Comparing Triflate and Hexafluorophosphate Anions of Ionic Liquids in Polymer Electrolytes for Supercapacitor Applications

Two different ionic liquid-based biopolymer electrolyte systems were prepared using a solution casting technique. Corn starch and lithium hexafluorophosphate (LiPF6) were employed as polymer and salt, respectively. Additionally, two different counteranions of ionic liquids, viz. 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) and 1-butyl-3-methylimidazolium trifluoromethanesulfonate (also known as 1-butyl-3-methylimidazolium triflate) (BmImTf) were used and studied in this present work. The maximum ionic conductivities of (1.47 ± 0.02) × 10−4 and (3.21 ± 0.01) × 10−4 S∙cm−1 were achieved with adulteration of 50 wt% of BmImPF6 and 80 wt% of BmImTf, respectively at ambient temperature. Activated carbon-based electrodes were prepared and used in supercapacitor fabrication. Supercapacitors were then assembled using the most conducting polymer electrolyte from each system. The electrochemical properties of the supercapacitors were then analyzed. The supercapacitor containing the triflate-based biopolymer electrolyte depicted a higher specific capacitance with a wider electrochemical stability window compared to that of the hexafluorophosphate system

Poly(Acrylic acid)–Based Hybrid Inorganic–Organic Electrolytes Membrane for Electrical Double Layer Capacitors Application

Nanocomposite polymer electrolyte membranes (NCPEMs) based on poly(acrylic acid)(PAA) and titania (TiO2) are prepared by a solution casting technique. The ionic conductivity of NCPEMs increases with the weight ratio of TiO2.The highest ionic conductivity of (8.36 ± 0.01) × 10−4 S·cm−1 is obtained with addition of 6 wt % of TiO2 at ambient temperature. The complexation between PAA, LiTFSI and TiO2 is discussed in Attenuated total reflectance-Fourier Transform Infrared (ATR-FTIR) studies. Electrical double layer capacitors (EDLCs) are fabricated using the filler-free polymer electrolyte or the most conducting NCPEM and carbon-based electrodes. The electrochemical performances of fabricated EDLCs are studied through cyclic voltammetry (CV) and galvanostatic charge-discharge studies. EDLC comprising NCPEM shows the specific capacitance of 28.56 F·g−1 (or equivalent to 29.54 mF·cm−2) with excellent electrochemical stability

High conducting poly(vinyl alcohol)–ionic liquid based electrolytes for electric double layer capacitors (EDLCS) application / Liew Chiam Wen

PVA/ammonium acetate (CH3COONH4)–based polymer electrolytes had been prepared using solution casting technique. The effect of addition of ionic liquid onto polymer electrolytes is investigated throughout this project. Three different types of ionic liquids are added into the PVA/ammonium acetate (CH3COONH4)–based polymer electrolytes that are 1–butyl–3–methylimidazolium chloride (BmImCl), 1–butyl–3– methylimidazolium bromide (BmImBr) and 1–butyl–3–methylimidazolium iodide (BmImI). The ionic conductivity of polymer electrolyte is increased about two orders of magnitude from (1.94±0.01)×10-5 S cm-1 to (8.97±0.01) mS cm-1, (9.29±0.01) mS cm-1 and (9.63±0.01) mS cm-1 upon addition of 50 wt.% of BmImCl, 60 wt.% of BmImBr and 70 wt.% of BmImI, respectively at ambient temperature. All the polymer electrolytes follow Vogel–Tamman–Fulcher (VTF) relationship which is associated with free volume theory. The complexation between PVA, CH3COONH4 and ionic liquids is proven in Fourier Transform Infrared (FTIR) studies. Addition of ionic liquids reduces the glass transition temperature (Tg) of polymer electrolytes as proven in differential scanning calorimetry (DSC), improves the thermal stability of polymer electrolytes as shown in thermogravimetric analysis (TGA) and widens the electrochemical potential window of polymer electrolytes as shown in linear sweep voltammetry (LSV). The crystallinity of polymer electrolytes and the coherence length of crystallites are determined in X–ray diffraction (XRD) studies. Electric double layer capacitors (EDLCs) are assembled using carbon–based electrodes. The specific capacitance of EDLC containing ionic liquid– added polymer electrolytes is much higher than the EDLC containing ionic liquid–free polymer electrolyte. The electrochemical properties of the EDLCs are analyzed using cyclic voltammetry (CV), low frequency electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge (GCD) studies

Comparing Triflate and Hexafluorophosphate Anions of Ionic Liquids in Polymer Electrolytes for Supercapacitor Applications

Two different ionic liquid-based biopolymer electrolyte systems were prepared using a solution casting technique. Corn starch and lithium hexafluorophosphate (LiPF6) were employed as polymer and salt, respectively. Additionally, two different counteranions of ionic liquids, viz. 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) and 1-butyl-3-methylimidazolium trifluoromethanesulfonate (also known as 1-butyl-3-methylimidazolium triflate) (BmImTf) were used and studied in this present work. The maximum ionic conductivities of (1.47 ± 0.02) × 10−4 and (3.21 ± 0.01) × 10−4 S∙cm−1 were achieved with adulteration of 50 wt% of BmImPF6 and 80 wt% of BmImTf, respectively at ambient temperature. Activated carbon-based electrodes were prepared and used in supercapacitor fabrication. Supercapacitors were then assembled using the most conducting polymer electrolyte from each system. The electrochemical properties of the supercapacitors were then analyzed. The supercapacitor containing the triflate-based biopolymer electrolyte depicted a higher specific capacitance with a wider electrochemical stability window compared to that of the hexafluorophosphate system

