Electrochemical Characteristics of Capacitor Systems Formed on Chemical Modified Carbon Basis
Influence of chemical modification of an activated carbon (AC) material on its
 specific capacity is studied using methods of impedance spectroscopy, cyclic
 voltammetry and chronopotentiometry. As shown, the total capacity is the sum
 of two components–double electric layer...
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Інститут металофізики ім. Г.В. Курдюмова НАН України
2009
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| Zitieren: | Electrochemical Characteristics of Capacitor Systems
 Formed on Chemical Modified Carbon Basis / B.K. Ostafiychuk, I.M. Budzulyak, V.I. Mandzyuk, R.P.Lisovskyy // Наносистеми, наноматеріали, нанотехнології: Зб. наук. пр. — К.: РВВ ІМФ, 2009. — Т. 7, № 2. — С. 371-381. — Бібліогр.: 7 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860077100739854336 |
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| author | Ostafiychuk, B.K. Budzulyak, I.M. Mandzyuk, V.I. Lisovskyy, R.P. |
| author_facet | Ostafiychuk, B.K. Budzulyak, I.M. Mandzyuk, V.I. Lisovskyy, R.P. |
| citation_txt | Electrochemical Characteristics of Capacitor Systems
 Formed on Chemical Modified Carbon Basis / B.K. Ostafiychuk, I.M. Budzulyak, V.I. Mandzyuk, R.P.Lisovskyy // Наносистеми, наноматеріали, нанотехнології: Зб. наук. пр. — К.: РВВ ІМФ, 2009. — Т. 7, № 2. — С. 371-381. — Бібліогр.: 7 назв. — англ. |
| collection | DSpace DC |
| container_title | Наносистеми, наноматеріали, нанотехнології |
| description | Influence of chemical modification of an activated carbon (AC) material on its
specific capacity is studied using methods of impedance spectroscopy, cyclic
voltammetry and chronopotentiometry. As shown, the total capacity is the sum
of two components–double electric layer (DEL) capacity and pseudocapacity;
the contribution of the latter is insignificant (8—14%). The alloying with rareearth
metals and their compounds results in the rise of specific capacity of AC.
Probably, the principal cause of such a growth is transformation of valence
band of carbon material caused by introduction of additional electron states
from the introduced metals. As a result, considerably greater number of ions
(especially, positive ones) will take part in DEL forming and, consequently,
predetermine growth of specific capacity.
З’ясовано вплив хемічної модифікації активованого вуглецевого (АВ) матеріялу на його питому місткість з використанням метод імпедансної спектроскопії, циклічної вольтамперометрії та хроноамперометрії. Показано, що загальна місткість є сумою двох складових – місткости подвійного
електричного шару (ПЕШ) та псевдомісткости, причому, внесок останньої
є незначним (8—14%). Леґування рідкісноземельними металами та їх
сполуками призводить до підвищення питомої місткости АВ. Ймовірно,
основною причиною такого зростання є трансформація валентної зони
вуглецевого матеріялу за рахунок привнесення додаткових електронних
станів від втілених матеріялів, в результаті чого значно більша кількість
йонів (насамперед, позитивних) буде приймати участь у формуванні
ПЕШ, а отже, й зумовлювати ріст питомої місткости.
Изучено влияние химической модификации активированного углеродного материала на его удельную ёмкость с использованием методов импедансной спектроскопии, циклической вольтамперометрии и хроноамперометрии. Показано, что общая ёмкость является суммой двух составляющих – ёмкости двойного электрического слоя (ДЭС) и псевдоёмкости, причем, вклад последней незначителен (8—14%). Легирование редко-земельными металлами и их соединениями улучшает удельную ёмкость
активированного углерода. Вероятно, основной причиной такого роста
является трансформация валентной зоны углеродного материала за счет
добавления дополнительных электронных состояний от внедренных материалов, вследствие чего значительно большее количество ионов (в первую очередь, положительных) будет принимать участие в формировании
ДЭС, а, следовательно, и обуславливать рост удельной ёмкости.
