Stacking Faults Inducing Oxygen Anion Activities in Li₂ MnO₃

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Next-generation lithium-ion batteries require higher energy density.
• Anionic redox in cathode materials offers a pathway to increased energy density.
• Controlling the local oxygen environment is crucial but challenging for activating anionic redox.

Purpose of the Study:

• To demonstrate the tuning of anionic redox by controlling the local oxygen environment.
• To investigate the role of stacking faults in Li2MnO3 on anionic redox.
• To provide guidance for designing high-capacity layered cathode materials.

Main Methods:

• Experimental control of stacking fault density in Li2MnO3.
• Computational analysis of local coordination environments.
• Spectroscopic studies to probe oxygen and manganese reactivity.

Main Results:

• Increased stacking faults lead to smaller Li-O-Li bond angles and larger Li-O bond distances.
• These structural changes activate oxygen redox reactivity.
• Activated oxygen redox enhances manganese reactivity during reduction.

Conclusions:

• The local structure environment critically influences anionic redox reactivity.
• Adjusting stacking faults is a viable strategy to tune anionic redox in layered cathodes.
• This approach offers a new avenue for designing high-capacity lithium-ion battery materials.