Imidazolium-Type Poly(ionic liquid) Endows the Composite Polymer Electrolyte Membrane with Excellent Interface...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Developing solid-state polymer electrolytes is crucial for advancing lithium metal battery safety and performance.
• Poly(ethylene oxide)-based electrolytes often face challenges with ionic conductivity and mechanical strength.

Purpose of the Study:

• To create a composite polymer electrolyte (CPE) with enhanced organic/inorganic interface compatibility for all-solid-state lithium metal batteries (ASSLMBs).
• To investigate the properties and electrochemical performance of a novel poly(ionic liquid)-modified PEO-based electrolyte.

Main Methods:

• Synthesis of an imidazolium-type poly(ionic liquid) and its incorporation into a PEO-based polymer electrolyte.
• Systematic characterization of micromorphologies, thermal behavior, crystallinity, lithium-ion transference number (tLi+), and mechanical properties.
• Electrochemical performance evaluation, including ionic conductivity and cycling stability.
• Density functional theory (DFT) simulations to understand interfacial interactions.

Main Results:

• The novel poly(ionic liquid) significantly improved the organic/inorganic interface compatibility of the CPE due to strong electrostatic and ion-dipole interactions.
• The developed CPE exhibited a high ionic conductivity of 1.46 × 10⁻⁴ S cm⁻¹ at 40 °C.
• The electrolyte demonstrated remarkable mechanical strain tolerance (2000%), enabling dendrite-free lithium metal plating and stable battery operation.

Conclusions:

• The synergistic electrostatic and ion-dipole interactions effectively enhance CPE compatibility and performance.
• This PEO-based polymer electrolyte offers a promising strategy for the development of highly stable and efficient ASSLMBs.
• The findings accelerate the practical application of advanced polymer electrolytes in next-generation batteries.