Effect of electropolymerization potential on the preparation of PEDOT/graphene oxide hybrid material for supercapacitor application

Conducting polymer poly(3,4-ethylenedioxythipohene) (PEDOT) hybrid with carbon-based material, graphene oxide (GO), was prepared for supercapacitor application. Different applied potentials were employed in order to study the effect of electropolymerization potential on PEDOT/GO thin film. Field emission scanning electron microscopy (FESEM) images showed that PEDOT/GO possessed more pronounced wrinkle paper-like sheet surface morphology as the potential increased from 1.0 to 2.0 V. Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy revealed that GO was successfully incorporated into PEDOT during electropolymerization. The cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements revealed that the PEDOT/GO composite electropolymerized at the applied potential of 1.2 V exhibited a maximum specific capacitance of 115.15 F/g with energy density and power density of 13.60 Wh/kg and 139.09 W/kg, respectively at current density 0.3 A/g. The EIS result showed that the Rct decreased as the electropolymerization potential rose from 1 V to 1.2 V and increased when the electropolymerization further increased to 2 V due to a large electron transfer resistance that makes the rate of charge transfer becomes slower

Fabrication PEDOT coated PVA-GO nanofiber for supercapacitor

Conducting nanofibers comprised of poly(vinyl alcohol) (PVA)-graphene oxide (GO) nanofiber coated with poly(3,4-ethylenedioxythiophene) (PEDOT) for supercapacitor application was prepared through integrated techniques i.e. electrospinning and electrodeposition. The formation of smooth cross-linking nanofibers without beads proved that GO has uniformly distributed into PVA with an average diameter of 117 ± 32 nm. Field emission scanning electron microscopy (FESEM) images revealed that cauliflower-like structure of PEDOT grew well on the surface of PVA-GO nanofibers with high porosity. Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy proved the existence of PVA, GO, and PEDOT. PVA-GO/PEDOT nanocomposite showed the highest specific capacitance (224.27 F/g) compared to PEDOT (167.92 F/g) and PVA/PEDOT (182.73 F/g). PVA-GO/PEDOT nanocomposite exhibited 1.8 V wide operating potential windows which significantly can enhance its capacitive behaviour. PVA-GO/PEDOT nanocomposite has also demonstrated superior performance with the energy density and power density of 9.58 Wh/kg and 304.37 W/kg, respectively at 1.0 A/g current density. PVA-GO/PEDOT nanocomposite revealed the smallest resistance of charge transfer (Rct) and equivalent series resistance (ESR) indicating excellent charge propagation behaviour at the interfacial region. The composite exhibits a good capacity retention of 82.41% after 2000 CV cycles and further drops 11.27% after 5000 cycles caused by the swelling and shrinkage of the electrode material during the charging and discharging processes

Polyaniline and manganese oxide decorated on carbon nanofibers as a superior electrode material for supercapacitor

A novel ternary composite of carbon nanofibers/polyaniline‑manganese oxide (CNFs/PANI-MnO2) was synthesized via electrospinning, carbonization followed by electrodeposition of PANI-MnO2. The CNFs/PANI-MnO2 composite exhibited excellent specific capacitance of 937.66 F/g at a scan rate of 5 mV/s and good cyclic stability with capacitance retention of 97.6% after 5000 consecutive cycles. The composite also exhibited superior performance with a specific energy of 66.12 Wh/kg at a specific power of 470.81 W/kg with low charge transfer resistance, Rct (1.81 Ω) and equivalent series resistance (32.18 Ω) indicating high electronic conductivity. Three symmetrical CNFs/PANI-MnO2 composites assembled in series using coin cells have successfully lighted up a red-light emitting diode (LED), proving its outstanding supercapacitive performance as an excellent electrode material for supercapacitors

Novel poly (3, 4-ethylenedioxythiophene)/reduced graphene oxide incorporated with manganese oxide/iron oxide for supercapacitor device

A new composite namely PEDOT/RGO/MnO₂/Fe₂O₃ was successfully developed from mixed metal oxides (MnO₂ and Fe₂O₃) incorporated with poly(3,4-ethylenedioxythiophene) (PEDOT) and reduced graphene oxide (RGO). The surface morphology of the prepared composite revealed that MnO₂ and Fe₂O₃ particles were successfully coated on the wrinkles and curly like-sheets of PEDOT/RGO in order to prevent aggregation of RGO layers and the composite was able to retain 80% of its initial specific capacitance in 1 M KCl. The PEDOT/RGO/MnO₂/Fe₂O₃ composite with Mn:Fe molar ratio of 2:3 displayed the highest specific capacitance of 287 F/g indicating that Mn:Fe molar ratio gives significant effect on the super capacitive performance of the composite. The specific capacitance of PEDOT/RGO/MnO₂/Fe₂O₃ was higher than the composites with monometallic oxide i.e. PEDOT/RGO/MnO₂ and PEDOT/RGO/Fe₂O₃. The PEDOT/RGO/MnO₂/Fe₂O₃ composite also revealed the lowest charge transfer resistance that leads to the superior supercapacitive performance. The specific energy and specific power of PEDOT/RGO/MnO₂/Fe₂O₃ composite were 11 Wh/kg and 1900 W/kg at 4 A/g, respectively. The results showed that the PEDOT/RGO/MnO₂/Fe₂O₃ composite is a promising electrode material for high-performance supercapacitor

