Molecule Crowding Strategy in Polymer Electrolytes Inducing Stable Interfaces for All-Solid-State Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Unstable electrode/electrolyte interfaces cause electrolyte decomposition and lithium dendrites in solid-state lithium batteries.
• These interfacial issues limit the performance and lifespan of polymer electrolyte-based batteries.

Purpose of the Study:

• To develop a molecule crowding strategy for in situ construction of stable interfaces in solid-state lithium batteries.
• To enhance the electrochemical performance and stability of polymer electrolyte-based lithium batteries.

Main Methods:

• Utilizing 15-crown-5 to modulate Li+ coordinated structure and induce anion crowding.
• Analyzing the decomposition of crowded anions to form LiF-rich passivation layers.
• Conducting symmetric Li-Li cell tests, LiFePO4||Li and NCM811||Li full battery tests, and flexible pouch cell evaluations.

Main Results:

• Achieved stable operation of symmetric Li-Li cells over 4360 hours.
• Demonstrated high capacity retention in LiFePO4||Li (97.18% over 700 cycles) and NCM811||Li (83.17% over 300 cycles) full batteries.
• Showcased excellent flexibility and stability in assembled pouch cells (2000+ folds, 89.42% retention over 400 cycles).

Conclusions:

• The molecule crowding strategy effectively regulates interfacial chemistry by modulating the ion environment.
• This approach successfully stabilizes electrode/electrolyte interfaces, leading to improved battery performance and longevity.
• The findings offer a promising strategy for addressing interfacial challenges in polymer electrolytes and inspire future interface engineering.