• Title, Summary, Keyword: electrical double layer capacitors

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Studies of Electric Double Layer Capacitors Used For a Storage Battery of Dye Sensitized Solar Cell Energy

  • Kim Hee-Je;Jeon Jin-An;Sung Youl-Moon;Yun Mun-Soo;Choi Jin-Young
    • Journal of Electrical Engineering and Technology
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    • v.1 no.2
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    • pp.251-256
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    • 2006
  • To design the effective usage of electric double layer capacitors (EDLCs) used for a storage device of dye sensitized solar cell (DSC) energy, we first investigated the accumulation state of electrical charges and the charge behavior in the EDLCs. Based on the results, the voltage characteristics of EDLCs connected to DSC energy were evaluated. The results showed that the charge accumulation region concentrated on the central part of the carbonaceous electrode in EDLCs and the required times for charging and discharging were almost the same.

Spatio-temporal Charge Distribution in Electric Double Layer Capacitors observed by pulsed Electro Acoustic Method

  • Sung, Youl-Moon
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.4
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    • pp.182-187
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    • 2007
  • The use of the pulsed electro acoustic (PEA) method allowed us to perform the direct observations of spatio-temporal charge distributions in Electric double layer capacitors (EDLCs) based on polarizable nanoporous carbonaceous electrode. The negative charge density became the maximum, about $205C/m^3$ at the region where was near to collector layer in EDLCs for case $V_{DC}=2.5V$, while the positively charged density became the maximum, about $61.1C/m^3$ at the region where it was located around the cathode layer. The performance of the best sample was found to be better in terms of the charge density (Cs) and specific energy ($E_s$) with a maximum value of ${\sim}8.4F/g$ and 26 Wh/kg. The $C_s$ obtained from the PEA method agreed well with that from the energy conversion method. The PEA measurement used here is a very useful method to quantitively investigates the spatio-temporal charge distribution in EDLCs.

Charging and Discharging Characteristics of Electric Double Layer Capacitors used for a Storage Battery of Solar Energy

  • Sung, Youl-Moon
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.2
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    • pp.97-102
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    • 2007
  • The charging/discharging characteristics of electric double layer capacitors (EDLCs) for an electric power storage device application were investigated. The specific area of the carbonaceous electrode surface by the BET method was in the range of $1800{\sim}2000\;m^2/g$. The charge distributions during charging and discharging were measured by means of a pulsed-electro-acoustic (PEA) method, and the voltage characteristics of EDLCs connected to solar cells were evaluated. The results showed that the distributions of positive and negative charges were spatially uneven, which was due to the mobility of the positive and negative charges in the carbonaceous electrode surface of the EDLCs. The charge accumulation region concentrated on central part of the carbonaceous electrode and the required times for charging and discharging were almost same.

Improved Mesoporous Structure of High Surface Area Carbon Nanofiber for Electrical Double-Layer Capacitors

  • Lee, Young-Geun.;An, Geon-Hyoung;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
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    • v.27 no.4
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    • pp.192-198
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    • 2017
  • Carbon nanofiber (CNF) is used as an electrode material for electrical double layer capacitors (EDLCs), and is being consistently researched to improve its electrochemical performance. However, CNF still faces important challenges due to the low mesopore volume, leading to a poor high-rate performance. In the present study, we prepared the unique architecture of the activated mesoporous CNF with a high specific surface area and high mesopore volume, which were successfully synthesized using PMMA as a pore-forming agent and the KOH activation. The activated mesoporous CNF was found to exhibit the high specific surface area of $703m^2g^{-1}$, total pore volume of $0.51cm^3g^{-1}$, average pore diameter of 2.9 nm, and high mesopore volume of 35.2 %. The activated mesoporous CNF also indicated the high specific capacitance of $143F\;g^{-1}$, high-rate performance, high energy density of $17.9-13.0W\;h\;kg^{-1}$, and excellent cycling stability. Therefore, this unique architecture with a high specific surface area and high mesopore volume provides profitable synergistic effects in terms of the increased electrical double-layer area and favorable ion diffusion at a high current density. Consequently, the activated mesoporous CNF is a promising candidate as an electrode material for high-performance EDLCs.

Studies of electric double layer capacitors used for a storage battery of dye sensitized solar cell energy (염료감응형 태양전지의 축전지로 사용되는 전기이중층콘덴서에 대한 연구)

  • Choi, Jin-Young;Lee, Im-Geun;Hong, Ji-Tae;Kim, Hee-Je
    • 한국신재생에너지학회:학술대회논문집
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    • pp.673-676
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    • 2005
  • To design the effective usage of electric double layer capacitors (EDLCs) used for a storage device of dye sensitized solar cell(DSC) energy, we first investigated the accumulation state of electrical charges and the charge behavior in the EDLCs. Based on the results. the voltage characteristics of EDLCs connected to DSC energy were evaluated. The results showed that the charge accumulation region concentrated on central part of the carbonaceous electrode in EDLCs and the required times for charging and discharging were almost the same.

