Recently, organic thermoelectric (TE) materials especially conducting polymers have attracted increasing attention. In this work, we successfully synthesized ultrafine poly (3,4-ethylenedioxythiophene) (PEDOT) nanowires (NWs) (similar to 10 nm) by a simple self-assembled micellar soft-template method and then obtain highly flexible free-standing PEDOT NW films by vacuum-assisted filtration. The films are with very high electrical conductivity (similar to 1340 S cm(-1)). After being treated with 6 M H2SO4 and then with 1 M NaOH at room temperature, the film shows an enhanced power factor of 46.51 mu W m(-1)K(-2) (Seebeck coefficient of 25.5 mu V K-1, electrical conductivity of 715.3 S cm(-1)), which increases by 54% compared with that of the pristine film. To the best of our knowledge, it outperforms the TE performance of all reported one dimensional conducting polymer-based films. In addition, the TE performance of the film almost remains unchanged even after being bent for 200 times, indicating excellent flexibility. A flexible TE prototype composed of six strips (7 mm x 30 mm) of the as-prepared PEDOT NW films connected in series shows an output power of 157.2 nW at a temperature difference of 51.6 K. The free-standing PEDOT NW films show promise to a new generation of wearable TE devices. (C) 2018 Elsevier Ltd. All rights reserved.

TA free-standing and highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) nanowire (NW) film was used as a working electrode for electrodepositing tellurium (Te). By adjusting the electrodeposition time, the thermoelectric (TE) performance of the free-standing hybrid filmwas optimized. The maximum power factor of 240.0 mu Wm(-1) K-2 (with the electrical conductivity of 561.4 S cm(-1) and the Seebeck coefficient of 65.4 mu VK-1) was obtained from a hybrid film electrodeposited for 7 h, which was 8 times higher than that of the pristine PEDOT NW film. In addition, the electrical conductivity of the film almost did not change even after being bent for 400 times around a rod with radius of 4 mm, indicating an excellent flexibility. This work offers a facile approach to prepare multilayered TE films, and desirable combination of excellent flexibility, high electrical conductivity, and facile process scalability makes the free-standing PEDOT NW film particularly promising for portable and flexible electronics. (C) 2019 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.

As an important binary IV-VI semiconductor compound, tin selenide ( SnSe) has been investigated intensively for a wide range of applications in energy storage and photovoltaic devices, due to its unique electronic and optoelectronic properties. In this work, we successfully synthesized SnSe powders by a simple, rapid and high-yield method called microwave-assisted synthesis for the first time and also measured their electrochemical performances. By rationally controlling the microwave heating time, we found that the 15-min reacted sample exhibited the most outstanding specific capacitance and rate capability ( 214.3 F/g at 1 A/g and 182.8 F/g at 20 A/g), and excellent cycling stability. The microwave-assisted synthesis method is efficient and rapid for preparing SnSe electrode materials. (C) 2017 Elsevier B.V. All rights reserved.

Flexible solid-state supercapacitors based on free-standing PEDOT NW films with PVA–H2SO4–polydopamine robust gel films show high electrochemical performance.

A Zn-doped Ni-based metal - organic framework (Ni-MOF) material with honeycomblike hierarchical spherical structure is synthesized by a microwave-assisted method using HCl as the modulator for the first time. By adjusting the amount of the Zn ions doped, an optimal Zn doped Ni-MOF electrode material is obtained, which possesses a superior electrochemical performance: specific capacity of 237.4mA h g(-1) and 122.3 mA h g(-1) at 1 A/g and 20 A/g, respectively. This is one of the highest performances reported so far for MOFs. The excellent electrochemical properties are ascribed to the unique crystal structure and special morphology of the Zn-doped Ni-MOF material. This work shows that the microwave-assisted synthesis is a rapid and efficient method for preparation of Ni-MOF supercapacitor electrode material. (C) 2018 Elsevier Ltd. All rights reserved.

MoS2 nanosheets have been prepared by a rapid and simple microwave-assisted wet-chemical method using MoS2, LiOH·H2O and ethylene glycol as the raw materials. The structure and morphology of the obtained product have been characterized by X-Ray diffraction (XRD), Raman spectroscopy, Atomic force microscopy (AFM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). The thickness of the MoS2 nanosheets is about 4.42nm. The MoS2 nanosheets after cold pressing have a low electrical conductivity and a high Seebeck coefficient of 690μV/K. The Seebeck coefficient is much higher than that (280μV/K) of raw MoS2 powders. In addition, the MoS2 nanosheets have enhanced capacitive performance compared with the raw MoS2 powders, too.

Supercapacitors, known as ultracapacitors, have been supposed to be one of the most promising candidates to meet requirements of human's sustainable development, due to their advantages such as high capacitance and rate capability, long cycle life and low processing cost. Electrode materials play a decisive role on performance of supercapacitors, thus researches on electrode materials are critical to supercapacitors. Conducting polymer (CP)-based materials exhibit high potential in supercapacitors because of their unique advantages including good conductivity, flexibility, relatively cheap, easy of synthesis and so on. This review summarizes recent research progress of CPs (including polypyrrole (PPy), polyaniline (PANi), and polythiophene (PTh)), the CP-based binary composite, and the CP-based ternary composite electrode for supercapacitors. In the end, we give a brief outline of development directions of CP-based supercapacitors in the future.

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.

In this work, three-dimensional (3D) tubular molybdenum disulfide (MoS2)/PPy composites have been prepared, in which the MoS2 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 MoS2. 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 MoS2 leads to a significant synergistic effect. For MoS2/PPy particle composites, the best performance (specific capacitance of 350F/g at a current density of 1A/g) is obtained from a sample prepared with the mass ratio of pyrrole to MoS2 being 2:1. While for MoS2/PPy nanowire composites, the best performance (specific capacitance of 462F/g at 1A/g and a good cycling stability of 82% after 2000 cycles at 3A/g) is obtained from a sample prepared with the mass ratio of pyrrole to MoS2 being 5:1, which shows much better supercapacitor performance than the MoS2/PPy composite. Moreover, the composite electrode material delivers an energy density as high as 25.5 Wh/kg at a power density of 266.3W/kg and maintains 14.5 Wh/kg at a high power density of 4002W/kg. These performances feature the composite as advanced negative electrode materials and are superior to previous reports.

Conductive poly(p-phenylenediamine) (PpPD) nanopowders doped with different-concentration hydrochloric acid (HCI) were synthesized by a typical chemical oxidative polymerization method. The PpPD powders were characterized by the Fourier transform infrared spectroscopy, UV-vis spectroscopy, H-1 nuclear magnetic resonance spectroscopy and transmission electron microscope. The results showed that the morphology of the products changed from mainly spherical nanoparticles of the pure PpPD to rod-like nanoparticles of HCI doped PpPD. The pure PpPD showed n-type conduction whereas the HCI doped PpPD exhibited p-type conduction. The PpPD doped by 1 M HCI showed a maximum power factor of about 0.56 mu W m(-1) K-2 at room temperature. The mechanism of the change of the conduction type has also been discussed. (C) 2017 Elsevier B.V. All rights reserved.