Fluorine-Enriched Graphdiyne as an Efficient Anode in Lithium-Ion Capacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-ion capacitors (LICs) are promising for energy storage but face limitations in energy and power density.
• These limitations stem from electrode materials with insufficient active sites and restricted ion diffusion.

Purpose of the Study:

• To develop a novel anode material for enhanced lithium-ion storage.
• To investigate the potential of fluorine-enriched graphdiyne (F-GDY) for high-performance energy storage devices.

Main Methods:

• Fluorine-enriched graphdiyne (F-GDY) was synthesized using a solvothermal reaction.
• F-GDY was characterized for its structural and chemical properties.
• Electrochemical performance was evaluated in lithium-ion battery and lithium-ion capacitor configurations.

Main Results:

• F-GDY exhibits a unique 42-C hexagonal porous structure with abundant sp and sp2 carbon atoms and uniform fluorine distribution.
• As a lithium-ion battery anode, F-GDY demonstrated excellent rate capability (1825.9 mAh g⁻¹ at 0.1 A g⁻¹) and cycling stability.
• A lithium-ion capacitor utilizing F-GDY as the anode and activated carbon (AC) as the cathode achieved an energy density of 200.2 Wh kg⁻¹ at a power density of 131.17 W kg⁻¹.
• The AC/F-GDY based LIC showed robust cycling stability, retaining ~80% capacity after 5000 cycles at 2 A g⁻¹ and over 80% after 6000 cycles at 5 A g⁻¹.

Conclusions:

• Fluorine-enriched graphdiyne is a highly effective anode material for lithium-ion storage.
• The developed lithium-ion capacitor demonstrates exceptional energy density, power density, and long-term cycling stability.
• F-GDY holds significant promise for advancing next-generation electrochemical energy storage systems.