Prussian Blue Analog as a Functional Additive for Restoring Sulfide Solid Electrolytes: Enhancing Moisture Stability...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Sulfide solid-state electrolytes (SSEs) are promising for all-solid-state batteries (ASSBs).
• Moisture sensitivity of SSEs hinders practical application and long-term stability.
• Developing effective strategies to mitigate moisture-induced degradation is crucial.

Purpose of the Study:

• To introduce Prussian blue analogs (PBAs) as functional additives in SSEs.
• To investigate the role of PBAs in enhancing moisture stability and electrochemical performance.
• To explore the mechanism behind PBA-mediated degradation suppression and recovery.

Main Methods:

• Incorporation of PBAs into sulfide SSEs.
• Exposure of SSEs with PBAs to humid conditions.
• Electrochemical testing of ASSBs incorporating PBAs.
• Analysis of PBA structure and interaction with water and gases.

Main Results:

• PBAs effectively suppress moisture-induced degradation of SSEs.
• PBAs demonstrate a unique reviving function, restoring performance of degraded SSEs.
• Postmixed PBAs in degraded SSEs achieved 99.9% Coulombic efficiency over 500 cycles.
• PBAs absorb water and H2S, preserving ionic conductivity and interfacial properties.

Conclusions:

• PBAs are multifunctional additives for sulfide SSEs, offering protection and recovery.
• PBAs enable stable and durable ASSBs assembled under ambient conditions.
• This work presents a viable strategy for overcoming moisture-related challenges in ASSBs.