Solid polymer electrolytes description

For the sake of discussion, we have divided the separators into six types—microporous films, non-wovens, ion exchange membranes, supported liquid membranes, solid polymer electrolytes, and solid ion conductors. A brief description of each type of separator and their application in batteries are discussed below. 

The description given here is a basic outline of the principles of the solid polymer electrolyte fuel cell used in the first Gemini space flights with nonfluorinated membranes (Fig. 13.23). Because the cell is slated for development as part of the electrochemical engine in cars, stages in its modern development are described in another section. 

SPE solid polymer electrolyte, GDE gas diffusion electrodes (description see later), Clark Clark-type gas sensor, SPE solid... 

Bruce etui, established a potentiostatic polarization method for solid polymer electrolytes [450], which is also used for diluted solutions because of its simphcity. For infinitely dilute electrolytes it was shown that this method is suitable for hquids as well [451]. Applying a small constant potential to a solution between nonblocking electrodes leads to decrease of the initial current value until a steady-state value is reached. The steady-state current is caused by the cations [450], so the cation transference number can be easily determined by dividing the cationic current by the initial current. Because electrode surfaces or rather passivating layers vary with time, this inaccurate description can be corrected by impedance measurements shortly before and after the potentiostatic polarization [452]. For small polarization potentials (< 10 mV), the steady-state current hs and initial current Iq are described as [450]... 

The physical chemistry of electrolytic solutions is a special area of physical chemistry with a large number of reference literatures. Classical descriptions are given in the books of Hamed and Owen or Robinson and Stokes. A more recent advanced treatment is found in the book of Barthel, Krienke, and Kunz. The special problems of ionic-conducting polymers and ionic solid electrolytes are described in various other reviews. Grajd described polymer electrolytes. A classical treatment of ionic solid electrolytes is the book by Rickert or the Kudo and Fueki compilation. Because these materials are used in batteries and fuel cells, there is much hterature for this research field including such detailed reviews in the book by Julien and Nazri. Another source for details and data compilations is the CRC Handbook of Solid State Electrochemistry f... 

Polymer electrolyte, alkaline, phosphoric acid, molten carbonate, and solid oxide fuel cell technology descriptions have been updated from the previous edition. Manufacturers are focusing on reducing fuel cell life cycle costs. In this edition, we have included over 5,000 fuel cell patent abstracts and their claims. In addition, the handbook features a new fuel cell power conditioning section, and overviews on the hydrogen industry and rare earth minerals market. 

A detailed description of the energy conversion processes through electrochemical reactions in a fuel cell is given here by considering a hydrogen-oxygen polymer electrolyte membrane fuel cell (PEMFC) and a solid oxide fuel cell (SOFC) with basic cell components as shown in Figures 4.6 and 4.7, respectively. Similar descriptions for other types of fuel cells will be presented in Chapter 9. 

The importance of polymer segmental motion in ion transport has already been referred to. Although classical Arrhenius theory remains the best approach for describing ion motion in solid electrolytes, in polymer electrolytes the typical curvature of the log a vs. 1/T plot is usually described in terms of Tg-based laws such as the Vogel-Tamman-Fulcher (VTF) [61] and Williams-Landel-Ferry (WLF) [62] equations. These approaches and other more sophisticated descriptions of ion motion in a polymer matrix have been extensively reviewed [6, 8, 63]. 

The idea that ions can diffuse as rapidly in a solid as in an aqueous solution or in a molten salt may seem astonishing. However, since the 1960s, a variety of solids that include crystalline compounds, glasses, polymers, and composite materials with exceptionally high ionic conductivities have been discovered. Materials that conduct anions (e.g. and 0 ) and cations including monovalent (e.g. H+, Fi+, Na+, Cu+, Ag+), divalent, and even trivalent and tetravalent ions have been synthesized. A variety of names that have been used for these materials include solid electrolytes, superionic conductors, and fast-ionic conductors. Solid electrolytes arguably provides the least misleading and broadest description for this class of materials. 

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