Poly(Ionic Liquid)-Derived Graphitic Nanoporous Carbon Membrane Enables Superior Supercapacitive Energy Storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High performance energy storage electrodes require high energy/power density, capacitance, and cycle life.
• Porous carbons are widely used but often limited by moderate performance due to their powdery nature.

Purpose of the Study:

• To develop a novel carbon membrane electrode with enhanced electrochemical properties.
• To explore the potential of poly(ionic liquid)s as templates for advanced energy storage materials.

Main Methods:

• Controlled vacuum pyrolysis of a poly(ionic liquid) membrane template.
• Characterization of conductivity, porosity, and surface area.
• Fabrication and testing of membrane electrodes in aqueous and solid-state supercapacitors.
• Theoretical calculations for heteroatom doping effects.

Main Results:

• A single carbon membrane electrode with good conductivity (132 S cm^-1), interconnected hierarchical pores, and a large specific surface area (1501 m² g^-1) was fabricated.
• High areal capacitances of 3.1 F cm^-2 (aqueous) and 1.0 F cm^-2 (solid-state) were achieved.
• Superior energy densities of 1.72 mW h cm^-2 (aqueous) and 0.14 mW h cm^-2 (solid-state) were obtained without a current collector.
• Theoretical calculations confirmed the synergistic benefits of heteroatom co-doping.

Conclusions:

• The developed poly(ionic liquid)-derived carbon membrane electrode offers a promising pathway for advanced energy storage applications.
• The material's properties, including scalability and device compatibility, highlight its potential for practical implementation.
• Synergistic effects from hierarchical pores and heteroatom doping significantly enhance supercapacitive performance.