Branimir Grgur | University of Belgrade (original) (raw)

Papers by Branimir Grgur

Journal of Polymer Research, Aug 25, 2017

Poly(aniline-co-(m-aminobenzoic acid)) was synthesized electrochemically at graphite electrode un... more Poly(aniline-co-(m-aminobenzoic acid)) was synthesized electrochemically at graphite electrode under galvanostatic conditions. Aqueous electrolyte for synthesis was consisted of HCl and different amount of aniline and m-aminobenzoic acid. The presence of the meta positioned carboxylic group in m-aminobenzoic acid influenced higher co-polymerization potential, different morphology and electrochemical behavior of copolymers compared to polyaniline. Electrochemical activity is achieved by proton exchange in neutral environment that can result in a faster charge/discharge process, which is in the case of PANI limited by slow anion exchange, making this material promising for consideration in supercapacitors and in biological system.

Electrochimica Acta, Sep 1, 2019

Poly(o-toluidine) (POT) is electrochemically synthesized on graphite electrode at constant curren... more Poly(o-toluidine) (POT) is electrochemically synthesized on graphite electrode at constant current density of 1.5 mA cm-2 from aqueous electrolyte of 1.0 mol dm-3 H 2 SO 4 and 0.25 mol dm-3 o-toluidine. Electrochemical characterization of POT electrode is performed using cyclic voltammetry, Mot Schottky analysis and galvanostatic measurements at different currents. POT electrode exhibited high energy storage features, with specific energy up to 17.5 Wh kg-1 and specific power up to 3300 W kg-1. Cyclic stability exceeding 90% is obtained over 2000 charge/discharge cycles at 13.1 A g-1 indicating the perspective application of POT electrode as energy storage material.

Progress in Organic Coatings, May 1, 2011

The polyaniline thin film electrode and powder have been synthesized on graphite electrodes from ... more The polyaniline thin film electrode and powder have been synthesized on graphite electrodes from 0.5M hydrochloric acid solution under galvanostatic conditions. The water insoluble and acetone soluble polyaniline mass fractions of the powder, as well as the polymerization efficiency, based on the emeraldine salt have been determined. The morphology of the obtained emeraldine salt powder has been investigated by the

Materials Chemistry and Physics, Apr 1, 2009

Електрохемијска синтеза и карактеризација електроде од полианилина за потенцијалну употребу у еле... more Електрохемијска синтеза и карактеризација електроде од полианилина за потенцијалну употребу у електрохемијским изворима енергије Полианилин на графитној електроди је синтетисан електрохемијски под галваностатским режимом таложења при густини струје од 2.0 mA cm-1 из раствора 1.0 mol dm-3 HCl и 0.25 mol dm-3 анилина. Електрохемијска карактеризација ПАНИ електроде је урађена у раствору 0.5 М HCl цикличном волтаметријом и галваностатским мерењима. Капацитет ПАНИ електроде је израчунат на 0.154 mA h cm-2 што одговара 25 % од теоретске масе ПАНИ која може да размени допанте. Током циклизације при ниским рН вредностима удео удео деградационих продуката је мали и нема утицај на капацитет ПАНИ електроде.

Metals

Composite coatings prepared by mixing 5 wt.% polyaniline with commercial alkyd-based paints were ... more Composite coatings prepared by mixing 5 wt.% polyaniline with commercial alkyd-based paints were applied on carbon steel. The polyaniline emeraldine chloride salt was prepared by procedure recommended by IUPAC, including deprotonation by ammonia hydroxide, and reprotonation with sulfamic, succinic, citric, and acetic acids with different doping degrees or oxidation states. The steel samples with base and composite coatings were immersed in 3% NaCl and the corrosion current density was determined after 96 h in situ using the ASTM 1,10-phenanthroline method. The samples were also inspected by optical microscopy. It was shown that the composite coatings reduced the possibility of blister formations and delamination. The corrosion current density and the appearance of the corrosion products, whose area was determined by ImageJ software, closely followed the initial oxidation state of the polyaniline. It was also shown that damaged composite coatings with higher degrees of oxidized (dope...

