Mechanically Adaptive Polyrotaxane Interlayers for Low-Pressure High Energy Density Sulfide-Based All-Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• All-solid-state batteries (ASSBs) offer high energy density but struggle with performance under low stack pressure, especially with lithium metal or anode-less designs.
• Mechanical instability and void formation at interfaces lead to battery degradation, limiting practical applications.

Purpose of the Study:

• To develop a mechanically adaptive anode interface for ASSBs that maintains performance under low stack pressure.
• To enable stable and reliable operation of high-energy-density ASSBs in commercially relevant conditions.

Main Methods:

• Design of an elastic polymer interface incorporating mechanically interlocked polyrotaxane (PR).
• Integration of indium fluoride (InF3) for spontaneous chemical interface stabilization.
• Testing of the interface under low stack pressure (0.8 MPa) at 25°C, including anode-less configurations.

Main Results:

• The PR-based interface demonstrated robust cycling stability and reliable performance.
• The synergistic combination of PR's elastic resilience and InF3's chemical stability prevented void formation.
• Successful operation was achieved even in anode-less configurations (N/P = 0) under low-pressure conditions.

Conclusions:

• Mechanically interlocked molecular architectures offer a promising strategy for void-free interfaces in low-pressure ASSBs.
• The developed adaptive interface significantly enhances the practical applicability of high-energy-density ASSBs.
• This approach paves the way for more stable and efficient solid-state battery technologies.