• Title/Summary/Keyword: $^{55}Mn$

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Stability of Li[Co0.1Ni0.15Li0.2Mn0.55]O2 Cathode Material for Lithium Secondary Battery (리튬 2차 전지용 Li[Co0.1Ni0.15Li0.2Mn0.55]O2 양극물질의 안정성 고찰)

  • Park, Yong-Joon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.5
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    • pp.443-449
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    • 2007
  • The structural and thermal stability of $Li[Co_{0.1}Ni_{0.15}Li_{0.2}Mn_{0.55}]O_2$ electrode during cycling process was studied. The sample was prepared by simple combustion method. Although there were irreversible changes on the initial cycle, O3 stacking for $Li[Co_{0.1}Ni_{0.15}Li_{0.2}Mn_{0.55}]O_2$ structure was retained during the first and subsequent cycling process. Impedance of the test cell was decreased after the first charge-discharge process, which would be of benefit to intercalation and deintercalation of lithium ion on subsequent cycling. As expected, cycling test for 75 times increased impedance of the cell a little, instead, thermal stability of $Li[Co_{0.1}Ni_{0.15}Li_{0.2}Mn_{0.55}]O_2$ was improved. Moreover, based on DSC analysis, the initial exothermic peak was shifted to high temperature range and the amount of heat was also decreased after cycling test, which displayed that thermal stability was not deteriorated during cycling.

Recoil Effects of Neutron-Irradiated Metal Permanganates (중성자조사 금속 과망간산염의 반조효과)

  • Lee, Byung-Hun;Kim, Jung-Gwan
    • Nuclear Engineering and Technology
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    • v.20 no.2
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    • pp.105-111
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    • 1988
  • The chemical effects resulting from the capture of the thermal neutron by manganese in various crystalline permanganates, that is, potassium permanganate ammonium permangante and barium permanganate, have been investigated. The effect of pH of solvent on the distribution of radioactive manganese chemical species, that is, cationic $^{56}$ Mn, $^{56}$ MnO$_2$ and $^{56}$ MnO$_4$$^{[-10]}$ produced in the permanganates by $^{55}$ Mn(n, r) $^{56}$ Mn reaction was studied by using various adsorbents and ion-exchanger, that is, zeolite A-3, kaolinite, alumina, manganese dioxide and Dowex-50 The distribution of radioactive MnO$_4$$^{[-10]}$ in kaolinite and alumina has higher than that in other adsorbents and ion-exchanger at a representative pH value of 4, 7 and 9, respectively. The yield of radioactive MnO$_4$$^{[-10]}$ is higher at pH 4 End pH 9 than at pH 7. The thermal annealing behavior of recoil manganese atoms produced in the permanganates by $^{55}$ Mn(n, r) $^{56}$ Mn reaction was also studied. The retention of MnO$_4$$^{[-10]}$ in the thermal annealing is increased as annealing temperature increases when it was treated at 10$0^{\circ}C$ and 13$0^{\circ}C$. The recoil effect of permanganates was explained by the hot zone model.

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Microwave Dielectric Properties of $MnO_2$ Added $(Pb_{0.45}Ca_{0.55})(Fe_{0.5}Nb_{0.5})O_3$ Ceramics ($MnO_2$가 첨가된 $(Pb_{0.45}Ca_{0.55})(Fe_{0.5}Nb_{0.5})O_3$ 세라믹스의 마이크로파 유전특성)

  • Lee, Sang-Min;Lee, Doo-Hee;Yoon, Hyen-Sang;Park, Chang-Yub
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.237-239
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    • 1993
  • $MnO_2$ added $(Pb_{0.45}Ca_{0.55})(Fe_{0.5}Nb_{0.5})O_3$ was calcined at $850^{\circ}C$ for two hours and sintered at $1100^{\circ}C$ for two hours. The microstructure was examined using XRD and SEM. The dielectric constant, the quality factor, and the temperature stability was measured using Hakki and Coleman method. Dielectric constant was improved to 94 from 0.5wt% $MnO_2$ added sample with $Q{\cdot}f=4260GHz$ and acceptable ${\tau}_f$ (< $20ppm/^{\circ}C$).

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Electrochemical Properties of 0.3Li2MnO3·0.7LiMn0.55Ni0.30Co0.15O2 Electrode Containing VGCF for Lithium Ion Battery

  • Kim, Jeong-Min;Jeong, Minchan;Jin, Bong-Soo;Kim, Hyun-Soo
    • Journal of Electrochemical Science and Technology
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    • v.5 no.1
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    • pp.32-36
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    • 2014
  • The $0.3Li_2MnO_3{\cdot}0.7LiMn_{0.55}Ni_{0.30}Co_{0.15}O_2$ cathode material was prepared via a co-precipitation method. The vapor grown carbon fiber (VGCF) was used as a conductive material and its effects on electrochemical properties of the $0.3Li_2MnO_3{\cdot}0.7LiMn_{0.55}Ni_{0.30}Co_{0.15}O_2$ cathode material were investigated. From the XRD pattern, the typical complex layered structure was confirmed and a solid solution between $Li_2MnO_3$ and $LiMO_2$ (M = Ni, Co and Mn) was formed without any secondary phases. The VGCF was properly distributed between cathode materials and conductive sources by a FE-SEM. In voltage profiles, the electrode with VGCF showed higher discharge capacity than the pristine electrode. At a 5C rate, 146 mAh/g was obtained compared with 232 mAh/g at initial discharge in the electrode with VGCF. Furthermore, the impedance of the electrode with VGCF did not changed much around $9-10{\Omega}$ while the pristine electrode increased from 21.5${\Omega}$ to $46.3{\Omega}$ after the $30^{th}$ charge/discharge cycling.

Impurity Analysis of Domestic $MnSO_4{\cdot}H_2O$ Introduced to Manganese Bath Method (망간용액조방법에 도입되는 국산 황산망간중의 불순물 분석)

  • Hwang, Sun-Tae;Lee, Kyung-Ju;Choi, Kil-Oung;Lee, Kwang-Woo;Woo, Jin-Chun;Lee, Ki-Bum
    • Journal of Radiation Protection and Research
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    • v.12 no.1
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    • pp.48-53
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    • 1987
  • The manganous sulphate bath method is widely used for measurements of neutron source strength. In this study, the analytical chemistry method based on the argon supported inductively coupled plasmas emission spectrometry was used for examining the impurity contents of domestic $MnSO_4{\cdot}H_2O$ the product of Chemical Industry, to induce $^{55}Mn(n,{\gamma})^{56}$ Mn reactions. From the analytical results, mainly potassium, cobalt, and zinc as well as trace amounts of cadmium, lithium, etc. have turned out to be the relevant impurities absorbing the neutrons, and the fraction of neutrons absorbed by the total impurities was calculated. The value obtained was about 1.37% of the neutrons captured by manganese.

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