The composite coatings prepared by mixing the 5 wt.% of polyaniline with commercial alkyd-based p... more The composite coatings prepared by mixing the 5 wt.% of polyaniline with commercial alkyd-based paint are applied on carbon steel. The polyaniline emeraldine chloride salt is prepared by procedure recommended by IUPAC, deprotonated by ammonia hydroxide, and reprotonated with the sulfamic, succinic, citric, and acetic acids with different doping degrees or oxidation states. The steel samples with base and composite coatings are immersed in 3% NaCl and the corrosion current density is determined after 96 h in-site using ASTM 1,10-phenanthroline method. The samples are also inspected by the optical microscope. It is shown that composite coatings reduce the possibility of blister formations and delamination. The corrosion current density and the appearance of the corrosion products, which area is determined by ImageJ softer, closely follow the initial oxidation state of the polyaniline. The role of the initial state of the polyaniline is discussed. It is suggested that such behavior cou...

1st INTERNATIONAL SYMPOSIUM ON BIOTECHNOLOGY : proceedings, Mar 1, 2023

1st INTERNATIONAL SYMPOSIUM ON BIOTECHNOLOGY : proceedings, Mar 1, 2023

Primary seawater magnesium-based cell with AgCl or PbCl2 cathodes is widely used as power sources... more Primary seawater magnesium-based cell with AgCl or PbCl2 cathodes is widely used as power sources. In this paper, we consider the cyclic galvanostatic formation of silver and lead chloride, and their electrochemical behavior for potential applications in the new concept of the seawater quasi-rechargeable magnesium cell. For potential cells, the voltage for Mg alloy AZ63 and AgCl is ~ 1.5 V, and for the PbCl2, ~ 1 V. High discharge specific capacity, energy, and power are obtained under the very high discharge rate. Consideration of the improvements for the application in a real cell is given.

Transactions of Nonferrous Metals Society of China

Progress in Organic Coatings, 2018

The chemically synthesized polyaniline in the powdered form by the procedure recommended by IUPAC... more The chemically synthesized polyaniline in the powdered form by the procedure recommended by IUPAC is reprotonated using sulfamic, citric, succinic and acetic acid. The UV-vis spectroscopy is applied to estimate doping degree of the reprotonated samples. The estimated doping degrees are as follows: the polyaniline doped with sulfamic acid 0.28, with succinic acid 0.18, with citric acid 0.15 and with acetic acid 0.13. The composite coatings are prepared by mixing the alkyd based commercial paint with 5 wt.% of the reprotonated samples and painted on mild steel. Using linear polarization method, the polarization resistances of the composite and base coatings are determined in 3% NaCl. It is shown that initial oxidation state of the polyaniline determined the values of polarization resistance which decrease in the following order: R p (sulfamic) > R p (succinic) > R p (citric) > R p (acetic) ∼R p (base coating). For all composite coatings, increases in the corrosion potentials are observed during the time, while for base coating decrease. The steel samples with base and composite coatings are also immersed in 3% NaCl, after 150 h visually inspected, and by the optical microscope. It is shown that composite coatings reduce the possibility of blister formations and delamination. The appearance of the corrosion products closely follow the initial oxidation state of the polyaniline. It is suggested that such behavior could be connected with the oxygen reduction mechanism that proceed mainly via two electron path on the polyaniline particles, releasing a much smaller amount of hydroxyl ions, responsible for the delamination and blister formations.

Chemical Physics Letters, 2017

The charge transfer complex formation between TiO 2 powder and variety of phenol derivatives (phe... more The charge transfer complex formation between TiO 2 powder and variety of phenol derivatives (phenol, 4-nitrophenol, 4-bromophenol, 4-tert-butylphenol, hydroquinone) was achieved. The red-shift of optical absorption was observed upon surface modification of TiO 2 powders with phenol derivatives. The influence of substituent functional groups in para position on the optical band gap and conduction band edge of inorganic/organic hybrids was studied using reflection spectroscopy and cyclic voltammetry. The experimental findings were supported by density functional theory calculations. The measured reflection spectra of surface-modified TiO 2 powders with phenol derivatives were compared with calculated electronic excitation spectra of corresponding model systems.

