Papers by Keyword: Polymer Electrolyte

Abstract: Solid polymer electrolyte (SPE) with PVdF polymer and LiBOB salt has been prepared with the doctor blade method. To improve the membrane ionic conductivity, TiO₂ was added in different variations: 0%, 5%, 10%, and 15%. Surface morphology analysis was performed using SEM and energy-dispersive X-ray (EDX) spectroscopy. The conductivity behavior was studied using AC impedance spectroscopy (EIS). SEM and EDXS analyses revealed that TiO₂ addition played a role in pore formation in the solid polymer electrolyte membrane. The highest room-temperature ionic conductivity of the PVdF–LiBOB solid polymer electrolyte system in this study was 4.65 mS cm⁻¹ at 10% TiO₂. It was also found that the agglomeration of TiO₂ particles on the surface of the membrane resulted in a decrease in ionic conductivity.

Abstract: Safer alternative for lithium-ion battery containing liquid electrolyte was proposed using solid polymer electrolyte as a combo separator/electrolyte. In this work, cellulose acetate (CA) was used to replace fossil-based polymer as battery separator. To further promote sustainable membrane fabrication, dimethylsulfoxide (DMSO) and citric acid was used as solvent and cross-linking agent, respectively. Branched polyethyleneimine (bPEI) was also incorporated in the polymer electrolyte complex to promote electrolyte salt dissociation within the matrix. Crosslinking of CA-bPEI using citric acid showed promising properties compared to unmodified CA membrane. Better thermal stability and lower crystallinity were seen in the modified CA membrane, resulting in better ionic conductivity.

Abstract: A biopolymer electrolyte made from natural polymer consists of jackfruit seed starch (JSS) and polyvinyl alcohol (PVA) with a different composition of zinc oxide (ZnO) was prepared using the solution casting method. The incorporation of metal oxides such as ZnO into natural polymers can improve the electrical properties, which can produce biodegradable energy storage devices. This innovation may aid in the reduction of the use of electronic devices, which generate e-waste. Thus, this study was conducted to investigate the effect of ZnO addition to the biopolymer in terms of its electrical properties. The samples were prepared by using the solution casting method. Different percentages of ZnO were mixed with JSS, PVA, hydrocloric acid, sodium hydroxide, and glycerol before being moulded in a petri dish and dried at room temperature. The electrical properties of the blends were then characterized by using an Agilent 4284a Precision LCR meter. The highest ionic conductivity value for JSS and PVA after the addition of ZnO is 1.10x10-6 Scm-1 with 10% of ZnO, and the lowest conductivity is 2.11x10-7 Scm-1 with 14% of ZnO. The dielectric and electric modulus were further studied in order to understand the electrode polarization effect.

Abstract: Due to the interesting properties of polymerized ionic liquids (PILs), studies are carried out to evaluate its performance when in composite with other synthetic polymers. Research on blend films prepared through solution casting are typically done to investigate their properties, however, electrospun fibers are of particular interest especially on technologies requiring mechanically robust and high surface area functional materials. In this work, poly (vinylidene fluoride)/poly (ionic liquid) (PVdF/PIL) nanofibers were produced through electrospinning. The PIL, poly (1-hexyl-3-vinyl imidazolium bromide), was synthesized through sonochemical solventless reaction followed by free radical polymerization. The structures of the synthesized IL and PIL were confirmed using FT-IR, ¹H-NMR and ¹³C-NMR spectroscopy. Pseudocapacitor prototypes consisting of electrodeposited ZnO-based electrodes and the electrospun PVdF/PIL nanofibers as the polymer electrolyte were then fabricated at varied PIL concentrations. Contact angle measurements using sessile drop method revealed the decreasing wettability of the fibers attributed to the inherent hydrophobic nature of both the PVdF and PIL. Scanning electron micrographs also showed that increasing fiber diameters were obtained as the PIL concentration increases. In addition, cyclic voltammetry results showed that the calculated areal capacitance also increases with increasing PIL concentration. The development of pseudocapacitor assemblies utilizing ZnO-based electrodes and electrospun polymer electrolyte-separator membranes presents a better promise for the next-generation energy storage devices.

Abstract: In this work, the film contained a mixture of PMMA, salt, and plasticizers are studied. PMMA as a host polymer, ammonium trifluoromethane sulphonate or ammonium triflate (NH₄CF₃SO₃) as a doping salt and ethylene carbonate (EC) as a plasticizer is used in this present study. PMMA salt complexes system and plasticized PMMA salt complexes system are prepared by solution cast technique at room temperature. FTIR is used to study the interaction between polymer and salt, and between polymer–salt and plasticizer. The carbonyl group C=O asymmetric stretching mode observed at 1721 cm^-1 is broadened and shifted to lower wavenumber when ammonium triflate was added into PMMA. The broadening, shifting and reduction in wavenumbers of FTIR spectra show that the complexation has occurred between the polymer and salt. EIS is performed to measure the electrical conductivity of the polymer–salt system prepared at ambient temperature. The electrical conductivity of film containing 1.0 g of PMMA–35 wt% NH₄CF₃SO₃–16 wt% EC exhibit the highest electrical conductivity with the value of 2.461 x 10^-4 S/cm². XRD is carried out to study the pattern of pure PMMA, PMMA–NH₄CF₃SO₃ and PMMA–NH₄CF₃SO₃–EC. The XRD analysis shows the addition of plasticizer to the polymer–salt system increase the amorphousness of the polymer electrolytes hence increases in conductivity.

