• Journal of the Korean Electrochemical Society
• /
• v.17 no.4
• /
• pp.237-244
• /
• 2014

We report novel and simple structure of supercapacitors fabricated by using flexible glass fibre separators as templates. This method does not require separate electrodes, binders and high pressure/temperature to build the supercapacitor unit cells as required by the conventional technology. The supercapacitors were fabricated by drop-casting solution mixtures of carbonaceous active materials/gel electrolytes onto two sides of glass fibre separators. Two carbonaceous materials (nanoscaled activated carbons, multi-walled carbon nanotubes) were investigated as electrode materials. The electrochemical measurements reveal that the separatorbased supercapacitors using ACs successfully demonstrated significant mass specific capacitance ($22.3F\;g^{-1}$) and energy density ($9.7Wh\;kg^{-1}$), indicating this method can be useful in fabricating flexible, wearable and stretchable energy storage devices in more straightforward and cost-effective way than current technology.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.335-338
• /
• 2007

Cost effectiveness is an important parameter for producing DSSCs as compared to the widely used conventional silicon based solar cells. A fluorine-doped tin oxide (FTO) substrate coated with a catalytic amount of platinum is used as counter electrode in dye-sensitized solar cell. Carbonaceous materials are quite attractive to replace platinum due to their high electronic conductivity, corrosion resistance towards $I_{2}$, good catalytic effect and low cost. In this paper, the unit DSSCs with Pt and CNT as a counter electrode were connected in series-parallel externally, then the current-voltage curves were investigated to find out the connection characteristics of the DSSC with CNT counter electrode. The connection characteristics of the DSSC with CNT counter electrode is superior to that of the DSSC with Pt counter electrode. And a parallel connection of the DSSC with CNT counter electrode has higher efficiency than a series connection of that.

• Journal of the Microelectronics and Packaging Society
• /
• v.6 no.2
• /
• pp.69-74
• /
• 1999

Graphite and carbonaceous materials intercalate and deintercalate Li-ion reversibly into their layered structures. These materials show an excellent capacity for using a negative electrode in Li-ion batteries, because the electrochemical potential of Li-ion intercalated carbon is almost identical with that of lithium metal. Carbon used in this study was obtained by the pyrolysis of petroleum pitch, and heat-treated at the several temperatures between $700^{\circ}C$ and $1300^{\circ}C$. XRD analysis revealed that crystallization of carbon increased with increasing the heat treatment temperature. Charge/discharge properties were studied by a constant-current step at the rate of 0.1C, and the interfacial reaction between the electrolyte and the surface of carbon electrode was studied by cyclic voltammetry. Cell capacities were investigated in terms of the heat treatment temperature and the cycle number. Reversible capacity increased with the heat treatment temperature up to $1000^{\circ}C$, thereafter decreased continuously. Also, charge capacity decreased with the cycle number, while the reversibility improved with it.

• Proceedings of the KIEE Conference
• /
• 1999.07d
• /
• pp.1821-1823
• /
• 1999

Carbon is an attractive material on electro double capacitor which depend on charge storage in the electrode/electrolyte interfacial double layer. Carbonaceous material for double layer capacitor can be obtained from carbon powder, fiber, film and porous carbon sheet. The capacitance of electrodes using an activated carbon was influenced by a filling density of the carbon, thickness and internal resistance of the electrode. In this study. to reduce internal resistance and increase electric conductivity of the electrode. activated carbon/carbon(AC/C) composite electrode was fabricated. The capacitors which have energy densities of 68F/g(at $30^{\circ}C$), 109F/g(at $60^{\circ}C$) and $68F/cm^3$(at $30^{\circ}C$), $111F/cm^3$(at $60^{\circ}C$) were fabricated by using AC/C composite electrodes.