Progress in Organic Coatings, 2016

Novel TiO 2-PANI core-shell nanocomposite, prepared by in situ oxidative polymerization of anilin... more Novel TiO 2-PANI core-shell nanocomposite, prepared by in situ oxidative polymerization of aniline in the presence of TiO 2 nanoparticles surface modified with vitamin B6, was used to reinforce epoxy resin. The size of prepared TiO 2 nanoparticles and TiO 2-PANI nanocomposite were determined by a transmission electron microscopy (TEM). The surface modification of TiO 2 nanoparticles was confirmed by FTIR and UV-vis spectroscopy, while the morphology of PANI and TiO 2-PANI nanocomposite was investigated by scanning electron microscopy (SEM). The influence of TiO 2-PANI nanocomposite on glass transition temperature, dielectric and dynamic mechanical properties, thermooxidative stability, mechanical and anticorrosion properties of epoxy based nanocomposites was investigated and compared to the properties of epoxy/PANI nanocomposites. It has been observed that the glass transition temperature of epoxy resin increases after introduction of PANI and TiO 2-PANI nanocomposite, as well as with increasing their content. Prepared nanocomposites exhibited higher value of dielectric constant than pure epoxy resin. Epoxy based coating containing TiO 2-PANI nanocomposite showed lower dielectric loss, higher hardness and better anticorrosion properties than pure epoxy resin and epoxy/PANI nanocomposite.

Chemical Papers, May 27, 2017

The electrocatalytic degradation of C.I. Acid Orange 3 from simulated wastewater by indirect elec... more The electrocatalytic degradation of C.I. Acid Orange 3 from simulated wastewater by indirect electrochemical oxidation using an IrO x electrode was investigated. The effects of different operating parameters on the rate of dye decolorization were studied. The influences of mixing, electrolyte concentration, applied current, and initial dye concentration were examined. The change in dye concentration was followed by ultraviolet-visible spectroscopy, while the formation of reaction intermediates was established using high-performance liquid chromatography-mass spectrometry analysis. Ultraviolet-visible spectroscopy showed a decrease of the absorption peak at 374 nm during the electrolysis and the appearance of a new absorption maximum at 460 nm. The decolorization reaction can be followed only at 460 nm. Four intermediate products (two mono-and two dichlorinated) were detected. At the end of the study, a phytotoxicity assay was performed to determine the effectiveness of the applied method. The results showed that the applied electrochemical treatment of C.I. Acid Orange 3 leads to a decrease in phytotoxicity from 53 to 28%.

Metals

In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for the first t... more In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for the first time as a natural, ecological, and sustainable corrosion inhibitor for the acid cleaning of carbon steel. The essential oil was extracted by hydrodistillation using a Clevenger-type apparatus, and the oil was analyzed by gas chromatography–flame–ionization detection (GC–FID) and gas chromatography–mass spectrometry (GC–MS). The most abundant components in the essential oil were α-pinene, germacrene D, (E)-cariophyllene, and β-pinene. The inhibition efficiency was determined by electrochemical methods (electrochemical impedance spectroscopy and potentiodynamic polarization measurements). The results showed that the inhibitory efficiency of the black pine essential oil increases with time, reaching the highest values after 4 h of immersion for all inhibitor concentrations. It was also shown that black pine essential oil is a mixed-type inhibitor. The contact angle measurements confirmed tha...

