Hierarchical porous carbon fibers prepared using a SiO2 template for high-performance EDLCs

•To examine the EDLCs performance, hierarchical porous carbon fibers were prepared.•The samples were prepared by chemical activation and hard templating.•The hierarchical pore structure was developed with network.•The retained capacitance ratio was enhanced according to pore structure.

A simple method for preparing hierarchical porous carbon fibers with micropores and mesopores was developed using electrospun PAN (polyacrylonitrile) fibers, a SiO2 (silica) template, and KOH (potassium hydroxide) activation. The diameter of well-developed hierarchical porous carbon fibers was presented 500 nm and 1 μm by using FE-SEM. The prepared hierarchical porous carbon fibers had high specific surface areas (1625–1796 m2/g) and hierarchical pore structures with micropore (below 2 nm), mesopore (2–5 nm, and 10–50 nm), and macropore (>50 nm). The hierarchical porous carbon fibers were used as electrodes in electric double-layer capacitors (EDLCs) to measure the specific capacitance and retained capacitance ratio. This unique hierarchical pore structure had a synergistic effect, resulting in excellent specific capacitances (197 and 172 F/g at scan rate 5 and 50 mV/s, respectively) and retained capacitance ratios improved from 60.8% to 87.3%. The enhanced EDLC performance demonstrates the potential of hierarchical porous carbon fibers prepared with a SiO2 template and KOH activation.

Graphical abstractTo investigate the EDLCs performance with retained capacitance ratio, dual-porous carbon nanofibers with network pore structure were prepared by chemical/physical activation using SiO2 template and KOH agent.Figure optionsDownload full-size imageDownload as PowerPoint slide