Facile synthesis of PEDOT-rGO/HKUST-1 for high performance symmetrical supercapacitor device

A novel poly(3,4-ethylenedioxythiophene)-reduced graphene oxide/copper-based metal–organic framework (PrGO/HKUST-1) has been successfully fabricated by incorporating electrochemically synthesized poly(3,4-ethylenedioxythiophene)-reduced graphene oxide (PrGO) and hydrothermally synthesized copper-based metal–organic framework (HKUST-1). The field emission scanning microscopy (FESEM) and elemental mapping analysis revealed an even distribution of poly(3,4-ethylenedioxythiophene) (PEDOT), reduced graphene oxide (rGO) and HKUST-1. The crystalline structure and vibration modes of PrGO/HKUST-1 were validated utilizing X-ray diffraction (XRD) as well as Raman spectroscopy, respectively. A remarkable specific capacitance (360.5 F/g) was obtained for PrGO/HKUST-1 compared to HKUST-1 (103.1 F/g), PrGO (98.5 F/g) and PEDOT (50.8 F/g) using KCl/PVA as a gel electrolyte. Moreover, PrGO/HKUST-1 composite with the longest charge/discharge time displayed excellent specific energy (21.0 Wh/kg), specific power (479.7 W/kg) and an outstanding cycle life (95.5%) over 4000 cycles. Thus, the PrGO/HKUST-1 can be recognized as a promising energy storage material

Synergistic Enhancement of Ternary Poly(3,4-ethylenedioxythiophene)/Graphene Oxide/Manganese Oxide Composite as a Symmetrical Electrode for Supercapacitors

A novel facile preparation of poly(3,4-ethylenedioxythiophene)/graphene oxide/manganese oxide (PEDOT/GO/MnO2) ternary composite as an electrode material for a supercapacitor was evaluated. The ternary composite was sandwiched together and separated by filter paper soaked in 1 M KCl in order to investigate the supercapacitive properties. The ternary composite exhibits a higher specific capacitance (239.4 F/g) compared to PEDOT/GO (73.3 F/g) at 25 mV/s. The incorporation of MnO2 which act as a spacer in the PEDOT/GO helps to improve the supercapacitive performance by maximizing the utilization of electrode materials by the electrolyte ions. The PEDOT/GO/MnO2 ternary composite displays a specific energy and specific power of 7.9 Wh/kg and 489.0 W/kg, respectively. The cycling stability test revealed that the ternary composite is able to achieve 95% capacitance retention even after 1000 cycles due to the synergistic effect between the PEDOT, GO, and MnO2 that helps to enhance the performance of the ternary composite for supercapacitor application

Incorporation of metal oxides in electropolymerization of poly(3,4-ethylenedioxythiophene)/graphene oxide for supercapacitor

Supercapacitor is a type of energy storage device which is useful for storing a large amount of energy that can be charged and discharged in short amount of time with long life span. Electrode material which is the most important part of supercapacitor plays an important role in storing a high amount of energy. In this study, composites consisting of poly(3,4-ethylenedioxythiophene) (PEDOT), graphene oxide (GO) and metal oxides were prepared and its supercapacitive performances as electrode materials for supercapacitor were studied. Initially, different applied potentials, concentration of GO and electropolymerization times were studied for the preparation of PEDOT/GO. It was revealed that PEDOT/GO with 1 mg/ml GO electropolymerized for 10 minutes at 1.2 V exhibited the highest specific capacitance. In order to further improve the supercapacitive performance of the composite, metal oxides (MnO2, Fe2O3 and MnO2/Fe2O3) which are recognized for their high specific capacitance were introduced into the optimized PEDOT/GO composite. Various concentrations and the molar ratio of metal oxides precursor were studied to prepare PEDOT/GO/MnO2, PEDOT/GO/Fe2O3 and PEDOT/GO/MnO2/Fe2O3. Raman spectroscopy and Fourier transform infrared (FTIR) spectra revealed the composites were successfully incorporated with metal oxides upon the addition of MnO2, Fe2O3 and MnO2/Fe2O3 into PEDOT/GO. The presence of metal oxides in the PEDOT/GO was further confirmed via X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements and the results displayed all the distinctive peaks of MnO2, Fe2O3 and MnO2/Fe2O3. In addition, from the XRD and XPS, the phases of the metal oxides were also confirmed as MnO2 and Fe2O3 (hematite) with oxidation states of Mn4+ and Fe3+, respectively. The supercapacitive properties of the composites were studied by sandwiching two electrodes together and separated by a filter paper soaked in 1 M KCl. PEDOT/GO/MnO2/Fe2O3 composite exhibited the highest specific capacitance (287 F/g) compared to PEDOT/GO/MnO2 (239 F/g), PEDOT/GO/Fe2O3 (221 F/g) and PEDOT/GO (73 F/g) at 25 mV/s. The MnO2 and Fe2O3 particles were successfully anchored on the wrinkled paper-like sheets of PEDOT/GO as can be seen from FESEM images which acted as spacers in order to improve the supercapacitive performances by maximizing the utilization of electrode materials by the electrolyte ions. The PEDOT/GO/MnO2/Fe2O3 is a suitable candidate for a high-performance supercapacitor due to the synergistic effect provided by the PEDOT, GO, MnO2 and Fe2O3 that help to enhance the performance of the composite for supercapacitor application as revealed from GCD with specific energy and power of 11 Wh/kg and 1900 W/kg at 4 A/g, respectively. The PEDOT/GO/MnO2/Fe2O3 composite also revealed the lowest charge transfer resistance that leads to the superior supercapacitive performances. Thus, PEDOT/GO/MnO2/Fe2O3 composite displayed the highest supercapactive performances compared to PEDOT/GO/MnO2 and PEDOT/GO/Fe2O3

