Surface Chemical Disorder Engineering Enabled Superior Anion Redox for Li-Rich Mn-Based Cathode

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Li-rich Mn-based oxides are promising for high-capacity batteries due to anion redox.
• Poor reversibility and oxygen loss hinder their practical application.
• Surface structure evolution and interface side reactions are critical challenges.

Purpose of the Study:

• To improve the reversibility and kinetics of anion redox reactions in Li-rich Mn-based oxides.
• To enhance the structural stability and cycling performance of these cathode materials.
• To explore the role of surface chemical disorder in optimizing cathode performance.

Main Methods:

• Integration of chemical disorder-based crystallographic texture into the cathode surface.
• Spatial rearrangement of lattice oxygen via supersaturated cation occupation.
• Analysis of oxygen electronic structure, metal-oxygen orbital hybridization, and interface stability.

Main Results:

• Achieved a high specific capacity of 291.8 mAh g⁻¹.
• Demonstrated excellent long cycling stability with 90.5% capacity retention over 300 cycles.
• Showcased reduced voltage fade (0.68 mV/cycle) and suppressed detrimental phase evolution.

Conclusions:

• Surface chemical disorder effectively enhances anion redox reversibility and kinetics.
• The robust surface architecture mitigates interface side reactions and maintains structural integrity.
• This approach offers a new paradigm for designing high-performance cathode materials for batteries.