Revealing the role of the cathode-electrolyte interface on solid-state batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Interfaces play a critical role in solid-state battery performance, yet their behavior remains poorly understood.
• Conventional thin-film and composite electrodes obscure the direct impact of interface crystallography and morphology.
• Understanding interface instabilities is crucial for advancing battery technology.

Purpose of the Study:

• To directly assess the influence of cathode crystallography and morphology on long-term solid-state battery performance.
• To investigate interface instabilities in a controlled manner using unique cathode structures.
• To establish a correlation between interface stability and overall cell performance.

Main Methods:

• Fabrication of crystallographically oriented, highly faceted thick cathodes.
• Controlled manipulation of interface crystallography, area, and microstructure.
• Testing of both lithium- and sodium-based cathodes with various solid electrolytes.

Main Results:

• A direct correlation between cell performance and interface stability was revealed.
• Interface instabilities, hidden in conventional electrodes, were identified and understood.
• Minimizing interfacial area proved crucial for improving cell performance and understanding instabilities.

Conclusions:

• Dense, thick cathodes with minimized interfacial area are key to enhancing solid-state battery energy density and stability.
• The findings offer a new paradigm for designing high-performance solid-state batteries.
• This research provides a pathway to overcome critical interface challenges in next-generation batteries.