이차전지 음극활물질 Si/PC/CNF/PC 복합 소재의 전기화학적 특성

전도만,나병기,이영우 한국화학공학회 2018 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.56 No.6

Si을 리튬이온전지 음극활물질로 사용하기 위해 입도를 0.5 μm 보다 작은 크기로 제어하였고 표면에 탄소를 약 10 nm 두께로 코팅하였다. 그 위에 탄소섬유를 50~150 wt% 양으로 성장시키고 다시 한 번 탄소코팅을 진행하였다. 이렇게만들어진 Si 합성물질은 전기전도성을 높이기 위한 공정으로 이종 금속을 혼합하였으며 수명 특성을 개선하기 위해 흑연과 복합화하였다. 실험 변수에 따른 재료들의 물리화학적 특성을 XRD, SEM 및 TEM을 사용하여 측정하였고 코인셀을 제조하여 전기화학적 특성을 평가하였다. Si/PC (Pyrolytic Carbon)/CNF (Carbon Nano Fiber)보다 Si/PC/CNF/PC 가 전체적으로 Si 함량이 줄어 방전용량은 상대적으로 낮게 나타났지만 전지평가에서 중요한 수명특성에서는 좋은 결과를 보여주었다. 0.2 C rate에서 1512 mA h g-1의 초기 방전 용량과 78%의 초기 효율을 나타내었고 10 싸이클 에서94%의 용량 보존율을 보여주었다. In order to use Si as an anode material for lithium-ion battery, the particle size was controlled to less than 0.5 μm and carbon was coated on the surface with the thickness less than 10 nm. The carbon fiber was grown on the Si surface with 50~150 wt%, and the carbon coating was carried out once again. The Si composite material was mixed with dissimilar metals to increase the conductivity, and graphite was mixed to improve cyclic life characteristics. The physical and electrochemical characteristics of composite materials were measured with XRD, SEM, TEM and coin cell. The discharge capacity of Si/PC/CNF/PC was lower than that of Si/PC (Pyrolytic Carbon)/CNF (Carbon Nano Fiber). However, the cyclic life of Si/PC/CNF/PC was higher. Initial discharge capacity of 1512 mA h g-1 at 0.2 C rate and initial efficiency of 78% were shown. It also showed a capacity retention of 94% in 10 cycles.

회전킬른반응기를 이용한 리튬이온전지용 Si/C/CNF 음극활물질의 제조 및 전기화학적 특성 조사

전도만,나병기,이영우 한국화학공학회 2018 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.56 No.6

Graphite is used as a sample anode active material. However, since the maximum theoretical capacity is limited to 372 mA h g-1, a new anode active material is required for the development of a high capacity lithium ion battery. The maximum theoretical capacity of Si is 4200 mA h g-1, which is higher than that of graphite. However, it is not suitable for direct application to the anode active material because it has a volume expansion of 400%. In order to minimize the decrease of the discharge capacity due to the volume expansion, the Si was pulverized by the dry method to reduce the mechanical stress and the volume change of the reaction phase, and the change of the volume was suppressed by coating the carbon layers to the particle size controlled Si particles. And carbon fiber is grown like a thread on the particle surface to control secondary volume expansion and improve electrical conductivity. The physical and chemical properties of the materials were measured by XRD, SEM and TEM, and their electrochemical properties were evaluated. In this study, we have investigated the synthesis method that can be used as anode active material by improving cycle characteristics of Si. 흑연은 리튬이온전지에 사용 되는 대표적인 음극활물질이다. 그러나 최대 이론 용량이 372 mA h g-1으로 제한되기 때문에 고용량의 리튬이온전지 개발을 위해서는 새로운 음극 소재 활물질이 필요하다. 실리콘의 최대 이론 용량은 4200 mA h g-1으로 흑연보다 높은 값을 나타내지만 부피 팽창이 400%로 크기 때문에 음극 소재 활물질로 바로 적용하기에는 적합하지 않다. 따라서 부피 팽창으로 인한 방전 용량의 감소를 최소화하기 위해 건식 방법으로 실리콘을 분쇄 하여 기계적 응력 및 반응상의 체적 변화를 감소시키고 입도 제어 된 실리콘 입자에 탄소를 코팅하여 체적의 변화를 억제하였다. 그리고탄소 섬유를 입자 표면에 실타래처럼 성장시켜 2차적으로 부피 팽창을 제어하고 전기전도성을 개선하였다. 실험 변수에따른 재료들의 물리화학적 특성을 XRD, SEM 및 TEM을 사용하여 측정하였고 전기화학적 특성을 평가 하였다. 본 연구에서는 실리콘의 수명 특성을 향상시켜 음극 소재 활물질로 사용 할 수 있는 합성 방법에 대하여 알아보았다.

