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Development of ion-exchange composite polymeric membranes for polymer electrolyte hydrogen fuel cells
The methods of synthesis of hyperbranched and star-shaped (organosilicon) polymers of acid-base type, which are capable of ionic conductivity under anhydrous conditions, were proposed. The techniques of obtaining oligomeric donors of hydroxide-anions, namely an oligomer with ionic terminal groups and the one containing ionic groups in the main chain (polyionene type), were developed. The obtained donors of protons and anions were used as dopants in sol-gel synthesis of organic-inorganic polymeric ion-exchange membranes for hydrogen fuel cells capable of performing at temperatures above 100°C under anhydrous conditions and at temperatures below 80°C under humidification in alkaline media.
Areas of applications
The obtained ionic-exchange membranes except use in fuel cells can be used in chemical separation, sensors, energy storage devices, windows with controlled permeability of light («smart windows»), electrochromic displays, process of water electrolysis.
Brief description
The method of synthesis of protic ion-extended oxyethylene polymers of acid-base type on the basis of developed sulfonic hyperbranched and star-shaped (siliconorganic compounds) oligomers capable of proton conductivity under anhydrous conditions were proposed. As the initial basic oligomer, α,ω-diamino-derivative of oligooxyethylene was used. Synthesis of ion-extended oligomeric dopants was carried out both by partial (50%) and by complete neutralization of sulfonic acid groups of the proposed sulfonic oligomers by the terminal tertiary amine groups of the α,ω-diamino-derivative of oligooxyethylene.
The method of synthesis of hydroxyl-containing oligomeric and polymeric donors of anions which includes several stages, namely obtaining reactive oligomers with terminal chlorine atoms, preparation of oligomers with terminal tertiary nitrogen atoms, synthesis of oligomeric and polymeric dopants with quaternary ammonium cations and substitution of chloride anions by hydroxides anions, was developed.
The developed oligomeric and polymeric donors of protons and hydroxide-anions were used as dopants in sol-gel synthesis of nanostructured organic-inorganic polymeric ion-exchange membranes in a mixture with α,ω-dialkoxysilyl oligoethylene urethane-ureic precursor and phenyltriethoxysilane at different ratios using acidic (HCl) and neutral (NaF) catalysis. The structure and the properties of the obtained membranes were investigated. The relationships between chemical structure, structure and properties of the synthesized solid polymeric electrolytes were established and the methods for controlling them were developed.
Expected results
High thermal stability of the obtained membranes and their ability for ion conductivity under dry conditions at temperatures above 100°C as well as under humidification in alkaline environment.
Advantages
The synthesized organic-inorganic nanostructured hybrid ion-exchange membranes are characterized by high mechanical durability and thermal stability combined with reasonable ionic conductivity both under anhydrous conditions at temperatures above 100°C and in humidified state at temperatures below 80°C under alkaline conditions, low fuel crossover, ease of synthesis and a significant cost reduction.
Competitors
DuPont Co.,
Asahi Glass Co.Ltd ,
Asahi Chemicals Co. Ltd ,
Dow Chemical Co.
Project development
The methods of synthesis of organic-inorganic nanostructured hybrid ion-exchange membranes for fuel cells capable of ion conduction in anhydrous conditions at temperatures above 100°C and at temperatures below 80°C in alkaline media, based on new types of oligomeric and polymeric donors of protons and anions in combination with film-forming α,ω-dialkoxysilyl oligoether precursor of the segmented structure were developed. The developed membranes are characterized by thermal stability up to 300°C and ion conductivity of 10-4-10-3 S/cm at temperatures of 100-120°C under anhydrous conditions, and 10-5 S/cm at temperatures of 20-60°C in hydrated state under alkaline conditions. These membranes according to above-mentioned parameters are on par with the best domestic and foreign analogues of this type. Among the proposed ion-exchange solid-polymer electrolytes, the proton-exchange membranes based on star-shaped organosilicon sulfonated (including amphiphilic) proton donors in combination with film-forming α,ω-dialkoxysilane oligoether precursors are closest to implementation.
Contact information
Executing : Institution-Executive: Institute of Macromolecular Chemistry, National Academy of Sciences of Ukraine
Project 26 «Development of ion-exchange composite polymeric membranes for polymer electrolyte hydrogen fuel cells».
Project leader:
Valery V. Shevchenko
Doctor of Chemical Sciences
Tel. +38 044 559-55-00
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