• Title/Summary/Keyword: Conversion material

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Effect of Carbon Content of Sulfur Electrode on the Electrochemical Properties of Lithium/Sulfur Battery Using PEO Electrolyte (유황전극의 탄소량 변화에 따른 리튬/유황 전지의 방전특성 변화)

  • Kang, K.Y.;Ryu, H.S.;Kim, J.S.;Kim, K.W.;Ahn, J.H.;Lee, G.H.;Ahn, H.J.
    • Journal of Hydrogen and New Energy
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    • v.17 no.3
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    • pp.317-323
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    • 2006
  • Electric conductive material should be homogeneously mixed with sulfur in sulfur electrode fabrication of lithium/sulfur battery, because sulfur is electric insulator. In this paper electrochemical properties of Li/S battery was studied with various compositions of sulfur electrodes. When content of sulfur changed from 40 wt.% to 80 wt.%, the 60 wt.% sulfur electrode showed the maximum capacity of 1489 mAh/g-sulfur. Electrochemical properties of Li/S battery using 60 wt.% sulfur was also investigated with various carbon contents. The discharge capacity changed as a function of carbon contents. The optimum composition was 25 wt.% carbon for 60 wt.% sulfur electrode.

A study on the Conversion Loss by the Thickness of the Bonding Medium in the Elastic Delay Lines. (탄성파지연선에서 접착제의 두께에 의한 변환손실에 관하여)

  • 김종상;이전영
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.13 no.6
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    • pp.1-6
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    • 1976
  • In this paper, the methode of calculating conversion loss is proposed by considering the thickness of bonding medium between electrode and delay material in the vibrator of Elastic delay lines. As the result of computations using digital computer, it is shown that the thickness of bonding medium must be less than about 1/100 of the thickness of vibrator and when the thickness of electrode is about 1110 of vibrator, the center fnequency is shifted. When the thickness of bonding medium is equal to or more than the thickness of vibrator, the 리uctuations in frequency Bandwidth become larger and larger.

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Effect of Performance in Dye-sensitized Solar Cells by PEG Contents (PEG 함량변화가 염료감응형 태양전지의 효율에 미치는 영향)

  • Baek, Hyoung-Youl;Han, Zhen-Ji;Li, Hu;Gu, Hal-Bon;Park, Kyung-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.2
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    • pp.178-181
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    • 2008
  • A solar cell based on dye-sensitized photoelectric conversion was studied by investigating the effects of the amount of polyethylene glycol(PEG), added to the $TiO_2$ paste, on surface morphology of the $TiO_2$ films and on the solar cell performance. Energy conversion efficiency was found to increase with PEG addition up to 20 % by weight of $TiO_2$ and then decrease with further addition due to the aggregation of $TiO_2$ nano particles in the $TiO_2$ film. In this study, the best result of dye-sensitized solar cell was the short circuit current(Isc) of $22.6mAcm^{-2}$, the open circuit voltage (Voc) of 0.73 V, the fill factor (ff) of 0.55 and the overall energy conversion efficiency (${\eta}$) of 9.1 % under illumination with AM 1.5 simulated sunlight.

Wavelength Conversion Lanthanide(III)-cored Complex for Highly Efficient Dye-sensitized Solar Cells

  • Oh, Jung-Hwan;Song, Hae-Min;Eom, Yu-Kyung;Ryu, Jung-Ho;Ju, Myung-Jong;Kim, Hwan-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2743-2750
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    • 2011
  • Lanthanide(III)-cored complex as a wavelength conversion material has been successfully designed and synthesized for highly efficient dye-sensitized solar cells, for the first time, since light with a short wavelength has not been effectively used for generating electric power owing to the limited absorption of these DSSCs in the UV region. A black dye (BD) was chosen and used as a sensitizer, because BD has a relatively weak light absorption at shorter wavelengths. The overall conversion efficiency of the BD/WCM device was remarkably increased, even with the relatively small amount of WCM added to the device. The enhancement in $V_{oc}$ by WCM, like DCA, could be correlated with the suppression of electron recombination between the injected electrons and $I_3{^-}$ ions. Furthermore, the short-circuit current density was significantly increased by WCM with a strong UV light-harvesting effect. The energy transfer from the Eu(III)-cored complex to the $TiO_2$ film occurred via the dye, so the number of electrons injected into the $TiO_2$ surface increased, i.e., the short-circuit current density was increased. As a result, BD/WCM-sensitized solar cells exhibit superior device performance with the enhanced conversion efficiency by a factor of 1.22 under AM 1.5 sunlight: The photovoltaic performance of the BD/WCM-based DSSC exhibited remarkably high values, $J_{sc}$ of 17.72 mA/$cm^2$, $V_{oc}$ of 720 mV, and a conversion efficiency of 9.28% at 100 mW $cm^{-2}$, compared to a standard DSSC with $J_{sc}$ of 15.53 mA/$cm^2$, $V_{oc}$ of 689 mV, and a conversion efficiency of 7.58% at 100 mW $cm^{-2}$. Therefore, the Eu(III)-cored complex is a promising candidate as a new wavelength conversion coadsorbent for highly efficient dye-sensitized solar cells to improve UV light harvesting through energy transfer processes. The abstract should be a single paragraph which summaries the content of the article.

