Elucidating anionic oxygen activity in lithium-rich layered oxides

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-capacity lithium-ion cathodes are crucial for advanced energy storage.
• Combining transition-metal redox with anionic lattice oxygen redox is a promising strategy for cathode development.
• Understanding the role of transition metals in oxygen redox activity is key.

Purpose of the Study:

• To elucidate the effect of transition metals on anionic oxygen redox activity in lithium-rich layered oxides.
• To investigate the material-specific mechanisms governing oxygen redox.
• To provide insights for designing advanced high-capacity lithium-ion cathodes.

Main Methods:

• Studied two lithium nickel metal oxides (Mn vs. Ru) with similar structures but different charge profiles.
• Employed X-ray spectroscopy to analyze material properties.
• Utilized operando differential electrochemical mass spectrometry (DEMS) to probe electrochemical activity.

Main Results:

• Demonstrated distinctly different oxygen redox activity between the manganese and ruthenium-containing oxides.
• Observed that transition metal-oxygen interactions significantly influence oxygen redox behavior.
• Identified unique electrochemical responses attributed to the specific transition metal present.

Conclusions:

• The interaction between lattice oxygen and transition metals dictates oxygen redox activity.
• This study provides critical insights into the complex oxygen redox mechanisms in lithium-ion cathodes.
• Findings pave the way for developing next-generation high-capacity cathode materials.