Cationic Point Defect Fluoride to Improve Reaction Kinetics in (All) Solid-State Li Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Nickel-rich cathode materials (NCM) offer high capacity for lithium-ion batteries (LIBs) and all-solid-state batteries (ASSBs).
• Interfacial side reactions between NCM and electrolytes cause increased resistance and capacity fading, limiting practical applications.
• Controlling interfacial reactions is crucial for developing high-energy LIBs and ASSBs.

Purpose of the Study:

• To propose and implement a cationic defect concept for stabilizing NCM cathodes.
• To reduce interfacial resistance and enhance structural stability in both LIBs and ASSBs.
• To improve the electrochemical properties and cycling performance of NCM cathodes.

Main Methods:

• Development of Li3+xAl1-x/3F6 coating models based on the cationic defect concept.
• Application of Li3.3Al0.9F6 coating on NCM cathodes.
• Investigation of coating composition effects on reversibility and interfacial stability under various conditions (high-temperature, high-voltage).

Main Results:

• The Li3.3Al0.9F6 coating exhibits high ionic conductivity and voltage stability.
• Effective control of interfacial side reactions at both liquid and solid electrolyte interfaces.
• Significant reduction in interfacial resistance and improvement in cycling performance of NCM cathodes.

Conclusions:

• The cationic defect concept successfully enhances the interfacial stability and electrochemical properties of NCM cathodes.
• The Li3.3Al0.9F6 coating contributes to the realization of high-energy LIBs and ASSBs.
• This approach provides a pathway for developing highly stable cathode materials for advanced battery applications.