Innovative polycarbonates for lithium conducting polymer electrolytes

205 p.The highly qualified life, demanded by the society of the 21st century, requires constant scientific and technological developments. Energy is the essential ingredient for the economic and social development. In order to provide, clean energy, safe energy storage system has to be developed. The continuous research on polymer electrolytes will lead us into a promising energy storage system. Up to now, poly(ethylene oxide) (PEO) has been extensively explored polymer matrix in solid polymer electrolytes for lithium batteries. However, recently, polycarbonate-solid polymer electrolytes show considerable enhancements respect to PEO-solid polymer electrolytes, such as improved lithium conductivity and electrochemical stability. The main objective of this thesis is to evaluate and compare new polycarbonates¿ structures as SPEs in lithium batteries. For this purpose, the versatile and simple polycondensation technique was chosen as synthetic tool to develop polycarbonates. This synthetic method allowed to easily change the functionality of the diol and the properties of the polycarbonates, and therefore, to analyze the consequences in polymer electrolytes.Université de Pau et des Pays de l'Adour Polymat JPREM: Institut des sciences analytiques et de physics-chimie pour l'environnement et les matériau

Innovative polycarbonates for lithium conducting polymer electrolytes

205 p.The highly qualified life, demanded by the society of the 21st century, requires constant scientific and technological developments. Energy is the essential ingredient for the economic and social development. In order to provide, clean energy, safe energy storage system has to be developed. The continuous research on polymer electrolytes will lead us into a promising energy storage system. Up to now, poly(ethylene oxide) (PEO) has been extensively explored polymer matrix in solid polymer electrolytes for lithium batteries. However, recently, polycarbonate-solid polymer electrolytes show considerable enhancements respect to PEO-solid polymer electrolytes, such as improved lithium conductivity and electrochemical stability. The main objective of this thesis is to evaluate and compare new polycarbonates¿ structures as SPEs in lithium batteries. For this purpose, the versatile and simple polycondensation technique was chosen as synthetic tool to develop polycarbonates. This synthetic method allowed to easily change the functionality of the diol and the properties of the polycarbonates, and therefore, to analyze the consequences in polymer electrolytes.Université de Pau et des Pays de l'Adour Polymat JPREM: Institut des sciences analytiques et de physics-chimie pour l'environnement et les matériau

Characterization of pTMCnLiPF6 solid polymer electrolytes

In this study the results our characterization of a solid polymer electrolyte based on poly(trimethylene carbonate), henceforth designated as p(TMC), and lithium hexafluorophosphate (LiPF6) are described. Samples of solvent-free electrolytes were prepared with a range of concentration of guest salt using solvent casting from tetrahydrofuran and characterized by conductivity measurements, thermal analysis and electrochemical stability. Electrolytes based on this host polymer, with LiPF6, were obtained as mechanically robust, flexible, transparent and completely amorphous films.Fundação para a Ciência e a Tecnologia (FCT

Characterisation of lithium-based solid polymer electrolytes

Sol-gel derived poly(oxyethylene)/siloxane hybrids doped with lithium hexafluoroantimonate, LiSbF6, have been prepared. Compositions of these novel xerogel electrolytes were identified using the conventional d-U(2000)nLiSbF6 notation, (where n is the molar ratio of oxyethylene moieties per Li+ ion) and samples with n between ∞ and 2.5 were characterized by conductivity measurements, cyclic voltammetry at a gold microelectrode and thermal analysis. The electrolyte films produced were obtained as transparent and amorphous monoliths with encouraging electrochemical and thermal properties.Fundação para a Ciência e Tecnologi

