Fundamentals of the Cathode-Electrolyte Interface in All-solid-state Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium batteries (ASSBs) are gaining attention as safer alternatives to conventional lithium-ion batteries (LIBs).
• Solid-state electrolytes (SEs), including oxide and sulfide types, offer high ionic conductivity.
• However, high interfacial resistance between cathodes and SEs limits ASSB performance.

Purpose of the Study:

• To review critical issues at the cathode-solid electrolyte interface in ASSBs.
• To discuss fundamental principles, formation mechanisms, and solutions for interfacial instability.
• To highlight advancements in characterization and future research directions.

Main Methods:

• Literature review of cathode-solid electrolyte interfacial phenomena.
• Analysis of electro-chemo-mechanical instability mechanisms.
• Summary of interfacial modification strategies and characterization techniques.

Main Results:

• Cathode-SE interfaces present significant challenges, primarily due to electro-chemo-mechanical instability.
• Specific issues and solutions for oxide and sulfide SEs are detailed.
• Advanced characterization techniques are essential for understanding these interfaces.

Conclusions:

• Optimizing cathode-SE interfaces is key to unlocking the full potential of ASSBs.
• Further research is needed to address remaining interfacial challenges and advance SE applications.
• Improved interfacial engineering will drive the development of next-generation ASSBs.