Proton conducting polymer electrolytes

Zawodzinski, T. A., Davey, J., Valerio, J. and Gottesfeld, S. 1995. The water-con-tent dependence of electro-osmotic drag in proton-conducting polymer electrolytes. Electrochimica Acta 40 297-302. 

M. Eikerling, A. A. Kornyshev, and E. Spohr. Proton-conducting polymer electrolyte membranes Water and structure in charge. Advances in Polymer Science 215 (2008) 15-54. 

Polymer-electrolyte fuel cells (PEFC and DMFC) possess a exceptionally diverse range of applications, since they exhibit high thermodynamic efficiency, low emission levels, relative ease of implementation into existing infrastructures and variability in system size and layout. Their key components are a proton-conducting polymer-electrolyte membrane (PEM) and two composite electrodes backed up by electronically conducting porous transport layers and flow fields, as shown schematically in Fig. 1(a). 

Rikukawa, M. Sanui, K. Proton conducting polymer electrolyte membranes based on hydrocarbon polymers. Prog. Polym. Sci. 2000,25 (10), 1463-1502. 

K. Miyatake and M. Watanabe, Novel proton conducting polymer electrolyte membrane, Maku (Membrane), 2002, 27, 131-138. 

K. Bessho, T. Teramoto, T. Ishikawa, Proton conducting polymer electrolyte, Jpn. Pat., JP 9-87510 (unexamined application). 

While Nafion , a perfluorinated polymer developed by DuPont, is the most commonly used proton conductive polymer electrolyte membrane it is an insufficient solution in a number of areas. It has high cationic transport (approximately 9.56 5/cm) [8] but also has high levels of methanol fuel crossover, slow anode kinetics and very high cost [12]. Fuel cell membrane performance can be estimated from the ratio of proton conductivity (a) to methanol permeability (P). The higher the value of a/P, the better the membrane performance would be [13]. Chitosan has been shown to have a much lower methanol permeability than Nafion [14], and as such, a great deal of attention focused on developing chitosan membranes with high levels of ionic conduction and low methanol permeability as delineated in Table 3.1. 

Sulfonated PPE can be treated with imidazole to get proton conducting polymer electrolytes. ... 

Gao, H., Lian, K., 2014. Proton-conducting polymer electrolytes and their applications in solid supercapacitors a review. RSC Adv. 4,33091-33113. 

K. Miyatake, Y. Chikashige, M. Watanabe, Novel sulfonated poly(arylene ether) A proton conductive polymer electrolyte designed for fuel cells. Macromolecules 2003, 36(26), 9691-9693. 

Other proton-conducting polymer electrolytes based on sulfonated aromatic condensation polymers also show the onset of thermal degradation at temperatures between 200 and 400 °C. Desulfonation of arylsulfonic acids occurs readily upon heating their aqueous solution up to 100-175 °C. Therefore, desulfonation imposes limitations on the thermal stability of sulfonated aromatic condensation electrolytes. It should be mentioned that the presence of bulky substituents attached to the phenyl rings can, to some extent, favour an increase in the onset of thermal degradation temperature. 

Proton-conducting polymer electrolyte membranes based on ACPs such as S-PPBP and sulfonated poly(phenylene sulfide) contain rather large amoimts of bound water. This seems to be the reason for such a sahent featme of these membranes as an increased proton conductivity at high temperatmes and/or low humidities. This conclusion was confirmed by the results of differential scanning calorimetry (DSC) studies of these systems [7]. 

C. The thermal stability of alkylsulfonated polymer electrolytes can be attributed to the strong chemical bond between the alkyl and the sulfonic acid groups. The introduction of alkylsulfonic acid groups into thermostable polymers involving alkane sultone is one of the most important approaches to the preparation of thermostable proton-conducting polymer electrolytes. 

Recently, new proton-conducting polymer electrolyte membranes based on FBI - orthophosphoric and other strong acid complexes have been proposed for use in PEMFCs [181-188]. 

Typical proton-conducting polymer electrolytes undergo considerable degradation in the temperature range under study. 

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