http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Schlueter, John A (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
Enhanced Critical Temperature in a Dual-Layered Molecular Superconductor
Schlueter, John A.,Wiehl, Leonore,Park, Hyunsoo,de Souza, Mariano,Lang, Michael,Koo, Hyun-Joo,Whangbo, Myung-Hwan American Chemical Society 2010 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.132 No.46
<P>Single-crystal X-ray diffraction has shown that the high-critical-temperature (<I>T</I><SUB>c</SUB>) phase of the filamentary molecular superconductor (BEDT-TTF)<SUB>2</SUB>Ag(CF<SUB>3</SUB>)<SUB>4</SUB>(1,1,2-trichloroethane) [BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene] contains layers of BEDT-TTF radical cations with alternating κ- and α′-type packing motifs. This molecule-based superconductor with dual BEDT-TTF packing motifs has a <I>T</I><SUB>c</SUB> five times higher than that of its polymorph that contains only κ-type packing.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2010/jacsat.2010.132.issue-46/ja105854m/production/images/medium/ja-2010-05854m_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja105854m'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja105854m'>ACS Electronic Supporting Info</A></P>
-
Evidence for lithium superoxide-like species in the discharge product of a Li–O<sub>2</sub> battery
Yang, Junbing,Zhai, Dengyun,Wang, Hsien-Hau,Lau, Kah Chun,Schlueter, John A.,Du, Peng,Myers, Deborah J.,Sun, Yang-Kook,Curtiss, Larry A.,Amine, Khalil The Royal Society of Chemistry 2013 Physical chemistry chemical physics Vol.15 No.11
<P>We report on the use of a petroleum coke-based activated carbon (AC) with very high surface area for a Li–O<SUB>2</SUB> battery cathode without the use of any additional metal catalysts. Electrochemical measurement in a tetra(ethylene) glycol dimethyl ether–lithium triflate (TEGDME–LiCF<SUB>3</SUB>SO<SUB>3</SUB>) electrolyte results in two voltage plateaus during charging at 3.2–3.5 and 4.2–4.3 V <I>versus</I> Li<SUP>+</SUP>/Li. Herein we present evidence from Raman and magnetic measurements that the lower plateau corresponds to a form of lithium peroxide with superoxide-like properties characterized by a low temperature magnetic phase transition and a high O–O stretching frequency (1125 cm<SUP>−1</SUP>). The magnetic phase transition and the high O–O stretching frequency disappear when charged to above 3.7 V. Theoretical calculations indicate that a surface superoxide structure on lithium peroxide clusters and some lithium peroxide surfaces have an unpaired electron and a high O–O stretching frequency that help explain the observations. These results provide evidence that the form of the lithium peroxide discharge product is important to obtaining a low charge overpotential, and thus improving the round-trip efficiency between discharge and charge.</P> <P>Graphic Abstract</P><P>We report on the use of a petroleum coke-based activated carbon in a Li–O<SUB>2</SUB> battery that gives two voltage plateaus during charging and evidence for a superoxide-like species. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cp00069a'> </P>
-
Magnetism in lithium-oxygen discharge product.
Lu, Jun,Jung, Hun-Ji,Lau, Kah Chun,Zhang, Zhengcheng,Schlueter, John A,Du, Peng,Assary, Rajeev S,Greeley, Jeffrey,Ferguson, Glen A,Wang, Hsien-Hau,Hassoun, Jusef,Iddir, Hakim,Zhou, Jigang,Zuin, Lucia Wiley-VCH 2013 ChemSusChem Vol.6 No.7
<P>Nonaqueous lithium-oxygen batteries have a much superior theoretical gravimetric energy density compared to conventional lithium-ion batteries, and thus could render long-range electric vehicles a reality. A molecular-level understanding of the reversible formation of lithium peroxide in these batteries, the properties of major/minor discharge products, and the stability of the nonaqueous electrolytes is required to achieve successful lithium-oxygen batteries. We demonstrate that the major discharge product formed in the lithium-oxygen cell, lithium peroxide, exhibits a magnetic moment. These results are based on dc-magnetization measurements and a lithium-oxygen cell containing an ether-based electrolyte. The results are unexpected because bulk lithium peroxide has a significant band gap. Density functional calculations predict that superoxide-type surface oxygen groups with unpaired electrons exist on stoichiometric lithium peroxide crystalline surfaces and on nanoparticle surfaces; these computational results are consistent with the magnetic measurement of the discharged lithium peroxide product as well as EPR measurements on commercial lithium peroxide. The presence of superoxide-type surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as the reversible formation and decomposition of electrolyte molecules.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
