Advancing Sodium-Ion Battery Cathode Analysis With Cryogenic Ag-coated APT Specimens
Poonam Yadav1, Leonardo Shoji Aota1, Eric V Woods1
1Microstructure Physics and Alloy Design, Max Planck Institute for Sustainable Materials, Max-Planck-Straße 1, Düsseldorf 40237, Germany.
Summary
Silver coating enables atom probe tomography analysis of sodium-ion battery layered oxide cathodes. This technique reveals compositional heterogeneity, crucial for improving battery performance and lifespan.
Area of Science:
- Materials Science
- Electrochemistry
- Battery Technology
Background:
- Layered oxide cathodes are key for high-energy sodium-ion batteries (SIBs).
- Capacity fading and structural changes limit their practical application, especially at higher voltages.
- Understanding multi-component cathode compositional changes at the atomic scale is vital.
Purpose of the Study:
- To investigate compositional heterogeneity in layered oxide cathodes for SIBs.
- To overcome challenges in atom probe tomography (APT) analysis of these materials.
- To enable atomic-scale characterization of air-sensitive SIB cathode materials.
Main Methods:
- Atom probe tomography (APT) for 3D chemical analysis.
- Focused-ion beam (FIB) milling at cryogenic temperatures.
- Application of a silver (Ag) coating to SIB cathode specimens prior to APT analysis.
Main Results:
- Demonstrated successful APT analysis of air-sensitive sodium-ion-layered oxide cathode material.
- Showcased the effectiveness of silver coating in preventing preferential alkali metal migration during APT.
- Enabled detailed 3D visualization of compositional heterogeneity within the cathode material.
Conclusions:
- Silver coating is a viable method to enable APT analysis of SIB layered oxide cathodes.
- This approach provides atomic-scale insights into compositional heterogeneity.
- Understanding this heterogeneity is critical for enhancing SIB cathode performance and longevity.
