Influence of boron content on the structure and capacitive properties of electrospun polyacrylonitrile/pitch-based carbon nanofiber composites

Abstract

Electrospun boron-enriched PAN/pitch-based CNF composites (PPB) are developed by combining B2O3 as the boron source, and pitch and polyacrylonitrile as the carbon precursor, to introduce surface boron heteroatoms and enhance the electrical conductivity in CNF composites. PPB-10 electrodes prepared from 10 wt% B2O3 added to the PAN/pitch solution exhibit a high specific capacitance of 180 Fg−1 at a discharge current density of 1 mAcm−2 and energy density of 22.0–15.8 Whkg−1 in the power density range of 400–10,000 W kg−1 in 6 M KOH aqueous electrolyte, owing to the larger amount of heteroatoms such as boron and the addition of the pitch, thereby inducing fast and reversible surface redox reactions in aqueous electrolyte. Furthermore, the highly mesoporous PPB-10 composite offers 92% capacity retention of the initial current density and a low equivalent series resistance through quick pathways for ion transport and charge diffusion. Hence, these PPB composites exhibit a very promising potential as electrode materials for supercapacitor electrodes due to boron incorporated into the carbon framework, suitable porosity, and good electrical conductivity.