Polyimide-Based Solid-State Gel Polymer Electrolyte for Lithium-Oxygen Batteries with a Long-Cycling Life

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Metal-air batteries, especially lithium-oxygen (Li-O2) batteries, offer high theoretical energy densities.
• Liquid electrolyte evaporation in semi-open Li-O2 systems causes safety concerns and limits cycle life.

Purpose of the Study:

• To develop a solid-state gel polymer electrolyte (PI@GPE) to prevent liquid electrolyte leakage in Li-O2 batteries.
• To enhance the safety and cyclic performance of Li-O2 batteries.

Main Methods:

• A polyimide-based gel polymer electrolyte (PI@GPE) was synthesized to immobilize liquid electrolyte.
• Electrolyte uptake, ionic conductivity, lithium transference number, and interfacial compatibility were evaluated.
• Li-O2 battery cycling performance using PI@GPE was tested and compared to conventional separators.

Main Results:

• PI@GPE exhibited an 842% liquid electrolyte uptake, significantly higher than glass fiber separators.
• High ionic conductivity (0.44 mS cm⁻¹) and an enhanced lithium transference number (0.596) were achieved.
• PI@GPE-based Li-O2 batteries showed remarkable cycling stability of 366 cycles, four times longer than control.

Conclusions:

• The PI@GPE effectively mitigates liquid electrolyte leakage, improving safety and longevity.
• This solid-state gel polymer electrolyte shows significant potential for advanced, high-performance Li-O2 batteries.