Holey nickel hydroxide nanosheets for wearable solid-state fiber-supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Nickel hydroxide (Ni(OH)₂) is a promising electrode material for supercapacitors.
• Achieving high performance requires optimizing nanostructure and integration with conductive materials.

Purpose of the Study:

• To synthesize holey Ni(OH)₂ nanosheets and embed them in carbon nanotube (CNT) scaffolds.
• To fabricate and evaluate a hybrid fiber electrode for supercapacitor applications.
• To assess the electrochemical performance and mechanical stability of the resulting supercapacitor.

Main Methods:

• Facile synthesis of 2 nm thick holey Ni(OH)₂ nanosheets.
• Embedding Ni(OH)₂ nanosheets within CNT scaffolds to create a hybrid fiber electrode.
• Electrochemical characterization including capacitance and rate performance testing.
• Mechanical testing under repeated bending conditions.

Main Results:

• The Ni(OH)₂/CNT hybrid fiber electrode exhibited a high volumetric capacitance of 335.9 F cm^-3 at 0.8 A cm^-3.
• The hybrid supercapacitor demonstrated a specific capacitance of 24.8 F cm^-3 and an energy density of 5.8 mW h cm^-3.
• The electrode showed superior rate performance and outstanding mechanical stability during bending.

Conclusions:

• The facile synthesis of holey Ni(OH)₂ nanosheets and their integration with CNTs is effective for high-performance supercapacitors.
• The hybrid fiber electrode offers excellent electrochemical properties and mechanical robustness.
• This approach presents a viable strategy for developing advanced energy storage devices.