Composite polymer electrolytes conductor

There is considerable methanol permeation through Nafion, which affects the fuel cell performance in a DMFC. Using doped PBI the same proton conductivity as Nafion can be maintained while virtually eliminating the crossover of methanol. PBI is doped with a conducting solid, usually phosphoric acid, to make it suitable for DMFC applications [55, 56]. In another attempt PBI is modified by sulfonation to make it an intrinsic proton conductor and is deposited onto a layer of Nafion membrane. This gives a composite polymer electrolyte that is a reasonable proton conductor and reduces the crossover of methanol [57]. 

Hygroscopic solid inorganic proton conductor composite polymer electrolytes... 

Li, W., Xing, Y., Xing, X., Li, Y, Yang, G., and Xu, L. (2013) PVDF-based composite microporous gel polymer electrolytes containing a novel single ionic conductor Si02 (Li" ). Electrochim. Acta, 112, 183-190. 

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. 

That is why in the past 20 years, conductors having been designed that can be used as electron or ion. Moreover, a polymer material can be combined with appropriate salts, thus obtaining a composite whose ionic conductivity can be put to use as an electrolyte [6, 7],... 

It is well known that graphite is unstable in some aprotic electrolytes. For instance, when propylene carbonate (PC) is used as a solvent, the cointercalation of solvent molecules and the Li ions will lead to the exfoliation of graphite layers Only in some selected electrolyte systems such as LiPF in EC/DEC (EC for ethylene carbonate and DEC for diethyl carbonate), can graphite show better cycling behavior. Solvent decomposition on the surface of conductive carbon or lithium electrodes will lead to the formation of a passivating layer. Peled named this layer as solid electrolyte interphase (SEI). ° It is an ionic conductor but electron insulator, mainly composed of LijCOj and various lithium alkylcarbonates (ROCO Li) as well as small amounts of LiE, LijO, and nonconductive polymers. These compounds have been detected on carbon and Li electrodes in various electrolyte systems. Therefore, it would be an interesting question whether semiconductive nano-SnO anode is also sensitive to electrolyte and electrolyte decomposition takes place on it. This section will characterize the structures and compositions of the... 

In order to increase the stability, HPAs were incorporated in sols of alumina [11] and silica [12]. HPAs immobilized on supports like silica, although stable in the presence of water, could not be used as electrolytes in fuel cells in the powdered form. For this reason, composite membranes [13, 14] have been developed, using a polymer as binder for the formation of thermally and mechanically resistant membranes with low gas permeability and silicotungstic acid or phosphotungstic acid immobilized on silica as the inorganic proton conductor. 

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