In this paper formation of linear differential equations for approximate determination of electri... more In this paper formation of linear differential equations for approximate determination of electrical and molar conductivity of sulfuric-acid solutions, has been give.U radu je obrađena problematika formiranja sistema aproksimacionih linearnih diferencijalnih jednačina za približno izračunavanje električne i molarne provodljivosti vodenog rastvora sumporne kiseline. Pokazano je kako se na osnovu podataka eksperimentalnih merenja navedenih veličina vrši postavljanje aproksimacionih linearnih diferencijalnih jednačina ili njihovih sistema, koji praktično opisuju dinamiku procesa i osobine elektrohemijskog sistema. Rešavanjem tako postavljenih jednačina metodom Runge-Kuta četvrtog reda pomoću odgovarajućih funkcija Matlab računarskih programskih paketa, dobijaju se odgovarajuće karakteristike pogodne za analizu režima rada i ispitivanje uticaja parametara na osobine sistema. Dobijeni rezultati u vidu numeričkih vrednosti promenljivih, su veoma precizni, pouzdani i, zadovoljavajući za pr...

The electrochemical characteristics of LiCoO2 as a positive electrode for lithium-ion batteries, ... more The electrochemical characteristics of LiCoO2 as a positive electrode for lithium-ion batteries, have been investigated. The LiCoO2 were sintetized from Li2CO3 and Co203 by thermal treatment at 1273 K for 24 h in the air. All the electrochemical measurements were performed in 1 mol dm-3 LiClO4 solutions in propylene carbonate. By using the electrochemical impedance spectroscopy at the open circuit potential, the exchange current for different states of charges for Li1-xCoO2 (0,6 lt 1-x lt 0,9), with the values of ~190 do 40mA, have been determined. From the analysis of potentiostatic pulses, the diffusion coefficient of lithium for different states of charges (0.65 lt 1-x lt 0.9), with an average values of (1,7±2)x10-10 cm2s-1 have been determined. .U radu su ispitivane elektrohemijske karakteristike LiCoO2 kao pozitivne elektrode litijum-jon akumulatora. LiCoO2 je sintetizovan polazeći od LiCO3 i Co203 termičkim tretmanom na 1273 K u toku 24 sata u atmosferi vazduha. Sva elektrohem...

Journal of Polymer Research, Aug 25, 2017

Poly(aniline-co-(m-aminobenzoic acid)) was synthesized electrochemically at graphite electrode un... more Poly(aniline-co-(m-aminobenzoic acid)) was synthesized electrochemically at graphite electrode under galvanostatic conditions. Aqueous electrolyte for synthesis was consisted of HCl and different amount of aniline and m-aminobenzoic acid. The presence of the meta positioned carboxylic group in m-aminobenzoic acid influenced higher co-polymerization potential, different morphology and electrochemical behavior of copolymers compared to polyaniline. Electrochemical activity is achieved by proton exchange in neutral environment that can result in a faster charge/discharge process, which is in the case of PANI limited by slow anion exchange, making this material promising for consideration in supercapacitors and in biological system.

Electrochimica Acta, Sep 1, 2019

Poly(o-toluidine) (POT) is electrochemically synthesized on graphite electrode at constant curren... more Poly(o-toluidine) (POT) is electrochemically synthesized on graphite electrode at constant current density of 1.5 mA cm-2 from aqueous electrolyte of 1.0 mol dm-3 H 2 SO 4 and 0.25 mol dm-3 o-toluidine. Electrochemical characterization of POT electrode is performed using cyclic voltammetry, Mot Schottky analysis and galvanostatic measurements at different currents. POT electrode exhibited high energy storage features, with specific energy up to 17.5 Wh kg-1 and specific power up to 3300 W kg-1. Cyclic stability exceeding 90% is obtained over 2000 charge/discharge cycles at 13.1 A g-1 indicating the perspective application of POT electrode as energy storage material.

