전기용량적 탈이온 공정을 위한 다공성 탄소에어로젤-실리카젤 복합전극

양천모,최운혁,조병원,한학수,윤경석,조원일,Yang Chun-Mo,Choi Woon-Hyuk,Cho Byung Won,Han Hak-Soo,Yun Kyung Suk,Cho Won Il 한국전기화학회 2004 한국전기화학회지 Vol.7 No.1

Porous carbon aerogel-silica gel composite materials were used as the electrodes of capacitive deionization(CDI) process, which were prepared by a paste rolling method. The electrochemical parameters such at current values, coulombs af a function of cycle, and CDI efficiencies were investigated for 10th and 100th cycles in 1,000ppm NaCl solution. Carbon aerogel-silica gel composite electrodes showed good wet-ability and higher mechanical strengths even under the NaCl solutions as well. In our experimented runs, all of the composite electrodes also are showed good cycle-ability without destroy of active material during cycles and decreased manufacturing times by $50\%$. Conclusively, the adding of silica gel powder to carbon aerogel leads to the effective performance of CDI process due to effective utilization of active materials by increasing the wet-ability and mechanical hardness. 전기화학적으로 이온을 흡착시켜 제거시키는 capacitive deionization(CDI) 공정용 전극으로 탄소에어로젤에 실리카젤이 첨가된 다공성 탄소에어로젤 복합전극을 사유하여 1,000ppm NaCl수용액에서 10회와 100회 동안 싸이클을 변화시켜 탈염과 재생 특성에 대한 충전과 방전 시 시간에 따른 전류변화, 싸이클에 대한 전하량 변화, 그리고 CDI효율을 조사하였다. Paste rolling법으로 제조된 탄소에어로젤 복합전극은 CDI반응진행에 대한 전극 활물질의 탈락이 없이 전극의 성형성이 크게 향상되었고, 전극시트 제조시간을 $50\%$ 이상 단축시킬 수 있었다. 10분동안 충전과 방전으로 10회 싸이클까지의 전하량 결과를 살펴보면, $50wt.\%$의 실리카젤이 첨가된 C복합전극의 평균 충전 전하량이 실리카젤이 첨가되지 않은 A전극에 비해 $3\%$ 증가하였으며, 평균 방전 전하량은 $7\%$증가하였다. 5분동안 충전과 방전으로 100회 싸이클까지 평균 충전 전하량을 보면 $25w1.\%$와 $50wt.\%$의 실리카젤이 첨가된 B복합전극과 C복합전극은 A전극에 비해 각각 $6\%,\;14\%$증가하였으며, 또한 평균 방전 전하량도 각각 $9\%,\;21\%$증가하여 복합전극의 전하량 특성이 매우 우수하였다. 100회 싸이클까지의 CDI효율은 싸이클이 진행되면서 $70\%$ 이상으로 안정하게 유지하였고, 100회 싸이클에서는 B 복합전극이 $72.3\%$, C 복합전극이 $74.0\%$로 A 전극$(63.1\%)$보다 $10\%$이상 우수한 CDI 효율을 나타내었다.

유기전해질에 따른 EDLC의 전기화학적 특성

양천모,이중기,조원일,조병원,임병오,Yang Chun-Mo,Lee J.K.,Cho W.I.,Cho B.W.,Rim Byung-O 한국전기화학회 2001 한국전기화학회지 Vol.4 No.3

