Performance stability of solid-state polypyrrole-reduced graphene oxide-modified carbon bundle fiber for supercapacitor application

• Published in: Electrochimica acta 2018-09, Vol.285, p.9-15
• Main Authors: Hamra, A.A.B., Lim, H.N., Hafiz, S.M., Kamaruzaman, S., Rashid, S. Abdul, Yunus, R., Altarawneh, M., Jiang, Z.T., Huang, N.M.
• Format: Article
• Language: English
• Subjects: Bending vibration; Charge transfer; Charging; Discharge; Electroactive materials; Electrochemical analysis; Electrodes; Electron transfer; Fourier transforms; Graphene; Hydrogen storage; Morphology; Organic chemistry; Polypyrrole; Polypyrroles; Pore size; Porosity; Raman spectra; Solid state; Solid state physics; Stability; Supercapacitor; Supercapacitors; Systems stability; Thermogravimetric analysis
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2018.07.212

The stability performance of a solid-state polypyrrole-reduced graphene oxide (PPy-rGO) supercapacitor electrode after a series of charging-discharging cycles is investigated. The electrochemical performances show that the capacity retention, specific capacitance, equivalent series resistance, and charge transfer resistance all decrease after charging-discharging cycles. Thermogravimetric analysis shows the degradation of electroactive materials, causing decreased electrochemical performance of PPy-rGO. The morphology changes reveal that the pore size is reduced by ∼12 μm at the 1000th charge-discharge cycle, which limits the diffusion of electrolyte ions into the electrode. The positive shifts in the binding energy of the N1s spectra at the 500th and 1000th charge-discharge cycles indicate the formation of a hydrogen-bridge bond, affecting the electron transfer in the PPy-rGO composite as observed through X-ray photoelectron spectroscopy. Moreover, the structural properties of rGO change from amorphous to graphitic after a series of charging-discharging processes, as shown by the Raman spectra. Furthermore, the peak of the NH bending vibration is red-shifted by approximately 108 cm−1, indicating the changes in the chemical environment after a series of charging-discharging cycles, as shown by Fourier transform infrared spectroscopy. [Display omitted] •Electrochemical deposition of a highly porous PPy-rGO nanocomposite onto a carbon bundle fiber.•Fabrication of a flexible fiber supercapacitor device using a solid-state electrolyte.•Capacity retention of the supercapacitor decreased after 1000 charging-discharging cycles.