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An ionic liquid (IL) 1-ethyl, 2-methyl imidazolium thiocyanate incorporated biopolymer system is reported in this communication for applications in dual energy devices, i.e., electric double-layer capacitors (EDLCs) and dye-sensitized solar cells (DSSCs). The solution caste method has been used to synthesize ionic-liquid-incorporated biopolymer electrolyte films. The IL mixed biopolymer electrolytes achieve high ionic conductivity up to the order of 10 -3 S/cm with good thermal stability above 250 °C. Electrical, structural, and optical studies of these IL-doped biopolymer electrolyte films are presented in detail. The performance of EDLCs was evaluated using low-frequency electrochemical impedance spectroscopy, cyclic voltammetry, and constant current charge-discharge, while that of DSSCs was assessed using J-V characteristics. The EDLC cells exhibited a high specific capacitance of 200 F/gram, while DSSCs delivered 1.53% efficiency under sun conditions.

Polyvinyl alcohol‐based polymeric films with NaI and ionic liquid (1‐Butyl‐1‐methylpyrrolidinium hexafluorophosphate) have been developed by using the solution cast method. The produced polymer electrolyte sheets were evaluated using various methods. Electrochemical impedance spectroscopy was utilized to measure the conductivity of the polymeric films, and the ionic liquid doped films showed an increase with a maximum at 6 wt% ionic liquid with a value for conductivity of 4.545 × 10−4 S cm−1. The morphological features of the most conductive polymer were further investigated using polarized optical microscopy and x‐ray diffraction. Ionic doping causes an increase in the amorphous nature. Using Fourier transform infrared spectroscopy, an excellent complexity between PVA, salt NaI, and ionic liquid was assessed. Thermogravimetric analysis was used to inspect the polymer films' thermal stability. The highest conducting sample was used for manufacturing an electric double‐layer capacitor. The behavior of manufactured electric double‐layer capacitor has been evaluated through EIS, CV, and GCD. [ABSTRACT FROM AUTHOR]

Immiscibility between polymer and ionic liquid, and the loss of solid-state configuration when ionic liquid loading becomes too high have been addressed by creating poly(ethylene oxide)-immobilized ionogel through a facile mechanochemical method. The poly(ethylene oxide)-immobilized ionogel with ionic liquid loading as high as 50 wt% demonstrates a high room-temperature ionic conductivity in the order of 10-4 S cm-1. [ABSTRACT FROM AUTHOR]

The novel ionic liquid N -methyl- N -[2-(2-methoxyethoxy)-ethyl]piperidinium bis(trifluoromethylsulfonyl)imide was synthesized from N -methylpiperidine by a sequence of nucleophilic substitution and anion exchange reactions and characterized by physico-chemical and electrochemical methods. [ABSTRACT FROM AUTHOR]

Abstract Electrical conductivities of pure tetraalkylammonium- (N+Me 4 , N+Et 4 , N+Bu 4 , N+Me 3 Hex) and imidazolium- (EMIM+, BMIM+) based ionic liquids (ILs) with bis(trifluoromethylsulfonyl)imide (TFSI−) anion and their acetonitrile solutions were measured in two temperature ranges of 298–368 and 298–348 K. Acetonitrile was used as an organic solvent to decrease the viscosity of ILs and, therefore, to increase the mobility of charge carriers. The maximum conductivity of acetonitrile solutions of both tetraalkylammonium- and imidazolium-based ILs was found to decrease with cation size. The conductivity – temperature dependencies of pure ILs and their acetonitrile solutions were analyzed using three approaches based on the Arrhenius equation for non-associating electrolytes, the Vogel-Fulcher-Tammann equation for ionic conductivity of glass-forming liquids and the Litovitz equation for associated liquids. The dilution of ILs with acetonitrile significantly reduced their activation energies of conductivity. At the same time, the activation energy decreased with increasing the alkyl chain length because of the deceleration of the ion transfer and the growth of the viscosity. Graphical abstract Image 1 Highlights • Electrical conductivities of two classes of ionic liquids were measured. • Activation energies of conductivity were calculated using the Arrhenius, Vogel-Fulcher-Tammann and Litovitz equations. • Electrical conductivity and its activation energy depend on the alkyl chain length of IL. [ABSTRACT FROM AUTHOR]

[Display omitted] • New butyl-dimethyl-(ferrocenylmethyl)ammonium bis(trifluoromethanesulfonyl)imide ionic liquid. • Electrical conductivity of binary solutions of ionic liquid in acetonitrile. • Arrhenius and Vogel-Fulcher-Tammann activation energies of conductivity. • Density and isobaric thermal expansion coefficient. • Thermal stability and thermal degradation mechanism. Doping with transition metals is a promising way to expand the industrial applications of ionic liquids (ILs). This study reports the synthesis, structure and physicochemical properties of a novel butyl-dimethyl-(ferrocenylmethyl)ammonium bis(trifluoromethanesulfonyl)imide ([BDFA][NTf 2 ]) IL. The thermo-gravimetric analysis combined with mass spectrometry of evolved gases demonstrated the high thermal stability of [BDFA][NTf 2 ] up to 500 K. The thermal degradation of [BDFA][NTf 2 ] at higher temperatures is a multi-step process accompanied by the cation destruction through the Hofmann elimination reaction and the subsequent transformations, such as fragmentation of the products of thermal degradation of the [NTf 2 ]-anion and the direct interaction between these products. The glass transition and melting temperatures of [BDFA][NTf 2 ] measured by the differential scanning calorimetry are 229 and 320 K, respectively. The electrical conductivities and densities of binary mixtures of [BDFA][NTf 2 ] with acetonitrile (AN) were measured in the temperature range of 293 – 348 K at atmospheric pressure. The isobaric thermal expansion coefficients were calculated from the experimental data. The conductivity – temperature dependences were analyzed using the Arrhenius and Vogel-Fulcher-Tammann equations. The activation energy of ion transport and limiting conductivity increased with the IL mole fraction in AN. [ABSTRACT FROM AUTHOR]

