Dynamic Migration-Pulling Polymer Electrolyte Design Strategy for Low-Temperature Lithium-Sulfur Batteries.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Quasi-solid-state lithium-sulfur batteries offer high energy density but suffer from polysulfide issues and poor charge transport.
• Sluggish redox kinetics and the shuttle effect limit the practical application of these batteries.

Purpose of the Study:

• To develop a novel strategy to accelerate polysulfide redox kinetics in quasi-solid-state lithium-sulfur batteries.
• To enhance charge transport and improve the overall performance and stability of these batteries.

Main Methods:

• A dynamic migration-pulling strategy was employed using a GPE with boronic ester dynamic covalent bonds and polar side chains (BE-GPE).
• Theoretical calculations and experimental validation were used to analyze Li+ desolvation and charge transfer kinetics.
• Electrochemical performance was tested, including capacity, cycling stability, and low-temperature operation.

Main Results:

• The BE-GPE significantly reduced the Li+ desolvation barrier by restructuring the solvated structure.
• Rapid charge transfer kinetics were achieved, leading to high reversible capacity (1446 mAh g-1 at 0.1 C).
• Excellent cycling stability (0.04% decay over 1000 cycles at 0.5 C) and stable low-temperature performance (920 mAh g-1 at 0 °C) were demonstrated.

Conclusions:

• The dynamic migration-pulling strategy effectively accelerates redox kinetics and improves charge transport in quasi-solid-state lithium-sulfur batteries.
• The developed BE-GPE enables high-performance, stable energy storage, even under low-temperature conditions.
• This approach holds promise for advancing safe, high-energy electrochemical storage technologies.