• Journal of the Korean Electrochemical Society
• /
• v.6 no.3
• /
• pp.174-177
• /
• 2003

Electric double-layer capacitors based on charge storage at the interface between a high surface area activated carbon electrode and an electrolyte solution are characterized by their long cycle-life and high power density in comparison with batteries. However, energy density of electric double-layer capacitors obtained at present is about 6 Wh/kg at a power density of 500W/kg which is smaller as compared with that of batteries and limits the wide spread use of the capacitors. Therefore, a new capacitor that shows larger energy density than that of electric double-layer capacitors is proposed. The new capacitor is the hybrid capacitor consisting of activated carbon cathode, carbonaceous anode and an organic electrolyte. Maximum voltage applicable to the cell is over 4.2V that is larger than that of the electric double-layer capacitor. As a result, discharged energy density on the basis of stacked volume of electrode, current collector and separator is more than 18Wh/l at a power density of 500W/l.

• Applied Chemistry for Engineering
• /
• v.9 no.7
• /
• pp.1059-1064
• /
• 1998

We have investigated various kind of graphite and MCMB6-28 to develop carbon negative electrode for lithium ion secondary battery. The interlayer length of them was $3.358{\sim}3.363{\AA}$ and the BET specific surface area was $2.95{\sim}26.15m^2/g$. From this study, When the interlayer of them was large and the BET specific surface area was high, the electrochemical characteristics of them was very excellent. Adding 0, 3, 5, wt% of KJ-Black as conducting agent to various graphitic carbon active materials, interface resistance of electrode and electrolyte was less, but rechargeability was better at 3 wt%. At constant current charge and discharge test, discharge capacity was small according to large current.

• Journal of Electrochemical Science and Technology
• /
• v.1 no.1
• /
• pp.25-30
• /
• 2010

This study demonstrated the synthesis of high-surface-area metal-free carbonaceous electrodes (CE) from anodic aluminum oxide (AAO) templates, and their application as supercapacitors. Multi-walled Carbon nanotubes (MWCNTs) were interwoven into a porous network sheet that was attached to one side of AAO template through a vacuum filtration of the homogeneously dispersed MWCNT toluene solution. Subsequently, the conducting polymer was electrochemically grown into the porous MWCNT network and nanochannels of AAO, leading to the formation of a carbonaceous metal-free film electrode with a high surface area in the given geometrical surface area. Typical conducting polymers such as polypyrrole (PPY) and poly(3,4-ethylenedioxythiophene) (PEDOT) were examined as model systems, and the resulting electrodes were investigated as supercapacitors (SCs). These SCs exhibited stable, high capacitances, with values as high as 554 F/g, 1.08 F/$cm^2$ for PPY and 237 F/g, 0.98 F/$cm^2$ for PEDOT, that were normalized by both the mass and geometric area.

• Journal of Electrical Engineering and Technology
• /
• v.1 no.2
• /
• pp.251-256
• /
• 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.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.11a
• /
• pp.673-676
• /
• 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.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1110_1111
• /
• 2009

최근 광 캐패시터 전극 분야는 고효율과 넓은 응용분야로 인해 주목 받고 있다. 본 연구에서는 carbon, 활성 carbon을 사용하여 캐패시터샘플을 제작 하였고 간단한 샌드위치 구조에 각각의 캐패시터 전극은 $20{\times}15nm$의 셀을 사용하였다. 각 셀들은 제작방법에는 졸겔법이 사용되었다. 각 셀들의 수분 및 기타물질의 제거를 위해 $120^{\circ}C$에서 1시간동안 건조시켰고 $500^{\circ}C$에서 2시간동안 소결처리 하였다. 소결처리로 인한 carbon의 특성변화를 알아보기 위해 XRD분석을 실시하였다. 본 연구에서는 캐패시터의 특성을 파악하기 위해 임피던스 특성을 분석하였고 그에 따른 부수적인 결과들을 기술하였다. active carbon을 사용한 캐패시터의 충방전 특성을 측정하였고 최종적으로 평균 두께 $32{\mu}m$, 입자사이즈 $1\sim4.5{\mu}m$의 캐패시터전극용 샘플($20{\times}15nm$)을 제작하였다.