Dye-sensitized solar cells using size dependent SBM binder

  • Park, Gyeong-Hui;Kim, Eun-Mi;Jo, Hong-Gwan;Wang, Gyo;Hong, Chang-Guk;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.116-116
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    • 2009
  • $TiO_2$ pastes was synthesized to obtained of high efficiency dye-sensitized solar cells using size dependent co-polymer. SBM co-polymer binder is consist of styrene, n-butyl acrylate, and methacrylic acid (SBM) monodisperse co-polymer binder materials and this $TiO_2$ pastes were applied of dye-sensitized solar cells (DSSCs). The photoanodes were characterized by ATR-Fourier Transform spectrometer, X-ray diffraction (XRD) and morphology was investigated by field emission scanning electron microscopy (FE-SEM). The photoelectrochemical properties of the thin films and the performance of DSSCs were measured by photovoltaic-current density, AC impedance and monochromatic incident photon-to-current conversion efficiency (IPCE). DSSC based on the 100nm size co-polymer binder was obtained conversion efficiency of 8.1% under irradiation of AM 1.5(100 $mWcm^2$).

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Electrochemical Properties of Additive-Free Nanostructured Cobalt Oxide (CoO) Lithium Ion Battery Electrode (첨가제 없이 제작된 나노구조 코발트 산화물 리튬이온 배터리 전극의 전기 화학적 특성)

  • Kim, Juyun;Park, Byoungnam
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.31 no.5
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    • pp.335-340
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    • 2018
  • Transition metal oxide materials have attracted widespread attention as Li-ion battery electrode materials owing to their high theoretical capacity and good Li storage capability, in addition to various nanostructured materials. Here, we fabricated a CoO Li-ion battery in which Co nanoparticles (NPs) are deposited into a current collector through electrophoretic deposition (EPD) without binding and conductive agents, enabling us to focus on the intrinsic electrochemical properties of CoO during the conversion reaction. Through optimized Co NP synthesis and electrophoretic deposition (EPD), CoO Li-ion battery with 630 mAh/g was fabricated with high cycle stability, which can potentially be used as a test platform for a fundamental understanding of conversion reaction.

Electrochemical Characteristics of added $TiO_2$ Nanofiber for Dye-Sensitized Solar Cells ($TiO_2$ 나노파이퍼를 첨가한 염료감응형 태양전지의 전기화학적 특성)

  • Jin, En-Mei;Park, Kyung-Hee;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.243-244
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    • 2009
  • The $TiO_2$ nanofiber doped $TiO_2$ electrode area applied to dye-sensitized solar cells(DSSCs). The mixtures of $TiO_2$ nanofiber to $TiO_2$ photoelectrode has larger surface area than $TiO_2$ photoelectrode. In this research added 2.5, 5 and 10wt% $TiO_2$ nanofibers and the optimum condition of 5 wt% $TiO_2$ nanofiber's high surface area contributing the improvement of short-circuit photocurrent. The open-circuit voltage was 0.7V and solar energy conversion efficiency was 5.4%.

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Silent Discharge Characteristics of $CO_2$ for Alumina Imbedded-Discharge Reacted (알루미나 반응기에서의 이산화탄소의 무성방전 특성)

  • 조문수;곽동주
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.1061-1064
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    • 2001
  • Deep Interests have been paid on the application of non-thermal plasma technique to solve the environmental pollution problems. $CO_2$, is one of the severe pollutants which cause the acid rain and global warming. In this study, in order to improve the conversion efficiency of $CO_2$, the streamer corona discharge plasma and barrier discharge plasma reactors were made, and the conversion characteristics of $CO_2$by the corona discharge plasma and some discharge characteristics of these discharge chambers are studied experimentally.

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Sensing of ultra-low magnetic field by magnetoelectric (ME) composites (자기-전기(ME) 복합체를 활용한 초미세 자기장 감지 기술)

  • Hwang, Geon-Tae;Song, Hyunseok;Jang, Jongmoon;Ryu, Jungho;Yoon, Woon-Ha
    • Ceramist
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    • v.23 no.1
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    • pp.38-53
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    • 2020
  • Magnetoelectric (ME) composites composed of magnetostrictive and piezoelectric materials derive interfacial coupling of magnetoelectric conversion between magnetic and electric properties, thus enabling to detect ultra-low magnetic field. To improve the performance of ME composite sensors, various research teams have explored adopting highly efficient magnetostrictive and piezoelectric phases, tailoring of device geometry/structure, and developing signal process technique. As a result, latest ME composites have achieved not only outstanding ME conversion coefficient but also sensing of ultra-low magnetic field below 1pT. This article reviews the recent research trend of ME composites for sensing of ultra-low magnetic field.