• Korean Chemical Engineering Research
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• 제55권5호
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• pp.593-599
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• 2017

본 연구에서는 활성탄과 납 전구체를 사용하여 나노 Pb/AC 복합소재를 제조한 후, 울트라 전지용 음극소재의 전기화학적 특성을 조사하였다. 나노 Pb/AC 복합소재는 활성탄에 나노 Pb 입자를 흡착시킨 후 감압 수세하여 제조하였다. 제조된 복합소재의 물리적 특성은 SEM, BET, EDS를 통해 분석하였으며, $1740m^2/g$, 1.95 nm의 비표면적과 평균 기공크기를 얻었다. 울트라 전지의 음극은 납 극판에 나노 Pb/AC를 딥코팅하여 제조되었다. 울트라 전지는 이산화납을 사용한 양극과 나노 Pb/AC 복합소재 음극을 사용하였으며 전해액은 5M의 황산용액($1.31g/cm^3$)을 사용하였다. 전기화학적 성능은 충 방전, 순환전압전류, 임피던스, 사이클 테스트를 통해 조사되었다. 제조된 나노 Pb/AC를 이용한 울트라 배터리는 기존의 납 축전지와 AC를 코팅한 납 축전지보다 개선된 초기 용량과 사이클 특성을 보였다. 이러한 실험 결과로부터 나노 Pb/AC의 적절한 첨가가 수소발생 반응이 억제됨에 따라 용량 및 장기 사이클 안정성을 향상시킴을 알 수 있었다.

• Journal of Electrochemical Science and Technology
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• 제8권1호
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• pp.43-52
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• 2017

In this paper, for the first time, the electroanalytical study of Triethylenediamine, TEDA was done on a typically graphene modified carbon paste electrode (Gr/CPE) in pH=10.5 of phosphate buffer solutions (PBS). The surface morphology of the bare and modified electrodes was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electro-oxidation of TEDA was investigated at the surface of modified electrode. The results revealed that the oxidation peak current of TEDA at the surface of Gr/CPE is 2.70 times than that shown at bare-CPE. A linear calibration plot was observed in the range of 1.0 to 202.0 ppm. In this way, the detection limit was found to be 0.18 ppm. The method was then successfully applied to determination of TEDA in aqueous samples obtained from two kinds of activated carbon from the masks of war. On the other hand, density functional theory (DFT) method at B3LYP/6-311++G** level of theory and a conductor-like Polarizable Continuum Model (CPCM) was used to calculate the $pK_a$ values of TEDA. The energies of lowest unoccupied molecular orbital ($E_{LUMO}$) and highest occupied molecular orbital ($E_{HOMO}$), gap energy (${\Delta}E$) and some thermodynamic parameters such as Gibbs free energy of TEDA and its conjugate acid ($HT^+$) were calculated. The results of calculated $pK_a$ were found to be in good agreement with the experimental values.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 가을 학술발표회 논문집
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• pp.134-137
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• 2003

탄소섬유나 활성탄소섬유(activated carbon fiber, ACF)는 일반적으로 출발물질에 따라 polyacrylonitrile(PAN)계, 아크릴(acryl)계, 피치(pitch)계, 페놀(phenol)계 등으로 분류할 수 있다. 보통 습식, 용융 혹은 용융분사(melt-blown) 방사 방법에 의해 섬유 형태로 형성한 다음 산화성 가스 분위기에서 불융화 과정을 거쳐 열에 대한 안정성을 부여하여 불활성 분위기에서 탄소화하여 탄소섬유를 제조하거나, 수증기나 이산화 탄소와 같은 산화성 분위기에서 활성화하여 활성탄소섬유를 제조한다. (중략)

• 한국응용과학기술학회지
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• 제21권4호
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• pp.364-369
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• 2004

It has been confirmed that some Trihalomethanes (THMs) suspected as carcinogens, can be formed during chlorination for water supply through the reaction of chlorine and humic substances in water. The electrochemical characteristics on activated carbon fiber filter (ACF) electrode were investigated to remove the THMs in the chlorination process of drinking water. The electrochemical removal efficiency depended on the applied voltage and flow rate. In this study, the best result showed that the removal efficiency of THMs was higher than 99%.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 1999년도 추계학술대회
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• pp.345-354
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• 1999

A new type of capacitor named "Super Capacitor" has been developed, in which the properties of electric double layer formed at the interface of activated carbon electrode- liquid organic electrolyte is applied. This capacitor is small In size, light in weight, wide In temperature range(-25~$70^{\circ}C$), large in charge-discharge capability and good in voltage preservation. And this super capacitor is applied as a power back-up for electricity failure in volatile memory devices etc., a power source for a short time and a power source for operating actuators. At present the development of high power back-up types of the capacitor system and improvement of their characteristics are being actively conducted in order to find wider applications.lications.