|
| first_indexed | 2025-12-07T17:14:24Z |
| format | Article |
| fulltext |
371
PACS numbers: 81.16.Be, 82.45.Aa,82.45.Yz,82.47.Uv,82.80.Fk,84.32.Tt, 84.60.Ve
Electrochemical Characteristics of Capacitor Systems
Formed on Chemical Modified Carbon Basis
B. K. Ostafiychuk, I. M. Budzulyak, V. I. Mandzyuk, and R. P. Lisovskyy
Vasyl Stefanyk Precarpathian National University,
Shevchenko Str., 57,
76025 Ivano-Frankivs'k, Ukraine
Influence of chemical modification of an activated carbon (AC) material on its
specific capacity is studied using methods of impedance spectroscopy, cyclic
voltammetry and chronopotentiometry. As shown, the total capacity is the sum
of two components–double electric layer (DEL) capacity and pseudocapacity;
the contribution of the latter is insignificant (8—14%). The alloying with rare-
earth metals and their compounds results in the rise of specific capacity of AC.
Probably, the principal cause of such a growth is transformation of valence
band of carbon material caused by introduction of additional electron states
from the introduced metals. As a result, considerably greater number of ions
(especially, positive ones) will take part in DEL forming and, consequently,
predetermine growth of specific capacity.
З’ясовано вплив хемічної модифікації активованого вуглецевого (АВ) ма-
теріялу на його питому місткість з використанням метод імпедансної спе-
ктроскопії, циклічної вольтамперометрії та хроноамперометрії. Показа-
но, що загальна місткість є сумою двох складових – місткости подвійного
електричного шару (ПЕШ) та псевдомісткости, причому, внесок останньої
є незначним (8—14%). Леґування рідкісноземельними металами та їх
сполуками призводить до підвищення питомої місткости АВ. Ймовірно,
основною причиною такого зростання є трансформація валентної зони
вуглецевого матеріялу за рахунок привнесення додаткових електронних
станів від втілених матеріялів, в результаті чого значно більша кількість
йонів (насамперед, позитивних) буде приймати участь у формуванні
ПЕШ, а отже, й зумовлювати ріст питомої місткости.
Изучено влияние химической модификации активированного углеродно-
го материала на его удельную ёмкость с использованием методов импе-
дансной спектроскопии, циклической вольтамперометрии и хроноампе-
рометрии. Показано, что общая ёмкость является суммой двух состав-
ляющих – ёмкости двойного электрического слоя (ДЭС) и псевдоёмко-
сти, причем, вклад последней незначителен (8—14%). Легирование редко-
Наносистеми, наноматеріали, нанотехнології
Nanosystems, Nanomaterials, Nanotechnologies
2009, т. 7, № 2, сс. 371—381
© 2009 ІМФ (Інститут металофізики
ім. Г. В. Курдюмова НАН України)
Надруковано в Україні.
Фотокопіювання дозволено
тільки відповідно до ліцензії
372 B. K. OSTAFIYCHUK, I. M. BUDZULYAK, V. I. MANDZYUK et al.
земельными металлами и их соединениями улучшает удельную ёмкость
активированного углерода. Вероятно, основной причиной такого роста
является трансформация валентной зоны углеродного материала за счет
добавления дополнительных электронных состояний от внедренных ма-
териалов, вследствие чего значительно большее количество ионов (в пер-
вую очередь, положительных) будет принимать участие в формировании
ДЭС, а, следовательно, и обуславливать рост удельной ёмкости.
Key words: activated carbon material, double electric layer, specific capac-
ity, Nyquist diagram, cyclic voltammogram.
(Received November 12, 2008)
1. INTRODUCTION
The use of various methods of after-activation modification of an acti-
vated carbon (AC) is related to the necessity to improve its parameters
as electrode material of electrochemical capacitors (EC) as it is not pos-
sible to attain necessary values of these parameters, in particular, spe-
cific resistance and specific capacity of a double electric layer (DEL)
formed by the given material and electrolyte, during activation [1].
