Properties Of Polymer Blend Electrolyte Research Articles

Investigate the Thermal Analysis Properties of Polymer Electrolyte

Propylene carbonate (PC) (1:1) have been used as plasticizer to synthesized two series of polymer blend electrolytes (As and Cs) composed of Poly (methyl methacrylate) (PMMA)/Polyacrylonitrile (PAN), (80/20) Wt.% and ethylene carbonate (EC) using solution cast technique. Mixed iodide salts and varying weight ratio of potassium iodide (KI) and cesium iodide (CsI) was used to study the thermal properties of polymer blend electrolytes (GPEs). Differential Scanning Calorimeter (DSC) results show a decrease in the glass transition of electrolytes when increasing the weight percentage of salts, while the melting point increases due to the reduction in the polymer fluidity. Thermogravimetric analysis (TGA) indicates that the increase in the thermal stability can be attributed to the high thermal stability of polymer blend and the existence of the strong interaction between the two polymers. The optimum value of glass transition (Ts) is 104.2 °C found in sample containing 35 Wt.% of KI salt which has a melting point (Tm) 194.7 °C.

Impact of nano-titania and ultrasonic irradiation on the physical properties of polymer blend electrolytes

Nanocomposite polymer blend electrolytes (NCPBEs) consisting of poly(ethylene oxide) and poly(vinylidene fluoride-co-hexafluoropropylene) as polymers, lithium triflate (LiCF3SO3) as an electrolyte and nano-titania (TiO2) as a filler were prepared by both conventional stirring and ultrasonic irradiation methods. Complex formation and an increase in the amorphicity of the sample were confirmed through X-ray diffraction analysis. From alternating current impedance spectroscopy studies, it was observed that the ultrasonically irradiated NCPBEs exhibited maximum ionic conductivity compared with the NCPBEs prepared through conventional mechanical stirring. The Arrhenius behavior was observed from temperature-dependent ionic conductivity studies. Wagner’s polarization studies revealed that the charge transport in the prepared NCPBEs was predominantly due to ions. The dielectric behavior was analyzed by complex dielectric permittivity (ε*) and loss tangent studies. Notable morphological changes of the samples were observed from scanning electron microscopy and atomic force microscopy studies. From thermogravimetry–differential thermal analysis, the sample with the maximum ionic conductivity was found to be thermally stable up to 300°C.

Electrochemical Properties of CMC–PVA Polymer Blend Electrolyte for Solid State Electric Double Layer Capacitors

In this work, the electrochemical properties of polymer blend electrolyte (PBE) based CMC-PVA is presented for electrical double layer capacitance (EDLC) application. CMC-PVA PBE is incorporated in two different systems which contain an (1) ammonium nitrate (NH4NO3) ionic dopant (System I), and (2) ethylene carbonate (EC) plasticizer (System II). The ionic conductivity of PBE based on CMC (55 wt.%)–PVA (15 wt.%)–NH4NO3 (30 wt.%) and CMC (53 wt.%)–PVA (13 wt.%)–NH4NO3 (28 wt.%)–EC (6 wt.%) were optimized at room temperature with value of 1.70 × 10−3 S/cm and 3.92 × 10−3 S/cm, respectively. The ionic conduction for both systems shows Arrhenius behavior when tested at different temperatures. Electrochemical properties of the fabricated EDLC cell were analyzed for their electrochemical properties and System II showed higher specific capacitance than System I with values of 64.9 F/g and 89.1 F/g, respectively, based on a CV scan rate of 2 mV/s. Both fabricated EDLC show outstanding cycling stability over 10,000 cycles, which indicates that the present PBE based CMC–PVA has outstanding electrochemical performance and is a promising candidate for EDLC application.

Influence of nano SrTiO3 and ultrasonic irradiation on the properties of polymer blend electrolytes

