Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Materials Science Poland

2 2006

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Ionic conductivity of polymer electrolytes comprising acrylonitrile-butyl acrylate copolymer and a lithium salt

Łasińska A., Dygas J.R., Krok F., Marzantowicz M., Florjańczyk Z., Tomaszewska A., Zygadło-Monikowska E.

Materials Science Poland

2006

Vol. 24, No. 1

187--194

New polymer electrolytes were prepared by mixing random copolymers of acrylonitrile and butyl acrylate (poly(AN-co-BuA)) with lithium bis(trifluoromethanesulfone) imide (LiTFSI). Electrical properties were studied by the impedance spectroscopy. The glass transition temperature was studied by DSC. Presented results concern a broad range of compositions, from a pristine copolymer to the system with 98 wt. % of salt. Correlation was established between the glass transition temperature, ionic conductivity, and salt content in the system. Mixtures of poly(AN-co-BuA) and LiTFSI exhibit much lower glass transition temperatures than the parent copolymer. Effects of ageing were observed for electrolytes with high salt content.

In-situ study of the influence of crystallization on the ionic conductivity of polymer electrolytes

Marzantowicz M., Dygas J.R., Krok F., Zygadło-Monikowska E., Florjańczyk Z.

Materials Science Poland

2006

Vol. 24, No. 1

195--203

Simultaneous impedance measurements and optical observations of polymer electrolytes were conducted in an automated experimental setup, combining an impedance analyser, polarizing microscope with a heating stage and a digital camera. The polymer film was placed between glasses with indium tin oxide conductive layers, forming a transparent cell mounted in a custom-designed holder, which preserved an argon atmosphere. Results of in-situ studies for various compositions of poly(ethylene oxide) (PEO) with LiN(CF3SO2)2 salt (LiTFSI), as well as pure PEO, are presented. In the investigated systems, crystallization had a strong impact on ionic conductivity. It was found that the initial growth of crystalline structures caused only a small fraction of the total decrease of conductivity. A large decrease in conductivity was observed during the second stage of crystallization, when no significant changes in microscope picture were observed. In pure PEO and the PEO:LiTFSI 6:1 system, a dense crystalline structure developed, resulting in a decrease in conductivity of over two orders of magnitude. In dilute PEO:LiTFSI systems, a "loose" structure was formed, with amorphous areas preserved between crystallites, and conductivity decreased by only a factor of about 6.