Microwave-Assisted Oxidation of Electrospun Turbostratic Carbon Nanofibers for Tailoring Energy Storage Capabilities

Abstract

We report the systematic structural manipulation of turbostratic electrospun carbon nanofibers (ECNFs) using a microwave-assisted oxidation process, which is extremely rapid, highly controllable, and affords controlled variation of the capacitive energy storage capabilities of ECNFs. We find a non-monotonic relationship between the oxidation degree of ECNFs and their electrocapacitive performance, and present a detailed study on the electronic and crystalline structures of ECNFs to elucidate the origin of this non-monotonic relation. The ECNFs with an optimized oxidation level show ultrahigh capacitances at high operation rates, exceptional cycling performance and an excellent energy-power combination. We have identified three key factors required for optimal energy storage performance for turbostratic carbon systems: (i) an abundance of surface oxides, (ii) microstructural integrity and (iii) an appropriate interlayer spacing.

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Nonhalogenated Surface-Active Ionic Liquid as an Electrolyte for Supercapacitors

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