Enhanced Energy Storage Performance through Controlled Composition and Synthesis of 3D Mixed Metal-Oxide Microspheres

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Binary transition metal oxide complexes (BTMOCs) in 3D layered structures are promising for supercapacitors (SCs) due to high specific capacitance.
• Synthesizing 3D BTMOCs is challenging but critical for SC applications.

Purpose of the Study:

• To develop a simple, effective method for fabricating 3D BTMOCs for supercapacitor electrodes.
• To evaluate the electrochemical performance of the novel NiCo-based complex for energy storage.

Main Methods:

• A single-step hydrothermal technique was used to synthesize flower-shaped NiCo-based microspheres composed of mesoporous nanosheets.
• Electrochemical performance was tested using the NiCo microspheres as a working electrode in SCs and an aqueous asymmetric supercapacitor (ASC) configuration with activated carbon (AC).

Main Results:

• The NiCo microspheres exhibited a high specific surface area (23.66 m² g⁻¹), leading to a specific capacitance of 888.8 F g⁻¹ at 1 A g⁻¹.
• The material showed good stability (52.08% retention after 10,000 cycles) and power density (225 W·kg⁻¹).
• An ASC device achieved 250 F g⁻¹ at 1 A g⁻¹, with 69% retention over 10,000 cycles, and powered LEDs for 40 s.

Conclusions:

• The facile hydrothermal synthesis yields NiCo microspheres with excellent electrochemical properties for supercapacitors.
• The developed electrode material demonstrates significant potential for practical energy storage applications.
• The NiCo microspheres/AC ASC configuration shows promise for powering small electronic devices.