanum zirconium oxide (LLZTO) nanoparticles.
• Fabrication and testing of Li||CPE-L||Li symmetric batteries and full cells.

Main Results:

• The amorphous p-electrolyte exhibits a wide electrochemical window (4.2 V) and high ionic conductivity (1.58 × 10⁻⁵ S cm⁻¹), significantly exceeding traditional PEO electrolytes.
• The composite polymer electrolyte (CPE-L) demonstrates remarkable ionic conductivity (1.02 × 10⁻³ S cm⁻¹) and a high Li+ transference number (0.58) due to synergistic effects.
• The Li||CPE-L||Li symmetric battery shows stable cycling for over 700 hours, and the full battery achieves a specific capacity of approximately 153 mAh g⁻¹.

Conclusions:

• The developed amorphous polymer electrolyte and subsequent composite structure offer efficient Li+ transport pathways, addressing limitations of conventional materials.
• The synergistic integration of Cu-BTC MOF and LLZTO nanoparticles in the polymer matrix leads to superior ionic conductivity and electrochemical stability.
• This advanced polymer electrolyte design holds significant promise for high-performance and stable lithium-ion battery applications.