Electrical, thermal, and structural studies on highly conducting additive-free biopolymer electrolytes for electric double-layer capacitor application

Biopolymer electrolytes consisting of poly(vinyl alcohol) (PVA) and lithium trifluoromethanesulfonate (LiTf) were prepared by solution casting technique. The ionic conductivity of polymer electrolyte is increased about seven orders of magnitude which is from 3.53 ± 0.01 × 10−10 to 2.87 ± 0.01 × 10−3 S cm−1 at ambient temperature with the addition of 40 wt% of LiTf. All the polymer electrolytes follow Vogel–Tamman–Fulcher (VTF) relationship which is associated with free volume theory. The complexation between PVA and LiTf salt is proven by Fourier transform infrared spectroscopy (FTIR) study. The glass transition temperature (Tg) of polymer electrolyte was decreased with the addition of LiTf as shown in differential scanning calorimetry (DSC) thermogram. The potential difference of the polymer electrolyte showed wider range, up to 4.6 V, as proven in linear sweep voltammetry (LSV) study. Electric double-layer capacitor (EDLC) cell was assembled using prepared polymer electrolytes and two identical activated carbon-based electrodes and its electrochemical properties were also investigated. The specific capacitance of 0.37 F g−1 was obtained for the EDLC with the most conducting polymer electrolyte. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

Rheological studies of PMMA-PVC based polymer blend electrolytes with LiTFSI as doping salt.

In this research, two systems are studied. In the first system, the ratio of poly (methyl methacrylate) (PMMA) and poly (vinyl chloride) (PVC) is varied, whereas in the second system, the composition of PMMA-PVC polymer blends is varied with dopant salt, lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) with a fixed ratio of 70 wt% of PMMA to 30 wt% of PVC. Oscillation tests such as amplitude sweep and frequency sweep are discussed in order to study the viscoelastic properties of samples. Elastic properties are much higher than viscous properties within the range in the amplitude sweep and oscillatory shear sweep studies. The crossover of G' and G'' is absent. Linear viscoelastic (LVE) range was further determined in order to perform the frequency sweep. However, the absence of viscous behavior in the frequency sweep indicates the solid-like characteristic within the frequency regime. The viscosity of all samples is found to decrease as shear rate increases

Some tax aspects of the abolition of par value.

This report aims to examine whether certain changes that were introduced by the Singapore’s Income Tax (Amendment) Act 2005 are merely consequential to the abolition of the par value (as intended by the authorities), and whether the abolition of par value affects Singapore’s Avoidance of Double Taxation Agreements

Poly(Acrylic acid)–Based Hybrid Inorganic–Organic Electrolytes Membrane for Electrical Double Layer Capacitors Application

Nanocomposite polymer electrolyte membranes (NCPEMs) based on poly(acrylic acid)(PAA) and titania (TiO2) are prepared by a solution casting technique. The ionic conductivity of NCPEMs increases with the weight ratio of TiO2.The highest ionic conductivity of (8.36 ± 0.01) × 10−4 S·cm−1 is obtained with addition of 6 wt % of TiO2 at ambient temperature. The complexation between PAA, LiTFSI and TiO2 is discussed in Attenuated total reflectance-Fourier Transform Infrared (ATR-FTIR) studies. Electrical double layer capacitors (EDLCs) are fabricated using the filler-free polymer electrolyte or the most conducting NCPEM and carbon-based electrodes. The electrochemical performances of fabricated EDLCs are studied through cyclic voltammetry (CV) and galvanostatic charge-discharge studies. EDLC comprising NCPEM shows the specific capacitance of 28.56 F·g−1 (or equivalent to 29.54 mF·cm−2) with excellent electrochemical stability

Effect of PVC on ionic conductivity, crystallographic structural, morphological and thermal characterizations in PMMA-PVC blend-based polymer electrolytes

In this paper temperature dependence of ionic conductivity crystallographic structural morphological and thermal characteristics of polymer blends of PMMA and PVC with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI!) as a dopant salt are investigated The study on the temperature dependence of ionic conductivity shows that these polymer blends exhibit Arrhenius behavior The highest ionic conductivity was achieved when 70 wt% of PMMA was blended with 30 wt% of PVC Xray diffraction (XRD) and scanning electron microscopy (SEM) reveal the amorphous nature and surface morphology of polymer electrolytes respectively In DSC analysis it was found that the glass transition temperature (TO and melting temperature (T(m)) decreased whereas the decomposition temperature (T(d)) increased In contrast the shift towards higher decomposition temperature and decrease in weight loss of polymer electrolytes in TGA studies indicates that the thermal stability of polymer electrolytes improved (C) 2010 Elsevier B V All rights reserve