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Ionic liquid EMIBF4 (EMI) was combined with propylene carbonate (PC) and/or 1,2-dimethoxyethane (DME) for electric double-layer capacitors (EDLCs). The effects of these support solvents on physicochemical properties of the electrolyte and capacitance performances of the capacitor were investigated. Compared to pure EMI, the existence of support solvent of PC or PC-DME provides better power characteristic mainly profited from improved ion conductivity, but sacrifices the stable potential window to some extent. The capacitor employing activated carbon and the electrolyte EMI-PC-DME yields an active mass normalized energy density of 38.5 Wh kg−1 at ~ 900 W kg−1 for the cut-off voltage of 3 V. It is a significant performance improvement compared to EMI and EMI-PC system at identical operation condition. This research guides an attractive direction to construct advanced 3 V based EDLC with excellent overall properties.

A series of electrolytes based on ionic liquid (IL) N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl) amide (DEMETFSI) and individual or binary co-solvent(s) consisting of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) and/or 1,3-dioxolane (DOL) were investigated. The alterative solvent composition results in very different electrolyte properties (conductivity/viscosity, polysulfide solubility and film formation ability) and Li-S cell performances (specific capacity, cycle stability and rate capability). The hybrid system of DEMETFSI/TTE/DOL provides better overall performances compared to the IL with non- or single co-solvent, which is mainly profited from the synergistic function of TTE and DOL, together favorable for the improvement of ionic conduction of the electrolyte and Li surface chemistry. It is further emphasized that the construction of a rational counterbalance between polysulfide dissolution and shuttle suppression is more significant for the advanced Li-S batteries.

1,1,2,2-Tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) was selected as a co-solvent of ionic liquid for fabricating the functional electrolyte of Li-S batteries. The basic properties of the electrolyte and electrochemical performances of the cell with alterative TTE contents were intensively investigated. It is found that the fluorinated ether helps to promote ion conduction in the electrolyte, modify and stabilize SEI on Li metal, reduce charge transfer impedance, as well as restrict dissolution and shuttle of polysulfides. Consequently, high reversible capacity, good cycle, and rate capability are achieved at moderate TTE addition. The novel electrolyte guides a promising direction to construct Li-S batteries with high-energy density, long life, and high safety.

Recently, the fabrication of electronics-related components via direct ink writing (DIW) has attracted much attention. Compared to the conventionally fabricated electronic components, DIW-printed ones have more complicated structures, higher accuracy, improved efficiency, and even enhanced performances that arise from well-designed architectures. The DIW technology allows directly print materials on a variety of flat substrates, even a conformal one, well suiting them to applications such as wearable devices and on-chip integrations. Here, recent developments in DIW printing of emerging components for electronics-related applications are briefly reviewed, including electrodes, electronic circuits, and functional components. The printing techniques, processes, ink materials, advantages, and properties of DIW-printed architectures are discussed. Finally, the challenges and outlooks on the manufacture of 3D structured electronic devices by DIW are outlined, pointing out future designs and developments of DIW technology for electronics-related applications. The combination of DIW and electronic devices will help to improve the quality of human life and promote the development of science and society.

Porous polypyrrole (PPy) free-standing films are prepared by the self-assembly of a mixture of two long-chain surfactants (Span80 and OP10) via interfacial polymerization. The micromorphology of synthesized PPy is investigated by scanning electron microscope (SEM), while its electrochemical performance is evaluated by the means of cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results show that the morphology of obtained PPy can be controlled from ruptured vesicle-like structure to network-like structure, then to coral-like structure by tuning the HLB (Hydrophile-Lipophilic Balance) value of mixed surfactant in the synthetic process, and the HLB value plays a crucial role in improving the electrochemical performances of as-prepared PPy. Particularly, interconnected PPy network bonded with ∼800 nm PPy particles could be perfectly prepared at HLB value of 10.4. Because of its larger active surface area, more excellent conductivity and higher porosity than other samples, the maximum specific capacitance and energy density are obtained up to 286 F g−1 and 39.7 Wh kg−1, respectively, at a current density of 0.5 A g−1. Furthermore, 88.6% of the initial specific capacitance is retained even after 2000 cycles.

