Multifunctional sulfur doping in cobalt-based materials for high-energy density supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing advanced electrode materials is crucial for high-performance energy storage devices.
• Core-shell structures and doping strategies offer promising pathways to enhance material properties.

Purpose of the Study:

• To synthesize sulfur-doped CCO@Co(OH)2 core-shell nanostructures (S-CCO@Co(OH)2).
• To investigate the synergistic effects of sulfur doping and the 3D core-shell architecture on electrochemical performance.
• To evaluate the potential of S-CCO@Co(OH)2 as an electrode material for supercapacitors.

Main Methods:

• Hydrothermal synthesis followed by electrodeposition.
• Characterization of material structure, composition, and electrochemical properties.
• Fabrication and testing of supercapacitor devices using S-CCO@Co(OH)2 electrodes.

Main Results:

• Sulfur doping induced reduction of Cu2+ and Co3+ to Cu+ and Co2+, and created oxygen vacancies.
• Formation of S-Co bonds between the shell and core facilitated electron and ion transport.
• S-CCO@Co(OH)2 exhibited a specific capacitance of 1730 Fg-1, 4.28 times higher than CCO.
• The assembled supercapacitor achieved an energy density of 83.89 Whkg-1 and 98.48% capacitance retention after 5000 cycles.

Conclusions:

• The combination of sulfur doping and a core-shell structure significantly enhances the electrochemical performance of CCO-based materials.
• S-CCO@Co(OH)2 demonstrates excellent potential for high-performance supercapacitor applications.
• Synergistic effects between sulfur doping and the core-shell structure are key to improved electrochemical activity.