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High-performance, breathable, conductive, and flexible polypyrrole (PPy) coated paper electrodes are prepared by an interfacial polymerization method using air-laid paper as a substrate. Owing to the synergistic effect of superior electrical conductivity, high wettability, and the porous architecture, the prepared electrode not only shows an outstanding specific capacitance and rate abilities (3100 and 2579 mF cm−2 at 1 and 20 mA cm−2 for a PPy coated paper electrode), but also exhibits excellent flexibility, wearability, and breathability. Based on these superior features, an all-solid-state supercapacitor assembled with the PPy coated paper electrodes shows an outstanding energy density of 62.4 µW h cm−2, remarkable air permeability and excellent flexibility to sustain various deformations. Furthermore, large-scale fabrication of conductive flexible paper electrode can be easily achieved through this method. Therefore, this work offers a new vision for flexible energy storage. [ABSTRACT FROM AUTHOR]

The poly(3,4-ethylenedioxythiophene)/single walled carbon nanotube (PEDOT/SWCNT) composite films with various SWCNT contents (0–50 wt.%) have been prepared by a vapor phase polymerization technique for the first time. The Seebeck coefficients of the composite films increase with the SWCNT contents. The maximum power factor is 37.8 μW mK −2 for a composite film with 35 wt% SWCNT, which is 1.7 times as high as that of the film without SWCNTs. The composite film with 35 wt% SWCNT has then been treated with a 0.04 wt% NaBH 4 /DMSO solution and the power factor increases to 44.1 μW mK −2 after the treatment. The PEDOT chains are more orderly arranged and with decreased doping level by forming composites with SWCNT and may be de-doped further after further treated with NaBH 4 /DMSO. Therefore, the Seebeck coefficient of the composite film has been further enhanced. [ABSTRACT FROM AUTHOR]

Multi-walled carbon nanotubes (MWCNTs)/polypyrrole (PPy) thermoelectric composites with MWCNT content ranging from 0 to 68 wt% have been prepared by in-situ polymerization or interfacial polymerization method. Both methods have enhanced the thermoelectric properties of PPy significantly. TEM observation shows that the in-situ polymerized composite consists of MWCNTs/PPy core/shell structures, while the interfacial polymerized composite is inhomogeneous: only a small amount of MWCNTs being coated with PPy and most of the MWCNTs aggregated into bundles and clusters. Due to the uniform dispersion of MWCNTs in the PPy matrix and therefore the stronger π–π interactions between MWCNTs and PPy, the in-situ polymerized composite shows higher electrical conductivity than the interfacial polymerized composite. Both of the composites have similar Seebeck coefficients. The power factor of an in-situ polymerized composite with 68 wt% MWCNTs reaches 2.20 μW/mK 2 , which is 26.5 times greater than that of pure PPy. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxythiophene)–tosylate–polyethylene glycol–polypropylene glycol–polyethylene glycol (PEDOT–Tos–PPP) films were prepared via a vapor phase polymerization (VPP) method. The films possess good electrical conductivity (1550 S cm −1 ), low Seebeck coefficient (14.9 μV K −1 ) and thermal conductivity (0.501 W m −1 K −1 ), and ZT ∼ 0.02 at room temperature (RT, 295 K). Then, the films were treated with NaBH 4 /DMSO solutions of different NaBH 4 concentrations to adjust the redox level. After the NaBH 4 /DMSO treatment (dedoping), the electrical conductivity of the films continuously decreased from 1550 to 5.7 S cm −1 , whereas the Seebeck coefficient steeply increased from 14.9 to 143.5 μV K −1 . A maximum power factor of 98.1 μW m −1 K −2 has been achieved at an optimum redox level. In addition, the thermal conductivity of the PEDOT–Tos–PPP films decrease from 0.501 to 0.451 W m −1 K −1 after treated with 0.04% NaBH 4 /DMSO solution. A maximum ZT value of 0.064 has been achieved at RT. The electrical conductivity and thermal conductivity (Seebeck coefficient) of the untreated and 0.04% NaBH 4 /DMSO treated PEDOT–Tos–PPP films decrease (increases) with increasing temperature from 295 to 385 K. And the power factor of the films monotonically increases with temperature. The ZT at 385 K of the 0.04% NaBH 4 /DMSO treated film is 0.155. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxythiophene)–tosylate–polyethylene glycol–polypropylene glycol–polyethylene glycol (PEDOT–Tos–PPP) films were prepared via a vapor phase polymerization (VPP) method. The thermoelectric (TE) properties of the films before and after treated with H 2 SO 4 at different concentrations were measured at 295 K. The TE properties of the films have been significantly improved by the H 2 SO 4 treatment. For example, after treated with H 2 SO 4 at 1 M, the electrical conductivity of the film has increased remarkably from 944 to 1750 S cm −1 , the Seebeck coefficient of the film reduced slightly from 16.5 to 14.6 μV K −1 , and the thermal conductivity decreased from 0.495 to 0.474 W/mK. Hence, the ZT value at 295 K has increased from 0.016 to 0.024. The electrical conductivity (Seebeck coefficient) of the untreated and 1 M H 2 SO 4 treated PEDOT-Tos-PPP films decreases (increases) with increasing temperature from 295 to 375 K. And the power factor of the films monotonically increases with temperature. The power factor at 375 K of the 1 M H 2 SO 4 treated film is almost twice as high as that at 295 K. Atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) analyses, and the thickness measurement of the films indicate that the tri-block copolymer PPP have been removed from the PEDOT-Tos-PPP films after the H 2 SO 4 treatment, and the UV–Vis-NIR absorption spectroscopy and Raman spectroscopy analyses reveal an increasing in the doping level in the PEDOT chains after the H 2 SO 4 treatment. Therefore, the TE properties enhancement may be attributed to the combined effects of the removal of the insulating PPP from the PEDOT-Tos-PPP film, increase the doping level and conformational change of the PEDOT chains resulted from the H 2 SO 4 treatment. [ABSTRACT FROM AUTHOR]