Abstract: This study focuses on preparation and characterization of polymer gel electrolytes (PGEs) based on agarose–LiBOB–DMSO and poly(1-vinylpyrrolidone-co-vinyl acetate)–LiBOB–DMSO. Two systems of PGEs were prepared by dissolving a different amount (1-8 wt.%) of agarose and (1-8 wt.%) P(VP-co-VAc) as host polymer in 0.8 M of LiBOB–DMSO solution. The addition of host polymer into 0.8 M of LiBOB–DMSO solution will result an optimum conductivity which is 6.91 x 10^-3 S.cm^-1 for agarose–LiBOB–DMSO system and 7.83 x 10^-3 S.cm^-1 for P(VP-co-VAc)–LiBOB–DMSO system. In the temperature range of conductivity studies discovered that the agarose–LiBOB–DMSO and P(VP-co-VAc)–LiBOB–DMSO polymer gel electrolytes abide by Arrhenius rule indicating that this PGEs could run at elevated temperature conditions. Furthermore, lithium transference number confirms that both electrolyte systems have 0.03 and 0.12 respectively at room temperature (298 K). Linear sweep voltammetry (LSV) measurements demonstrate the agarose–LiBOB–DMSO system has a potential of 4.26 V and P(VP-co-VAc)–LiBOB–DMSO system has a potential of 4.50 V which is good in electrochemical stability.

Abstract: Proton-conducting membranes were fabricated from a new short-side chain ionomer Inion (Russian analogue of Aquivion) by solution casting method. A series of temperature treatment experiments was conducted to show that annealing of Inion membranes at the temperature range from 160 °C to 170 °C leads to a significant increase of specific proton conductivity to values even higher than those of commercial membrane Nafion NR212. An explanation of this fact can be given by considering the membranes’ proton transport mechanism and water behavior models in nanopores. Matching the proton conductivity mechanism of the membranes, which is realized in nanostructured channels with the diameter of about several nanometers according to the Grotthuss proton hopping mechanism, and the model of water and ice states in nanopores leads to the comprehensive understanding for the further optimization of the membranes to achieve high transport characteristic. For example, it can be improved by increasing the number of side-chain branches of the polymer.

Abstract: Carboxylic acids of various carbon chain lengths (C_n); i.e. butanoic acid (C₄), octanoic acid (C₈), dodecanoic acid (C₁₂) and hexadecanoic acid (C₁₆) have been used to organically modify silicon dioxide (SiO₂). The acid modification involve replacing the hydrogen atom of the silanol group (Si-OH) of SiO₂ with the R_nCOO-of the acid via esterification technique. SiO₂ and acid modified SiO₂ (MoC_n-SiO₂) were used as filler in preparation of polymethyl methacrylate/50% epoxidized natural rubber electrolytes containing SiO₂ (PEL-SiO₂) and MoC_n-SiO₂ (PEL-MoC_n-SiO₂) via solvent casting method with lithium tetrafluoroborate (LiBF₄) as dopant salt. Field-emission scanning electron microscopy (FESEM) analysis of PEL-SiO₂ and PEL-MoC_n-SiO₂ films show LiBF₄ accumulated to the fillers. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed formation of hydrogen bonding between LiBF₄ with fillers and polymers in the polymer electrolyte films. Interestingly, the ionic conductivity of PEL-MoC_n-SiO₂ films increases as the C_n of acids increased with the highest ionic conductivity of 5.56 x 10^-7 Scm^-1 was achieved in PEL-MoC₁₂-SiO₂ film.

Abstract: Chitosan-Starch blend biopolymer electrolyte system doped with different percentage of BMIMNO₃ was prepared via solution casting technique. The crystalinity of the system was calculated using data extracted from x-ray diffraction (XRD). The film was characterized by impedance spectroscopy HIOKI 3531-01 LCR Hi-Tester to measure its ionic conductivity over a wide range of frequency between 50Hz-5MHz and at temperatures between 298 K and 378 K. The result exhibit the advantages of ionic liquid as a charge carrier and also revealed that addition of 5% of BMIMNO₃ shows the highest conductivity of (2.26 +-0.96) x 10^-4 Scm^-1 .Conductivity-temperature relationship indicate that the system seems to obey the Vogel-Tamman-Fulcher (VTF) behaviour.

Abstract: Corn starch (CS) – sodium chloride (NaCl) based polymer electrolytes were prepared by solution casting technique. At room temperature, CS-NaCl film with ratio of 70 wt. % - 30 wt. % demonstrates the highest ionic conductivity in the range of (1.72 ± 0.12) x10^-5 Scm^-1. Temperature-dependence ionic conductivity study follows Arrhenius model and using related plot, the activation energy for highest conducting composition is 0.16eV. The transport number measurement studies confirmed that the ionic conductivity of this polymer electrolyte is due to ions. Fourier transform infrared spectroscopy (FTIR) analysis proved the interaction between CS and NaCl.