Polyacrylonitrile-b-Polystyrene Block Copolymer-Derived Hierarchical Porous Carbon Materials for Supercapacitor

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Block copolymers serve as effective sacrificial templates for synthesizing porous carbon materials.
• Porous carbons are crucial electrode materials for advanced energy storage devices.
• Electrospinning offers a versatile method for fabricating carbon-based nanostructures.

Purpose of the Study:

• To synthesize porous carbon fibers and powders using polystyrene-polyacrylonitrile (PS-b-PAN) block copolymer as a precursor.
• To compare the structural and electrochemical properties of the resulting carbon materials.
• To evaluate the potential of these porous carbons as electrode materials in energy storage applications.

Main Methods:

• Electrospinning of PS-b-PAN block copolymer to form fibers.
• Pyrolysis of electrospun fibers to produce porous carbon fibers.
• Characterization of porous structure, surface area, and surface chemistry (O/N content).
• Electrochemical testing to assess capacitance, cycle stability, and performance.

Main Results:

• High carbon yield (~50%) achieved with low sacrificial block content (f_PS ≈ 0.16).
• Porous carbon fibers exhibited a hierarchical porous structure with high surface area (~492 m²/g) and significant O/N surface content.
• Electrochemical performance demonstrated excellent cycle stability (near 100% retention after 10,000 cycles) and high capacitance (254 F/g at 1 A/g).

Conclusions:

• PS-b-PAN block copolymers are efficient precursors for high-performance porous carbon electrode materials.
• Porous carbon fibers synthesized via electrospinning show superior pore formation and electrochemical properties compared to powdered carbons.
• These materials hold significant promise for enhancing energy storage device performance through improved capacitance and cycle life.