Layered/Olivine Composite Structure-Induced Stable Gradient Interfacial Chemistry toward High-Temperature Lithium-Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Layered oxide cathodes are crucial for lithium-ion batteries but suffer from instability and parasitic reactions at high temperatures.
• High-temperature operation is essential for high-energy and high-safety energy storage but remains a significant challenge.

Purpose of the Study:

• To develop a stable cathode material for high-temperature lithium-ion battery applications.
• To mitigate structural instability and interfacial degradation in layered oxide cathodes under harsh conditions.

Main Methods:

• Designed a layered/olivine composite structure at the grain surface of the cathode.
• Developed a gradient lithium fluoride (LiF) interlayer to suppress interfacial degradation.
• Employed interfacial-sensitive characterizations and theoretical analysis to understand interphase formation.

Main Results:

• The composite cathode demonstrated excellent high-temperature cycling stability (90.8% retention over 300 cycles in half cells, 95.6% over 1000 cycles in pouch cells).
• Achieved approximately 51% enhancement in thermal stability compared to conventional cathodes.
• Revealed the formation mechanism of a stable interphase induced by the composite structure.

Conclusions:

• The developed composite structure cathode with a LiF interlayer significantly improves high-temperature performance and thermal stability.
• This approach offers a promising strategy for creating robust cathodes for extreme environment energy storage applications.