ABSTRACT Lithium (Li+) ion conducting nanocomposite polymer blend electrolytes (NCPBEs) based on poly(ethylene oxide) (PEO), poly(vinylidene fluoride hexafluoropropylene) (P(VdF-HFP)) as polymer hosts, lithium perchlorate (LiClO4) as an electrolyte and strontium titanate (SrTiO3) as a nanofiller have been prepared by both the conventional stirring and ultrasonic irradiation methods. Complex formation and hence the structural changes of the prepared samples have been confirmed by X-ray diffraction analysis. Conductivity studies have been carried out by means of AC impedance spectroscopy. In order to highlight the role of ultrasonic irradiation, conductivity values have been compared with the values obtained through conventional mechanical stirring method. It has been found that the system with 15 minutes of ultrasonic irradiation resulted in better homogenous dispersion of SrTiO3 in PEO/P(VDF-HFP)/LiClO4 matrix. Maximum ionic conductivity of 2.519 × 10−4 Scm−1 has been obtained for 6 wt% of SrTiO3 system which is a magnitude higher than the ionic conductivity value, 2.031 × 10−5 Scm−1 obtained for the original NCPBE prepared using conventional mechanical stirring at room temperature. Further, ionic conductivity value increases with the increase of temperature and it exhibit the Arrhenius relation. Higher degree of free ionic motion in the samples has been proven by the increase in intensity of photoluminescence spectra peaks. The dielectric properties of the prepared samples have also been studied using the complex dielectric permittivity spectra and complex electric modulus spectra. The morphology and hence the surface roughness of the samples have been depicted through AFM study.

Effect of PEG as a plasticizer on the electrical and optical properties of polymer blend electrolyte MC-CH-LiBF4 based films

Plasticized polymer blend electrolyte films based on methylcellulose (MC), chitosan (CH), lithium tetrafluoroborate (LiBF4), and polyethylene glycol (PEG) as a plasticizer were prepared and investigated. The effect of different concentrations of PEG was studied using AC impedance spectroscopy, and UV–Visible spectroscopy. The electrical and optical properties of polymer electrolytes have been improved upon addition of PEG. The DC conductivity was evaluated from the bulk resistance achieved from Nyquist impedance plots. Results from temperature studies reveal that all samples comply with the Arrhenius formula in the investigated temperature range. The sample with 10 wt% of PEG exhibits the highest ionic conductivity of 2.12×10-5S/cm with the minimum activation energy of 0.528eV at ambient temperature. The lowest relaxation time for highest ion conductive sample indicates the faster ion dynamics. The frequency-dependence AC conductivity was found to follows the Jonscher’s power law at various temperatures, and the conduction mechanism for this system followed the overlapping large polaron tunneling (OLPT) model. The increase in absorption and a decrease in optical band-gap in the UV region was confined by UV–Visible spectroscopy.

A concentrated poly(ethylene carbonate)/poly(trimethylene carbonate) blend electrolyte for all-solid-state Li battery

Electrochemical and ion-transport properties of polymer blend electrolytes comprising poly(ethylene carbonate) (PEC), poly(trimethylene carbonate) (PTMC) and lithium bis(fluorosulfonyl) imide (LiFSI) were studied in this work, and the electrolyte with the best blend composition was applied in all-solid-state Li batteries. The ionic conductivity of both PEC and PTMC single-polymer electrolytes increased with increasing Li salt concentration. All PEC and PTMC blend electrolytes show ionic conductivities on the order of 10−5 S cm−1 at 50 °C, and the ionic conductivities increase slightly with increasing PEC contents. The PEC6PTMC4-LiFSI 150 mol% electrolyte demonstrated better Li/electrolyte electrochemical and interfacial stability than that of PEC and PTMC single-polymer electrolytes and maintained a polarization as low as 5 mV for up to 200 h during Li metal plating and stripping. A Li|SPE|LFP cell with the PEC6PTMC4-LiFSI 150 mol% electrolyte exhibited reversible charge/discharge capacities close to 150 mAh g−1 at 50 °C and a C/10 rate, which is 88% of the theoretical value (170 mAh g−1). Concentrated poly(ethylene carbonate) (PEC) and poly(trimethylene carbonate) (PTMC) blend electrolytes with 150 mol% of LiFSI were prepared and the PEC6PTMC4 electrolyte was applied in all-solid-state Li batteries. The blend electrolyte has an ionic conductivity of 10−5 S cm−1 and a Li+ transference number (t+) of 0.73. Meanwhile, the PEC6PTMC4 electrolyte exhibits a good electrochemical stability with Li electrode than those of PEC and PTMC single-polymer electrolytes. An LFP half-cell exhibits a discharge capacity of 150 mAh g−1 at 50 °C and a C/10 rate.

