High-performance supercapacitors using a nanoporous current collector made from super-aligned carbon nanotubes

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Conventional metallic current collectors in supercapacitors are heavy and limit device performance.
• Developing lightweight, high-performance current collectors is crucial for advancing energy storage technologies.

Purpose of the Study:

• To fabricate and evaluate nanoporous current collectors using super-aligned carbon nanotube (SACNT) films.
• To develop an efficient and environmentally friendly method for synthesizing nanosized active materials on SACNT films.
• To integrate these composite films into a metallic current collector-free supercapacitor and assess its electrochemical performance.

Main Methods:

• Cross-stacking of super-aligned carbon nanotube (SACNT) films to create nanoporous current collectors.
• One-step, in situ decomposition strategy for direct synthesis of nanosized active materials (NiO, Co(3)O(4), Mn(2)O(3)) on SACNT films.
• Fabrication and electrochemical testing of supercapacitors utilizing the SACNT-based composite films as both current collectors and active material supports.

Main Results:

• The SACNT-film current collectors exhibit excellent conductivity, extremely low density (27 μg cm⁻²), high specific surface area, flexibility, and electrochemical stability.
• Nanosized active materials were successfully synthesized directly onto the SACNT films.
• The resulting metallic current collector-free pseudo-capacitors demonstrated high specific capacitance (~500 F g⁻¹), reliable electrochemical stability (<4.5% degradation over 2500 cycles), and high rate capability (245 F g⁻¹ at 155 A g⁻¹).

Conclusions:

• Nanoporous SACNT films are effective replacements for conventional metallic current collectors in supercapacitors.
• The developed in situ synthesis method is efficient and environmentally friendly for creating composite electrode materials.
• The metallic current collector-free supercapacitors exhibit promising performance for next-generation energy storage applications.