Phase Transition Regulation Mechanisms in P2-Type Oxide Cathodes
Xinyin Cai1, Zulipiya Shadike1
1Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China.
Advanced Materials (Deerfield Beach, Fla.)
|February 4, 2026
Summary
Layered sodium transition metal oxides (NaxTMO2) are promising sodium-ion battery cathodes. This study explores phase transitions in P2-type oxides, offering insights into designing advanced materials by understanding structural geometry and doping strategies.
Area of Science:
- Materials Science
- Electrochemistry
- Solid-State Chemistry
Background:
- Layered sodium transition metal oxides (NaxTMO2) are key cathode materials for sodium-ion batteries, offering high energy density and scalability.
- P2-type oxides are particularly interesting due to oxygen redox chemistry, but suffer from phase transitions upon Na+ depletion.
- Element doping has shown promise in mitigating these phase transitions, yet a universal design rule remains elusive.
Purpose of the Study:
- To analyze phase transitions in P2-type sodium transition metal oxide cathodes during sodium-ion battery operation.
- To elucidate the governing principles and regulation mechanisms behind these phase transitions.
- To provide guidance for the rational design of high-performance P2-type oxide cathodes.
Main Methods:
- Analysis of structural geometry evolution during charge/discharge processes.
- Review of recent publications and internal research group findings.
- Examination of intrinsic physical and chemical properties influencing phase stability.
Main Results:
- Phase transitions in P2-type cathodes are linked to structural geometry changes driven by Na+ depletion.
- Oxygen redox chemistry, while beneficial for energy density, exacerbates phase instability.
- Understanding the interplay between structure, properties, and doping is crucial for stabilization.
Conclusions:
- Phase transitions in P2-type oxides are a critical challenge for sodium-ion battery cathodes.
- Elucidating the principles of structural geometry evolution offers a pathway to control phase stability.
- This work provides a framework for designing superior P2-type oxide cathodes through informed doping strategies.
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