Bio-Inspired Membranes for Advanced Polymer Electrolyte Fuel Cells. Anhydrous Proton-Conducting Membrane via Molecular Self-Assembly

Abstract

Bio-inspired materials or natural biopolymers have attracted much attention for industrial applications as biocompatible materials. Although these materials have been discarded as industrial waste around the world, there is an increasing interest in environmental, engineering, and electrical applications of the biomaterials because of their well-controlled structures and superior conducting properties. The controlled structures of the hydrogen-bonding network in biomolecules, such as bioenergetic proteins, are essential for efficient energy transduction in living systems and application of a biomolecular mechanism could make it possible to prepare efficient electrolytes with superior conducting properties. We report here a recent investigation on the new class and new concept of electrolyte materials with bio-inspired molecular architectures of acid-base pairs for anhydrous proton conduction and its application in intermediate temperature C) polymer electrolyte fuel cells (PEFC). Although some membranes were composed from entirely biomolecular materials, they showed large anhydrous proton conductivities from room temperature to 160 C, and fuel cells employing biomembranes as a polymer electrolyte produced electrical power under non-humidified H 2 /O 2 condition at 160 C. These bio-inspired materials may have many potential applications not only because of its superior ion conducting properties, in particular, under anhydrous (water-free) or extremely low-humidity conditions, but also because of its biocompatibility.Increasing interest toward the global sustainable energy has occurred in relation to political, economical, and environmental protection aspects, whereas, from an industrial development point of view, advanced energy technology is becoming intensively important recently in ordered to reduce fossil fuel consumption and keep the environment clean for human activities. The Kyoto protocol has stimulated research activities in renewable energy technology in every nation and every industrial sector. Among them, polymer electrolyte fuel cells (PEFC) have been recognized as most promising energy conversion devices because they are much very efficient and emit less of CO 2 from automobile, terrestrial, and industrial power sources.

Proton conduction of DNA–imidazole composite material under anhydrous condition

“…In contrast, the E a of 1.0-1.8 eV at low mixing ratio is higher than that of the general anhydrous proton conductor. 15,18,19 These results suggest that the DNA-Im composite material has two proton conductive mechanisms. On the other hand, since the pure DNA material undergoes a thermal decomposition at approximately 160 1C, the Arrhenius plot of the proton conductivity of the pure DNA material could not demonstrate a least-squares fitting in the range of 90-160 1C (see in Figure 5).…”

“…[11][12][13][14][15] However, since the proton conduction of the customary perfluorinated sulfonic acid membranes, such as the humidified Nafion membrane, is based on the presence of mobile water molecules in the membrane, the proton conductivity above the boiling point (4100 1C) abruptly decreases because of the evaporation of water. 16,17 In addition, the production cost is extremely high.…”

Inorganic–Organic Hybrid Surfactant Crystals: Structural Aspects and Functions

“…Emergence of anhydrous proton conductivity at intermediate temperatures is demanded for solid electrolyte application for fuel-cell technology [29][30][31][32][33]. Although the proton conductivity of C 10 NC 3 -V 10 is rather unstable and lower than other POM hybrid materials [34,35], the proton-containing POM-surfactant crystals would pave the way for an unprecedented class of proton conductors. would be possible for another class of hybrid solid electrolytes.…”

Conductive Supramolecular Architecture Constructed from Polyoxovanadate Cluster and Heterocyclic Surfactant

“…Heteropolyacids, Keggin-type POMs with a proton as counter cation, have been investigated as high proton conductors [20][21][22][23][24][25][26]. Such POMs have been successfully hybridized by surfactant cations to form inorganic-organic hybrids [27][28][29][30][31][32][33][34][35] and single crystals [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55].…”