Progress in Organic Coatings, May 1, 2011

The polyaniline thin film electrode and powder have been synthesized on graphite electrodes from ... more The polyaniline thin film electrode and powder have been synthesized on graphite electrodes from 0.5M hydrochloric acid solution under galvanostatic conditions. The water insoluble and acetone soluble polyaniline mass fractions of the powder, as well as the polymerization efficiency, based on the emeraldine salt have been determined. The morphology of the obtained emeraldine salt powder has been investigated by the

Materials Chemistry and Physics, Apr 1, 2009

Електрохемијска синтеза и карактеризација електроде од полианилина за потенцијалну употребу у еле... more Електрохемијска синтеза и карактеризација електроде од полианилина за потенцијалну употребу у електрохемијским изворима енергије Полианилин на графитној електроди је синтетисан електрохемијски под галваностатским режимом таложења при густини струје од 2.0 mA cm-1 из раствора 1.0 mol dm-3 HCl и 0.25 mol dm-3 анилина. Електрохемијска карактеризација ПАНИ електроде је урађена у раствору 0.5 М HCl цикличном волтаметријом и галваностатским мерењима. Капацитет ПАНИ електроде је израчунат на 0.154 mA h cm-2 што одговара 25 % од теоретске масе ПАНИ која може да размени допанте. Током циклизације при ниским рН вредностима удео удео деградационих продуката је мали и нема утицај на капацитет ПАНИ електроде.

Metals

Composite coatings prepared by mixing 5 wt.% polyaniline with commercial alkyd-based paints were ... more Composite coatings prepared by mixing 5 wt.% polyaniline with commercial alkyd-based paints were applied on carbon steel. The polyaniline emeraldine chloride salt was prepared by procedure recommended by IUPAC, including deprotonation by ammonia hydroxide, and reprotonation with sulfamic, succinic, citric, and acetic acids with different doping degrees or oxidation states. The steel samples with base and composite coatings were immersed in 3% NaCl and the corrosion current density was determined after 96 h in situ using the ASTM 1,10-phenanthroline method. The samples were also inspected by optical microscopy. It was shown that the composite coatings reduced the possibility of blister formations and delamination. The corrosion current density and the appearance of the corrosion products, whose area was determined by ImageJ software, closely followed the initial oxidation state of the polyaniline. It was also shown that damaged composite coatings with higher degrees of oxidized (dope...

The composite coatings prepared by mixing the 5 wt.% of polyaniline with commercial alkyd-based p... more The composite coatings prepared by mixing the 5 wt.% of polyaniline with commercial alkyd-based paint are applied on carbon steel. The polyaniline emeraldine chloride salt is prepared by procedure recommended by IUPAC, deprotonated by ammonia hydroxide, and reprotonated with the sulfamic, succinic, citric, and acetic acids with different doping degrees or oxidation states. The steel samples with base and composite coatings are immersed in 3% NaCl and the corrosion current density is determined after 96 h in-site using ASTM 1,10-phenanthroline method. The samples are also inspected by the optical microscope. It is shown that composite coatings reduce the possibility of blister formations and delamination. The corrosion current density and the appearance of the corrosion products, which area is determined by ImageJ softer, closely follow the initial oxidation state of the polyaniline. The role of the initial state of the polyaniline is discussed. It is suggested that such behavior cou...

1st INTERNATIONAL SYMPOSIUM ON BIOTECHNOLOGY : proceedings, Mar 1, 2023

1st INTERNATIONAL SYMPOSIUM ON BIOTECHNOLOGY : proceedings, Mar 1, 2023

Primary seawater magnesium-based cell with AgCl or PbCl2 cathodes is widely used as power sources... more Primary seawater magnesium-based cell with AgCl or PbCl2 cathodes is widely used as power sources. In this paper, we consider the cyclic galvanostatic formation of silver and lead chloride, and their electrochemical behavior for potential applications in the new concept of the seawater quasi-rechargeable magnesium cell. For potential cells, the voltage for Mg alloy AZ63 and AgCl is ~ 1.5 V, and for the PbCl2, ~ 1 V. High discharge specific capacity, energy, and power are obtained under the very high discharge rate. Consideration of the improvements for the application in a real cell is given.

