ZnO@MnO₂ Core-Shell Nanofiber Cathodes for High Performance Asymmetric Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Asymmetric supercapacitors (ASCs) are gaining research interest for energy storage applications.
• High-performance ASCs require carefully selected cathode materials, with core-shell nanostructures showing promise.

Purpose of the Study:

• To synthesize ZnO@MnO2 core-shell nanofibers (NFs) for high-performance ASCs.
• To construct and evaluate an ASC device using these novel core-shell NFs.

Main Methods:

• Hydrothermal modification of electrospun ZnO NFs with MnO2 nanoflakes to create ZnO@MnO2 core-shell NFs.
• Fabrication of an ASC using ZnO@MnO2 NFs as the cathode and activated carbon as the anode.

Main Results:

• The ZnO@MnO2 core-shell NFs exhibited a specific capacitance of 907 Fg-1 at 0.6 Ag-1.
• The fabricated ASC operated effectively within a 0-2.0 V voltage window, powering an LED.
• The device achieved an energy density of 17 Whkg-1 and a power density of 6.5 kWkg-1 with excellent stability.

Conclusions:

• The ZnO@MnO2 core-shell nanofibrous material demonstrates significant potential for high-performance energy storage.
• The study highlights the effectiveness of simple, fiber-based electrode designs with tailored core and shell components for ASCs.