Investigation on the structure and the conductivity of plasticized polymer electrolytes (original) (raw)
Related papers
Electrochimica Acta, 1998
AbstractÐThe in¯uence of two plasticizers, propylene carbonate and dimethyl sulphoxide, as well as dierent salt concentrations of Li(TFSI), on properties of a polymer gel electrolyte material has been studied using dierential scanning calorimetry (DSC) and ac impedance and FTIR spectroscopy. Variations of glass transition temperature and the conductivity behaviours of the systems were examined, and found to be highly dependent on the amount and type of the plasticizer used. Characteristic band-shifts in FTIR spectra, indicating coordination of lithium ions, have been found for the polymer and both the plasticizers in the corresponding binary solutions. These shifts were used to study the coordination preferences in the complete ternary electrolyte system. The combined results from the three experimental techniques have been discussed. #
Glass Transition and Relaxation Processes of Nanocomposite Polymer Electrolytes
The Journal of Physical Chemistry B, 2012
This study focus on the effect of δ-Al 2 O 3 nano-fillers on the dc-conductivity and dielectric relaxations in the polymer electrolyte (PEO) 4 :LiClO 4 . The results show that there are three dielectric relaxation processes, α, β and γ, in the systems, although the structural α-relaxation is hidden in the strong conductivity contribution and could therefore not be directly observed. However, by comparing an enhanced dcconductivity, by approximately two orders of magnitude with 10 mol% δ-Al 2 O 3 added, with a decrease in calorimetric glass transition temperature, we are able to conclude that the dc-conductivity is directly coupled to the hidden α-relaxation, even in the presence of nano-fillers (at least in the case of δ-Al 2 O 3 nano-fillers at concentrations up to 10 mol%). This filler induced speeding up of the segmental polymer dynamics, i.e. the α-relaxation, can be explained by a non-attractive nature of the polymer-filler interactions, which enhance the 'free volume' and mobility of polymer segments in the vicinity of filler surfaces.
Influence of crystallization on dielectric properties of PEO:LiTFSI polymer electrolyte
Journal of Non-Crystalline Solids, 2006
Impedance spectra of the PEO 8 :LiN(CF 3 SO 2 ) 2 electrolyte were measured in the frequency range from 0.01 Hz to 10 MHz at temperatures between À65°C and 90°C in various heating and cooling runs. Polarizing microscope observations confirmed that a rapidly cooled electrolyte remained amorphous below À15°C. Crystallization during slow cooling took place at +15°C. Presence of the crystalline phase caused significant reduction of the strength of b relaxation and to a lesser degree the strength of a relaxation. The a relaxation time in the amorphous phase of semicrystalline electrolyte is considerably shorter than that in the entirely amorphous sample. Ionic conductivity fell more than 10 times during crystallization. Conductivity of the semicrystalline electrolyte decreased upon cooling much slower than in the case of the amorphous electrolyte. At temperature about À35°C conductivity became equal in both states of the electrolyte. The temperature dependence of conductivity and frequency of a relaxation indicated that the glass transition in the semicrystalline electrolyte occurred at a temperature about 10°C lower than in the amorphous sample. This finding was confirmed by the results of DSC study. Lower glass transition temperature of the amorphous regions is a consequence of depletion of the salt, which is accumulated in the lamellae of the PEO 6 :LiN(CF 3 SO 2 ) 2 crystalline complex.
New trends in polymer electrolytes: a review
e-Polymers , 2009
Since the work of Armand, polymer electrolytes have received great attention and lots of publication can be found in the literature. Each publication has its particular orientation and tries to emphasize only limited points to prove their system as the better one. But to really get some good fruitful material we need to look simultaneously for different aspects of the electrolyte such as good conductivity and mechanical property, understanding of interaction between the salt and other materials present in the system, nature of solid electrolyte/ electrode interface, electrochemical window, working temperature window etc. Hence a brief summary of the variety of polymer electrolytes is given in the paper with their advantages and disadvantages. Paper discusses polymer electrolytes starting from Dry SPE to the latest IL/Zwitterionic electrolytes and the behavior of the some devices using these materials.
Conductivity studies on solid polymer electrolytes
Le Journal de Physique IV, 1994
This thematic lecture addresses electrochemical conductivity techniques for the study of solid polymer electrolytes. Types of conductivity are discussed first, followed by an outline of the features, applicability, and validity of DC and AC conductivity measurements. Techniques for the identification of the individual species responsible for conduction are then briefly reviewed. Résumé Cette étude aborde des méthodes de mesure de conductivité électrique des électrolytes polymères solides. On considère d' abord la conductivité ionique et électronique, par des mesures en courant continu et en courant alternatif. La détermination des nombres de transport pour qu' on puisse avoir des informations plus complètes sur les espèces responsables de la conduction est examinée ultérieurement.
Thermal and electrochemical properties of poly(butylene sulfite)-based polymer electrolyte
Ionics, 2017
Poly(butylene sulfite) (poly-1) was synthesized by cationic ring-opening polymerization of butylene sulfite (1), which was prepared by the reaction of 1,4-butanediol and thionyl chloride, with trifluoromethanesulfonic acid (TfOH) in bulk. The polymer electrolytes composed of poly-1 with lithium salts such as bis(trifluoromethanesulfonyl)imide (LiN(SO 2 CF 3) 2 , LiTFSI) and bis(fluorosulfonyl)imide (LiN(SO 2 F) 2 , LiFSI) were prepared, and their ionic conductivities, thermal, and electrochemical properties were investigated. Ionic conductivities of the polymer electrolytes for the poly-1/LiTFSI system increased with lithium salt concentrations, reached maximum values at the [LiTFSI]/[repeating unit] ratio of 1/10, and then decreased in further more salt concentrations. The highest ionic conductivity values at the [LiTFSI]/[repeating unit] ratio of 1/10 were 2.36 × 10 −4 S/cm at 80°C and 1.01 × 10 −5 S/cm at 20°C. On the other hand, ionic conductivities of the polymer electrolytes for the poly-1/LiFSI system increased with an increase in lithium salt concentrations, and ionic conductivity values at the [LiFSI]/[repeating unit] ratio of 1/1 were 1.25 × 10 −3 S/cm at 80°C and 5.93 × 10 −5 S/cm at 20°C. Glass transition temperature (T g) increased with lithium salt concentrations for the poly-1/LiTFSI system, but T g for the poly-1/LiFSI system was almost constant regardless of lithium salt concentrations. Both polymer electrolytes showed high transference number of lithium ion: 0.57 for the poly-1/LiTFSI system and 0.56 for the poly-1/LiFSI system, respectively. The polymer electrolytes for the poly-1/LiTFSI system were thermally more stable than those for the poly-1/LiFSI system.
Preparation and characterization of plasticized high molecular weight PVC-based polymer electrolytes
2010
Poly(vinyl chloride) (PVC)-based polymer electrolytes films consisting of lithium trifluromethanesulfonate (LiCF 3 SO 3)-ethylene carbonate (EC) were prepared by the solution-casting method. Ionic conductivities of the electrolytes have been determined by an impedance studies in the temperature range of 298-373 K. Complexation of the prepared electrolytes is studied by X-ray diffraction (XRD) analysis. Thermogravimetric analysis (TGA) was used to confirm the thermal stability of the polymer electrolytes. The conductivity-temperature plots were found to follow an Arrhenius nature. All these films are found to be thermally stable until 132-167 • C.