Synthesis of new composite materials based on carbon felt-polypyrrole-silver-chloride as rechargeable cathodes for magnesium-based systems

[A. S. Popović]

142 str.

Tehnološko inženjerstvo - Hemijsko inženjerstvo / Technological engineering - Chemical engineering

Predmet naučnog istraživanja ove disertacije je ispitivanje mogućnosti primene punjivih pozitivnih elektroda na bazi kompozita polipirola, srebro-hlorida i ugljenične tkanine u sistemima sa elektrolitom na bazi morske vode i legurom magnezijuma kao negativnom elektrodom ćelije, kao mogućih izvora električne energije elektronskih i električnih komponenti signalne opreme za spašavanje i plutajućih bova za monitoring životne sredine. U prvoj fazi izrade disertacije ispitano je elektrohemijsko ponašanje legure magnezijuma AZ63, polipirola i srebro-hlorida sintetisanih elektrohemijskim metodama na grafitnoj, odnosno srebrnoj elektrodi, kao model sistema u cilju ispitivanja elektrohemijskih i električnih karakteristika. U cilju povećanja vrednosti specifičnih kapaciteta, energije i snage i poboljšanja ciklizacionog ponašanja polipirol je sintetisan na ugljeničnoj tkanini visoko razvijene površine. Na tako pripremljenu elektrodu nanet je sloj srebro-hlorida jednostavnom i brzom modifikovanom metodom sukcesivne jonske adsorpcije i reakcije (od eng: Sucesive Ion Layer Adsorption and Reaction, SILAR) u cilju povećavanja napona ćelije i specifičnog kapaciteta. Ispitana je i funkcionalizacija ugljenične tkanine jefitnim komercijalnim rastvorom natrijum-hipohlorita u cilju poboljšanja karakteristika punjive katode. Elektrodni materijali su okarakterisani klasičnim elektrohemijskim metodama u cilju određivanja potencijala, odnosno napona punjenja i pražnjenja, specifičnog kapaciteta, energije i snage, kao i ciklizacione stabilnosti, a takođe i spektroskopskim metodama: FE - SEM, XRD, XPS i FT-IR. Na kraju je ispitano ponašanje realne ćelije u simuliranoj morskoj vodi i pokazano je da dati sistem može omogućiti pražnjenje tokom kratkih režima sa velikim strujama i snagom za slanje podataka, i kontinualno tokom dužeg vremena pri malim strujama i velikom energijom za napajanje signalnog svetla ili različitih senzora, pri čemu dolazi do redukcije rastvorenog kiseonika na pozitivnoj elektrodi.

The main subject of this dissertation is to examine the possibility to apply rechargeable positive electrodes based on a composite of polypyrrole, silver chloride and carbon felt in systems with an electrolyte based on seawater, and a magnesium alloy as the negative electrode of the cell as a potential source of electric energy for electronic and electrical components of signal equipment for rescue and floating buoys for environmental monitoring. In the first part of the dissertation, the electrochemical behavior of magnesium alloy AZ63, polypyrrole, and silver chloride synthesized by electrochemical methods on a graphite and silver electrode, respectively, was examined, as a model system to test electrochemical and electrical characteristics. To increase the value of specific capacity, energy, and power and improve the cyclization behavior, polypyrrole was synthesized on a carbon felt with a high surface area. A layer of silver chloride was applied to the electrode thus prepared by a simple and fast modified method of successive ion adsorption and reaction (Successive Ion Layer Adsorption and Reaction, SILAR) to increase the cell voltage and specific capacity. The functionalization of the carbon felt with an inexpensive commercial solution of sodium hypochlorite was also tested to improve the characteristics of the rechargeable cathode. Electrode materials were characterized by fundamental electrochemical methods to determine the potentials, i.e. charge and discharge voltage, specific capacity, energy, and power, as well as cycling stability. Additionally, spectroscopic methods: FE - SEM, XRD, XPS, and FT- IR were used. Finally, the behavior of a real cell in simulated seawater was examined, showing that the given system can enable discharge in short regimes with high currents and power for sending data, and continuously for a long time applications with low currents for powering a signal light or various sensors, whereby a reduction of dissolved oxygen can occur on a positive electrodes.

Polipirol, ugljenična tkanina, punjiva katoda, baterije, katoda

Polypyrrole, carbon cloth, rechargeable cathode, battery, cathode Scientific field:

544.653.1:66.017/.018(043.3)

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