Transactions of Nonferrous Metals Society of China

Progress in Organic Coatings, 2018

The chemically synthesized polyaniline in the powdered form by the procedure recommended by IUPAC... more The chemically synthesized polyaniline in the powdered form by the procedure recommended by IUPAC is reprotonated using sulfamic, citric, succinic and acetic acid. The UV-vis spectroscopy is applied to estimate doping degree of the reprotonated samples. The estimated doping degrees are as follows: the polyaniline doped with sulfamic acid 0.28, with succinic acid 0.18, with citric acid 0.15 and with acetic acid 0.13. The composite coatings are prepared by mixing the alkyd based commercial paint with 5 wt.% of the reprotonated samples and painted on mild steel. Using linear polarization method, the polarization resistances of the composite and base coatings are determined in 3% NaCl. It is shown that initial oxidation state of the polyaniline determined the values of polarization resistance which decrease in the following order: R p (sulfamic) > R p (succinic) > R p (citric) > R p (acetic) ∼R p (base coating). For all composite coatings, increases in the corrosion potentials are observed during the time, while for base coating decrease. The steel samples with base and composite coatings are also immersed in 3% NaCl, after 150 h visually inspected, and by the optical microscope. It is shown that composite coatings reduce the possibility of blister formations and delamination. The appearance of the corrosion products closely follow the initial oxidation state of the polyaniline. It is suggested that such behavior could be connected with the oxygen reduction mechanism that proceed mainly via two electron path on the polyaniline particles, releasing a much smaller amount of hydroxyl ions, responsible for the delamination and blister formations.

Chemical Physics Letters, 2017

The charge transfer complex formation between TiO 2 powder and variety of phenol derivatives (phe... more The charge transfer complex formation between TiO 2 powder and variety of phenol derivatives (phenol, 4-nitrophenol, 4-bromophenol, 4-tert-butylphenol, hydroquinone) was achieved. The red-shift of optical absorption was observed upon surface modification of TiO 2 powders with phenol derivatives. The influence of substituent functional groups in para position on the optical band gap and conduction band edge of inorganic/organic hybrids was studied using reflection spectroscopy and cyclic voltammetry. The experimental findings were supported by density functional theory calculations. The measured reflection spectra of surface-modified TiO 2 powders with phenol derivatives were compared with calculated electronic excitation spectra of corresponding model systems.

Progress in Organic Coatings, 2016

Novel TiO 2-PANI core-shell nanocomposite, prepared by in situ oxidative polymerization of anilin... more Novel TiO 2-PANI core-shell nanocomposite, prepared by in situ oxidative polymerization of aniline in the presence of TiO 2 nanoparticles surface modified with vitamin B6, was used to reinforce epoxy resin. The size of prepared TiO 2 nanoparticles and TiO 2-PANI nanocomposite were determined by a transmission electron microscopy (TEM). The surface modification of TiO 2 nanoparticles was confirmed by FTIR and UV-vis spectroscopy, while the morphology of PANI and TiO 2-PANI nanocomposite was investigated by scanning electron microscopy (SEM). The influence of TiO 2-PANI nanocomposite on glass transition temperature, dielectric and dynamic mechanical properties, thermooxidative stability, mechanical and anticorrosion properties of epoxy based nanocomposites was investigated and compared to the properties of epoxy/PANI nanocomposites. It has been observed that the glass transition temperature of epoxy resin increases after introduction of PANI and TiO 2-PANI nanocomposite, as well as with increasing their content. Prepared nanocomposites exhibited higher value of dielectric constant than pure epoxy resin. Epoxy based coating containing TiO 2-PANI nanocomposite showed lower dielectric loss, higher hardness and better anticorrosion properties than pure epoxy resin and epoxy/PANI nanocomposite.

