Designing Solvated Double-Layer Polymer Electrolytes with Molecular Interactions Mediated Stable Interfaces for...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Unstable interfaces at the cathode-electrolyte and anode-electrolyte boundaries significantly degrade the cycle performance of polymer-based sodium-ion batteries (SIBs).
• Addressing these interfacial instabilities is crucial for developing high-performance SIBs.

Purpose of the Study:

• To design a unique solvated double-layer quasi-solid polymer electrolyte (SDL-QSPE) that enhances interfacial stability on both the cathode and anode sides.
• To improve the overall cycle performance and ionic conductivity of polymer-based SIBs.

Main Methods:

• Development of a laminated SDL-QSPE featuring cathode- and anode-facing polymer electrolyte layers.
• Incorporation of functional fillers solvated with plasticizers to boost Na+ conductivity and thermal stability.
• Utilizing theoretical calculations and 3D X-ray microtomography to analyze interfacial evolution.

Main Results:

• The developed SDL-QSPE demonstrates high Na+ ion conductivity and improved thermal stability.
• Sodium-ion batteries utilizing the SDL-QSPE achieved a capacity of 80.4 mAh/g after 400 cycles at 1C.
• Coulombic efficiency remained close to 100% throughout the cycling process.

Conclusions:

• The SDL-QSPE effectively stabilizes both the cathode and anode interfaces in polymer-based SIBs.
• This dual interfacial stabilization significantly enhances cycle performance compared to monolayer quasi-solid polymer electrolytes.
• The findings present a promising strategy for advancing the development of stable and high-performance sodium-ion batteries.