Entropic Design of Anionic Site to Improve Anionic Redox Stability in Lithium-Rich Cathode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Cobalt-free, manganese-rich layered oxides are promising cathode materials for lithium-ion batteries due to high capacity and low cost.
• Irreversible anionic redox (OAR) causes significant failure, limiting their practical application.

Purpose of the Study:

• To address OAR issues in manganese-rich cathodes using entropy design at anionic sites.
• To enhance structural stability and electrochemical performance of lithium-rich layered oxide cathodes.

Main Methods:

• Entropy design strategy applied to anionic sites of manganese-rich layered oxides.
• In-situ/ex-situ characterization techniques.
• Theoretical calculations to investigate charge compensation and performance mechanisms.

Main Results:

• Entropy design effectively inhibited oxygen release and structural strain, alleviating degradation.
• Achieved excellent cycling stability with minimal capacity and voltage decay after 400 cycles at 1C.
• Demonstrated remarkable rate capability (175 mAh g⁻¹ at 10C) and long-term stability over 1000 cycles at 10C.

Conclusions:

• Anionic site entropy design is a viable strategy for stabilizing lithium-rich cathodes.
• This approach offers a new pathway for developing high-performance, stable lithium-ion batteries with enhanced structural adaptability.