Proton conducting polymer electrolytes poly

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. 

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]. 

Sellam, and S. A. Hashmi. 2013. High rate performance of flexible pseudocapacitors fabricated using ionic-liquid-based proton conducting polymer electrolyte with poly(3, 4-ethylenedioxythiophene) poly(styrene sulfonate) and its hydrous ruthenium oxide composite electrodes. ACS Applied Materials Interfaces 5 3875-3883. 

Yamada M, Honma I (2005) Anhydrous proton conducting polymer electrolytes based on poly (vinylphosphonic acid)-heterocycle composite material. Polymer 46 2986-2992... 

Sevil F, Bozkurt A (2004) Proton conducting polymer electrolytes on the basis of poly (vinylphosphonic acid) and imidazole. J Phys Chem Solids 65 1659-1662... 

Abstract During the last two decades, extensive efforts have been made to develop alternative hydrocarbon-based polymer electrolyte membranes to overcome the drawbacks of the current widely used perfluorosulfonic acid Nafion. This chapter presents an overview of the synthesis, chemical properties, and polymer electrolyte fuel cell applications of new proton-conducting polymer electrolyte membranes based on sulfonated poly(arylene ether ether ketone) polymers and copolymers. 

Liew C-W, Ramesh S, Arof AK (2014) A novel approach on ionic liquid-based poly(vinyl alcohol) proton conductive polymer electrolytes for fuel cell appUcations. Int J Hydrog Energy 39(6) 2917-2928. doi 10.1016/j.ijhydene.2013.07.092... 

Sellam HSA (2013) High rate performance of flexible pseudocapacitors fabricated using ionic-liquid-based proton conducting polymer electrolyte with poly(3,... 

Proton-conducting polymer electrolyte based on poly (vinyl alcohol) (PVA)/(imidazole)/ NH4H2PO4... 

Acar, O. Sen, U Bozkurt, A. and Ata, A., Blend membranes from poly(2,5-benzimidazole) and poly(styrene sulfonic acid) as proton-conducting polymer electrolytes for fuel cells, J. Mater. Set, 45 993-998 (2010) DOI 10.1007/ sl0853-009 030-6. 

M. Kawahara, J. Morita, M. Rikukawa, K. Sanui, and N. Ogata. Synthesis and proton conductivity of thermally stable polymer electrolyte Poly(benzimidazole) complexes with strong acid molecules. Electrochimica Acta 45, 1395-1398 2000. 

Many approaches have been developed for the production of ionic liquid-polymer composite membranes. For example, Doyle et al. [165] prepared RTILs/PFSA composite membranes by swelling the Nafion with ionic liquids. When 1-butyl, 3-methyl imidazolium trifluoromethane sulfonate was used as the ionic liquid, the ionic conductivity ofthe composite membrane exceeded 0.1 S cm at 180 °C. A comparison between the ionic liquid-swollen membrane and the liquid itself indicated substantial proton mobility in these composites. Fuller et al. [166] prepared ionic liquid-polymer gel electrolytes by blending hydrophilic RTILs into a poly(vinylidene fiuoridej-hexafluoropropylene copolymer [PVdF(HFP)] matrix. The gel electrolytes prepared with an ionic liquid PVdF(HFP) mass ratio of 2 1 exhibited ionic conductivities >10 Scm at room temperature, and >10 Scm at 100 °C. When Noda and Watanabe [167] investigated the in situ polymerization of vinyl monomers in the RTILs, they produced suitable vinyl monomers that provided transparent, mechanically strong and highly conductive polymer electrolyte films. As an example, a 2-hydroxyethyl methacrylate network polymer in which BPBF4 was dissolved exhibited an ionic conductivity of 10 S cm at 30 °C. 

Among the proton-conducting membranes, Nafion or Nafion-like sulfonated perfluorinated polymers should also be mentioned. These materials are used for polymer electrolyte membrane (PEM) FCs, and in addition to being chemically very stable, they exhibit high proton conductivity at temperatures lower than 100°C. It is believed that permeability and thermal stability may be increased if tailor-made lamellar nanoparticles are added to a proton-conducting polymer. The sulfonated poly(ether ether ketone) (S-PEEK) type of polymers is also widely reported as an alternative to fluorinated polymers such as Nafion or Hyflon [51]. 

Over the last decade, several new proton exchange membranes have been developed. The new polymers in fuel cell applications are based mostly on hydrocarbon structures for the polymer backbone. Poly(styrene sulfonic acid) is a basic material in this field. In practice, poly(styrene sulfonic acid) and the analogous polymers such as phenol sulfonic acid resin and poly(trifluorostyrene sulfonic acid), were frequently used as polymer electrolytes for PEMFCs in the 1960s. Chemically and thermally stable aromatic polymers such as poly(styrene) [ 3 ], poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbony 1-1,4-phenylene) (PEEK) [4], poly(phenylenesulfide) [5], poly(l,4-phenylene) [6, 7], poly (oxy-1,4-phe-nylene) [8], and other aromatic polymers [9-11], can be employed as the polymer backbone for proton conducting polymers. These chemical structures are illustrated in Fig. 6.2. 

Nafion is a copolymer of poly(tetrafluoroethylene) and polysulfonyl fluoride vinyl ether. It has fixed anions, which are sulfonic acid sites, and consequently, by electroneutrality, the concentration of positive ions is fixed. Furthermore, the transference number of protons in this system is 1, which greatly simplifies the governing transport equations, as seen below. There can be different forms of Nafion in terms of the positive counterion (e.g., proton, sodium, etc.). Most models deal only with the proton or acid form of Nafion, which is the most common form used in polymer-electrolyte fuel cells due to its high proton conductivity. 

Novel polymer electrolytes exhibiting high proton conductivity (higher than 10 Scm ) were prepared by sulfonation of poly(ether sulfone) (PES) (97,98). In these polymers the protons of the sulfonic acid groups are partially replaced by metal ions (Mg, Ti, Al, Ln) which leads to extension of the durabihty of the electrolytes. 

Sulfonated poly(phenylene sulfide) and S-PPBP exhibit stable proton conductivities at elevated temperatures. For this reason, they are considered as prospective polymers for manufacture of proton-conducting electrolyte membranes operating at elevated temperatures and low humidity. 

Hashmi, S. S. A. 2014. Quasi-solid-state pseudocapacitors using proton-conducting gel polymer electrolyte and poly(3-methyl thiophenej-ruthenium oxide composite electrodes. Journal of Solid State Electrochemistry 18 465-475. 

Asencio JA, Borr6s S, G6mez-Romero P (2004) Sulfonated poly(2,5-benzimidazole) (SABPBI) impregnated with phosphoric acid as proton conducting membranes for polymer electrolyte fuel cells. Electrochim Acta 49 4461-4466... 

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