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Fabrication of Mesoporous Carbon Nanofibers for Electrical Double-Layer Capacitors (전기 이중층 커패시터용 메조 다공성 탄소 나노섬유의 제조)

  • Lee, Do-Young;An, Geon-Hyoung;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
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    • v.27 no.11
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    • pp.617-623
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    • 2017
  • Mesoporous carbon nanofibers as electrode material for electrical double-layer capacitors(EDLCs) are fabricated using the electrospinning method and carbonization. Their morphologies, structures, chemical bonding states, porous structure, and electrochemical performance are investigated. The optimized mesoporous carbon nanofiber has a high sepecific surface area of $667m^2\;g^{-1}$, high average pore size of 6.3 nm, and high mesopore volume fraction of 80 %, as well as a unifom network structure consiting of a 1-D nanofiber stucture. The optimized mesoporous carbon nanofiber shows outstanding electrochemical performance with high specific capacitance of $87F\;g^{-1}$ at a current density of $0.1A\;g^{-1}$, high-rate performance ($72F\;g^{-1}$ at a current density of $20.0A\;g^{-1}$), and good cycling stability ($92F\;g^{-1}$ after 100 cycles). The improvement of the electrochemical performance via the combined effects of high specific surface area are due to the high mesopore volume fraction of the carbon nanofibers.

Investigation of Charge distribution in an Electric double layer capacitor (전기이중층 캐패시터 내의 전하분포 고찰)

  • Endrowednes, Kuantama;Jessi, Darma;Sung, Youl-Moon;Kim, Kwang-Tae
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • pp.201-204
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    • 2008
  • The use of the pulsed electro acoustic (PEA) method allowed us to perform the direct observations of spatio-temporal charge distributions in Electric double layer capacitors (EDLCs) based on polarizable nanoporous carbonaceous electrode. The negative charge density became the maximum, about 205 C/$m^3$ at the region where was near to collector layer in EDLCs for case $V_{DC}$ = 2.5 V, while the positively charged density became the maximum, about 61.1 C/$m^3$ at the region where it was located around the cathode layer. The PEA measurement used here is a very useful method to quantitively investigates the spatio-temporal charge distribution in EDLCs.

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Experimental Verification of Electric Vehicle Using Electric Double Layer Capacitor

  • Ikeda, Hidehiro;Ajishi, Hideki;Hanamoto, Tsuyoshi
    • Journal of international Conference on Electrical Machines and Systems
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    • v.2 no.2
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    • pp.171-178
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    • 2013
  • This paper discusses to conduct experimental verification of two types of micro electric vehicles (EV) in order to realize improvement in electric mileage and shorten a charging time of the battery. First, electric double layer capacitor (EDLC) systems to use as a secondary battery are proposed. The internal resistance of EDLC is small compared with a rechargeable battery, and it is suitable for momentary charge-discharge of EV. Next, control circuits of the capacitors to increase the regenerative electric power are utilized. Then, a novel method to charge a main battery of the EV is introduced. Finally, experimental results demonstrate the validity of the proposed method.

Development of EDLC using aqueous polymeric gel electrolytel (수용성 고분자 젤 전해질을 이용한 전기이중층 커패시터 의 개발)

  • 오길훈;김한주;최원경;박수길
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.581-584
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    • 2001
  • For the first time, a totally solid state electric double layer capacitor has been fabricated using an alkaline polymer electrolyte and an activated carbon powder as electrode material. The polymer electrolyte serves both as separator as well as electrode binder. The capacitor has a three-layer structure; electrode-electrolyte-electrode. A cyclic voltammetry and constant current discharge have been used for the determination of the electro chemical performance of capacitors.

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Fabrication of Activated Porous Carbon Using Polymer Decomposition for Electrical Double-Layer Capacitors (고분자 융해 반응을 이용한 전기 이중층 커패시터용 다공성 활성탄 제조)

  • Sung, Ki-Wook;Shin, Dong-Yo;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
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    • v.29 no.10
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    • pp.623-630
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    • 2019
  • Because of their excellent stability and highly specific surface area, carbon based materials have received attention as electrode materials of electrical double-layer capacitors(EDLCs). Biomass based carbon materials have been studied for electrode materials of EDLCs; these materials have low capacitance and high-rate performance. We fabricated tofu based porous activated carbon by polymer dissolution reaction and KOH activation. The activated porous carbon(APC-15), which has an optimum condition of 15 wt%, has a high specific surface area($1,296.1m^2\;g^{-1}$), an increased average pore diameter(2.3194 nm), and a high mesopore distribution(32.4 %), as well as increased surface functional groups. In addition, APC has a high specific capacitance($195F\;g^{-1}$) at low current density of $0.1A\;g^{-1}$ and excellent specific capacitance($164F\;g^{-1}$) at high current density of $2.0A\;g^{-1}$. Due to the increased specific surface area, volume ratio of mesopores, and surface functional groups, the specific capacitance and high-rate performance increased. Consequently, the tofu based activated porous carbon can be proposed as an electrode material for high-performance EDLCs.