Ag-poly(3,4-ethylenedioxythiophene) (PEDOT) and Cu-PEDOT nanocomposites have been synthesized by an interfacial polymerization method, using 3,4-ethylenedioxythiophene (EDOT) and AgNO or Cu(NO) as starting materials. Ag-PEDOT or Cu-PEDOT nanocomposites prepared at an interface of n-hexane and acetonitrile are spherical Ag- or Cu- nanoparticle (0D)-modified PEDOT nanostructures, while a Cu-PEDOT nanocomposite prepared at an interface of n-hexane and a mixture of acetonitrile and glycol exhibits a different morphology: Cu nanostructures are needle-like (1D) and embedded in a PEDOT matrix. Ag- or Cu-nanoparticle contents in the composites can be tuned by changing oxidant (AgNO or Cu(NO))/EDOT molar ratios, and thermoelectric properties of the pellets cold pressed from composite powders with different Ag or Cu contents have been measured at room temperature. When the oxidant/EDOT molar ratio is 2, both Ag-PEDOT and Cu-PEDOT nanocomposites with spherical Cu nanoparticles reach their largest power factors of 1.49 and 7.07 μW mK, respectively, while Cu-PEDOT nanocomposite with needle-like Cu nanoparticles has consistently higher power factor than the above composites. When the oxidant/EDOT molar ratio is 1, it reaches its largest power factor of 12.47 μW mK and the highest ZT value of 0.01 at room temperature. [ABSTRACT FROM AUTHOR]

In this work, three-dimensional (3D) tubular molybdenum disulfide (MoS 2 )/PPy composites have been prepared, in which the MoS 2 is as the framework to promote the insertion and extraction of electrolyte ions, and PPy spherical particles or nanowires are synthesized by an in-situ oxidative polymerization method in the presence of the MoS 2 . FT-IR, XRD, XPS, FESEM and HRTEM are used to characterize the structures and morphologies of the as-prepared materials. The combination of conductive PPy and 3D tubular MoS 2 leads to a significant synergistic effect. For MoS 2 /PPy particle composites, the best performance (specific capacitance of 350 F/g at a current density of 1 A/g) is obtained from a sample prepared with the mass ratio of pyrrole to MoS 2 being 2:1. While for MoS 2 /PPy nanowire composites, the best performance (specific capacitance of 462 F/g at 1 A/g and a good cycling stability of 82% after 2000 cycles at 3 A/g) is obtained from a sample prepared with the mass ratio of pyrrole to MoS 2 being 5:1, which shows much better supercapacitor performance than the MoS 2 /PPy composite. Moreover, the composite electrode material delivers an energy density as high as 25.5 Wh/kg at a power density of 266.3 W/kg and maintains 14.5 Wh/kg at a high power density of 4002 W/kg. These performances feature the composite as advanced negative electrode materials and are superior to previous reports. [ABSTRACT FROM AUTHOR]