Coming from general principles of physics and topology of the de-
veloped surface, the principle decision of the indicated problem is pos-
sible by mean of the increase of electronic states density in AC matrix
[2] and also participation of the most possible part of the developed
surface in DEL forming, because, as known [3], as much as 50% of
working pores do not wet by an electrolyte due to their chemical-
structural features. One of possibilities of the indicated ideas realiza-
tion is modification of AC by its alloying with rare-earth metals and
their compounds, that would give possibility to multiply substantially
the DEL capacity, and, consequently, capacity of capacitors formed on
the basis of AC modified in such a manner. Erbium is used as rare-
earth metal (its percentage in AC makes 0.1, 0.2, and 0.4 wt.%),
Tm2O3, Eu2O3, Dy2O3, Ho2O3, Pr2O3, content of which in AC made 0.1
wt.% are used as rare-earth compounds. Copper additive in an amount
of 0.1 wt.% was introduced into obtained alloyed materials to increase
their electronic conductivity. The aim of this work was to study influ-
ence of introduction of the specified metals into AC on its physical and
chemical properties and operating characteristics of capacitors with
the DEL, formed on its basis [4].
2. EXPERIMENTAL
AC made of fruit stones by their carbonization with subsequent activa-
tion in a closed reactor at high pressure was used as research object [5].
ELECTROCHEMICAL CHARACTERISTICS OF CAPACITOR SYSTEMS 373
The alloying of AC with erbium was carried out using erbium ni-
trate. Research of alloying admixtures distribution in AC was con-
ducted by the method of second ion mass spectrometry on MS-7201
mass-spectrometer.
A three-electrode electrochemical cell (Fig. 1) was used to obtain Ny-
quist diagrams. AC with a proper percentage of the alloyed material was
used as working electrode; a comparative electrode was similar to the
working one, a silver chloride electrode Ag/AgCl was used as a reference
electrode. Potential of carbon material in relation to the reference elec-
trode was −0.33—−0.28 V. 30% KOH—water solution + 0.3% LiOH water
solution was used as electrolyte. The impedance measuring was per-
formed using Autolab PGSTAT/FRA-2 spectrometer (Holland) within
the frequency range from 10−2
to 105
Hz.
Registration of cyclic voltamperograms of carbon electrodes was
performed within the potential range of −1—+0,2 V using the three-
electrode cell described above with silver chloride reference electrode;
scan rates were 5, 8, 10, 20, 30, 40, and 50 mV/s.
3. RESULTS AND DISCUSSION
Properties of rather wide rows of the systems, especially electrochemi-
cal ones, can be conveniently studied by the response of these systems
to an external sinusoidal signal. The use of impedance spectroscopy
method for solving of the problems indicated above is the most expedi-
ent for that, as it enables us to conduct research within the frequency
range wide enough (f = 106—10−3
Hz) [6].
Nyquist diagram for Er-modified carbon materials (Fig. 2) consists
6
1
5
3
4
2 Potentiostate–galvanostate
Fig. 1. Electrochemical cell: 1–glass cell; 2–pressurizing cover; 3–
electrolyte; 4–working electrode; 5–reference electrode; 6–comparative
electrode.
374 B. K. OSTAFIYCHUK, I. M. BUDZULYAK, V. I. MANDZYUK et al.
in two asymmetric semicircles in the frequencies region of 1—105
Hz.
Low-frequency branch tends to infinity at ω → 0 for AC with Er con-
tent 0.1 and 0.2 wt.% that testifies to the typical behaviour of capaci-
tor systems. It is inclined to the actual resistance axis for material
with Er content of 0.4 wt.% by ∼ 45° that can testify the presence of
diffusive processes in the material under investigation, which are de-
scribed by Warburg impedance.
Equivalent schemes, which simulate electrochemical processes, which
take place on the electrode—electrolyte interface and in the material, fa-
vour the assumption described above (Fig. 3). Relative error for each pa-
rameter of the equivalent scheme does not exceed 5%; parameter
χ2 = 10−4—10−5
that testifies to legitimacy of the offered choice.
