Dmitry Belov - Academia.edu (original) (raw)
Uploads
Papers by Dmitry Belov
The thin film composite was obtained with polymerization of acetyl-ene into r o w olymer matrix. ... more The thin film composite was obtained with polymerization of acetyl-ene into r o w olymer matrix. The film was combined with A1 foil this electrode were invest1 ted in 3M LiBF4/ propylenecarbonate + dimethoxyethane (1 : l + V N) e P ectrolyte. It wa8 shown that Li penetrated through the composite film and formed Li 1 alloy. Such an electrode wa8 under ne to a great member tion. covering K B th si es of the latter. Electrochemical properties of of ch $r ge /discharge cycles without destruct Y on and dendrite forma
A series of well-known overcharge protecting electrolyte additives for Li-ion batteries (diphenyl... more A series of well-known overcharge protecting electrolyte additives for Li-ion batteries (diphenyl ether (PE), biphenyl (BP), cyclohexyl benzene (CHB) and N, N-dimethylacetamide (DMAC) were tested at equal conditions. A high energy density prismatic cell with LiCoO2 as a cathode ...
Journal of Solid State Electrochemistry, 2012
Abstract Thermal stability, flammability, and electrochemical performances of the cyclic carbonat... more Abstract Thermal stability, flammability, and electrochemical performances of the cyclic carbonate-based electrolytes [where γ-butyrolactone (GBL) is a main component (at least 50 vol.%) among of EC and PC with LiBF 4] have been examined in comparison with ...
Journal of Power Sources, 2014
ABSTRACT Electrochemical behavior and flammability of tetrabromobisphenol A (TBBA)-mixed electrol... more ABSTRACT Electrochemical behavior and flammability of tetrabromobisphenol A (TBBA)-mixed electrolyte solutions are investigated using 1 mol L-1 LiPF6-EC:EMC (1:2 vol.%) with 0 wt.% (reference electrolyte) and 1-3 wt.% of TBBA. The cycling performance (at room and elevated temperature) and rate capability of the 18650 cell (LiMn2O4:Li(Ni1/3Co1/3Mn1/3)O2 (8:2)/Li4Ti5O12) cell containing TBBA-mixed electrolyte is similar to that of cell containing the reference electrolyte. A detailed analysis of the surface on both the anode and the cathode electrodes via X-ray photoelectron spectroscopy (XPS) indicated that the cathode electrode contains more Br components than the anode electrode. Within the first few cycles, on the positive electrode, we observe competing redox processes between the cathode material containing Mn and TBBA, which generate hydroxy radicals and other by-products. This process and the electrochemical reductive decomposition of TBBA to HBr, Br2 and bisphenole A are responsible for the increased flame retardant properties of the electrolyte containing TBBA. Safety tests were performed using an 18650 cell showed that even 1 wt.% of TBBA in the electrolyte significantly reduces cell flammability.
Russian Journal of Electrochemistry, 2000
The overcharge kinetics of a commercial prismatic Li-ion battery at different current rates (1 C,... more The overcharge kinetics of a commercial prismatic Li-ion battery at different current rates (1 C, 2 C, and
3 C) has been studied. Battery surface temperature, heat
output, and voltage were monitored and analyzed during
overcharge testing. It has been shown that the heat rate of
the battery surface does not increase in proportion to the
applied current rate. Separator shutdown properties may be
realized for heat rates less than 3 °C/min. Li-ion batteries
have been submitted to different stages of overcharge by a
“ soft ” overcharge technique (1 C to 4.4, 4.6, and 5.0 V).
Differential scanning calorimetry (DSC) tests of the
charged anode, cathode, and separator recovered from
overcharged cells have been performed. It was found that
the anode at different overcharged states has two main
exothermic peaks at 120 and 300 – 320 °C. At a higher state
of overcharge (SOOC), the second peak shifts to a lower
temperature. DSC for overcharged cathodes has more
complicated profiles depending on SOOC. Increasing the
cutoff voltage from 4.4 to 5.0 V shifts the maximum of the
first temperature peak from 235 to 200 °C and the second
from 345 to 320 °C. Electrical impedance spectroscopy and
scanning electron microscopy have been used to characterize electrode materials at different SOOC and overcharge
conditions. The heat rate (related to current), cell construction, and design are considered as the main factors of Li-ion
battery failure at overcharge.