Polymer-based composites with the advantages of ceramics and polymers exhibit high dielectric constant, good processing properties and low dielectric loss. The composites with a varied content of irregular alumina ( i -Al 2 O 3 ) filler were prepared by UV-cured epoxy acrylic (EA). Spherical alumina ( s -Al 2 O 3 ) was used as a filler to further investigate the effect of alumina (Al 2 O 3 ) shapes on dielectric properties of composites in the frequency range of 50 Hz–1 MHz. Fourier transform infrared spectroscopy proved that the UV-cured epoxy acrylic/alumina (Al 2 O 3 /EA) composites were successfully fabricated. Scanning electron microscopy demonstrated that i -Al 2 O 3 particles have superior homodispersion in the matrix. Through testing, for all samples, with the addition of Al 2 O 3 , the relative permittivity of composites increased as expected, and the dielectric loss decreased accordingly. These data show that the incorporation of i -Al 2 O 3 particles presents better properties when compared with s -Al 2 O 3 /EA, which indicates that i -Al 2 O 3 particles have more influence on the dielectric properties of the composites than those of s -Al 2 O 3 particles. According to Weibull distribution, the characteristic breakdown strength of the Al 2 O 3 /EA composites was obtained and the results suggested that the composites of i -Al 2 O 3 /EA exhibited better breakdown performance.

Concentrated lithium salt-monoglyme complex was used as an electrolyte candidate of lithium-sulfur (Li-S) batteries. It is found that the limited content of monoglyme suppresses the solubility and shuttle of polysulfides in the electrolyte. Then 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (TFTFE) was selected as a second solvent of the complex, and the effect of adding TFTFE on electrolyte properties and cell performances was investigated. The results indicate that the fluorinated ether further reduces the dissolution of polysulfides and improves the specific capacity and cycle stability of the cells. Certain polarization appears in the discharge stage if using excess TFTFE, but it is nearly harmless to the operation of the cell at higher rates. The combination of concentrated complex and fluorinated ether in the electrolyte is an effective approach to achieve excellent performance for Li-S batteries.

1,1,2,2-Tetrafluoroethyl 2,2,2-trifluoroethyl ether (TFTFE) was added to a solvate ionic liquid (SIL) based on glyme-lithium salt as a support solvent. The fluorinated ether improves cycle and rate capability of Li–S cells. The key role that TFTFE played in the cell system with SIL is an ionic conduction-enhancing ingredient, especially for high-rate cycle environment.

Electrode materials with a high specific capacitance, outstanding reversibility and excellent cycle stability are constantly pursued for supercapacitors. In this paper, we present an approach to improve the electrochemical performance by combining the advantages of both inorganic and organic. Ni-MnO2/PANi-co-PPy composites are synthesized, with the copolymer of aniline/pyrrole being coated on the surface of Ni-doped manganese dioxide nanospheres. The inorganic–organic composite enables a substantial increase in its specific capacitance and cycle stability. When the mass ratio of Ni-MnO2 to aniline and pyrrole mixed monomer is 1:5, the composite delivers high specific capacitance of 445.49[Formula: see text]F/g at a scan rate of 2[Formula: see text]mV/s and excellent cycle stability of 61.65% retention after 5000 cycles. The results indicate that the Ni-MnO2/PANi-co-PPy composites are promising electrode materials for future supercapacitors application.

Nickel-doped manganese dioxide (Ni-MnO2) synthesized by sol-gel method has been used as an electrode material for supercapacitors. The structure and electrochemical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectrometry (EIS). Results showed that the nickel-doped manganese dioxide sample exhibited irregular particles with the diameter of about 500 nm. The crystallographic structure of MnO2 was the poorly crystallized γ-MnO2. The doping ratio had a great influence on the electrochemical properties of the materials. When the molar ratio of Ni/Mn was 3/100, the specific capacitance of Ni-MnO2 achieved to 252.61 F/g. After 2000 charge/discharge cycles, the specific capacitance of Ni-MnO2 was still maintained at 74.36%, which was attributed to its excellent cycling stability.

A new type of side-chain liquid-crystalline polysiloxane was synthesised by graft copolymerisation, using (trans, trans)-4-propyl-4'-vinylbicyclohexane exhibiting platelet texture of a blue phase as a mesogenic monomer. The graft copolymerisation was confirmed by characterising the chemical structure of the mesogenic monomer and the polymer by FT-IR, 1H NMR and 13C NMR. Microstructures of the mesogenic monomer and the polymer were analysed by polarising optical microscopy and X-ray diffraction. Thermal properties of the mesogenic monomer and the polymer were studied by differential scanning calorimetry (DSC). Meanwhile, the spherulite texture of the polymeric smectic A phase of the mesogenic polymer was revealed in the cooling process by polarising optical microscopy. This texture is uncommon in other liquid crystalline polymers.