건식 분쇄 공정으로 Si 입도 제어를 통한 고용량 리튬이온전지 음극 소재의 개발

전도만,나병기,이영우 한국청정기술학회 2018 청정기술 Vol.24 No.4

Currently graphite is used as an anode active material for lithium ion battery. However, since the maximum theoretical capacity of graphite is limited to 372 mA h g-1, a new anode active material is required for the development of next generation high capacity and high energy density lithium ion battery. The maximum theoretical capacity of Si is 4200 mA h g-1, which is about 10 times higher than the maximum theoretical capacity of graphite. However, since the volume expansion rate is almost 400%, the irreversible capacity increases as the cycle progresses and the discharge capacity relative to the charge is remarkably reduced. In order to solve these problems, it is possible to control the particle size of the Si anode active material to reduce the mechanical stress and the volume change of the reaction phase, thereby improving the cycle characteristics. Therefore, in order to minimize the decrease of the charge / discharge capacity according to the volume expansion rate of the Si particles, the improvement of the cycle characteristics was carried out by pulverizing Si by a dry method with excellent processing time and cost. In this paper, Si is controlled to nano size using vibrating mill and the physicochemical and electrochemical characteristics of the material are measured according to experimental variables. 현재 리튬이온전지의 음극 소재 활물질로는 흑연이 주로 사용되고 있다. 그러나 흑연의 최대 이론 용량이 372 mA h g-1으로제한되기 때문에 차세대 고용량 및 고에너지 밀도의 리튬이온전지 개발을 위해서는 새로운 음극 소재 활물질이 필요하다. 여러 음극 소재 활물질 중에서 Si의 최대 이론 용량은 4200 mA h g-1으로 흑연의 최대 이론 용량보다 약 10배 이상 높은 값을나타내고 있지만 부피 팽창율이 거의 400%로 크기 때문에 사이클이 진행될수록 비가역 용량이 증가하여 충전 대비 방전 용량이 현저히 감소하는 현상을 나타내고 있다. 이러한 문제점을 해결하기 위한 방법으로 Si 음극 소재 활물질의 입자 크기를조절하여 기계적 응력 및 반응상의 체적 변화를 감소시켜 사이클 특성을 다소 향상시킬 수 있다. 따라서 Si 입자의 부피 팽창율에 따른 충전 및 방전 용량의 감소를 최소화하기 위해 공정 시간 및 원가 절감이 우수한 건식 방법으로 Si을 분쇄하여 사이클 특성 향상에 관한 연구를 진행 하였다. 본 논문에서는 진동밀을 이용하여 Si을 나노 크기로 제어하고 실험 변수에 따른 재료들의 물리화학적 특성과 전기화학적 특성을 측정하였다.

물류흐름 가시성, 시스템 확장성, 시스템 자기효능감이 물류정보시스템 전유에 미치는 영향과 개인성과

전도흠,백승령 한국경영정보학회 2015 한국경영정보학회 학술대회논문집 Vol.2015 No.8

韓國에서 分離한 Salmonella 및 Shigella의 抗生物質耐性

全燾基,李在九,許東燮,朴秉琦 中央醫學社 1941 中央醫學 Vol.10 No.6

One hundred and fifty-six strains of salmonellae isolated in 1964 and 1965 and 109 strains of shigellae isolated in 1963, 1964 and 1965 in Taegu area were studied on the resistance to chloramphenicol (CM), tetracycline (TC), terramycin (TM) and streptomycin (SM). Antibiotic resistance was tested by the plate dilution method. Briefly, antibiotic was diluted serially_ by doubling dilution method in distilled water and one volume of respective dilution was added to a series of nine volumes of melted nutrient agar. Nutrient agar containing antibiotic was then throughly mixed and poured into Petri dish (20m1) . The final concentration, of antibiotic in nutrient agar ranged from 400-0:78 mcg/ml. One loopful of inoculum containing varyingg numbers of bacilli (500,000; 5,000; and 50 per loop) was streaked on the surface of nutrient agar plate and incubated for 20 hours at 37°C. The results were read by the inhibition of growth of inoculum and the minimum inhibitory concentration of antibiotics to test strains was determined. A strain is considered as resistant if it is capable of growing in the presence of 25 mcg/ml of respective antibiotic. The results obtained were as follows 1. Most of the salmonella strains was inhibited their growth in the presence of 1.56-6.25 mcg/ml of CM, TC or TM in nutrient agar, and 25 rncg/ml of SM. 2. The minimum inhibitory concentration (MIC) of antibiotics to shigellae was distributed widely ranging from less than 0.78 to more than 400 mcg/rnl. However, a majority of strains was inhibited their growth in the presence of 100-400 mcg/ml of CM, TC or TM. Sixty-five strains out of 109 were not inhibited their growth even in the presence of 400 mcg/ml of SM. 3. MIC of antibiotics to test strains varied slightly by the inoculum size used for testing antibiotic resistance. MIC became slightly lowered in most cases when small size of inoculum was used, as compared with the MIC tested with large size of inoculum. - 4. The rate of resistant strains to CM, TC, TM and/or SM among salmonellae was 1.9 to 4. 5 per cents and that of resistant strains among shigellae ranged from 67.9 to 77.1 per cents to four antibitoics. 5. There is a tendency of yearly increase in the rates of resistant strains among salmonellae and shigellae. 6. The multiple antibiotic-resistant strains were only four among 156 strains of salmonellae tested, but those were 82 among 109 strains of shigellae. Seventy-three out of 82 multiple resistant strains of shigellae were resistant to all of four antibiotics.

