Highly Nanoporous Nickel Foam as Current Collectors in 3D All-Solid-State Microsupercapacitors

Area of Science:

• Materials Science and Engineering
• Electrochemistry
• Nanotechnology

Background:

• Microsupercapacitors (MSCs) require advanced current collectors to enhance energy storage capacity.
• Existing commercial Ni foams have limitations in specific surface area and active material deposition.
• Nanoporous structures offer potential for significantly improved electrode performance.

Purpose of the Study:

• To develop a streamlined method for producing a highly nanoporous current collector for MSCs.
• To enhance the specific surface area and active material loading of Ni-based electrodes.
• To evaluate the electrochemical performance of the novel electrode in both liquid and solid-state MSCs.

Main Methods:

• Patterning commercial Ni foams into interdigitated structures using laser cutting.
• Infusing Ni foams with NiO nanopowders via dip coating, sintering, and H2 atmosphere reduction.
• Growing MnO2 on the NiO-infused Ni foam through a redox reaction to create a 3D nanoporous structure.

Main Results:

• The fabricated 3D nanoporous electrode exhibits porosity in the 200-600 nm range, increasing specific surface area by 30 times.
• Liquid electrolyte evaluations show an areal capacity of 19.3 F/cm², 95% capacitance retention at 5 mA/cm², and 671 μW h/cm² energy density (25x greater than commercial Ni foams).
• Solid-state MSCs using the electrode achieve 7.22 F/cm² areal capacity and 263.9 μW h/cm² energy density.

Conclusions:

• The developed streamlined method effectively produces highly nanoporous current collectors with significantly enhanced electrochemical properties.
• The 3D nanoporous electrode architecture dramatically improves specific surface area and active material deposition for superior energy storage.
• This advanced electrode material is exceptionally suitable for high-performance microsupercapacitor applications, both in liquid and solid-state configurations.