Composite Gel Electrolytes with Ion-Mediated Compatibilization and Matrix-Assisted Conduction for Wide-Temperature...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Gel polymer electrolytes (GPEs) face a conductivity-mechanical property trade-off.
• Conventional GPEs like single-material polymers or polymer/ceramic composites have limitations.
• Existing solutions fail to adequately address the GPE performance challenges.

Purpose of the Study:

• To enhance the phase consistency of composite GPEs.
• To improve ionic conductivity and mechanical properties of GPEs.
• To develop high-performance GPEs for demanding battery applications.

Main Methods:

• Incorporated lithium sulfonate groups for ion-mediated compatibilization of PVHF/PEEK polymer blends.
• Optimized ionic environment using pendent lithium sulfonate at domain interfaces.
• Investigated matrix-assisted ion conduction within the GPE.

Main Results:

• Achieved high ionic conductivity (1.87 mS cm^-1 at 20 °C, 1.28 mS cm^-1 at -20 °C).
• Demonstrated excellent Li||LiFePO₄ battery performance (157.0 mAh g^-1 at 1 C, 90.7% retention after 1500 cycles).
• Showcased superior performance under harsh conditions (5 C rate, -20 °C to 80 °C, 30-µm Li metal anode).

Conclusions:

• The developed composite gel electrolyte overcomes the GPE trade-off.
• Innovative nanostructure and molecular design advance GPE technology.
• The GPE shows promise for next-generation high-performance batteries.