Molecular Engineering Enabled In Situ 3D Cross-Linked and Thermo-Electrochemically Stable Poly(1,3-dioxolane) Solid...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Poly(1,3-dioxolane) (PDOL) solid polymer electrolytes have limited applications due to narrow electrochemical stability windows and poor thermal stability.
• Unstable terminal hydroxyl groups in PDOL hinder its performance in lithium metal batteries.

Purpose of the Study:

• To design and synthesize a novel poly(1,3-dioxolane) dimethacrylate (PDOL-DMA) for improved solid polymer electrolytes.
• To enhance the electrochemical and thermal stability of electrolytes for lithium metal batteries.

Main Methods:

• Synthesis of poly(1,3-dioxolane) dimethacrylate (PDOL-DMA).
• Fabrication of a cross-linked quasi-solid electrolyte (CPDOL-DMA QSE).
• Electrochemical testing, including stability window and cycling performance evaluation.
• Thermal stability assessment using microcalorimetry and accelerated calorimetry.

Main Results:

• The CPDOL-DMA QSE exhibits a wide electrochemical stability window of 4.5 V vs. Li+/Li.
• Achieved a high Li+ transference number of 0.64, facilitating ion transport.
• Demonstrated excellent cycling stability with 83% capacity retention after 400 cycles at 25 °C.
• Maintained 82% capacity retention after 200 cycles at 80 °C, indicating thermal stability.
• Confirmed high safety through microcalorimetry and accelerated calorimetry due to high oxygen content.

Conclusions:

• The cross-linked network in CPDOL-DMA QSE improves lithium salt dissociation and Li+ transport.
• PDOL-DMA is a promising material for developing stable and safe solid polymer electrolytes for lithium metal batteries.
• This research offers valuable insights into designing high-performance polyether polymer electrolytes with enhanced thermo-electrochemical stability.