Chemical Papers, May 27, 2017

The electrocatalytic degradation of C.I. Acid Orange 3 from simulated wastewater by indirect elec... more The electrocatalytic degradation of C.I. Acid Orange 3 from simulated wastewater by indirect electrochemical oxidation using an IrO x electrode was investigated. The effects of different operating parameters on the rate of dye decolorization were studied. The influences of mixing, electrolyte concentration, applied current, and initial dye concentration were examined. The change in dye concentration was followed by ultraviolet-visible spectroscopy, while the formation of reaction intermediates was established using high-performance liquid chromatography-mass spectrometry analysis. Ultraviolet-visible spectroscopy showed a decrease of the absorption peak at 374 nm during the electrolysis and the appearance of a new absorption maximum at 460 nm. The decolorization reaction can be followed only at 460 nm. Four intermediate products (two mono-and two dichlorinated) were detected. At the end of the study, a phytotoxicity assay was performed to determine the effectiveness of the applied method. The results showed that the applied electrochemical treatment of C.I. Acid Orange 3 leads to a decrease in phytotoxicity from 53 to 28%.

Metals

In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for the first t... more In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for the first time as a natural, ecological, and sustainable corrosion inhibitor for the acid cleaning of carbon steel. The essential oil was extracted by hydrodistillation using a Clevenger-type apparatus, and the oil was analyzed by gas chromatography–flame–ionization detection (GC–FID) and gas chromatography–mass spectrometry (GC–MS). The most abundant components in the essential oil were α-pinene, germacrene D, (E)-cariophyllene, and β-pinene. The inhibition efficiency was determined by electrochemical methods (electrochemical impedance spectroscopy and potentiodynamic polarization measurements). The results showed that the inhibitory efficiency of the black pine essential oil increases with time, reaching the highest values after 4 h of immersion for all inhibitor concentrations. It was also shown that black pine essential oil is a mixed-type inhibitor. The contact angle measurements confirmed tha...

In this paper formation of linear differential equations for approximate determination of electri... more In this paper formation of linear differential equations for approximate determination of electrical and molar conductivity of sulfuric-acid solutions, has been give.U radu je obrađena problematika formiranja sistema aproksimacionih linearnih diferencijalnih jednačina za približno izračunavanje električne i molarne provodljivosti vodenog rastvora sumporne kiseline. Pokazano je kako se na osnovu podataka eksperimentalnih merenja navedenih veličina vrši postavljanje aproksimacionih linearnih diferencijalnih jednačina ili njihovih sistema, koji praktično opisuju dinamiku procesa i osobine elektrohemijskog sistema. Rešavanjem tako postavljenih jednačina metodom Runge-Kuta četvrtog reda pomoću odgovarajućih funkcija Matlab računarskih programskih paketa, dobijaju se odgovarajuće karakteristike pogodne za analizu režima rada i ispitivanje uticaja parametara na osobine sistema. Dobijeni rezultati u vidu numeričkih vrednosti promenljivih, su veoma precizni, pouzdani i, zadovoljavajući za pr...

The electrochemical characteristics of LiCoO2 as a positive electrode for lithium-ion batteries, ... more The electrochemical characteristics of LiCoO2 as a positive electrode for lithium-ion batteries, have been investigated. The LiCoO2 were sintetized from Li2CO3 and Co203 by thermal treatment at 1273 K for 24 h in the air. All the electrochemical measurements were performed in 1 mol dm-3 LiClO4 solutions in propylene carbonate. By using the electrochemical impedance spectroscopy at the open circuit potential, the exchange current for different states of charges for Li1-xCoO2 (0,6 lt 1-x lt 0,9), with the values of ~190 do 40mA, have been determined. From the analysis of potentiostatic pulses, the diffusion coefficient of lithium for different states of charges (0.65 lt 1-x lt 0.9), with an average values of (1,7±2)x10-10 cm2s-1 have been determined. .U radu su ispitivane elektrohemijske karakteristike LiCoO2 kao pozitivne elektrode litijum-jon akumulatora. LiCoO2 je sintetizovan polazeći od LiCO3 i Co203 termičkim tretmanom na 1273 K u toku 24 sata u atmosferi vazduha. Sva elektrohem...