Resistance Rct corresponds to series equivalent resistance, which
consists of the electrolyte resistance, resistance of lead and con-
tacts. Two R || CPE-links can be linked to heterogeneity of DEL and
fractal structure of electrode, resistance R4 is polarization or elec-
tronic resistance of the material, Cdl is DEL capacity, constant
phase element CPE3 of capacity type corresponds to Faraday capac-
Fig. 2. Nyquist diagram of Er-modified АC.
à
á
Fig. 3. Equivalent schemes for Nyquist diagrams for Er-modified АC: a–
Er content is 0.1 and 0.2 wt.%; б–Er content is 0.4 wt.%.
ELECTROCHEMICAL CHARACTERISTICS OF CAPACITOR SYSTEMS 375
ity, Wo is diffusive Warburg impedance.
The increase of Er percentage results in the insignificant increase of
total resistance R2 + R3 (from 16 to 25 Ohm). It testifies that Er intro-
duction blocks C+
ions transport through the electrode-electrolyte
boundary and inhibits formation of DEL by them. Except for it,
growth of Er content predetermines formation of heterogeneous DEL
TABLE 1. Specific capacity of AC [F/g].
Material
Method
Impedance
spectrometry
Voltampero-
metry
Chrono-
potentiometry
АC 56 64 69
АC + 0.1% Er 71 77 73
АC + 0.2% Er 75 83 72
АC + 0.4% Er 59 66 65
АC + 0.2% Er + 0.1% Cu 61 69 68
АC + 0.2% Er + 0.4% Cu 72 81 77
АC + 0.1% Tm2O3 – 68 63
АC + 0.1% Tm2O3
+ 0.1% Cu 89 101 81
АC + 0.1% Eu2O3 80 86 67
АC + 0.1% Eu2O3 + 0.1% Cu 82 84 68
АC + 0.1% Dy2O3 78 83 65
АC + 0.1% Ho2O3 80 83 70
АC + 0.1% Pr2O3 54 59 58
Fig. 4. Cyclic voltamperograms of Er-modified АC.
376 B. K. OSTAFIYCHUK, I. M. BUDZULYAK, V. I. MANDZYUK et al.
and intensification of diffusive processes in it (growth of CPE1 and
CPE2 parameters confirms it). The first parameter is the constant
phase element of capacity type (n ∼ 0.83), the second one is of diffusive
type (n ∼ 0.55).
The n-parameter is present in a formula for determination of CPE
element impedance ZCPE = A−1(jω)−n
and characterizes a phase deviation.
Growth of erbium concentration in AC results in the increase of CPE3
parameter, which represents the constant phase element with the het-
erogeneously distributed capacity (n = 0.82—0.91). Owing to this fact,
the total capacity of material is multiplied not only because of DEL ca-
Fig. 5. Nyquist diagrams for Er- and Er + Cu-modified АC.
Fig. 6. Cyclic voltamperograms of Er + Сu-modified АC.
ELECTROCHEMICAL CHARACTERISTICS OF CAPACITOR SYSTEMS 377
pacity, but also due to Faraday processes. Electronic resistance of ma-
terial according to impedance spectroscopy data is 22.6, 22.7, and 24.3
Ohm, respectively. There is a maximum for DEL capacity at 0.2% Er
content (Table 1). It is believed that the electronic state density is mul-
tiplied at Fermi level of carbon material owing to erbium presence and,
as a result, higher number of C
+
ions takes part in DEL formation. Sub-
sequent erbium introduction results in blocking of working pores of
AC, as a result, reduction of DEL capacity takes place [7].
This assumption is confirmed by the results of potentiodynamic re-
searches (Fig. 4). There is the difference in I—E curves, especially in
the region of negative potentials, at which DEL capacity is provided by
C+
ions from the electrolyte side. Dissymmetry of these curves in rela-
tion to zero current line (I = 0) is the characteristic feature, which is
evidence for the passing of processes unconnected with DEL forming
(above all Faraday processes).
