Interfacial Radical Reaction Enables High-Performance Graphite Anode for Potassium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Potassium-ion batteries (PIBs) are crucial for large-scale energy storage.
• Graphite anodes face challenges with solid electrolyte interface (SEI) stability and K+-solvent co-intercalation, limiting cycling stability and reaction kinetics.

Purpose of the Study:

• To develop a stable and efficient graphite anode for PIBs.
• To overcome the limitations of SEI instability and K+-solvent co-intercalation.

Main Methods:

• A mechanochemical-induced radical reaction between graphite and Spiro-O8 radicals was employed.
• A uniform organic layer was constructed on graphite, facilitating KFSI salt decomposition to form an inorganic-rich outer layer.

Main Results:

• The modified graphite anode demonstrated enhanced K+ transport kinetics and inhibited K+-solvent co-intercalation.
• The Spiro-O8 inner film accommodated volume changes during cycling.
• Achieved reversible capacity of 241.0 mAh g-1 at 100 mA g-1, with 147.2 mAh g-1 at 1 A g-1.
• Exhibited stable cycling over 600 cycles with 89.4% capacity retention.

Conclusions:

• The interfacial radical reaction provides a new strategy for stabilizing graphite anodes in PIBs.
• This approach significantly enhances cycling stability and rate capability for high-performance PIBs.