Characterization of lithium-based solid polymer electrolytes

Sol-gel derived poly(oxyethylene)/siloxane hybrids doped with lithium hexafluoroantimonate, LiSbF6, have been prepared. Compositions of these novel xerogel electrolytes were identified using the conventional d-U(2000)nLiSbF6 notation, (where n is the molar ratio of oxyethylene moieties per Li+ ion) and samples with n between ∞ and 2.5 were characterized by conductivity measurements, cyclic voltammetry at a gold microelectrode and thermal analysis. The electrolyte films produced were obtained as transparent and amorphous monoliths with encouraging electrochemical and thermal properties.Fundação para a Ciência e Tecnologia (FCT) - contracto POCI/QUI/59856/2004, POCTI/SFA/3/686, bolsa SFRH/BD/22707/2005, SFRH/BD/38616/200

Preparation and characterization of chitosan grafted PMMA via gamma radiation for electrolyte in supercapacitor / Nor Kartini Jaafar

Solid polymer electrolytes may generally be defined as membranes that possess transport properties comparable with that of common liquid ionic solutions. In the present study, Chitosan (Ch), methyl methacrylate (MMA) were used to produce a grafted polymer Chg- PMMA using gamma irradiation grafting method. The grafted polymer Ch-g-PMMA, lithium triflouromethanesulfate (LiCF3S03 or LiTf), ethylene carbonate (EC) and silicon dioxide (SiCh) were then used in the preparation of solid polymer electrolytes (SPE), gel polymer electrolyte (GPE) and composite polymer electrolyte (CPE). All samples were prepared by solution cast technique. Physical and electrical properties of SPE, GPE and CPE were investigated to find the suitable grafted polymer electrolytes composition for fabrication in lithium polymer supercapacitor. The conductivity of all samples was calculated from the complex impedance plot in the frequency range 100 Hz to 1 MHz

Solid polymer electrolytes for ion selective membranes

The work described in this thesis was carried out as part of a project to explore the use of solid polymer electrolytes as pH electrodes, the properties of which would be superior to those of the fragile glass membranes traditionally used. To this end, potentiometry was used to study ion transport in membranes which were composites of poly(vinyl chloride) and poly(ethylene oxide). The idea was that the hydrophilic polymer (PEO) would interact with water molecules and ionic species, and the hydrophobic polymer (PVC) would serve as an inert matrix, intimately tangled with the hydrophilic polymer to prevent its diffusion into the aqueous solution phase. It was shown that membranes prepared by co-casting polymers from solution were indeed stable in water and that the properties could be changed by change in fabrication procedure which changed the microstructure. This thesis describes the development of the membrane preparation procedure from initially pure PEO gels to processed pure PEO membranes then co-cast composite PEO and PVC membranes and finally rotary evaporated PEO-PVC membranes. The effect of the preparation procedure on the potential difference response of these membranes was investigated to correlate any structural changes to the membrane electrochemical behaviour. Membranes prepared by the various procedures were tested with thermal analysis, FTIR and polarised light optical spectroscopy to observe any trends in physical characteristics associated with structural changes. The electrical properties of these membranes were correlated with the microscopic and macroscopic membrane structure and chemical composition. It is postulated that the membranes are a nano-scale composite structure comprising interpenetrating networks of hydrophobic and hydrophilic regions of size determined by the preparation procedure. The size of these regions determine the transport properties of ions moving through the membrane. It is proposed that the dominant effect on permselectivty in the membranes studied here is a modification of the interaction between ions and water within the membrane channels formed by a hydrated hydrophilic polymer

Flexible fiber batteries for applications in smart textiles

Here we discuss two alternative approaches for building flexible batteries for applications in smart textiles. The first approach uses well-studied inorganic electrochemistry (Al-NaOCl galvanic cell) and innovative packaging in order to produce batteries in a slender and flexible fiber form that can be further weaved directly into the textiles. During fabrication process the battery electrodes are co-drawn within a microstructured polymer fiber, which is later filled with liquid electrolyte. The second approach describes Li-ion chemistry within solid polymer electrolytes that are used to build a fully solid and soft rechargeable battery that can be furthermore stitched onto a textile, or integrated as stripes during weaving process