Constructing An Oxyhalide Interface for 4.8 V-Tolerant High-Nickel Cathodes in All-Solid-State Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium batteries (ASSBs) are promising for next-generation energy storage.
• Sulfide electrolytes with layered oxide cathodes offer high energy density and safety.
• Interfacial incompatibility between oxide cathodes and sulfide electrolytes is a key challenge.

Purpose of the Study:

• To address the interface compatibility issues in sulfide-based ASSBs with layered oxide cathodes.
• To develop a simple and effective surface modification strategy for enhancing ASSB performance.
• To improve the kinetic performance and cyclic stability of high-voltage ASSBs.

Main Methods:

• A controllable gas-solid reaction was employed to create a uniform oxyhalide coating on LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes.
• The surface alkali was transformed into an oxyhalide layer to improve interfacial contact.
• Electrochemical performance was evaluated across a broad temperature range and under high cutoff voltages.

Main Results:

• The oxyhalide coating significantly improved the kinetic performance of ASSBs, especially at low temperatures.
• ASSBs with the coated cathode demonstrated excellent cyclic stability at high cutoff voltages (e.g., 94.0% capacity retention after 500 cycles at 4.5 V).
• The protective layer exhibited high voltage tolerance, crucial for demanding applications.

Conclusions:

• The proposed oxyhalide coating strategy effectively resolves interfacial issues in high-voltage ASSBs.
• This approach enhances both the rate capability and long-term stability of ASSBs.
• The findings provide valuable insights for developing advanced, high-energy-density all-solid-state batteries.