Solid State Ionics, Sep 30, 2008
Commercial Li-ion batteries have been submitted to different stage of overcharge by a “soft” over... more Commercial Li-ion batteries have been submitted to different stage of overcharge by a “soft” overcharging technique. This technique gives us flexibility to investigate each step of the overcharging process. DSC and SEM tests of the anode, cathode and separator recovered from overcharged cells have been performed. It was shown that the thermal runaway will happen when the heat generation is not equal to the heat dissipation during the battery operated at an overcharge condition. The high overcharging rate shows short responding time for the cell thermal runaway and large amount of heat generation. A kinetic mechanism proposed in this study for interpreting the observation of species growth on the surface of separator in the anode side and causing soft shorting of the cell.
A series of new plasticized electrolytes based on a lithium salt, polyacrylonitrile, propylene ca... more A series of new plasticized electrolytes based on a lithium salt, polyacrylonitrile, propylene carbonate, and such crown ethers as 15-crown-5 and benzo-15-crown-5 as additives is synthesized and studied. According to impedance spectroscopy, the electrolytes’ conductivity is 6 ×10–3S cm –1 at room temperature.
The electrolytes’ compatibility with a new thin-film material (polyacetylene-covered porous polypropylene, which is used for protecting lithium anodes) is investigated
The photochemical reactions of a~'lhydrazides ArCONHN=CHR in solution were studied, The ... more The photochemical reactions of a~'lhydrazides ArCONHN=CHR in solution were studied, The main photochemical process was shown to be trans--cis isomerization with a quantum yield of 0.2--0.8 and an activation eneNy of 21--24 kcal tool -t.
Polyacetylene films irradiated by gamma-rays up to 100 MRad were studied by means of TM... more Polyacetylene films irradiated by gamma-rays up to 100 MRad were studied by means of TMA, DTG and DSC methods. It is shown that as the irradiation dose increases the concentration of topological branching knots into the polymer chains and the Tg values decrease, the total mass loss and the enthalpy of the thermal isomerization reaction also decrease.
The procedures of the preparation of laminated polyacetylene (PA)-Al-Mg and PA-microporous polypr... more The procedures of the preparation of laminated polyacetylene (PA)-Al-Mg and PA-microporous polypropylene (PORP) composites are developed. The electrochemical behaviour is studied under the conditions of Li+ intercalation. It is shown that PA application on a metal surface facilitates the formation of Li-Al-Mg alloy. The composites can be used as materials for negative electrodes in Li batteries.
ELECTRICAL AND OPTICAL POLYMER SYSTEMS FUNDAMENTALS, METHODS, AND APPLICATIONS , Mar 27, 1998
"Organic polymers have such useful properties as durability, easy processibility, low density, an... more "Organic polymers have such useful properties as durability, easy processibility, low density, and a rather low cost. One more property, namely electrical conductivity of the polymers with conjugated double bonds, was unexpected. Attempts to combine the properties of metals (conductivity) and those of polymers mentioned above were made for a long time. Mechanical mixing of powders of a metal or graphite with polymers could not give a material with high parameters without a deterioration of electrical conductivity or economic utility. Increasing the metal content results in an increase in conductivity but raises the cost of the product and lowers the mechanical parameters inherent in polymers [I]. A new class of organic polymers that conduct an electrical current, which are sometimes called "organic
metals," occupies an intermediate position between semiconductors and metals in the 10-9-l@ S/cm range"
"Production techniques, structure, and electrochemical properties of conducting thin-film ma... more "Production techniques, structure, and electrochemical properties of conducting thin-film materials
consisting of a polyethylene (PE) substrate covered with a polyacetylene (PA) layer are studied. Properties of
a free PA film are determined by the catalyst used in its synthesis. Properties of composites depend on the opti-
mum selection of the PA/PE ratio (by weight), the catalyst used for polymerizing PA, and the PE structure. The
capacity of composites is higher than that of free PA films. This points to the possible role of an increased trans-
port of lithium cations at interfaces."
Direct acetylene polymerization at ambient temperature on a Li metal surface and polyolefin separ... more Direct acetylene polymerization at ambient temperature on a Li metal surface and polyolefin separator with Ziegler–Natta catalyst was developed. Thin conducting polyacetylene films with strong adhesion to Li or polyolefin surface was formed and studied by electrochemical methods. AC impedance measurements and charge/discharge tests were applied for prepared coin cells with LiCoO2 as a cathode material in the presence of 1 M LiPF6in dimethyl carbonate, ethylene carbonate, propylene carbonate (5:3:2 vol) electrolyte. Three kinds of polyolefins were used to prepare composite separators with polyacetylene: polypropylene (PP), polyethylene (PE) and three-layer type: PP–PE–PP.
The polyacetylene film thickness on Li metal or polyolefin separator was easily controlled by catalyst concentration and polymerization time. It was shown that high ionic conductivity (7.5×10−5 Scm −1) might be achieved due to higher porosity of a polyethylene separator. Li–polyacetylene electrodes showed highest ionic conductivity and stability in charge/discharge tests.
