Properties of In situ polymerized poly(3,4‐ethylenedioxythiophene)/alumina composites for energy storage applications

Abstract

Composites formed by poly (3,4-ethylenedioxythiophene) and alumina (PEDOT/Al 2 O 3 ) have been prepared by in situ anodic polymerization. For this purpose, the stability of 1:1 and 4:1 monomer:alumina aqueous solutions has been examined as a function of the pH (2.3, 4.0, 7.0, 8.8 or 10.8). Results indicate that the monomer behaves as a dispersant that remains stable at the studied basic pHs despite they are close to the isoelectric point of alumina. Although the thermal stability of the composites is considerably affected by the pH of the reaction medium, its influence on the surface morphology is very small. Independently of the synthetic conditions, the electrochemical properties were better for PEDOT/Al 2 O 3 than for pure PEDOT, reflecting that alumina particles promote the charge mobility. The highest specific capacitance (141 F/g), which was 55% higher than that obtained for pure PEDOT, was achieved for the composite prepared at pH= 8.8 using a 4:1 monomer:alumina ratio.These conditions favour the participation of OH -groups as secondary doping agents without degrading the polymer matrix and enhance the specific surface of the films, facilitating the ionic mobility. On the other hand, application of a multi-step polymerization strategy has shown that interfaces originated by consecutive steps enhance the specific capacitance.

Flexible Electrodes for Supercapacitors Based on the Supramolecular Assembly of Biohydrogel and Conducting Polymer

“…Thus, the incorporation of CP inside the dielectric hydrogel matrix does not cause an increment in the electrochemical activity, even though the oxidation and reduction of PEDOT and PHMeDOT are typically detected. 37 The first oxidation peak of chains occurs at 0. Table 1.…”

“…[27][28][29][30] The unique characteristics of PEDOT are due to the oxygen atoms attached at the ,'-positions of the thiophene ring, which induce strong electron-donating effects and prevent the formation of parasitic - linkages during the polymerization of the 3,4ethylenedioxythiophene (EDOT) monomers. 31 Moreover, the electrochemical performance of PEDOT can be improved if properly combined with other materials such as graphene, 23,[32][33][34] carbon nanotubes, 35 inorganic oxides, 36,37 and even biomolecules. 26,[38][39][40][41] The present work represents a step ahead with respect to the setup of ESCs composed of PEDOT electrodes and γ-PGA solid electrolytic medium.…”

Free-Standing, Flexible Nanofeatured Polymeric Films Prepared by Spin-Coating and Anodic Polymerization as Electrodes for Supercapacitors

“…It should be noted that GCD cycles are much less aggressive than CV cycles. Thus, previous studies showed that potentiostatic redox cycles alter drastically the structure of polymers [ 48 , 49 ]. This feature explains that AC values derived from GCD measures are, in general, higher than those obtained using CV, as shown in Figure 5 c and Figure 7 c.…”

Prototyping flexible supercapacitors produced with biohydrogel

“…Al 2 O 3 particles were prepared introducing the properly mass quantity into a vial containing magnetic stirrers, which was placed in a vortex at maximum power during 2 hours. 39 After that, particles were homogenized using a mortar. The size of the particles was controlled by both dynamic light scattering (DLS) and scanning electron microscopy (SEM).…”

“…In a recent work, we proved that incorporation of alumina (Al 2 O 3 ) to PEDOT through in situ polymerization at pH 8.8 significantly improves the electrochemical activity of such EAP. 39 In this work we combine our previous experience on γPGA biohydrogels and Al 2 O 3 composites to develop a solid organic symmetric supercapacitor prototype containing the following elements: 1) two self-supported electrodes made of γPGA, PEDOT microparticles, poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PHMeDOT), which is a PEDOT derivative with an exocyclic hydroxyl group that facilitates its preparation in aqueous environments, and Al 2 O 3 ; and 2) a solid supporting electrolyte composed by γPGA biohydrogel doped with NaHCO 3 . The elements of the prototype have been synthesized, characterized and subsequently assembled using simple and low-cost techniques.…”