Electrospun polyethylenimine (PEI)-derived nitrogen enriched carbon nanofiber for supercapacitors with artificial neural network modeling

Abstract

This paper presents the utilization of polyethylenimine (PEI) polymer to obtain freestanding, binder-free, and nitrogen- enriched carbon nanofibers (NCNFs) by electrospinning which is an easy and fast method. The PEI polymer played a significant role as a poring agent for the adjustment of surface area and as the heteroatom doping to increase conductivity. NCNFs-10 electrode exhibited a specific capacitance of 200 F/g at 1 A/g with a good retention of 84.25 % at 10 A/g in three electrode system. The assembled supercapacitor had a specific energy of 5.57 Wh/kg at 125 W/kg with a good cycling performance of 80.5 % after 10,000 cycles. Furthermore, an artificial neural network (ANN) method was utilized to understand the relationship between the CNF's structure and supercapacitor performance by modeling the specific capacitance. The input factors were specific surface area (SBET), nitrogen doping (N% at), graphitization degree (ID/IG), internal resistance (Rs), pore size (Vpor), micropore volume (Vmic), the average diameter (Dave), and mesopore volume (Vmeso). Results showed that the first three remarkable variables are SBET, N (%at), and ID/IG.