Introduction of copper in amounts of 0.1 and 0.4 wt.% into Er-
modified material, which possesses maximal specific capacity, does
not noticeably change the type of Nyquist diagram, predetermining
the change of general impedance of the electrochemical system only
(Fig. 5). Consequently, the equivalent scheme, which simulates mo-
tion of electrochemical processes in the system under investigation, is
Fig. 7. Nyquist diagrams of AC doped by oxides of rare-earth metals.
R
s
CPE
f CPE
R
f Cdl R W
Fig. 8. Equivalent scheme for Nyquist diagram of chemically modified AC.
378 B. K. OSTAFIYCHUK, I. M. BUDZULYAK, V. I. MANDZYUK et al.
of a similar form (see Fig. 3, a).
Electrochemical system based on the Er-modified material with 0.1
wt.% Cu content is characterized by slightly higher values of R2 and R3
parameters (2.8 and 3.7 Ohm, and 19.1 and 24.9 Ohm, respectively) and
by practically unchanging electronic resistance R4 (22.8 and 23.2 Ohm,
respectively) in comparison with the material without copper. However,
there is a reduction of all three resistances at 0.4 wt.% Cu concentra-
tions in carbon material, especially electronic one (R4, 14.2 Ohm). It is
readily apparent on —ImZ = f(ReZ) dependence. According to Table 1,
such modification by copper does not lead to the increase of specific ca-
pacity of carbon material, and can be used to increase its electronic con-
ductivity. Except for it, almost identical capacities of unalloyed and al-
loyed (0.4 wt.%) materials were achieved due to Faraday processes,
which were caused by the run of mass-transfer processes (probably, re-
dox reactions), rather than to DEL capacity. It was confirmed by the re-
sults of voltamperometric researches, according to which there is an ‘in-
flux’ in the negative potential region for the material with 0.4 wt.% Cu
content, which is attributed to Faraday processes (Fig. 6). A horizontal
plateau on the anode branch of І—Е-curve of other material points to the
fact that the specific capacity of material is provided mainly by DEL ca-
pacity.
The use of rare-earth metals oxides as alloying material (Tm2O3,
Dy2O3, Pr2O3, Eu2O3, Ho2O3) does not change cardinally the general type
of impedance curve (Fig. 7) (except for AV alloyed with Tm2O3). How-
ever, equivalent schemes, which simulate electrochemical processes,
slightly differ. In particular, for AC doped with Dy2O3 and Pr2O3 the
TABLE 2. Internal resistance [Ohm].
Material
Method
Impedance
spectroscopy
Chronopotentiometry
АC + 0.1% Er 22.6 24.3
АC + 0.2% Er 22.7 23.2
АC + 0.4% Er 24.3 29.4
АC + 0.2% Er + 0.1% Cu 23.2 25.2
АC + 0.2% Er + 0.4% Cu 14.2 17.8
АC + 0.1% Tm2O3 39.5 47.3
АC + 0.1% Tm2O3
+ 0.1% Cu 14.9 18.2
АC + 0.1% Eu2O3 9.2 11.3
АC + 0.1% Eu2O3 + 0.1% Cu 7.4 8.4
АC + 0.1% Dy2O3 11.9 13.3
АC + 0.1% Ho2O3 11.7 13.4
АC + 0.1% Pr2O3 30.9 32.8
ELECTROCHEMICAL CHARACTERISTICS OF CAPACITOR SYSTEMS 379
schemes are similar to that in Fig. 3. There is also a difference: the con-
stant phase element CPE3 is the element of capacity type for the first
material, while for the second material it is diffusive one. For Eu2O3-
and Ho2O3-doped materials, a scheme is the same as well as for Cr- and
Mn-doped AC (Fig. 8) [2]. For AC doped with Tm2O3, we could not find
an equivalent scheme, which would describe satisfactory the behaviour
of the electrochemical system.
As follows from Table 1, specific capacities for Eu2O3-, Ho2O3-, and
Dy2O3-doped materials are practically identical. Taking into account
the results of impedance spectroscopy and voltamperometry (Fig. 9), it
is believed that the total specific capacities of the materials under in-
vestigation are provided by DEL capacity and pseudocapacity. For two
other materials, in which Pr2O3 and Tm2O3 are used as alloying addi-
tions, the contribution of pseudocapacity is insignificant.
