Design and Fabrication of Ultracapacitor based on Paper Substrate and BaTiO3/PEDOT: PSS Separator Film.

Background: In this study, the ultracapacitor has been fabricated based on the BaTiO3/ PEDOT: PSS separator film and polyvinyl alcohol (PVA) electrolyte. On the paper-substrate was coated a film of the graphite nanoparticles (GNPs) as an electrode. The GNPs and surface morphology of the separator, electrolyte and electrode have been characterized using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) respectively.

Method: A piece of white commercial paper (3×6 cm) as a substrate was used. The typical paper has a porosity which transferred electrons between both sides of the separator. For the prevalence of this defect, the dielectric solution was coated on both sides of the separator and blocking layer was fabricated. For the preparation of the dielectric layer, at first PEDOT/PSS (3 g) was added to BaTiO3 (3 g) and the mixture was dispersed with ultrasonic for 10 min.

Results: To further explore the electrochemical performance of the paper ultracapacitor, several measurements are carefully analyzed including cyclic voltammetry and galvanostatic. From the cyclic voltammetry method (C-V curves) the specific capacitance of the ultracapacitor were 350 F g-1, 98 F g-1 and 58 F g-1 for voltage scan rate 20 mV/s, 150 mV/s and 300 mV/s respectively.

Conclusion: Electrochemical Impedance Spectroscopy test is an effective method to analyze and measure the internal resistance of the paper ultracapacitor. From the Nyquist curve, the internal resistance was 80 Ω. The ultracapacitor based on the GNPs electrode due to flexibility and high performance is more suitable for energy storage. In this paper few relevant patents to the ultracapacitors have also been reviewed and cited.