In Situ Deprotection of Polymeric Binders for Solution-Processible Sulfide-Based All-Solid-State Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Sulfide-based all-solid-state batteries (ASSBs) offer enhanced safety compared to lithium-ion batteries (LIBs).
• Scalable manufacturing of ASSBs is hindered by polarity incompatibility between binders, solvents, and sulfide electrolytes during slurry preparation.

Purpose of the Study:

• To develop a solution-based scalable manufacturing method for sulfide-based ASSBs.
• To overcome the challenge of polarity incompatibility in electrode slurry preparation.
• To improve electrode adhesion and electrochemical performance in ASSBs.

Main Methods:

• Utilizing acrylate (co)polymeric binders with protection-deprotection chemistry.
• Employing tert-butyl group protection for homogeneous binder dispersion in less polar solvents.
• Implementing heat treatment during drying to cleave tert-butyl groups and expose polar carboxylic acid groups.

Main Results:

• Achieved homogeneous binder dispersion and improved electrode adhesion, comparable to commercial LIBs.
• Demonstrated enhanced electrochemical performance in both half-cell and full-cell configurations.
• Successfully addressed polarity incompatibility issues in ASSB electrode fabrication.

Conclusions:

• Protection-deprotection chemistry is a viable strategy for the scalable manufacturing of sulfide-based ASSBs.
• This approach enhances electrode integrity and battery performance.
• The protection-deprotection strategy can be broadly applied to other battery chemistries facing component polarity challenges.