탄소계 전극을 사용하는 EDLC(Electric Double Layer Capacitor)용의 축전용량과 충방전속도는 전해질의 종류, 충방전 조건 그리고 탄소계 물질의 물리화학적 성질에 따라 크게 달라질 수 있다. 이에 본 연구에서는 dip coating method에 의해 제조된 EDLC용 활성탄소 전극에서 유기 전해질의 종류를 달리하여 충방전 실험과 전기화학적인 실험을 시행하였다. 또한 충전전류밀도와 방전전류밀도의 변화에 따른 비축전 용량의 변화를 조사하였고, 최적 유기전해질의 조건에서 leakage current 특성, 자가방전 특성 그리고 시간전압곡선을 기존의 $1M-Et_4NBF_4/PC$와 비교하였다 활성탄, 소전극으로 비표면적이 $2000m^2/g$인 MSP-20을 사용하고 유기전해질로는 $1M-LiPF_6/PC-DEC(1:1)$를 사용한 EDLC에서 130 F/g 정도의 우수한 비축전 용량을 나타내었고 저항면에서도 가장 낮은 수치를 나타내었다 $1M-LiPF_6/PCDEC(1:1)$를 사용한 EDLC는 15분동안 0.0004A의 낮은 leakage current와 100시간 경과 후 0.8V의 우수한 자가 방전 특성 그리고 IR-drop이 적은 선형의 시간-전압곡선을 보여주었다. Specific capacitance and charge-discharge rate of EDLC using activated carbon electrode were affected by the compositions of electrolytes, the conditions of charge-discharge and physical properties of activated carbon materials. The activated carbon electrode was prepared by dip coating method. Charge-discharge test and electrochemical experiments were carried out for various kinds of organic electrolytes. Effects of charge and discharge current density on the specific capacitance were studied. Characteristics of leakage current, self-discharge and time-voltage curves in optimum conditions of organic electrolytes were compared with conventional $1M-Et_4NBF_4/PC$ electrolyte. The EDLC using MSP-20(specific surface area: $2000m^2/g$) electrode and $1M-LiPF_6/PC-DEC(1:1)$ was exhibited th highest specific capacitance of 130F/g and low polarization resistances. The EDLC using MSP-20 electrode at $1M-LiPF_6/PC-DEC(1:1)$ was small leak current of 0.0004A for 15min, long voltage retention of 0.8V after 100h and linear time-voltage curves with small IR-drop.

활성탄소 전극의 제조공정에 따른 EDLC의 전기화학적 특성

양천모,김현중,조원일,조병원,윤경석,임병오,Yang Chun-Mo,Kim H.J.,Cho W.I.,Cho B.W.,Yun K.S.,Rim Byung-O 한국전기화학회 2001 한국전기화학회지 Vol.4 No.3

EDLC(electric double layer capacitor)용 활성탄소전극의 제조공정을 dip coating method, doctor blade coating method, paste rolling method로 달리하여 전기화학적 특성과 비축전 용량을 조사하였다. Dip coating method에 의한 전극제조시 전해질염으로 LiPF6를 이용하고 유기용매로 PC-DEC를 이용한 EDLC의 비축전 용량이 130F/g으로 가장 우수하였고, 선형의 시간전압곡선에서의 IR-drop도 0.11V로 작았으며 CV(cyclic voltammetry) 분석 또한 이상적인 EDLC의 특성을 나타내었다. The electrochemical characteristics and specific capacitance were investigated by preparation processes (dip coating method, doctor blade coating method and paste rolling method) of activated carbon electrode for an EDLC(electric double layer capacitor). The EDLC using $LiPF_6$ salts and PC-DEC solvents showed good specific capacitance, 130F/g and small IR-drop at linear time-voltage curve. 0.11V, Cyclic voltammetry analysis using the activated carbon electrode prepared by dip coating method was shown closer to ideal EDLC characterization.

CuxFe3-xO4-δ 를 이용한 이산화탄소의 분해

양천모(Chun Mo Yang),박영구(Young Goo Park),김승호(Seung Ho Kim),임병오(Byung O Rim) 한국공업화학회 2000 공업화학 Vol.11 No.6

N/A

ZnxFe3-xO4-δ 를 이용한 이산화탄소의 분해

양천모(Chun Mo Yang),조영구(Young Koo Cho),임병오(Byung O Rim) 한국유화학회 2000 한국응용과학기술학회지 Vol.17 No.1

