Investigating Element Composition of High-Entropy Layered Oxides: Insights on Performance Influence for Sodium-Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Layered oxides are promising for sodium-ion batteries.
• Entropy stabilization is a key strategy for enhancing material properties.
• Limited understanding exists regarding element selection and function in high-entropy materials.

Purpose of the Study:

• To develop and investigate novel high-entropy layered oxide materials for sodium-ion batteries.
• To elucidate the impact of specific elemental substitutions (Ti, Sn) on material properties.
• To establish structure-property relationships for optimizing high-entropy cathode design.

Main Methods:

• Synthesis of multiple high-entropy layered oxide compositions (HEO-TS, HEO-ST, HEO-Ti, HEO-Sn).
• Comprehensive analysis of physical and electrochemical properties.
• Systematic investigation of elemental effects on stability, performance, and crystallinity.

Main Results:

• Titanium incorporation enhances air stability and rate performance, enabling high-voltage operation.
• Partial tin substitution increases voltage difference and polarization.
• Excessive tin content leads to poor electrochemical properties and reduced crystallinity.

Conclusions:

• Element selection is critical for designing high-entropy layered oxides.
• Titanium and tin play distinct roles in tuning electrochemical performance.
• This study provides a framework for rational element design in high-entropy cathode materials for sodium-ion batteries.