Effect of electron beam irradiation on structure, morphology, and optical properties of PVDF-HFP/PEO blend polymer electrolyte films

The effect of 8 MeV energy electron beam (EB) on poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/polyethylene oxide (PEO) (@ w/w 90:10, PHP10) polymer blend films have been prepared and studied. The change in structure, morphology, and optical properties at 40, 80, and 120 kGy EB doses were investigated. The effect of the radiation process may responsible to occurs the degradation (chain scission) and chain link (cross linking) which are confirmed by the FT-IR analysis. The band at 1401 cm−1 corresponding to the –CH2– bending or scission mode have shifted to 1397 cm−1 after 120 kGy EB dose is due to the intermolecular interaction and the changes of the macromolecular chain by breaking of bonds with increased EB dose was observed. The XRD pattern shows decreased in the crystallinity from 60.03 to 23.42% and increased amorphousity for 120 kGy EB dose the and the surface morphology was drastically changed by decreasing the size of spherulites upon increased EB dose. The increase in optical absorption and the shifting of wavelength toward a higher end (red shift) was observed after the irradiation. The energy band gaps (Eg), and Urbach energy were estimated and they are found to be decreased, but the number of carbon atoms in a cluster of was increased with increased EB dose. The obtained results notice that the physical properties of polymer blend electrolytes can be improved by EB irradiation to use in different potential applications.

Effects of potassium iodide (KI) on crystallinity, thermal stability, and electrical properties of polymer blend electrolytes (PVC/PEO:KI)

Potassium ion conducting solid polymer blend electrolytes based on PVC/PEO:KI of various compositions were prepared by solution-casting technique. The structural changes along with K+ ion–polymer blend electrolyte interactions and the thermal stability of the samples were studied by X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, and thermo-gravimetric analysis. Electrical properties were measured as a function of composition and temperature using complex impedance spectroscopy. The electrical conductivity exhibited Arrhenius type of behavior, with the activation energy decreasing with increasing KI concentration. The conductivity of the polymer blend (PVC/PEO) sample was obtained at ambient temperature (303K) as 3.09×10−6Scm−1, and for the PVC/PEO:KI (42.5:42.5:15) electrolyte as 3.66×10−4Scm−1, the conductivities were greatly enhanced at 363K to 8.23×10−4 and 1.30×10−2Scm−1, respectively. The ionic transference number of the PVC/PEO:KI (42.5:42.5:15) electrolyte was determined to be 0.98. The increase in amorphous phase and free K+ ion concentration was responsible for the conductivity improvement in the electrolyte system.

Preparation and characterization of pure and KBr doped polymer blend (PVC/PEO) electrolyte thin films

A potassium ion conducting polymer blend electrolyte based on polyvinyl chloride (PVC) and polyethylene oxide (PEO) complexed with KBr was prepared using solution cast technique. The structural properties of these electrolyte films were examined by XRD studies. The XRD data revealed that the amorphous domains of polymer blend matrix increased with increase of KBr salt concentration. The complexation of the salt with the polymer blend was confirmed by FT-IR studies. Electrical conductivity of the films was measured with impedance analyzer in the frequency range of 100Hz to 1MHz and in the temperature range of 303–363K. It was observed that the magnitude of conductivity increased with the increase in the salt concentration as well as the temperature. UV–VIS absorption spectra in wavelength region of 200–600nm were used to evaluate the optical properties like direct band gap, indirect band gap and absorption edge. The optical band gaps decreased with increasing of K+ ion concentration. This suggests that, KBr is a good dopant to improve the electrical properties of PVC+PEO polymer blend electrolytes. Studies on the electrical and optical properties of polymer blend electrolyte have attracted much attention in view of their application in electronic and optical devices like electro-chromic display devices, fuel cells, gas sensors and solid state batteries. The thermal properties of these films were investigated with differential scanning calorimetry (DSC). The variation in film morphology is examined by scanning electron microscopy examination (SEM).

Effect of different plasticizer on structural and electrical properties of PEMA-based polymer electrolytes

Plasticized poly(vinyl chloride)/poly(ethyl methacrylate) PVC/PEMA-based blend polymer electrolyte films containing lithium perchlorate (LiClO4) as a salt were prepared by solvent casting technique. The effects of the plasticization on structural, thermal and electrical properties of the plasticized polymer blend electrolytes were investigated. The changes in the structural and complex formation properties of the materials were studied by XRD and FTIR techniques. Dielectric relaxation studies of the polymer electrolyte have been undertaken, and the results are discussed. TG/DTA technique is used to study the thermal stability. Complex impedance analysis is used to calculate the bulk resistance of the complexes. The effect of different plasticizer on the structural and physical properties of polymer blend electrolyte is well correlated.