• 한국전기전자재료학회논문지
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• 제18권12호
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• pp.1133-1138
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• 2005

In this study, we have prepared, as the pluse power source, a commercially supplied Li-ion battery with a capacity of 700 mAh and AC resistivity of 60 md at 1 kHz and nonaqeous asymmetric hybrid capacitor composed of an activated carbon cathode and MCMB anode, and have examined the electrochemical characteristics of hybrid capacitor and the pulse performances of parallel connected hybrid capacitor/Li-ion battery source. The nonaqueous asymmetric hybrid capacitors constituted with each stack number of pairs composed of the cathode, the porous separator and the anode electrode were housed in Al-laminated film cell. The 10 stacked hybrid capacitor, which was charged and discharged at a constant current at 0.25 $mA/cm^2$ between 3 and 4.3 V, has exhibited the capacitance of 108F and the lowest equivalent series resistance was 32 $m{\Omega}$ at 1 kHz. On the other hand, the enhanced run time of Li-ion battery assisted by the hybrid capacitor was obtained with increasing of current density and pulse width in Pulse mode. The best improvement, $84\;\%$ for hybrid capacitor/Li-ion battery was obtained in the condition of a 7C-rate pulse (100 msec)/0.5C-rate standby/$10\;\%$ duty cycle.

• 한국수소및신에너지학회논문집
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• 제26권5호
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• pp.416-422
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• 2015

Lithium Ion capacitor (LIC) is a new storage device which combines high power density and high energy density compared to conventional supercapacitors. LIC is capable of storing approximately 5.10 times more energy than conventional EDLCs and also have the benefits of high power and long cycle-life. In this study, LICs are assembled with activated carbon (AC) cathode and pre-doped graphite anode. Cathode material of natural graphite and artificial graphite kinds of MAGE-E3 was selected as the experiment proceeds. Super-P as a conductive agent and PTFE was used as binder, with the graphite: conductive agent: binder of 85: 10: 5 ratio of the negative electrode was prepared. Lithium doping condition of current density of $2mA/cm^2$ to $1mA/cm^2$, and was conducted by varying the doping. Results Analysis of Inductively Coupled Plasma Spectrometer (ICP) was used and a $1mA/cm^2$ current density, $2mA/cm^2$, when more than 1.5% of lithium ions was confirmed that contained. In addition, lithium ion doping to 0.005 V at 10, 20 and $30^{\circ}C$ temperature varying the voltage variation was confirmed, $20^{\circ}C$ cell from the low internal resistance of $4.9{\Omega}$ was confirmed.

• 한국수소및신에너지학회논문집
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• 제27권3호
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• pp.298-305
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• 2016

In this study, we treated pitch-based activated carbon fibers (ACFs) in hydrogen peroxide using electron beam (E-beam) irradiation to improve nitrogen monoxide (NO) sensing ability as an electrode material of gas sensor. The specific surface area of ACFs treated by E-beam irradiation with 400 kGy increased from $885m^2/g$ (pristine) to $1160m^2/g$ without any changes in structural property and functional group. The increase in specific surface area of the E-beam irradiated ACFs enhanced NO gas sensing properties such as response time and sensitivity. When the ACFs irradiated with 400 kGy, response time was remarkably reduced from 360 s to 210 s and sensitivity was increased by 4.5%, compared to the pristine ACFs. These results demonstrate convincingly that surface modification of ACFs using E-beam in hydrogen peroxide solution can enhance textural properties of ACFs and NO gas sensing ability of gas sensor at room temperature.

• 전기화학회지
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• 제16권2호
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• pp.91-97
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• 2013

이온성 액체 전해질염 1-ethyl-3-methylimidazolium tetrafluoroborate ($EMIBF_4$)과 용매 acrylonitrile (ACN) 및 propylene carbonate (PC)와 각각 혼합한 용액에 poly(ethylene glycol)diacrylate (PEGDA)를 45-60 wt.% 첨가하고 자외선 조사를 통해 경화시켜 고체 고분자 전해질 필름을 제조하였다. 이 고체 고분자 전해질 필름을 분리막으로 채택하고 활성탄 전극을 사용하는 수퍼커패시터를 제조하여 그 전기화학적 특성을 사이클릭 볼타메트리와 임피던스 방법으로 조사하였다. 결과적으로 PEGDA를 45 wt.% 첨가하여 제조한 고체 고분자 전해질 필름을 채택한 경우가 스캔속도 $20mVs^{-1}$에서 $46Fg^{-1}$의 가장 우수한 축전용량을 나타내는데, 이것은 PEGDA의 저함량 때문에 상대적으로 자외선 경화가 약하게 진행되어 고분자 전해질 필름의 유연성이 충분히 확보되므로 필름 내 이온전도가 가장 활발히 진행될 수 있었기 때문이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.597-598
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• 2005

Recently, the performance of portable electric equipment can often improved by a Li-ion battery assisted by a supercapacitor. A supercapacitor can provide high power density as well as a low resistance in the hybrid system. In this study, we have prepared, as the pluse power souce, a commercially supplied Li-ion battery with a capacity of 700mAh and AC resistivity of $60m\Omega$ at 1kHz and nonaqeous asymmetric hybrid capacitor composed of an activated carbon cathode and MCMB anode, and have examined the electrochemical characteristics of hybrid capacitor and the pulse performances of parallel connected battery/hybrid capacitor source. The nonaqueous asymmetric hybrid capacitor, the stacks of 10 pairs of the cathode, the porous separator and the anode electrode were housed in Al-laminated film cell. The hybrid capacitor, which was charged and discharged at a constant current at $0.25mA/cm^2$ between 3 and 4.3V, has exhibited the capacitance of 100F. And the equivalent series resistance was $32m\Omega$ at 1kHz. By combining a Li-ion battery and a hybrid capacitor, the pulse performance of battery can be improved 23% in run time under a pulse discharge of 7C-rate.