Conference Presentations by Dmitry Belov
The thin film composite was obtained with polymerization of acetyl-ene into r o w olymer matrix. ... more The thin film composite was obtained with polymerization of acetyl-ene into r o w olymer matrix. The film was combined with A1 foil this electrode were invest1 ted in 3M LiBF4/ propylenecarbonate + dimethoxyethane (1 : l + V N) e P ectrolyte. It wa8 shown that Li penetrated through the composite film and formed Li 1 alloy. Such an electrode wa8 under ne to a great member tion. covering K B th si es of the latter. Electrochemical properties of of ch $r ge /discharge cycles without destruct Y on and dendrite forma
A series of well-known overcharge protecting electrolyte additives for Li-ion batteries (diphenyl... more A series of well-known overcharge protecting electrolyte additives for Li-ion batteries (diphenyl ether (PE), biphenyl (BP), cyclohexyl benzene (CHB) and N, N-dimethylacetamide (DMAC) were tested at equal conditions. A high energy density prismatic cell with LiCoO2 as a cathode ...
Journal of Solid State Electrochemistry, 2012
Abstract Thermal stability, flammability, and electrochemical performances of the cyclic carbonat... more Abstract Thermal stability, flammability, and electrochemical performances of the cyclic carbonate-based electrolytes [where γ-butyrolactone (GBL) is a main component (at least 50 vol.%) among of EC and PC with LiBF 4] have been examined in comparison with ...
Journal of Power Sources, 2014
ABSTRACT Electrochemical behavior and flammability of tetrabromobisphenol A (TBBA)-mixed electrol... more ABSTRACT Electrochemical behavior and flammability of tetrabromobisphenol A (TBBA)-mixed electrolyte solutions are investigated using 1 mol L-1 LiPF6-EC:EMC (1:2 vol.%) with 0 wt.% (reference electrolyte) and 1-3 wt.% of TBBA. The cycling performance (at room and elevated temperature) and rate capability of the 18650 cell (LiMn2O4:Li(Ni1/3Co1/3Mn1/3)O2 (8:2)/Li4Ti5O12) cell containing TBBA-mixed electrolyte is similar to that of cell containing the reference electrolyte. A detailed analysis of the surface on both the anode and the cathode electrodes via X-ray photoelectron spectroscopy (XPS) indicated that the cathode electrode contains more Br components than the anode electrode. Within the first few cycles, on the positive electrode, we observe competing redox processes between the cathode material containing Mn and TBBA, which generate hydroxy radicals and other by-products. This process and the electrochemical reductive decomposition of TBBA to HBr, Br2 and bisphenole A are responsible for the increased flame retardant properties of the electrolyte containing TBBA. Safety tests were performed using an 18650 cell showed that even 1 wt.% of TBBA in the electrolyte significantly reduces cell flammability.
Russian Journal of Electrochemistry, 2000
The overcharge kinetics of a commercial prismatic Li-ion battery at different current rates (1 C,... more The overcharge kinetics of a commercial prismatic Li-ion battery at different current rates (1 C, 2 C, and
3 C) has been studied. Battery surface temperature, heat
output, and voltage were monitored and analyzed during
overcharge testing. It has been shown that the heat rate of
the battery surface does not increase in proportion to the
applied current rate. Separator shutdown properties may be
realized for heat rates less than 3 °C/min. Li-ion batteries
have been submitted to different stages of overcharge by a
“ soft ” overcharge technique (1 C to 4.4, 4.6, and 5.0 V).
Differential scanning calorimetry (DSC) tests of the
charged anode, cathode, and separator recovered from
overcharged cells have been performed. It was found that
the anode at different overcharged states has two main
exothermic peaks at 120 and 300 – 320 °C. At a higher state
of overcharge (SOOC), the second peak shifts to a lower
temperature. DSC for overcharged cathodes has more
complicated profiles depending on SOOC. Increasing the
cutoff voltage from 4.4 to 5.0 V shifts the maximum of the
first temperature peak from 235 to 200 °C and the second
from 345 to 320 °C. Electrical impedance spectroscopy and
scanning electron microscopy have been used to characterize electrode materials at different SOOC and overcharge
conditions. The heat rate (related to current), cell construction, and design are considered as the main factors of Li-ion
battery failure at overcharge.
Solid State Ionics, Sep 30, 2008
Commercial Li-ion batteries have been submitted to different stage of overcharge by a “soft” over... more Commercial Li-ion batteries have been submitted to different stage of overcharge by a “soft” overcharging technique. This technique gives us flexibility to investigate each step of the overcharging process. DSC and SEM tests of the anode, cathode and separator recovered from overcharged cells have been performed. It was shown that the thermal runaway will happen when the heat generation is not equal to the heat dissipation during the battery operated at an overcharge condition. The high overcharging rate shows short responding time for the cell thermal runaway and large amount of heat generation. A kinetic mechanism proposed in this study for interpreting the observation of species growth on the surface of separator in the anode side and causing soft shorting of the cell.
