Carboxylated graphene oxide nanosheets as efficient electrodes for high-performance supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors require advanced electrode materials for enhanced energy storage.
• Graphitic materials offer potential but often need surface modification for improved performance.
• Carboxylation can introduce desirable functionalities for electrochemical applications.

Purpose of the Study:

• To synthesize carboxylated graphitic materials (ECGs) via ball milling graphite in dry ice.
• To investigate the impact of carboxylation duration on physiochemical and electrochemical properties.
• To evaluate ECGs as potential electrode materials for supercapacitors.

Main Methods:

• Synthesis of ECGs by ball milling graphite for 24, 36, and 46 hours in dry ice.
• Comprehensive characterization of material morphology, texture, and microstructure.
• Electrochemical performance testing of ECGs as supercapacitor electrodes, including capacitance and cycle stability.

Main Results:

• ECG-46 exhibited the highest specific capacitance (223 F g⁻¹ at 0.25 A g⁻¹).
• ECG-46 demonstrated excellent rate performance and cycle stability (90.8% retention over 10,000 cycles).
• A symmetric supercapacitor device using ECG-46 achieved high energy density (19.20 Wh kg⁻¹).

Conclusions:

• Ball milling graphite in dry ice is an effective method for producing porous graphitic materials with oxygen functionalities.
• Carboxylation significantly enhances the electrochemical performance of graphitic electrodes for supercapacitors.
• The developed ECGs show great promise as advanced electrode materials for high-performance energy storage devices.