http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
CoFe₂O₄ - PZT 복합체의 Magnetoelectric 효과
최임구(I. G. Choi),권순주(S. J. Kwon),박수현(S. H. Park),정윤희(Y. H. Jung) 한국자기학회 1997 韓國磁氣學會誌 Vol.7 No.6
We have studied magnetoelectric effect with cobalt ferrite -Pb (Zr, Ti)O₃ composites made by solid state reaction. The maximum magnetoelectric voltage coefficient, (dE/dH)max, increased with longer sintering time and higher volume fraction of the cobalt ferrite. The magnetic field for (dE/dH)max became lower with increasing the sintering time and decreasing the volume fraction of the cobalt ferrite. The phenomena were explained in terms of grain size change, mechanical coupling efficiency, easiness of magnetization and polarization. We obtained the highest magnetoelectric voltage coefficient of 0.174V/㎝-Oe, which is about 30 % higher than the best value reported.
고분자 도포를 이용한 실리콘-탄소의 합성 및 Si-C|Li Cell의 전기화학적 특성
도칠훈,정기영,진봉수,안계혁,민병철,최임구,박철완,이경직,문성인,윤문수,Doh, Chil-Hoon,Jeong, Ki-Young,Jin, Bong-Soo,An, Kay-Hyeok,Min, Byung-Chul,Choi, Im-Goo,Park, Chul-Wan,Lee, Kyeong-Jik,Moon, Seong-In,Yun, Mun-Soo 한국전기화학회 2006 한국전기화학회지 Vol.9 No.3
실리콘 분말에 polyaniline(PAn)을 중합하고 탄화하여 Si-C재료를 개발하고 물리적 특성 및 전기화학적 특성을 분석하였다. 평균입도는 PAn의 중합으로 증가하였으며 탄화로 일부 감소하였다. XRD분석으로 결정질의 실리콘과 비결정성의 탄소 재료가 공존함을 확인 하였다. Si-PAn 전구체로 부터 개발한 Si-C 재료를 이용한 Si-C|Li cell은 Si|Li cell에 비하여 우수한 특성을 나타내었으며, 탄소 전구체인 PAn의 HCl 탈도핑에 의해 전기화학적 특성을 개선할 수 있었다. 전해액 중 FEC 첨가한 경우 초기 방전 용량이 증가하였다. GISOC시험으로 구한 가역 비용량 범위는 Si-C(Si:PAn=50:50wt. ratio)|Li 전지의 경우 약 414mAh/g를 나타내었으며, 가역 범위에 대한 초기 충방전의 intercalation 효율(IIE)는 75.7%였으며, 표면 비가역 비용량은 35.4mAh/g을 나타내었다. Si-C composites were prepared by the carbonization of silicon powder covered by polyaniline(PAn). Physical and electrochemical properties of the Si-C composites were characterized by the particle size analysis, X-ray diffraction technique, scanning electron microscope, and electrochemical test of battery. The average particle size of the Si was increased by the coating of PAn and somewhat reduced by the carbonization to give silicone-carbon composites. XRD analysis' results were confirmed co-existence of crystalline silicon and amorphous-like carbon. SEM photos showed that the silicon particle were well covered with carbonacious materials depend on the PAn content. Si-C|Li cells were fabricated using the Si-C composites and were tested using the galvanostatic charge-discharge test. Si-C|Li cells gave better electrochemical properties than that of Si|Li cell. Si-C|Li cell using the Si-C from HCl undoped PAn Precursor showed better electrochemical properties than that from HCl doped PAn Precursor. Using the electrolyte containing FEC as an additive, the initial discharge capacity was increased. After that the galvanostatic charge-discharge test with the GISOC(gradual increasing of the state of charge) condition was carried out. Si-C(Si:PAn:50:50 wt. ratio)|Li cell showed 414 mAh/g of the reversible specific capacity, 75.7% of IIE(initial intercalation efficiency), 35.4 mAh/g of IICs(surface irreversible specific capacity).
PVDF 전구체를 이용한 탄소 도포 실리콘 재료의 개발 및 리튬이차전지 음극특성
도칠훈,정기영,진봉수,김현수,문성인,윤문수,최임구,박철완,이경직,Doh, Chil-Hoon,Jeong, Ki-Young,Jin, Bong-Soo,Kim, Hyun-Soo,Moon, Seong-In,Yun, Mun-Soo,Choi, Im-Goo,Park, Cheol-Wan,Lee, Kyeong-Jik 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.7
Si-C materials were synthesized by the heating the mixture of silicon and polyvinylidene fluoride (PVDF). The electrochemical properties of the Si-C materials as the high capacitive anode materials of lithium secondary batteries were evaluated by the galvanostatic charge-discharge test through 2032 type $Si-C{\mid}Li$ coin cells. Charge-discharge tests were performed at C/10 hour rate(C = 372 mAh/g). Initial discharge and charge capacities of $Si-C{\mid}Li$ cell using a Si-C material derived from PVDF(20wt.%) were found to be 1,830 and 526 mAh/g respectively. The initial discharge-charge characteristics of the developed Si-C electrode were analyzed by the electrochemical galvanostatic test adopting the capacity limited charge cut-off condition(GISOC). The range of reversible specific capacity IIE(intercalation efficiency at initial discharge-charge) and IICs(surface irreversible specific capacity) were 216 mAh/g, 68 % and 31 mAh/g, respectively.