A series of new plasticized electrolytes based on a lithium salt, polyacrylonitrile, propylene ca... more A series of new plasticized electrolytes based on a lithium salt, polyacrylonitrile, propylene carbonate, and such crown ethers as 15-crown-5 and benzo-15-crown-5 as additives is synthesized and studied. According to impedance spectroscopy, the electrolytes’ conductivity is 6 ×10–3S cm –1 at room temperature.
The electrolytes’ compatibility with a new thin-film material (polyacetylene-covered porous polypropylene, which is used for protecting lithium anodes) is investigated
The photochemical reactions of a~'lhydrazides ArCONHN=CHR in solution were studied, The ... more The photochemical reactions of a~'lhydrazides ArCONHN=CHR in solution were studied, The main photochemical process was shown to be trans--cis isomerization with a quantum yield of 0.2--0.8 and an activation eneNy of 21--24 kcal tool -t.
Polyacetylene films irradiated by gamma-rays up to 100 MRad were studied by means of TM... more Polyacetylene films irradiated by gamma-rays up to 100 MRad were studied by means of TMA, DTG and DSC methods. It is shown that as the irradiation dose increases the concentration of topological branching knots into the polymer chains and the Tg values decrease, the total mass loss and the enthalpy of the thermal isomerization reaction also decrease.
The procedures of the preparation of laminated polyacetylene (PA)-Al-Mg and PA-microporous polypr... more The procedures of the preparation of laminated polyacetylene (PA)-Al-Mg and PA-microporous polypropylene (PORP) composites are developed. The electrochemical behaviour is studied under the conditions of Li+ intercalation. It is shown that PA application on a metal surface facilitates the formation of Li-Al-Mg alloy. The composites can be used as materials for negative electrodes in Li batteries.
ELECTRICAL AND OPTICAL POLYMER SYSTEMS FUNDAMENTALS, METHODS, AND APPLICATIONS , Mar 27, 1998
"Organic polymers have such useful properties as durability, easy processibility, low density, an... more "Organic polymers have such useful properties as durability, easy processibility, low density, and a rather low cost. One more property, namely electrical conductivity of the polymers with conjugated double bonds, was unexpected. Attempts to combine the properties of metals (conductivity) and those of polymers mentioned above were made for a long time. Mechanical mixing of powders of a metal or graphite with polymers could not give a material with high parameters without a deterioration of electrical conductivity or economic utility. Increasing the metal content results in an increase in conductivity but raises the cost of the product and lowers the mechanical parameters inherent in polymers [I]. A new class of organic polymers that conduct an electrical current, which are sometimes called "organic
metals," occupies an intermediate position between semiconductors and metals in the 10-9-l@ S/cm range"
"Production techniques, structure, and electrochemical properties of conducting thin-film ma... more "Production techniques, structure, and electrochemical properties of conducting thin-film materials
consisting of a polyethylene (PE) substrate covered with a polyacetylene (PA) layer are studied. Properties of
a free PA film are determined by the catalyst used in its synthesis. Properties of composites depend on the opti-
mum selection of the PA/PE ratio (by weight), the catalyst used for polymerizing PA, and the PE structure. The
capacity of composites is higher than that of free PA films. This points to the possible role of an increased trans-
port of lithium cations at interfaces."
Direct acetylene polymerization at ambient temperature on a Li metal surface and polyolefin separ... more Direct acetylene polymerization at ambient temperature on a Li metal surface and polyolefin separator with Ziegler–Natta catalyst was developed. Thin conducting polyacetylene films with strong adhesion to Li or polyolefin surface was formed and studied by electrochemical methods. AC impedance measurements and charge/discharge tests were applied for prepared coin cells with LiCoO2 as a cathode material in the presence of 1 M LiPF6in dimethyl carbonate, ethylene carbonate, propylene carbonate (5:3:2 vol) electrolyte. Three kinds of polyolefins were used to prepare composite separators with polyacetylene: polypropylene (PP), polyethylene (PE) and three-layer type: PP–PE–PP.
The polyacetylene film thickness on Li metal or polyolefin separator was easily controlled by catalyst concentration and polymerization time. It was shown that high ionic conductivity (7.5×10−5 Scm −1) might be achieved due to higher porosity of a polyethylene separator. Li–polyacetylene electrodes showed highest ionic conductivity and stability in charge/discharge tests.