Composite solid polymer electrolyte

Figure 11.21 Long-term performance of a composite solid polymer electrolyte membrane consisting of 80 wt% AgBF4 dissolved in a propylene oxide copolymer matrix. Feed gas, 70 vol% ethylene/30 vol% ethane at 50 psig permeate pressure, atmospheric [33,61]...

R. M. Formato, R. F. Kovar, P. Osenar, N. Landrau, and L. S. Rubin. Composite solid polymer electrolyte membranes. US Patent 7 052793, assigned to Foster-MUler, Inc. (Waltham, MA), May 30, 2006. 

Abstract The chapter begins by discussing the characters and composition of polymer electrolytes for electrochromic devices. It then describes the four types of the polymer electrolytes dry solid polymer electrolyte, gel polymer electrolyte, porous gel polymer electrolyte and composite solid polymer electrolyte, their preparation procedures and properties especially ion conductivity of the samples. Finally, new types of polymer electrolytes including proton-conducting, alkaline, single ionic polymer electrolytes and electrolytes with ionic liquids are also introduced. 

Generally, polymer electrolytes used for ECDs can be classified into the following four types according to their physical configuration and chemical composition dry solid polymer electrolyte (DSPE), gel polymer electrolyte (GPE), porous gel polymer electrolyte (PGPE) and composite solid polymer electrolyte (CSPE). 

Porous gel polymer electrolyte (PGPE) and composite solid polymer electrolyte (CSPE)... 

Composite solid polymer electrolyte (CSPE) based on poly (ethylene oxide) (PEO)/siliceous hybrids... 

Composite solid polymer electrolytes (CSPE) based on poly(vinylidene fluoride)-hexaftuoropropylene (PVdF-HFP)/molecular sieve SBA-15... 

Skotheim et al. [286, 357, 362] have performed in situ electrochemistry and XPS measurements using a solid polymer electrolyte (based on poly (ethylene oxide) (PEO) [363]), which provides a large window of electrochemical stability and overcomes many of the problems associated with UHV electrochemistrty. The use of PEO as an electrolyte has also been investigated by Prosperi et al. [364] who found slow diffusion of the dopant at room temperature as would be expected, and Watanabe et al. have also produced polypyrrole/solid polymer electrolyte composites [365], The electrochemistry of chemically prepared polypyrrole powders has also been investigated using carbon paste electrodes [356, 366] with similar results to those found for electrochemically-prepared material. 

Yang J., Takeda Y., Li Q., Imanishi N., Yamamoto O. Lithium insertion into Sn- and SnSb-based composite electrodes in solid polymer electrolytes. J. Power Sources 2000 90 64-69. 

Lawrence, R. J., and Wood, L. D. Method of making solid polymer electrolyte catalytic electrodes and electrode made thereby. U.S. Patent 4,272,353,1981. Fedkiw, P. S., and Her, W. H. An impregnation-reduction method to prepare electrodes on Naifon SPE. Journal of the Electrochemical Society 1989 136 899-900. Aldebert, P, Novel-Cattin, R, Pineri, M., Millet, P, Doumain, G., and Durand, R. Preparation and characterization of SPE composites for electrolyzers and fuel cells. Solid State Ionics 1989 35 3-9. 

Note 4 An intrinsically conducting polymer should be distinguished from a conducting polymer composite and from a solid polymer electrolyte. 

Note 6 Electric conductance of a nonconducting polymer can be achieved by dispersing conducting particles (e.g., metal, carbon black) in the polymer. The resulting materials are referred to as conducting polymer composites or solid polymer-electrolyte composites. 

I. Pinnau and L.G. Toy, Solid Polymer Electrolyte Composite Membranes for Olefin/ Paraffin Separation, 7. Membr. Sci. 184, 39 (2001). 

Inaba et al. [29] have introduced a different cell to work with gaseous compounds (Fig. 4). A metal-plated solid polymer electrolyte (SPE) composite electrode faces the gas to be reduced. On the other side, the SPE is in contact with 0.1 M NaOH in which a Pt wire and an Ag/AgCl reference electrode are immersed. This system permits the electroreduction of insoluble reactants in water without employing organic solvents. For example, 2-chloro-l,l,l,2-tetrafluoroethane (HCFC 124) is transformed into 1,1,1,2-tetrafluoroethane (HFC 134a). The cathodic reaction can be written as follows ... 

Figure 4 Schematic diagram of the electrolytic cell with a solid polymer electrolyte composite electrode. SPE = Neosepta AM-1 CE = Pt wire RE = Ag/AgCl WEC = cathode compartment CEC = anode compartment. (From Ref. 29.)...

Inaba M, Sawai K, Ogumi Z, Takehara Z. Electroreduction of a chlorofluoro-ethane on a solid polymer electrolyte composite electrode. Chem Lett 1995 471 172. 

Delli E, Kouloumtzoglou S, Kyriacou G, Lambrou Ch. Electrochemical reduction of CCI2F2 on Nafion solid polymer electrolyte composite electrodes. Chem Commun 1998 1693-1694. 

The key achievements at Ballard (Wilkinson 1998)15 are low Pt loading (1 mg cm-2) in 50-kW fuel cell power plants, and that of a power-to-weight ratio of 1 kW/kg. The development of the solid polymer electrolyte membrane was by no means in a final state in the late 1990s. The quality of the membrane controls the highest current density at which the cell is viable. There are open areas, too, with regard to the composition (as apart from the loading and particle size) of the catalyst a PtRu alloy... 

SPE Solid Polymer Electrolyte Carbon Polymer Composit... 

Fig. 23. Schematic illustrations for solid polymer electrolyte fuel cell and composite electrode with Pt catalyst, carbon conducting material, and binding polymer material.

The necessary porosity for thicker layers was introduced by appropriate current densities [321-323], by co-deposition of composites with carbon black [28, 324] (cf. Fig. 27), by electrodeposition into carbon felt [28], and by fabrication of pellets from chemically synthesized PPy powders with added carbon black [325]. Practical capacities of 90-100 Ah/kg could be achieved in this way even for thicker layers. Self-discharge of PPy was low, as mentioned. However, in lithium cells with solid polymer electrolytes (PEO), high values were reported also [326]. This was attributed to reduction products at the negative electrode to yield a shuttle transport to the positive electrode. The kinetics of the doping/undoping process based on Eq. (59) is normally fast, but complications due to the combined insertion/release of both ions [327-330] or the presence of a large and a small anion [331] may arise. Techniques such as QMB/CV(Quartz Micro Balance/Cyclic Voltammetry) [331] or resistometry [332] have been employed to elucidate the various mechanisms. 

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