Supercapattery performance of carbon nanofibers decorated with poly(3,4-ethlenedioxythiophene) and cobalt oxide

Supercapattery epitomizes the next level of energy storage technology which demonstrates the pros of a supercapacitor and a battery. In this work, we developed a positive electrode of supercapattery comprised of porous functionalized carbon nanofibers (pfCNFs) as a template for the electrodeposition of poly(3,4-ethylenedioxythiophene) (PEDOT) and incorporation of cobalt oxide (Co3O4) through hydrothermal and annealing. Interestingly, the composite displays a flower-like structure observed on the fibers. The functionalized carbon nanofibers/poly(3,4-ethylenedioxythiophene)/cobalt oxide (pfCNFs/PEDOT/Co3O4) exhibited obvious redox peaks demonstrating its battery type property with high specific capacity (Csp) and specific capacity (Cs) of 849.65 F g-1 and 679.72 C g-1, respectively. As for the real application, the positive electrode of pfCNFs/PEDOT/Co3O4 and nitrogen-doped graphene as a negative electrode was assembled with a polyvinyl alcohol/potassium hydroxide gel used as a separator. The pfCNFs/PEDOT/Co3O4//NDG displayed specific energy of 14.54 Wh kg-1 and specific power of 1726.96 W kg-1 at 2 A g-1. In addition, the device also exhibited remarkable cycling stability with 106.26% capacitance retention over 2000 cycles revealing its prospect as an electrode for supercapattery

A bifunctional asymmetric electrochromic supercapacitor with multicolor property based on nickel oxide/vanadium oxide/reduced graphene oxide

A ternary nickel oxide/vanadium oxide/reduced graphene oxide (NiO/V2O5/rGO) was designed as a positive electrode of an asymmetric electrochromic supercapacitor. The uniform distribution of the elements (C, Ni, O, V) in the wrinkle-like sheet of NiO/V2O5/rGO was observed via elemental mapping. NiO/V2O5/rGO electrode demonstrated an outstanding specific capacitance of 1265.5 F/g compared to rGO (40.9 F/g), NiO (130.5 F/g), V2O5 (521.2 F/g) and NiO/V2O5 (707.3 F/g). The developed nickel oxide/vanadium oxide/ reduced graphene oxide//copper-based metal-organic framework/reduced graphene oxide (NiO/V2O5/rGO//MrGO) electrochromic supercapacitor (EC-SC) device that operated at wide operating potential successfully delivered maximum specific energy of 41.4 Wh/kg and excellent cycling stability (capacitance retention of 92.2%) over 4000 CV cycles. Interestingly, the level of energy stored in the prepared asymmetric EC-SC device can be visually detected as it implied color changes from dark green to orange. NiO/V2O5/rGO//MrGO with excellent optical and supercapacitive properties is designated as a promising electroactive material for next generation electrochromic supercapacitors

Influence of Concentration and Electrodeposition Time on the Electrochemical Supercapacitor Performance of Poly(3,4-Ethylenedioxythiophene)/Graphene Oxide Hybrid Material

Poly(3,4-ethylenedioxythiophene)/graphene oxide (PEDOT/GO) composites with wrinkled paper-like sheets morphology were electropolymerized potentiostatically at 1.2 V with different electrodeposition times (1–30 min) and various concentrations of GO (0.5, 1.0, 1.5, and 2.0 mg/mL). The electrochemical properties of PEDOT/GO composites as an electrode material for supercapacitor were investigated using cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD). The CV results revealed that PEDOT/GO containing 1.0 mg/mL GO and electropolymerized for 10 minutes exhibited the highest specific capacitance (157.17 F/g). This optimum PEDOT/GO was found to have energy and power density of 18.24 W/kg and 496.64 Wh/kg, respectively, at 1.0 A/g current density. The resistance of charge transfer obtained for PEDOT/GO is very low (13.10 Ω) compared to PEDOT (638.98 Ω), proving that PEDOT/GO has a good supercapacitive performance due to the synergistic effect of the high conductivity of PEDOT and large surface area of GO