Robust Interface Enabled by Bicontinuous-Structured Electrolyte Elastomers for Solid-State Battery Applications.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid-state electrolytes (SSEs) are crucial for safe lithium batteries but often lack mechanical resilience and good interface contact.
• Limited mechanical properties and poor interfacial adhesion hinder the practical application of current SSEs.

Purpose of the Study:

• To develop novel elastomeric solid-state electrolytes with a bicontinuous architecture for improved safety and performance in lithium batteries.
• To address the limitations of mechanical instability and poor interface contact in conventional SSEs.

Main Methods:

• An in situ phase separation strategy was employed to create elastomeric SSEs with a bicontinuous structure.
• Characterization of ionic conductivity, electrochemical stability, mechanical properties (elastic restorability, stretchability, adhesion), and dendrite suppression.

Main Results:

• The developed SSEs exhibit high ionic conductivity (7.8 × 10⁻⁴ S cm⁻¹ at 25 °C) and excellent elastic restorability (82%).
• The bicontinuous structure provides superior stretchability (1800%), fatigue resistance, and puncture strength, ensuring strong interface contact (adhesion energy ≈43.9 J m⁻²).
• Symmetric batteries showed no short-circuiting after 2000 h, and Li-metal and Li-O₂ batteries demonstrated high specific capacity and stable cycling (500 cycles).

Conclusions:

• The bicontinuous-structured elastomer electrolytes present a promising strategy for safe, high-energy solid-state batteries.
• These electrolytes maintain mechanical integrity and suppress dendrite growth, enabling stable operation under various conditions and abuse tests.