Fatigue-Resistant Interfacial Layer for Safe Lithium Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Lithium dendrite formation during plating/stripping fractures the solid electrolyte interphase (SEI) on Li anodes.
• This fracturing leads to poor battery cyclability and significant safety concerns.

Purpose of the Study:

• To design a self-adaptive interfacial layer for Li anodes to mitigate dendrite growth and improve battery performance.
• To investigate the properties of a tough polymer with a slide-ring structure as a protective layer.

Main Methods:

• Synthesis of a slide-ring polymer with a dynamically crosslinked network.
• Characterization of the polymer's mechanical properties (toughness, stretchability, self-healing).
• Electrochemical testing of Li anodes protected by the polymer in full cells with various cathodes.

Main Results:

• The slide-ring polymer effectively dissipates tension induced by Li dendrites, preventing SEI fracture.
• The polymer's self-healing ability maintains Li anode integrity even with pulverized Li.
• Achieved high critical current density (6 mA cm⁻²) and stable cycling with LiFePO₄, NCM, and S cathodes.

Conclusions:

• The slide-ring polymer serves as an effective self-adaptive interfacial layer for Li anodes.
• This approach significantly suppresses Li dendrite formation, enhancing battery safety and lifespan.
• Demonstrated potential for use in high-energy-density batteries.