낙동강 하구에서 분리한 Aeromonas spp.의 수리학적 분류 및 특성

전도용,하영칠 한국미생물학회 1989 미생물학회지 Vol.27 No.4

1986년 8월부터 12월까지 낙동강 하구에서 161주의 운동성 Aeromona를 분리한 후 42가지의 형태학적, 생화학적 특성은 조사하여 cluster 분석을 한 결과 85% 유사도 수준에서의 3개의 주 cluster와 84% 유사도 수준에서의 2개의 소수 cluster의 5 cluster로 나눌 수 있었다. 각 cluster는 MR반응과 glucose으로부터의 가스생성 여부의 생화학석 특성에 의하여 구분이 되었다. 2개의 소수 cluster를 포함한 5새의 cluster는 교차응집 실험에 의해 크게 2개의 혈청학적 cluster로 나뉘어졌으며, 이러한 결과는 독성실험에 의한 grouping 결과와 일치하였다. One hundred and sixty one strains of Aeromonas were isolated at three sites from August, 1986 to December, 1986 in Naktong Estuary. Cluster analysis was performed on total of 42 morphological and biochemical characteristics of the isolated strains. At the level of 85% and 84% similarity, three major clusters and two minor clusters had been identified: the first three clusters were different one another from MR reaction and gas production utilizing glucose. The five clusters were classified as two serotypes on the basis of serotyping, which was consistent with the result of cytotoxicity test.

조직의 공정성이 조직효과성에 미치는 영향에 관한 연구

전도성 서울행정학회 2014 서울행정학회 학술대회 발표논문집 Vol.2014 No.10

스크리닝기술에 의한 플렉소 제판의 품질 향상

전도신개 (사)한국포장협회 2017 包裝界 Vol.293 No.-

이메지를 활용한 심리치료법의 이론과 실제

전도성일 한국재활심리학회 1997 재활심리연구 Vol.4 No.1

This is a report on a new type of imagery method whose therapeutic manipulation is chiefly to control the experiential distance between the self and visual imagery. My method, called $quot;Tsubo$quot; Imagery Therapy, consists of the following steps: (1) preparation; (2) passive visualization of several $quot;tsuboes$quot;; (3) minimal feeling in each $quot;tsubo$quot;; (4) rearrangement of the $quot;tsubos$quot;; (5) maximal feeling in each $quot;tsubo$quot;; (6) sealing the $quot;tsubo$quot;; (7) distancing; and (8) entering the next one, or finish. In addition to the control of experiential distance, other major characteristics of our method are: first, the imaged $quot;tsuboes$quot; have the function of a safety device of capsule which protects the patient from being directly exposed to his intense critical experiences; second, special attention is paid to somatic experiences while imaging the $quot;tsuboes$quot;; third, the therapy proceeds in small steps set by the patient's own preferences. My method, effective and with the least danger, is applicable to cases of neurosis and also to relatively serious problems such as borderline.

Methicillin耐性葡萄球菌에 미치는 抗菌劑 倂用效果

全燾基,朴鍾旭 啓明大學校 醫科大學 1986 계명의대학술지 Vol.5 No.2

One hundred and thirty-one strains of staphylococci isolated from various clinical specimens in 1985 were tested for antimicrobial susceptibility to 16 drugs by microdilution broth method, and 24 strains were found to be resistant to methicillin (Mt). Mt-resistant staphylococci (MRS) were in most cases resistant to the other drugs tested except vancomycin (Vc) in high frequency, but most Mt-susceptible staphylococci were susceptible to the drugs except erythromycin (Em), teracycline, gentamicin (Gm), and kanmycin (Km). The combined activity of Mt with the other drugs was tested on MRS by checkerboard and time-killing methods. (FIC) index of 0.05 to 0.5 in 95% of strains. Vc, ampicillin, cephalothin, and penicillin also showed synergistic effects in more than 50% of strains. The combination of oxacillin also showed the synergistic activity with some toehr drugs, such as Em, rifampin, and trimethoprim. Gm was antagonistic with Mt in some strains, and Km was antagonistic with Mt in most strains. Vc was synergistic with Mt, and moxalactam.