Reduction-Induced Topological Phase Transition to Construct K2Mn[Fe(CN)6] Superstructures for High-Performance
Ruixue Wu1, Jie Lin2, Yang Shang1
1Key Laboratory of Advanced Functional Materials of Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, People's Republic of China.
Langmuir : the ACS Journal of Surfaces and Colloids
|January 15, 2025
Summary
Researchers developed a novel cubic superstructure of potassium manganese-based Prussian blue analogs (KMn-HCF) for sodium-ion batteries. This design enhances cathode stability and durability, achieving 89.1% capacity retention after 1000 cycles.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- Potassium manganese-based Prussian blue analogs (KMn-HCF) are promising cathodes for sodium-ion batteries (SIBs).
- Rapid synthesis leads to small KMn-HCF particles, causing increased surface area and detrimental side reactions with the electrolyte.
- These side reactions damage the cathode electrolyte interface (CEI) and reduce cycling stability.
Purpose of the Study:
- To design a strategy for assembling small KMn-HCF particles into a stable superstructure.
- To improve the cycling stability and durability of KMn-HCF cathodes in SIBs.
- To investigate the impact of structural and compositional changes on battery performance.
Main Methods:
- A topological phase transition strategy was employed to assemble KMn-HCF particles into a 600 nm cubic superstructure.
- Structural analysis focused on defect reduction, CEI layer uniformity, electrolyte contact minimization, and structural integrity.
- Compositional analysis examined Jahn-Teller distortion and the role of K+ ions in framework stabilization.
Main Results:
- The assembled KMn-HCF cubic superstructure demonstrated significantly improved cycling stability and durability.
- The strategy reduced defects and enhanced the uniformity and stability of the CEI layer.
- Lower Jahn-Teller distortion and K+ pillar effects prevented capacity degradation, achieving 88.4%/89.1% capacity retention after 1000 cycles at 0.1/0.5 A g-1.
Conclusions:
- The topological phase transition strategy effectively creates a robust KMn-HCF cubic superstructure for SIB cathodes.
- The enhanced CEI layer and structural integrity contribute to stable electrochemical performance and long cycle life.
- This approach offers a viable pathway for developing high-performance KMn-HCF materials for sodium-ion batteries.
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