(Digital Presentation) Electrospun N-Doped CNFs Embedded Metal Oxides with Improved Graphitization for Superior Pseudocapacitive Energy Storage

Abstract

One-dimensional carbon nanofibers (CNFs) based pseudocapacitive hybrid electrodes are the next step forward in achieving highly efficient supercapacitor(SCs) electrodes. However, it is still a paramount challenge to develop rationally designed CNFs with sufficient pseudocapacitive surface functionalities, and adequate porosity via a facile synthesis for better practical applicability. Herein, we are reporting a single-step electrospinning methodology followed by carbonization to generate a unique spatial 1D structure with metal oxide (MO) particles embedded in CNFs (M-CNFs). By optimizing the polymer ratio with that of MO, it was possible to obtain an in-situ N-enriched porous CNF network generating a predominant pseudocapacitive charge-storing mechanism. The resulting material is a synergistic combination of MOs, and surface-enriched N-CNFs with good electrical properties and high surface area, suitable to be employed as electrodes for SCs. A deep investigation of the M-CNFs properties has been performed to understand the physical characteristics of the hybrid MO/CNFs material. Further, a flexible symmetric SC device exploiting the polymeric gel-based (PVA+ H2SO4) electrolyte was assembled delivering a maximum energy density of up to 50 Wh Kg-1 and capacitance retention of 90% with a coulombic efficiency of 95%, enabling both electric double-layer and pseudo-capacitance behaviors. The resulting performances of the here-proposed material allow the prediction of the enormous potentialities of these flexible energy-storage devices for industrial-scale application. Keywords: surface N enrichment, electrospinning, hybrid CNFs, flexible symmetric supercapacitors.