[Display omitted] • New asymmetrical dioxidothiomorpholinium-morpholinium dicationic ionic liquid. • Electrical conductivities of IL binary solutions in propylene carbonate. • Activation energies of conductivity using Arrhenius, Litovitz and VFT equations. • Electrochemical window increases from 3.9 V at 363 K to 4.8 V at 233 K. A new asymmetrical 1,1-dioxidothiomorpholinium- and morpholinium-based dicationic ionic liquid (4-ethyl-4-[3-(4-ethyl-1,1-dioxidothiomorpholin-4-ium-4-yl)propyl]morpholin-4-ium tetrafluoroborate (EtDTMC 3 EtM·2BF 4)) was synthesized in four stages and characterized by 1H, 13C, 1H,1H–COSY NMR, single X-ray diffraction, XPS spectroscopy and simultaneous thermal analysis. Electrical conductivities of several EtDTMC 3 EtM·2BF 4 solutions in propylene carbonate (PC) were measured in the 298 – 368 K temperature range and analyzed using the Arrhenius, Litovitz, and Vogel–Fulcher–Tammann (VFT) equations. [ABSTRACT FROM AUTHOR]

Mesoporous nitrogen-doped graphene nanoflakes (N-GNFs) with high nitrogen doping level of 5.0–10.7 at.% were produced by a facile template CVD synthesis using the mixture of acetonitrile and benzene as a precursor. The pore structure, morphology and physicochemical properties of N-GNFs were characterized by TEM, XPS, Raman spectroscopy, and low-temperature nitrogen physisorption. The electrochemical performance of N-GNFs was tested in electric double-layer capacitor (EDLC) with ionic liquid electrolyte (1.2 M N+Et 4 TFSI− solution in CH 3 CN) by cyclic voltammetry, galvanostatic charge-discharge measurements, and electrochemical impedance spectroscopy. With increasing the nitrogen content in N-GNFs their specific capacitance increased and achieved 167 F g−1 at a scan rate of 5 mV s−1. The maximum delivered energy density was 46.3 Wh kg−1, which corresponded to a power density of 0.74 kW kg−1. The high electrochemical performance of N-GNFs was attributed both to the pseudo-capacitance of active nitrogen sites and to the developed mesoporosity. Different tetraalkylammonium bis(trifluoromethylsulfonyl)imide ionic liquids were used to evaluate the cation size effect on the stability and performance of N-GNFs-based EDLCs. In contrast to N+Et 4 TFSI− and N+Bu 4 TFSI− electrolytes, the cycling performance of N-GNFs in N+Me 4 TFSI− was limited because of the electrode degradation resulted from the intercalation of N+Me 4 ions between graphene layers and their exfoliation. Image 1 • EDLC electrodes from mesoporous nitrogen-doped graphene nanoflakes. • High specific capacitance in [N+R 4 ]TFSI− based electrolytes (up to 167 F g−1). • Significant contribution from pseudo-capacitance. • High cycling stability in N+Et 4 TFSI− and N+Bu 4 TFSI− based electrolytes. • Degradation in N+Me 4 TFSI− because of the cation intercalation. [ABSTRACT FROM AUTHOR]

Mesoporous graphene nanoflakes (GNFs) of different thickness with a specific surface area of 660–1720 m2/g were produced by the template synthesis via hexane pyrolysis over MgO. The structure and morphology of GNFs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and low-temperature N 2 physisorption. The electrochemical performance of GNF-based supercapacitors was tested in ionic liquid electrolyte (1.2 M N+Et 4 TFSI− in CH 3 CN) by cyclic voltammetry and galvanostatic charge – discharge measurements. The assembled symmetric supercapacitors with a wide voltage window of 3 V delivered specific capacitance of 112 F/g at 5 mV/s and 105 F/g at 0.5 A/g with a high rate capability of ~81% at a current density of 15 A/g. The energy density reached 32.8 Wh/kg corresponding to the power density of 0.7 kW/kg. Furthermore, even at a high power density of 19.9 kW/kg, GNFs still showed an energy density of 24.3 Wh/kg, which made them promising for application in supercapacitors. Image 1 • Mesoporous graphene nanoflakes were produced by template synthesis. • Template is a simple way to control porous structure of nanoflakes. • Specific surface area up to 1720 m2/g was reached. • High specific capacitance, power and energy density in supercapacitors. • Role of pore size and specific surface area was established. [ABSTRACT FROM AUTHOR]