N/A Zn_χFe_(3-χ)O_4(0.003<X<0.08) was synthesized by air oxidation method for the decomposition of carbon dioxide. We investigated the characteristics of catalyst, the form of methane by gas chromatograph after decomposition of carbon dioxide and kinetic parameter. Zn_χFe_(3-χ)O_4(0.003<X<0.08) was spinel type structure. The surface areas of catalysts(Zn_χFe_(3-χ)O_4(0.003<X<0.08)) were 15~27 m^2/g. The shape of Zn_0.003Fe_2.997O_4 was sphere. The optimum temperature for the decomposition of carbon dioxide into carbon was 350℃. Zn_0.003Fe_2.997O_4 showed the 85% decomposition rate of carbon dioxide and the degree of reduction by hydrogen(δ) of Zn_0.003Fe_2.997O_4 was 0.32. At 350℃, the reaction rate constant and activation energy of Zn_0.003Fe_2.997O_3.68 for the decomposition of carbon dioxide into carbon were 3.10 psi^(??-??)/min and 0.98 kcal/mole respectively. After the carbon dioxide was decomposed, the carbon which was absorbed on the catalyst surface was reacted with hydrogen and it became methane.

스피넬상 Fe3O4 를 이용한 CO2 분해에서 LiMn2O4 첨가효과

양천모(Chun Mo Yang),박영구(Young Goo Park),조영구(Young Koo Cho),임병오(Byung O Rim) 한국유화학회 2001 한국응용과학기술학회지 Vol.18 No.3

N/A The spinel Fe_3O_4 powders were synthesized using 0.2 M-FeSO_4·7H_2O and 0.5 M-NaOH by oxidation in air and the spinel LiMn_2O_4 powders were synthesized at 480℃ for 12 h in air by a sol-gel method using manganese acetate and lithium hydroxide as starting materials. The synthesized LiMn_2O_4 powders were mixed at portion of 5, 10, 15 and 20 wt% of Fe_3O_4 powders using a ball-mill. The mixed catalysts were dried at room temperature for 24 hrs. The mixed catalysts were reduced by hydrogen gas at 350℃ for 2 h. The carbon dioxide decomposition rates of the mixed catalysts were 90% in all the mixed catalysts but the decomposition rate of carbon dioxide was increased with adding LiMn_2O_4 powders to Fe_3O_4 powders.

CO2 분해용 스피넬상 LiMn2O4 에 대한 Fe3O4 첨가효과

양천모(Chun Mo Yang),임병오(Byung O Rim),김승호(Seung Ho Kim),김순태(Soon Tae Kim) 한국유화학회 2001 한국응용과학기술학회지 Vol.18 No.3

N/A The spinel LiMn_2O_4 powders were synthesized at 480℃ for 12 h in air by a sol-gel method using managanese acetate and lithium hydroxide as starting material and the Fe_3O_4 powders were synthesized by the precipitation method using 0.2M-FeSO_4·H_2O and 0.5M-NaOH. The synthesized Fe_3O_4 powders were mixed at portion of 5, 10, 15 and 20 wt% about LiMn_2O_4 powders through ball-milling followed by drying at room temperature for 48 h in air. The mixed catalysts were reduced at 350℃ for 3 h by hydrogen and the decomposition rate of carbon dioxide was measured at 350℃ using the reduced catalysts. As the results of CO_2 decomposition experiments, the decomposition rates of carbon dioxide were 85% in all catalysts but the initial decomposition rates of CO_2 were slightly high in the case of the 5%-Fe_3O_4 added catalyst.

탄소재료를 이용한 NaCl 용액에서 전기용량적 탈이온에 대한 연구

양천모(Chun-Mo Yang),최운혁(Woon-Hyuk Choi),조병원(Byung Won Cho),조원일(Won Il Cho),윤경석(Kyung Suk Yun),한학수(Hak-Soo Han) 한국에너지학회 2003 한국에너지공학회 학술발표회 Vol.2003 No.-

망간산화물의 합성과 수소환원에 의한 활성화

양천모(Chun Mo Yang),김순태(Soon Tae Kim),임병오(Byung O Rim) 한국유화학회 2000 한국응용과학기술학회지 Vol.17 No.1

N/A For decompose carbon dioxide, manganese oxide was synthesized with 0.25M-MnSO_4ㆍnH_2O and 0.5M-NaOH by coprecipitation. We made magnetite deoxidized manganese oxide by hydrogen reduction for 1hour at 330℃. We investigated characteristics of catalyst, hydrogen reduction degree and decomposition rate of carbon dioxide. The structure of the hausmannite certified spinel type. The specific surface area of synthesized hausmannite and deoxidized hausmannite were 22.36m^2/g, 33.56m^2/g respectively. The decomposition rate of CO_2 of deoxidized hausmannite was 57%.

