Graphite nanoparticles paper supercapacitor based on gel electrolyte

Abstract In this study, three-type paper supercapacitors based on the polyvinylidene fluoride (PVDF) and polyvinyl alcohol (PVA)/phosphoric acid (H3PO4) gel electrolytes and graphite nanoparticles (GNPs) electrodes have been fabricated. The gel electrolytes and electrodes films have been coated on the paper using push coating and then characterized by scanning electron microscopy (SEM). In two types of the paper supercapacitors, on the PVDF gel electrolyte film, a layer of PVA/water and BaTiO3 as a gel separator film has been coated. The specific capacitance of the paper supercapacitors using cyclic voltammetry (CV) and galvanostatic (charge–discharge) methods at the scan rates 20 and 150 mV s−1 have been investigated. The paper supercapacitor based on the BaTiO3 separator film showed higher specific capacitance (312 F g−1) compared to other samples. Also, using electrochemical impedance spectroscopy (EIS), the Nyquist and Bode curves of paper supercapacitors have been measured. For the paper supercapacitors based on the PVDF gel electrolyte film and BaTiO3 separator film using the Nyquist curves, the equivalent series resistance (ESR) was 306 Ω and 125 Ω, respectively. The paper supercapacitor based on BaTiO3 gel separator structure represents a new type of flexible supercapacitor with high performance that can be applied to electronic devices.