Three-dimensional polyimide nanofiber framework reinforced polymer electrolyte for all-solid-state lithium metal...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Traditional lithium batteries use flammable liquid electrolytes, posing safety risks.
• Polyethylene oxide (PEO) based composite polymer electrolytes (CPEs) offer flexibility and processability but suffer from low ionic conductivity and mechanical strength.
• These limitations hinder their use in room-temperature all-solid-state lithium metal batteries.

Purpose of the Study:

• To enhance the ionic conductivity and mechanical strength of PEO-based CPEs.
• To develop safer and more efficient solid-state lithium batteries.
• To address the limitations of current polymer electrolytes for demanding battery applications.

Main Methods:

• Fabrication of a three-dimensional (3D) framework using interweaved high-modulus polyimide (PI) nanofibers.
• Incorporation of succinonitrile (SN) plasticizers into the PI-PEO matrix.
• Synergistic reinforcement of ionic conductivity and mechanical properties through the combined PI framework and SN plasticizer.

Main Results:

• The developed PI-PEO-SN CPEs achieved high ionic conductivity (1.03 × 10⁻⁴ S cm⁻¹ at 30 °C).
• Exceptional tensile strength (4.52 MPa) and superior lithium dendrite blocking ability (>400 h).
• Demonstrated excellent performance in LiFePO₄/PI-PEO-SN/Li solid-state cells, including high specific capacity (151.2 mAh g⁻¹ at 0.2 C) and long cycling life (>150 cycles).

Conclusions:

• The synergistic combination of a 3D PI nanofiber framework and SN plasticizer effectively enhances PEO CPEs.
• These advanced CPEs exhibit a promising balance of ionic conductivity, mechanical strength, and dendrite suppression for high-performance solid-state batteries.
• This research provides a pathway for designing next-generation polymer electrolytes for high energy density and safe all-solid-state lithium batteries.