Self-stabilized copolymer nanoparticles are easily and productively synthesized by a chemical oxidative polymerization of pyrrole (Py) and 2-hydroxy-5-sulfonic aniline (HS) in 1 M HCl without any external template. UV-vis, IR, 1D 1H NMR, 2D 1H-1H COSY NMR, and 2D 1H-13C HSQC NMR all indicate that a real copolymerization occurs between HS and Py comonomers and Py units construct the main position of the copolymer. On the basis of the elemental analysis, the reactivity ratios of HS and Py comonomers are calculated to be 0.043 and 1.14, respectively. The polymerization yield, size, morphology, and electrical conductivity of the copolymer particles can significantly be optimized by the comonomer ratio, polymerization temperature, and ammonium persulfate oxidant/comonomer ratio. The copolymer particles always keep narrow size distribution with a small polydispersity index (PDI) of 1.05-1.08. HS/Py(50/50) copolymer nanoparticles synthesized at 0 °C are found to generally have irregular granular morphology with the smallest diameter of 35-60 nm and the lowest PDI of 1.05 by laser particle-size analyzer, FE-SEM, and TEM. The mechanisms of the formation and intrinsic self-stabilization of the nanoparticles are proposed based on the powerful static repulsion from negatively charged sulfonic and hydroxyl groups on the nanoparticles. Through simple dedoping and redoping procedures, the copolymer particles exhibit a widely adjustable conductivity from 10-9 to 1.12 S cm-1. These copolymer nanoparticles show high conductivity, good self-stability, and powerful redispersibility in water and organic media. Nanocomposite films of the copolymer nanoparticles in polyvinylalcohol possess a low percolation threshold down to 0.09 wt % as well as retain 80-95% transparency and 10 2-108 times the conductivity of the pure polyvinylalcohol film in the nanoparticle loading from 0.09 to 3 wt %. © 2009 American Chemical Society.

Poly(pyrrole-co-o-toluidine) (PPOT) nanoparticles for electrochemical capacitors are easily and productively synthesized by a chemical oxidative polymerization of pyrrole (PY) and o-toluidine (OT) in 0.5M HCl without any external additive. The polymerization yield, electrical conductivity, and size of the copolymer nanoparticles can significantly be optimized by the oxidant/monomer molar ratio and polymerization temperature. The chemical structure of the obtained copolymer is characterized by UV–vis and FTIR. The copolymer nanoparticles synthesized at 10°C are found to generally have irregular granular morphology with a diameter of 60–100 nm and a small polydispersity index of 1.06 by laser particle-size analyzer, FE-SEM, and TEM, and good dispersibility in water. The formation mechanism of the nanoparticles is proposed based on the powerful amphipathicity from comonomer aggregate formed by PY and OT in the monomer solution. The PPOT nanoparticles possess a specific capacitance of 310 F g−1 at 25 mV s−1 as well as retain 81% of the initial specific capacitance value after 1000 cycles, while its energy density and power density are found to be 40.2 and 1196 W Kg−1 at 2 A g−1. The enhanced electrochemical properties can be attributed to the nanostructural advantage of the PPOT. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42995.

Nanoporous ferric oxide has been prepared with nanoscale casting process using activated carbon template in supercritical carbon dioxide. The precursors with the cosolvent of acetone were dissolved in supercritical CO2, and then attached to activated carbon in the supercritical condition. After removal of the activated carbon template by calcinations in air at 873 K, the nanoporous Fe2O3 was obtained. Four factors were considered to study the effect on the coating ratio and yield. The structure and morphology of the products were characterized through nitrogen adsorption–desorption isotherms, thermal gravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM).

Microcellular foaming of biodegradable Bionolle in supercritical CO2 has been produced. The effects of a series of variable factors, such as saturation temperature, saturation pressure, and depressurization time and step on the foam structures and density, were studied through measurement of density and SEM observation. The experimental results show that higher saturation temperatures lead to an increase in bulk densities; and different depressurization time and step result in different product cell morphology. In addition, at some saturation temperature, the orientation of the cells can be found in the product morphology. XRD experimental results show that the foaming treatment with SC CO2 increased the crystallinity of Bionolle. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2901–2906, 2006

The grafting of polyacrylamide to polypropylene was realized with supercritical carbon dioxide as a substrate-swelling agent and monomer/initiator carrier. The effects of supercritical carbon dioxide assisted impregnation and graft polymerization conditions on the grafting ratio were studied. The original polypropylene and grafting products were characterized with infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2614–2618, 2006

A facile interfacial synthesis strategy is proposed to synthesize self-assembled polypyrrole (PPy) free-standing films for electrochemical capacitors with the assistance of surfactants. The chemical structure of the obtained samples is characterized by Fourier transform infrared. The morphologies of the samples are studied by scanning electron microscope. The results show that the prepared PPy films own highly porous structures using Tween80 as a surfactant, while the synthesized PPy films have vesicular structures by adding Span80 as a surfactant. Furthermore, lowering polymerization temperature makes PPy films have smaller and more pores or vesicles. The PPy films prepared at 0°C with Tween80 as a surfactant possess a high specific capacitance of 261 F g−1 at 25 mV s−1 as well as retain 75% of the initial specific capacitance value after 1000 cycles. The good electrochemical properties can be attributed to the highly porous structural advantage of the PPy films caused by Tween80. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41615.