Additional alloying of these materials with copper in an amount of
0.1 wt.% results not only in growth of specific capacity, but also in re-
duction of total impedance of the system (Fig. 10).
Internal resistance, which characterizes electrophysical properties
of electrode carbon material, is also parameter of significance. Its
measurement was carried out by the methods of impedance spectros-
copy and chronopotentiometry. In the first case, the value of internal
resistance was obtained from the results of simulation, and in the sec-
ond one, using formula
2
U
R
I
Δ= , where ΔU is voltage drop on a dis-
charge curve (Fig. 11), I–discharge current.
The values of internal resistance of the materials under study ob-
tained by both methods are presented in Table 2.
а b
Fig. 10. Nyquist diagrams of AC doped by oxides of rare-earth metals and
copper.
380 B. K. OSTAFIYCHUK, I. M. BUDZULYAK, V. I. MANDZYUK et al.
It should be noted that a difference between these values is not very
substantial (it does not exceed 7%). However, the chronopotentiome-
try method is more precise due to its simplicity.
Thus, chemical modification of AC by rare-earth metals and their
compounds results in the increase of specific capacity of AC. The prin-
cipal reason for such growth, according to previous researches, is
transformation of valence area of carbon material caused by additional
electronic states from the introduced metals, as a result considerably
higher number of ions (first of all, positive ones) participates in DEL
formation, and, consequently, predetermines the growth of specific
capacity.
CONCLUSIONS
The equivalent schemes of capacitor system based on modified AC are
proposed, which satisfactory describe electrochemical processes on
electrode—electrolyte interface and in AC-matrix.
The total capacity of the system under investigation is the sum of
two components–DEL capacity and pseudocapacity, and contribution
of the latter is insignificant (8—14%).
The alloying with rare-earth metals and their compounds can result
in the increase of specific capacity of AC up to 17%.
REFERENCES
1. V. V. Nemoshkalenko, X-Ray Emission Spectroscopy of Metals and Alloys
Fig. 11. A typical shape of charge—discharge curve.
ELECTROCHEMICAL CHARACTERISTICS OF CAPACITOR SYSTEMS 381
(Kiev: Naukova Dumka: 1972).
2. I. M. Budzulyak, V. I. Mandzyuk, R. P. Lisovskyy, R. I. Merena, and M. V.
Berkeshchuk, Nanosistemi, Nanomateriali, Nanotehnologii, 4, No. 3: 569 (2006).
3. А. Yu. Rychagov, N. А. Urinson, and Yu. М. Vol’fkovych, Electrochemistry,
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H01G2/00, H01G4/00,
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|
| id | nasplib_isofts_kiev_ua-123456789-76422 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1816-5230 |
| language | English |
| last_indexed | 2025-12-07T17:14:24Z |
| publishDate | 2009 |
| publisher | Інститут металофізики ім. Г.В. Курдюмова НАН України |
| record_format | dspace |
| spelling | Ostafiychuk, B.K. Budzulyak, I.M. Mandzyuk, V.I. Lisovskyy, R.P. 2015-02-10T12:38:59Z 2015-02-10T12:38:59Z 2009 Electrochemical Characteristics of Capacitor Systems
 Formed on Chemical Modified Carbon Basis / B.K. Ostafiychuk, I.M. Budzulyak, V.I. Mandzyuk, R.P.Lisovskyy // Наносистеми, наноматеріали, нанотехнології: Зб. наук. пр. — К.: РВВ ІМФ, 2009. — Т. 7, № 2. — С. 371-381. — Бібліогр.: 7 назв. — англ. 1816-5230 PACS numbers: 81.16.Be,82.45.Aa,82.45.Yz,82.47.Uv,82.80.Fk,84.32.Tt,84.60.Ve https://nasplib.isofts.kiev.ua/handle/123456789/76422 Influence of chemical modification of an activated carbon (AC) material on its
 specific capacity is studied using methods of impedance spectroscopy, cyclic
 voltammetry and chronopotentiometry. As shown, the total capacity is the sum
 of two components–double electric layer (DEL) capacity and pseudocapacity;
 the contribution of the latter is insignificant (8—14%). The alloying with rareearth
 metals and their compounds results in the rise of specific capacity of AC.