Poly[(ethylene glycol) diacrylate]-Poly(vinylidene fluoride) 전해질을 이용한 전기 이중층 캐패시터의 전기화학적 특성

양천모 ( Chun Mo Yang ),이중기 ( Joong Kee Lee ),조원일 ( Won Il Cho ),조병원 ( Byung Won Cho ),주재백 ( Jeh Beck Ju ),유관표 ( Kwan Pyo Yoo ),임병오 ( Byung O Rim ) 한국공업화학회 2002 공업화학 Vol.13 No.8

자외선 경화법으로 제조한 PEGDA-PVdF 젤상 고분자 전해질을 전기이중층캐패시터에 적용하였고, 액상 유기 전해질을 이용한 전기이중층캐패시터와 전기화학적 특성을 비교 조사하였다. 자외선 경화법으로 제조된 젤상 고분자 전해질[GPE:poly[(ethylene glycol) diacrylate]-poly(vinylidene fluoride) blend]을 이용한 전기이중층캐패시터의 경우, 비축전용량이 120 F/g으로 액상 유기 전해질 [LOE:1 M LiPF_6/EC:DMC:EMC (1:1:1 volume ratio)]을 이용한 전기이중층캐패시터의 비축전용량인 110 F/g보다 우수하였고, 100회 충방전 후에도 초기 비축전용량대비 92% 이상 유지하는 우수한 싸이클 특성을 나타내었으며 3.7 Ω의 낮은 ESR(equivalent series resistance)을 보여주었다. Cyclic voltammetry 분석 결과에서 보면 액상 유기 전해질과 젤상 고분자 전해질을 이용한 모든 전기이중층캐패시터에서 2.5 V까지 전해질의 분해 없이 전기화학적으로 안정하였고, 산화와 환원과 관련된 전류값 또한 관찰되지 않았다. 젤상 고분자 전해질을 이용한 전기이중층캐패시터의 경우에서 직사각형 모양의 이상적인 전기이중층캐패시터의 특성과 49 ㎂의 낮은 누설 전류값을 나타내었다. 자가방전 특성 결과, 젤상 고분자 전해질을 이용한 전기이중층캐패시터의 경우 2.5 V의 정전압 충전 시 OCV(open circuit voltage) 상태에서 100 h 경과 후 1.76 V의 전압을 유지하고 있어 0.25 V의 액상 유기 전해질을 이용한 전기이중층캐패시터보다 매우 우수함을 확인하였다. Poly[(ethylene glycol) diacrylate] (PEGDA)-poly(vinylidene fluoride) (PVdF) gel polymer was employed as an electrolyte for electric double layer capacitor (EDLC) and compared its electrochemical characteristics with that of liquid organic electrolyte. The used organic electrolyte was 1 mole of lithium hexafluorophosphate (LiPF_6) salt containing in the solvent mixture of ethylene carbonate(EC):dimethyl carbonate(DMC):ethylmethyl carbonate(EMC)(1:1:1 volume ratio). The specific capacitance of EDLC with gel polymer electrolyte showed 120 F/g, which was superior to that of 110 F/g with liquid organic electrolyte. Good cyclability was observed for gel polymer electrolyte of EDLC. The 92% of initial specific capacitance was retained after 100 cycles of charge-discharge runs. Equivalent series resistance of 3.7 Ω of the EDLC with gel polymer electrolyte was lower than that of EDLC with liquid organic electrolyte. The EDLC with gel polymer electrolyte exhibited rectangular cyclic voltammogram of ideal EDLC in operating voltage range of 0∼2.5 V and low leakage current of 49 ㎂. Voltage drop from self-discharge was low for gel polymer electrolyte. The 29.6% of initial voltage decreased for gel polymer electrolyte, but significantly decreased to 99% for liquid organic electrolyte. The good retentivity with gel polymer electrolyte possible comes from the difference in viscosity compared with that of liquid organic electrolyte.