Glass-polymer composite electrolyte

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. 

T. Zhang, N. Imanishi, S. Hasegawa, A. Hirano, J. Xe, Y. Takeda, O. Yamamoto, N. Sammes, Li/polymer electrolyte/water stable lithium-conducting glass ceramics composite for hthium-air secondary batteries with an aqueous electrolyte , J. of Electrochem. Soc., 155,A965-A969,2008. 

The possibility of plasma copolymerization and the production of composite materials allows to design at the molecular level thin films of very low electronic conductivity, but with very high ionic conductivity. Such films can be obtained in the polymer-like form (polymer electrolytes) and as ionic glasses (solid oxide electrolytes). These new solid electrolyte systems enable us to replace the conventional solid electrolytes by the much thinner elements, which in addition have all the other advantages of plasma fabricated materials, for example, selective permeability. Thin films of solid electrolytes produced by cold plasma deposition techniques have been of particular interest recently. 

Zhang, X., Wang, C., Appleby, A., Little, F. 2002. Characteristics of lithium ion-conducting composite polymer-glass secondary cell electrolytes. 

Typically, the solid-state electrolyte can function as both a substrate and separator in the fabrication of a flexible supercapacitor by two steps. For instance, a freestanding PVA/ H3PO4 film was obtained by first casting the gel electrolyte on a glass slide and then peeled off from the glass. It had been further sandwiched between two composite electrodes that were prepared from conducting polymers and nanoparticles to produce the flexible supercapacitor (Fig. 9.3G) (Liu et al., 2010,2013b). 

The construction of ISEs used in clinical measurements is of the membrane electrode type, i.e., the ion-sensitive membrane separates the sample from an internal reference electrolyte, which is the site of the internal reference element, usually a silver wire covered by silver chloride. The membrane can be shaped to different forms such as flat, convex, tubular, etc. Sodium sensitive membranes are made from special composition glass, the other ion-sensitive membranes from a polymer matrix such as plasticized polyvinylchloride (PVC) or silicon rubber. The particular selectivity of polymer membranes is first of all due to a small percentage of active material, e.g., valinomycin, dissolved in the polymer. Important secondary effects have been attributed to the type and permittivity of the polymer. The useful lifetime of the sensors also depends on the polymer. The time response [13] may again depend on membrane composition. 

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