Li-N Interaction Induced Deep Eutectic Gel Polymer Electrolyte for High Performance Lithium-Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Deep eutectic electrolytes (DEEs) offer unique properties for lithium-metal batteries (LMBs).
• Challenges include limited choices and poor electrode compatibility, hindering DEE advancement in LMBs.

Purpose of the Study:

• To develop a novel 1,2-dimethylimidazole (DMIm)-based deep eutectic gel polymer electrolyte for LMBs.
• To improve Li-ion transference and interface stability using Li-N interactions and PVDF incorporation.

Main Methods:

• Synthesized a DMIm-based DEE incorporating polyvinylidene difluoride (PVDF).
• Investigated the coordination environment of Li+ ions and interface stability with Li anode.
• Characterized ionic conductivity, non-flammability, and oxidation voltage.

Main Results:

• The developed electrolyte shows a high Li+ transference number (0.65) and superior interface stability.
• Exhibits excellent non-flammability, high ionic conductivity (1.67 mS cm-1 at 30°C), and high oxidation voltage (4.35 V).
• Li||LFP cells demonstrate robust long-term cycling stability across various rates.

Conclusions:

• The novel DMIm-based deep eutectic gel polymer electrolyte addresses key limitations in DEEs for LMBs.
• The Li-N interaction and PVDF incorporation are crucial for enhanced performance.
• This electrolyte shows significant potential for developing high-performance and safe LMBs.