Synergistic Multi-Scale Confinement Engineering Stabilizes Organic Anode for High-Performance Potassium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Organic small molecules offer high capacity for potassium-ion batteries (PIBs).
• Key challenges include active material dissolution, interface instability, and slow kinetics, leading to capacity fade.
• These issues limit the practical application of organic anodes in PIBs.

Purpose of the Study:

• To address the limitations of organic anodes in PIBs through multi-scale confinement engineering.
• To enhance structural stability, interfacial properties, and reaction kinetics of organic electrode materials.
• To develop a high-performance anode for advanced potassium-ion battery applications.

Main Methods:

• Synergistic multi-scale confinement engineering at molecule-ion-electron levels.
• Physical confinement of active molecules within ordered mesoporous conductive carbon (CMK3).
• Utilizing a high-concentration electrolyte (3 m KFSI in EC/DEC) to stabilize the solid-electrolyte interface.
• Molecular design with an electron-withdrawing fluorine substituent to optimize electronic structure.

Main Results:

• The 2FBA@CMK3 anode demonstrated excellent structural stability and efficient electron transport.
• The high-concentration electrolyte effectively regulated anion activity and stabilized the interface.
• The fluorine substituent enhanced potassium storage kinetics and capacity.
• Achieved a reversible capacity of 152 mAh/g after 400 cycles at 500 mA/g, outperforming most reported organic PIB anodes.

Conclusions:

• The multi-scale confinement strategy effectively addresses the drawbacks of organic anodes in PIBs.
• This approach establishes a rational design paradigm for developing advanced organic electrode materials.
• The developed anode shows significant potential for high-performance and stable potassium-ion batteries.