 Probably, the principal cause of such a growth is transformation of valence
 band of carbon material caused by introduction of additional electron states
 from the introduced metals. As a result, considerably greater number of ions
 (especially, positive ones) will take part in DEL forming and, consequently,
 predetermine growth of specific capacity. З’ясовано вплив хемічної модифікації активованого вуглецевого (АВ) матеріялу на його питому місткість з використанням метод імпедансної спектроскопії, циклічної вольтамперометрії та хроноамперометрії. Показано, що загальна місткість є сумою двох складових – місткости подвійного
 електричного шару (ПЕШ) та псевдомісткости, причому, внесок останньої
 є незначним (8—14%). Леґування рідкісноземельними металами та їх
 сполуками призводить до підвищення питомої місткости АВ. Ймовірно,
 основною причиною такого зростання є трансформація валентної зони
 вуглецевого матеріялу за рахунок привнесення додаткових електронних
 станів від втілених матеріялів, в результаті чого значно більша кількість
 йонів (насамперед, позитивних) буде приймати участь у формуванні
 ПЕШ, а отже, й зумовлювати ріст питомої місткости. Изучено влияние химической модификации активированного углеродного материала на его удельную ёмкость с использованием методов импедансной спектроскопии, циклической вольтамперометрии и хроноамперометрии. Показано, что общая ёмкость является суммой двух составляющих – ёмкости двойного электрического слоя (ДЭС) и псевдоёмкости, причем, вклад последней незначителен (8—14%). Легирование редко-земельными металлами и их соединениями улучшает удельную ёмкость
 активированного углерода. Вероятно, основной причиной такого роста
 является трансформация валентной зоны углеродного материала за счет
 добавления дополнительных электронных состояний от внедренных материалов, вследствие чего значительно большее количество ионов (в первую очередь, положительных) будет принимать участие в формировании
 ДЭС, а, следовательно, и обуславливать рост удельной ёмкости. en Інститут металофізики ім. Г.В. Курдюмова НАН України Наносистеми, наноматеріали, нанотехнології Electrochemical Characteristics of Capacitor Systems Formed on Chemical Modified Carbon Basis Article published earlier |
| spellingShingle | Electrochemical Characteristics of Capacitor Systems Formed on Chemical Modified Carbon Basis Ostafiychuk, B.K. Budzulyak, I.M. Mandzyuk, V.I. Lisovskyy, R.P. |
| title | Electrochemical Characteristics of Capacitor Systems Formed on Chemical Modified Carbon Basis |
| title_full | Electrochemical Characteristics of Capacitor Systems Formed on Chemical Modified Carbon Basis |
| title_fullStr | Electrochemical Characteristics of Capacitor Systems Formed on Chemical Modified Carbon Basis |
| title_full_unstemmed | Electrochemical Characteristics of Capacitor Systems Formed on Chemical Modified Carbon Basis |
| title_short | Electrochemical Characteristics of Capacitor Systems Formed on Chemical Modified Carbon Basis |
| title_sort | electrochemical characteristics of capacitor systems formed on chemical modified carbon basis |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/76422 |
| work_keys_str_mv | AT ostafiychukbk electrochemicalcharacteristicsofcapacitorsystemsformedonchemicalmodifiedcarbonbasis AT budzulyakim electrochemicalcharacteristicsofcapacitorsystemsformedonchemicalmodifiedcarbonbasis AT mandzyukvi electrochemicalcharacteristicsofcapacitorsystemsformedonchemicalmodifiedcarbonbasis AT lisovskyyrp electrochemicalcharacteristicsofcapacitorsystemsformedonchemicalmodifiedcarbonbasis |