Multifunctional COF Colloid Regulates Anion Coordination in Solid Poly(Ionic Liquid)-Based Electrolyte for Lithium...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid polymer electrolytes (SPEs) face challenges in ionic conductivity and uniform lithium metal anode deposition.
• Reducing polymer crystallization and creating stable ion transport pathways are crucial for improving SPE performance.

Purpose of the Study:

• To incorporate covalent organic framework colloid (COF-C) as an additive in SPEs.
• To regulate lithium transport and establish stable electrolyte-electrode interphases.
• To overcome limitations of low ionic conductivity and inhomogeneous lithium deposition in SPEs.

Main Methods:

• Incorporation of COF-C as a multifunctional additive into poly(ionic liquid) (PIL) based SPEs.
• Investigating the interaction between COF-C and PIL anions to control polymer crystallization.
• Analyzing the role of COF-C as an anion receptor for uniform Li+ distribution and enhanced ion transport.
• Evaluating the formation of stable solid-state electrolyte interphases.

Main Results:

• COF-C addition restricted PIL crystal growth, reducing electrolyte crystallinity.
• Optimized SPEs achieved an ionic conductivity of 2.70 × 10^-4 S cm^-1 at 25 °C.
• Solid-state batteries (Li/PIL-COF-C/LiFePO4) exhibited excellent cycle stability with 93.1% capacity retention after 500 cycles.
• The PIL-COF-C system supported higher mass loading of LiFePO4.

Conclusions:

• COF-C effectively enhances ionic conductivity and regulates lithium deposition in SPEs.
• The developed SPEs demonstrate significant potential for high-performance, stable solid-state lithium-ion batteries.
• This approach offers a viable strategy for advancing next-generation energy storage solutions.